CORRELATION OF LABORATORY TESTS WITH FULL SCALE SHIP …

/,,.

SERIAL NO. SSC-30

FINAL REPORT

(Proiect SR-96)

on

CORRELATION OF LABORATORY TESTS WITH

FULL SCALE SHIP PLATE FRACTURE TESTS

by

E, P. Klier

UNIVERSITY OF MARYLAND

and

M. Gensamer

COLUMBIA UNIVERSITY

Tmnwni+ ted through

NATIONAL RESEARCH COUNCIL8S

COMMITTEE ON SHIP STEEL

Advisory to

SHIP STRUCTURECOMMITTEE

Di,k;m of EngkmerkIQ and Industrial Re,mrch

National !+cedsmy of Sciences Nefionel Research Council

Washing!.., D. C.

January 30, 1953

SHIP STRUCTURE COMMITTEE

MEMBER AGENCIES:

B“.,.+” 0$= SHIPS, DEPT. 0, N,””

M,.,,.., SEA T. AN9P0. TATION SZ.VICL DrPT. 0. NAVY

U.,,,. s,,,,, c.,,, G.,.., T.,,, ”.” D, PT.

M,.,,,.. AD M$N8WRAT (ON, D.,,. OF CO... *C=

ADDRESS CORRESPONDENCE TD:

sccF!c7 An”

5“1, S’IFWCT” RE coMM!rr. E

u. s. COAST a.... HE . . . . . . . . . .

w,.”,..,.. 2s. D. C.

A“..,... BUREAU OF SHt,P#N.

January30,1953

Dear Sir:

As partof itsresearchprogramrelatedto theimprovementof hullstructuresof sr,ips,theShip5HxuctureCommitteehassponsoredan investigationon the“Correlationof IAoratoryTestswithFull-ScaleShipPlateFractureTestsr!at PennsylvaniaStateCollege.Herewithis a copyof theFinalReport,LXX-3O, of theinvestigation,entitledIICorrelation~f ~boratoryTestswithFull-ScaleShiPplateFractureTestsl!,by E. P. KlierandM. Gensamer.

Theprojecthasbeenconductedwiththeadvisoryassistanceof theConmitteeon ShipSteelof theNationalAcademyof Sciences-NationalResearchCouncil.

Anyquestions,comments,criticismor othermatterspertainingto theReportshouldbe addressedto the Secretary,ShipStructureCommittee.

ThisReportis beingdistributedto thoseindividualsandagenciesassociatedwithandinterestedin theworkof theShipStructureCommittee.

Yours sincerely,

~~$j%fa-(. .RearAdmiral,U. S. CoastGuardChairman,ShipStructureCommittee

FINAL REPORT(project sR-96)

on

CORRELATION OF LABORATORY TESTS WITH

FULL SCALE SHIP PLATE FRACTURE TESTS

by

E. P. KlierUniversity of Maryland

and

M. GensamerColumbia University

under

Department of the NavyBureau of Ships

Contract NObs-31217with the

Pennsylvania State College

EuShips Project NS-011-042

for

~ STRUCTURE COMMITTEII

j!ABLEOF CONTENTSPage

Introduction .........................................1

Materials Research Program ........................... 1

DavidW. Taylor Model Basin ..................2

The University of California, ProjectSR-92 . . . . . . . . . . . . . . . . . .........2

The University of Illinois, ProjectSR-93 .,........................ 2

The New York Na$:04hipyard, Project......................... 2

Swarthmore College, Project SR-98 ...... ..... 2

The Pennsylvania State College, ProjectSR-96 .......................... 2

University of California, Project SR-92 . . . . . . 3

David W. Taylor Model Basin, ProjectSR-105 ....................... . 3

New York NavalS~:;bYard, Project.,..,...... . ......... 3

Ductile-Brittle Transition Phenomena ................. 3

Uniaxial Stress-Loading - The TensileTest ...........................4

Biaxial Stress Loading ....................... ‘7

Triexial Stress ..............................10

Criteria of the Ductile-BrittleTransition .....................11

Bend Specimen ................................12

Tension Tear Specimens ...,...................12

Notched Tension Specimens ............ ... ...12

TABLE OF CONTENTS (Centinued)

Page

Metallurgical Structure and the 12uctile-Brittle Transition ............,12

Fatigue and The Ductile-Brittle Transition ..,,13

velocity of Loading and the Ductile-Brittle Transition .............lk

Size Effect and the Ductile-BrittleTransition .....................15

The Testing Program ...................................16

Experimental Results ..................................2o

Project Steels

The Ductile-Brittle Transition -Project Steels .................21

Tensile S~rength and Size Effect -Project Steels .................24

Additional Tests

Fractured Liberty Snip Plate Tests ............26

Tests of Other Steels .........................28

The Studies of Kahn and Imbembo ...............29

Discussion ........... .........,.,.,..........,....,..,32

The Ductile-Brittle Transition . . . . . . . . . . . . . ...33

Loading Condition in Structures ........ ,.....36

Ship Steel Selection ..!...,...................38

Acknowledgments .......................................4o

Bibliography ............,....,........................41

LIST @ TABLES

A.

B.

c.

D.

E,

F.

G.

H.

I.

J.

Chemical Analyses of the bteels.

Summary of Test Results - 20-in. Diameter ‘Eubes.

Transition Temperatures of Project Steels as Determinedby Various Notched Tests.

Chemical Analysis in ~ of Specimens From P$&UUI S. DUPONTand PONAGANSET (1-in. Wide Full-Thickness Specimens).

Meche.nicalProperties of Steel from PIERRE S. DUPbNT andPONAGANSET (l-in. Wide Full-Thickness.Specimens).

Transition Temperature in OF of Steels as Determined byVarious Tests.

Properties and Composition of High Yield Strength StructuralSteels Used in the Investigation .

Approximate Transition Temperatures of High Yield StrengthStructural Steels Determined by Means of Different Specimens.

Composition, Tensile and Tear-Test Properties of ship PlateSteels, bdium, Semiskilled,48-S-5, Normal Manganese (Mn/C~)and Medium Semi-killed ABS-B Manganese 0.60-0.90 (Mn/C <3)

Composition, Tensile and Tear Test Properties of Ship PlateSteels, Medium, Rimmed? Medium Rimmed and Fully Killed andHigh-tensile Vanity-type 48-s-5.

LIST OF FIGURES

1.

2*

3*

4.

5.

6,

7.

8.

9.

10.

11.

12.

13.

14.

15.

16,

17.

The transitions in energy absorption and fracture appearancein the Charpy keyhole impact specimen. Steel Dr.

The per cent reduction in area versus temperature of testingSteel E.

Effect of temperature on tensile properties of Steel “C” inthe ‘Iasrolledlicondition.

Hypothetical flow and fracture curves depicting conditionsleading to ductility and fracture transitions.

The strain hardening exponent ~) versus temperature forSteel E and Steel H.

Spherical

Variation

Slow bend

test specimen.

of nominal biaxial properties with temperature.

test results.

Torsion specimen.

Distribution of elastic stress at the base of the notch ina notch-bend test bar.

Charpy keyhole notch specimen.

Charpy V-notch specimens.

The change in transition temperature versus notch root radius-Charpy V-notch specimens.

Diagram showing types of transition curves obtained onnotched specimens.

Influence of normalizing on Lehigh Bend Test transition asindicated by fracture appearance. Silicon-killed steel,0.25%C9 0.66?%In,0.19~Si.

Influence of pre-strain on the transition temperature ofnotched and un-notched mild steel impact specimens.

Effect of fatigue on notched impact strength.

LIST OF FIGURES (Continued)

18.

19.

20.

21,

22,

23.

24.

25.

26.

27.

28.

29.

30.

31.

32.

33.

34.

35.

The transition temperature versus impactinp velocity forselecting project steels in tension impact. Adapted fromBruckner and Newmark, (24).

A suggested extrapolation of the curves of Figure 18.

Suggested variation of transition temperature in theCharpy v-notch impact test with impacting velocity. Thetwo experimental points were determined respectively inslow bending and impact bending.

Influence of specimen width on absorbed energy at constanttemperature.

Form of Taylor Model Basin tensile test specimens.

Details of slot - Taylrm Model Basin specimen.

Effect of ratio of length of slot to width of plate onenergy absorbed. Results are for Steel E specimensnotched with a jewelerfs saw.

Effect of temperature on energy absorbed for specimensof Steel E.

%:t~.h of wide plate specimens and type of stress-raiser.

72-inch specimen in 3,000,000-lb. testing machine.

Specimen cooling mechanism.

Revised design of the full scale hatch corner model.

Hatck corner tests. Specimen 4: Overall view from above.

Hatch corner tests. Specimen 4: Overall view from below.

Sections or apparatus for tests of 20” diameter tubes atlow temperatures.

Restrained welded specimen used for tests of high yieldstrength structural steels.

Restrained welded specimen in testing machine showingpuLling tabs andxnmganin wire extensometer.

Laboratory test specimens employed for correlation with largeplate test results.

QS~ OF FIGURIS (Continued)

36.

37.

38.

39.

40.

Keyhole Motch Summary - Project Steels

V-Notch Summary - Project Steels

Energy absorption, fracture appearance and lateral con-traction vs. testing temperature for v-notch milled andv-notch pressed (both Schnadt modification) charpy impactspecimens. Mild steel.

Charpy v-notch impact transition temperature in OF at 25and 50$ maximum energy absorption for specimens prestrainedin compression.

Charpy keyhole tests of Steel N following different heattreatments.

41-45. The influence of plate thickness and variations fromplate of constant thickness on notched bar test results,all steel from one heat. Project Steel Cc

46. Steel Br - Summary 01’test data

47. Steel C.

48, Steel A.

49. Steel Bn.

50. Steel Dr.

51. Steel Dn.

52. Steel E.

53. Steel H.

54. Steel N.

55. Wide Plate Test Results.

56. Hatch Corner Tests. Maximum noninal stress and energyabsorption (all tests at 700F.)

57* PIERRE S. DUPONT - Plan view of the upper deck showing theplate removed for testing and the adjacent crack..

58● PIERFUZS. DUPONT - Sample from deck plate C-10 showinglocation of test specimens.

59● PONAG.4NSET- Elevation of the starboard side-shell show-ing the location of test specimens in the topside strake.

60. PONAGANSET - Plan view of main deck showing the locationof test specimens.

61. Twelve-inch wide specimens. Results of tests of samplesremoved from fractured ships. 3/4 or 13/16-inch thickplate.

62-a. Eilergyto maximum load vs. temperature relation for re-strained welded specimens of high yield strength structuralsteels, results of tests of specimens made from mild steelwith E-6o2o electrode are shown for comparison.

62-b. Energy to failure VS. temperature relation for restrained

63.

64.

65.

66.

67.

68.

69.

70.

welde~-specimens of high yield strength structural steels.‘esults of tests of specimens made from mild steel withE-6o2o electrode are shown for comparison,

Transition temperatures for H. Y. S. S. Steels amd mildsteel B as determined by 12!!centrally notched specimens.

Tear-test transition temperatures of medium and high-tensileship plate steels, 1/2 and 5/8-inch thicknesses.

Tear-test transition temperatwes of medium and high-tensileship plate steels, 7/8, 1, 1-1/4 and 1-1/2 inch thicknesses.

Tear-test transition temperatures of medium and high-tensileship plate steels, 1/2, 5/8, 3/47 7/8, and l-1/b-inchthicknesses.

Tear-test transition temperatures of medium ship plate steels1/2, 5/8, 3/4, 1 and l-1/2-inch thicknesses, as rolled con-dition.

Tear-test transition temperatures of medium steel shipplate~ 3/k-inch thickness.

Stresses in upper deck of liberty ship.

Twelve inch wide flat plate tests.

The role of materials

If such materials were

problem would cease to

evaluation of weldable

vessel construction, a

not

INTRODUCTION

in the ship fracture problem is obvious.

susceptible to brittle failure, the

exist. With the objective of a final

steels as to their suitability for merchant

wide experimental program was Initiated by

the Board of Investigation to Inquire into the Design and Methods

of Construction of Welded Steel Merchant Vessels~l)* and continued

by the Ship Structure Commlttee(2~3). It was the objective of the

research program conducted at the Pennsylvania State College under

Bureau of Ships Contract NObs-31217 to correlate the work conducted

for the Board and the Ship Structure Committee. This final repcrt

attempts, therefore, tk correlation of the results of the entire

llmaterialllresearch program as conducted between 1944

mately the end of 1950. This program, in abbreviated

given below.

~TERIALS RESEARCH PROGRAM

and approxl-

outline, is

The specifications for the Liberty ship called for a medium

steel. Such steel can be furnished in rimming, semi-killed, and

fully killed grades. In order to supply a series of steels which

would have appreciably different fracture characteristics in the

projected tests, the steels listed in Table A were supplied by

different mills. These steels have been generally designated as

*For numbers in parenthesis see Bibliography

-2-

‘Iproject“ steels. These steels were studied extensively under the

cooperative research programs conducted at the University of Califor-

nia, the David W. Taylor Model Basin, the University of Illinois$

the New York Naval Shipyard, the Pennsylvania State College, and

Swarthmore College.

The research programs conducted at the respective laboratories

were designated as follows:

David W. Tavlor Mode~_: (a) Flat plate tests.

~ University ~ Califthmia, Project SR-92: (a) Flat plate

tests, (b) large tube tests, (c) similitude tests, (d)

bend tests, (e) full-scale hatch corner tests.

~Universit~ Q IlllnOIS, Pro.iectSR-91: (a) Flat plate

tests, (b) impact tests.

‘lQ2NQMXQZklJAQ.s~ 31ZQb2QQ&42!t: (a) Standard

Impact tests, (b) Navy tear tests.

Swarthmore Collece, Project SR-98: (a) 12-inch plate tests,

(b) aspect ratio tests.

~ ~ennsylvania _ Colleeep project -$ (a) Impact

tests, (b) slow bend tests, (c) edge-notched bar tension

test, (d) low-temperature tension tests, (e) strain-gradient

measurements.

In addition to the above tests conducted all or in part on

the project steels, tests were run on certain additional mild and

high strength steels. The augmented testing program Included the

-3-

indicated tests run at the following laboratories:

of California, ~=: (a) Restrained

welded specimen tests on high strength steels, (b) edge-

notched bar tension tests (c) 12-inch plate tests.

David W. Tavlor Model ksin, Project SR-10~; (a) 12-inch

plate tests on mild steels taken from fractured Liberty

ships, (b) edge-notched i.artension tests.

New York Naval ShiDyard, Project SR-104: (a) Tear tests

on selected mild and high strength steels.

The results of the tests conducted on the above program will

be discussed at length in the following, but before these data

are examined it may prove profitable to consider certain generali-

zations which may be made with reference to the ductile-brittle

transition and which must be considered in the ultimate evaluation

of the ship fracture problem.

DUCTILE-BRITTLE TRANSITION PHbNOMEN~— —

The ductile-brittle transition as it is encountered in mild

steel, has in the past generally been associated with the impact

test. In the impact test it is customary to give the results in

terms of the work required to break a specified test bar. This

work to failure has been found to vary with temperature for a

(4)suitable test specimen as in Figure 1 . Thus at relatively high

temperature much work is required to fracture the specimen, while

at relatively lower temperature little work is required to fracture

-4-

the specimen. The F.ightemperature condition

or tough condition, wi>ilethe low temperature

is known as the ductile

condition is known

as the brittle condition, with the intermediate range being desig-

nated as the transitional range, or the ductile-brittle transition.

Of the many factors which mcdify the ductile-brittle transi.

tion in mild steel, unquestionably the most important is the stress

system. It is not possible considering present knowledge to discuss

fully the phenomena associated with the ductile-brittle transition,

as the stress system is arbitrarily varied; but certain reasombly

integrated data are now available for consideration on this point.

In the sections immediately below, the behavior of steels tested

under certain uniaxial, biaxial, and triaxial stress systems~ will

be considered.

Following this.the criteria of the ductile-brittle transition

will be noted, and generalizations

ture, fatigue, velocity of loading

will be introduced.

concerning metallurgical struc-

and size effect, as pertd.nent,

Yniaxial Stress Loading -- The Tensile Test\ If a mild steel

is tested in tension in an appropriate temperature range, a trans&-

tion to brittle behavior will be observed as is indicated in Figure

2. This transitional behavior is comparable to that observed in

the impact test on notched bars, but the test bar used here is a

standard test bar and does not contain an artificial notch. Thus

it =Y be concluded that an external notch is not required to induce

* The terms “uniaxial, biaxial, and triaxial” are somewhat loOSelYapplied and at best apply with good approximation only during theinitial steps of loading.

-5-

brlttleness in such steels, and tk,ebrittleness observed must be

considered an intrinsic property of these materials tested in tension.

In the further analysis of ~ensile test data, it is informa-

tive to compare the yield strengths and the fracture strengths as

is done in Figure 3. It is evident that the transition from ductile

to brittle behavior takes place at a temperature at which the yield

and fracture strengths are in near coincidence. This does not per

se preclude ductile behavior, but this phenomenon has been used

explaining brittle behavior. Thusv Le Chatelier(5) has argued that

the coincidence of the yield and fracture strengths would serve to

localize plastic distortion with a consequent reduction in energy

absorption. On the other hand, Ludwik(6), in a consideration of

comparable data, has proposed that two strength factors exist,

mmely, flow and fracture strengths, and, in general, the flow

strength is less than the fracture strength. When the flow strength

atkains a value equal to that of the fracture strength, failure

ensues. In both of these analysea of the ductile-brittle transition,

the nature of the fracture process is not explained. There is no

differentiation, therefore, of two classes of fracture phenomena

as indicated by the terms shear (fibrous) and normal (CbEaWigf3) type

failures. This latter differentiation should be made, as from a

practical point of view it may be important.

The introduction of the concepts of two fracture types on the

fracture, flow-strength, temperature diagram was first undertaken

-6-

by Davidenkov(7) and has subsequently been variously modified as

for example in Figure 4(8). This type of diagram is phenomeno-

logical in character ariddoes not aid in a basic understanding of

the fracture process. It is, however, an informative construction

and because of this has proven to be of considerable value.

It is Interesting to consider the change in fracture appearance

as a means of differentiating ductile from b~ittle failure. Fracture

type data are plotted in Figure 1 for comparison with the energy

absorption data, and it is seen that the.two transitional phenomena

do not agree. This is a point well worth emphasizing, for as will

become evident below, the non-agreement in the transitions In energy

absorption and fracture appearance is the rule for small specimens

and it i.sonly for very limited conditions that agreement in these

two transitions is achieved.

The treatment of tensile test data by the method of Ludwlk,

while initially holding promise for a solution of the problems

associated with the intrusion of brittleness in mild steels under

certain conditions of testing and use, have under further inspection

proved to be unsatisfactory. This does not mean, however, that

tensile test data may not ultimately prove of much importance in

the analysis of the fracture behavior of steels.

Thus, it may be that the fracture characteristics of a steel

ar9 intimately connected with the ability of that steel tp pro-

pagate strain(9). The propagation of strain is envisaged as

depending on two quantities,

a velocity coefficient which

These two quantities are not

-7-

namely, a work hardening exponent and

is similar to a viscosity coefficient.

easy to separate and cannot be

separated in the standard tensile test. By testing at a series

of temperatures in the vicinity of that of liquid air, however,

it can be shown that the strain hardening exponent~ defined by

the equat5.on~=@#, varies with the temperature.*

Extreme values for the project steels studied are presented

in Figure ~. These data at present cannot be used directly to

predict the fracture characteristics of mild steel, but it is

significant that the steel showing tkmini!mnn value of~at low

temperature has the highest transition temperature In the notched

bar tests.

9Q.ZLQL &i.WiS&SKQaUi: Three sets of data will be considered

here comprising the results of sphere(10), tube(ll), and torsion

tests(12). For the sphere, to a close approximation, the stress

system is balanced biaxial tension; for the Cubes it is biaxial

tension with a variable ratio of the principal stresses; for the

torsion test, the principal stresses are a tensile stress and an

equal compression stress.

The spherical test specimen diagrmmmed in Figure 6 was made

of a steel comparable to Project Steel A. The fracture charac-

teristics of this specimen were studied at numerous temperatures,

*71here is a complex quantity comprising both a strain hardeningexponent%Oand a velocity coefficient

%. These two quantities

cannot be separated by ~ana of the da a collected here.

-8-

with the pertinent data being summarized in Figure 7. It is evident

from this figure that for the temperature range covered there i.S

indicated no transition in ductility, despite the fact that by

fracture appearance this transition was observed at about 60°F.

It should be noted that the presence of a flaw in the sphere (as

perhaps arising from a faulty weld) was a positive embrittling

factor.

For purposes of comparison, slow-bend test data for this steel

are described in Figure 8, wherein it is revealed that the transi-

tion as indicated by fracture appearance for the two tests is in

good agreement. This perhaps sug~ests that failure of the spheres

took place only after the development of effective notches in the

course of straining, wj.ththese notches bringing about failure.

The tube specimen which was tested in biaxial tension is

shown in Figure 32. The test data are summarized in Table 3(11).

The temperatures of testing of the tubes are so far apart that

it is not possible to state transition ranges, but the transition

in fracture appearance lies at about 700F., while the transition

in ductility presumably lies at a somewhat lower temperature(11).

It is interesting to note, however, that for these tubes either

welds or structural defects were primarily responsible for failure,

and therefore these tube specimens in the main may be considered as

having failed prematurely. In other words failure of the tubes was

Initiated by some localized stress raiser and only indirectly by the

principal biaxial stress system.

The sphere and tube tests were conducted on specimens which

may be considered as large compared to standard laboratory test

specimens. Despite the size o! the speci@ens, high ductilitY was

observable, particularly in the sphere tests, and presumably in-

dicated in the tube tests in the absence of crack initiators and

at temperatures which must be considered as low for the steel being

used. On the other hand, for both the sphere and tube tests the

transition in fracture appearance occurred at relatively high

temperatures, and these temperatures are sensibly those predicted

by small scale notched specimen tests.

In comparison with the sphere and tube tests, the torsion

tests conducted by Larson(12) may be considered as small scale

tests, and the element of size effect enters in the consideration

of transition phenomena. The test bar used by Larson is indicated

in Figure 9 and was made from steels C and E. The test data re-

ported are not sufficient to describe fully the transition phenomena,

but the transition in energy absorption definitely lies below

-190°C. while the transition in fracture appearance definitely lies

above -190°C, but below -700F. It will be noted that for these steels

the tranaitionin ductility in the tension test lies above -190%.

The above results may be summarized briefly by stating that the

loading of a specimen in biaxial tension will not in general lead

to brittle failure unless the temperature is excessively low. In

a specimen plastic flow is initiated which ultimately leads to the

-1o-

development of an effective notch. Once this condition is reached

for a large specimen, failure may result by the cleavage mechanism,

if the temperature of the specimen is at or below the transition

temperature indicated by a notched specimen such as, for example,

the slow bend test specimen.

From the torsion test data it may be emphasized that the

cleavage fracture and the temperature range in which it is found

for a given steel is by no means relatable to a basic reference

temperature which has a simple physical significance. Presumably

in the compression test these steels would have no ductile-brittle

transition.

Triaxial Stress ~oadin~~ Perhaps the simplest way in which

a triaxial stress system can be developed is by the introduction

of a notch in a bend test member. In general the more acute the

notch, the more marked is the triaxiality of the resultant stress

system, but for an edge-notched bend bar this stress system has in

general the characteristics indicated in Figure 10(13)0 This stress

system is complex and cannot be used directly to interpret notch-

bend-bar test results, but it has been observed that, in general,

the more acute is the notch in the test bar, the higher is the

temperature at which the transition from ductile to brittle behavior

occurs, Figures 11 and 12(14’.

It will be noted, however, that again as before there may be

disagreementin the transition temperatures revealed by energy

-u-

absorption and fracture appearance,

specimen, however, it is indicated,

cf. Figure 11. For the V-notch

cf. Figure 12, that under cer-

tain conditions of testing full agreeuent in the two

ductile-brittle transition does obtain.

The test data which are reviewed in this report

criteria of

will have been

largely obtained for notched specimens; therefore, specimens in

which triaxial stress systems obtain. The magnitude of these stress

systems will be largely unknown, and for this reason it may appear

surprising that correlation of a consistent nature is at all possible

In anticipation of this objection, it is noted that both on theore-

tical and experimental grounds, there are indications that the

triaxiality of the stress system arising from notch action has a

limiting value(15j16). Th~ theoretical aspect of this problem has

been thoroughly discussed by Neuber(13), while the results of Zeno

and LOW(17) and Bagsar(la) support the theoretical argummt. Thus

both Zeno and Low, and Bagsar studied the effect of notch acuity

on the temperature of the ductile-brittle transition and found that

it could be elevated to only a limited extent by increasing notch

acuity. Bagsarls data are reproduced in Figure 13.

Criteria of th~ Ductile-Brittle Transitio~: In the above dis-

cussion two criteria of the ductile-brittle transtion have been ex-

amined. Numerous other criteria of this transition have been used

but seemingly all are more or less intimately associated with either

the transition in energy absorption or the transition in fracture

-12-

appearance. These criteria have been examined by Stout and McGeady

for bend specimens and for the Navy tear test(19). The criteria

for determining the ductile-brittle transition may be summarized

as follows:

~ SDecimeq~ fracture appearance~ lateral contraction, bend

angle, energy absorption to failure, maximum nominal load;

Tension ~ S~ecimens: fracture appearance, Iate@l contrac-

tion, energy absorbed to initiate crack, energy absorbed to propagate

crack, nominal tensile strength, nominal yield strength;

Notched Tension Snecimens: fracture appearance, lateral con-

traction, elongation, energy absorbed to failure, ene~gy absorbed

to maximum load, and nominal tensile strength.

Of the above criteria, the most easily interpreted are energy

absorption and fracture appearance. That certain of the other

criteria may on occasion be misleading is indicated by consideration

of the idealized diagram, Figure 14, taken from Osborn, & ~. (20) .

The significance of these criteria has been discussed by Vanderbeck

ai~dGensamer(8).

~etal~ Structure @ the Ductile-Brittl~ Transition:

The steels which are of interest in the construction of merchant

vessels must be of welding grades, and, therefore, steels which can

undergo only limited metallurgical structural changes. In general,

modifications of metallurgical structure which are possibly beyond

the as-rolled structure result from normalizing or cold straining

operations, the latter of which usually leads to strain agihg.

-13-

Normalizing, when it clearly brinrs about a reduction in ferrite

grain size, may profoundly lower

but when normalizing is effected

grain size, this lowering of the

fully realized. As indicated by

the ductile-brittle transition(21)

without appreciable change in

transition temperature may not be

Lehigh Slow Bend test data, Figure

15, the optimum lowering of the transition

a normalizing temperature of about 165o%.

tures appreciably above and below 16500F.,

be efficacious.

temperature obtains for

At normalizing tempera-

this treatment may not

Cold straining, in general, is considered as undesirable and

leads to an elevation of the ductile-brittle transition as revealed

by,standard impact test data, but that the effects of cold straining

may be complex is indicated in Figure 16(22), For the notched im-

pact bars the transition temperature was found to rise regularly

with increasing strain. For the u.nnotchedimpact bars, however,

the transition temperature passed through a maximum at about 10$

elongation.

Fatigue and The Ductile-Brittle Transition: Pertinent data.—

on the effects of fatigue on the ductile-brittle transition are

summarized in Figure 17(23). It is clearly evident from this figure

that as fatigue damage increases, the ductile-brittle temperature

is adversely modified and is elevated by about the same order of

magnitude as results from strain-aging.

-14-

Velocity ~ Loading and the Ductile-Brittle Transition: The——

stress conditions in notched specimens are frequently complex beyond

the powers of convenient mathematical analysis. For this reason

alone loading effects cannot be considered in terms of true strain

rates. However, it is known that for a given specimen the rate of

loading may alter appreciably the temperature of,the ductile-brittle

transition. The manner in which this alteration is brought about

is not at present clear and the lin!iteddata available are in some

measure ambiguous. This is illustrated by a consideration of Figure~8(2k)

Here are plotted transitions in energy absorption and frac-

ture appearance for several of the project steels tested in tension

impact at several Impacting velocities.* ●

It will be noted that the curvatures of the respective lines

for energy absorption and fracture a~pearance are inverted and

in this sense are inconsistent. That the curvature of the fracture

appearance lines are the more nearly correct may be surmised from

an attempted extrapolation of the energy absorption curves to higher

impacting velocities. If this is done consistent with the data

$iven in Figure 18, first steel A and ultimately steels Dr and Dn

will be evaluated as of less merit than either steel C or steel E.

Since this conclusion does not seem warranted, on the basis of

other test data obtained on these steels, it is surmised that the

energy absorption curve un?ergoes a change of curvature perhaps

as indicated in Figure 19. The shape of the transition temperature-

velocity curve may be attributed to the experimental testing

*These velocities are converted from energy values and are consideredas approximate only.

-15-

condltions and probably is not of fundamental importance. It iS

important to note, however, that the transition temperature is

sensitive to the velocity of loading; and in a test where the

transitions in energy absorption and fracture appearance coincide,

it would appear that the ductile-brittle transition should increase

monotonically with velocity of loading to develop a curve as drawn

in Figure 20(14). This latter curve reveals that an increase in the

loading rate from that encountered under static loading conditions

(head movement 3 inches per min.) to that encountered in impact

testing (head movement 18 feet per sec.) produces a displacement

of the transition temperature of +70%. It will be noted that

loading rates appreciably less than those encountered in impact

loading may still result in an elevation of the transition tempera-

ture curve.

Q&i i2tG22t * U2,f2Qd&L.ka-Qd&tk hnsitim : ‘l%eterm

“size effect!!as used in a discussion of the mechanics of the

loading and deformation of different sized test bars presupposes

the use of similar test bars. The term cannot be extended with

this rigorous restriction to a consideration of the ductile-brittle

transition, because of intrinsic defection from the requirements

o: similarity, experienced in the testing of the larger test bars.

The modification of the ductile-brittle transition by ‘fsizeeffect’t

must be discussed with this reservation In mind.

-16-

Extensive research which is summarized by Fettweis(25) has

shown conclusively that the ductile-brittle transition for similar

specimens is higher, the larger the specimen. This for a given

steel in an appropriate temperature range leads to a ductile-brittle

transition with increasing size as is indicated in Figure 21. This

phenomenon is critical in the problem of merchant vessel failures?

in that because of it small-scale laboratory tests have not been

available for use in predicting the fracture characteristics of

structures. However, this difficulty can seemingly be overcome

in the bend specimen by the use of a suitably formed sharp notch.

Thus with a pressed notch of 0.0015 inch root radius transitions

in lateral contraction and fracture appearance for a Schnadt-type

slow-bend bar were in full agreement and constant as specimens di-

mensions were varied from 0.39k by 0339b by 2.1 inches to 1.187

by 1.172 by 2.1 inches.

The engineering properties of metals are also mcdified by

size effect. These properties have been extensively studied but

are modified to only a limited degree by the ductile-brittle

transition and so will be reviewed in a later section.

THE TESTING PROG~_

In the analysis of the ship fracture problem: early appraisal

of knowledge on the subject of the ductile-brittle transitionin-

dicated that “size effect” was largely responsible for these

-17-

failures. The testing program, therefore, was organized to include

large-scale tests along with small-scale tests, the latter designed

$0 attain correlation with the large-scale laboratory tests.

Toward the development of a large-scale laboratory test, ex-

ploratory work on flat plate specimens was completed at the David

W. Taylor Model Basin(26). The largest size specimen tested was

12 by 3/4 inches with an internal notch, Figure 22. Pertinent

details of the internal notch are given in Figure 23. Specimens

with suitable notch geometry were tested in both 6- and 12-inch

widths at appropriate temperatures. Pertinent results are

summarized in Figured 24 and 25.

From Figme 24, it is evident that a minimum length notch

must be used in this typ~ of specimsn to insure consistent re-

sults for comparison purposes, and this length has been standardized

as one fourth of plate width.

In keeping with the discussion on size effect it was expected

that the plate tests would give transition temperatures which would

be relatively lower than those for a ship structurs. By an adjust-

ment of notch acuity this condition could be minimized. The results

obtained in the study of notch terminus radius are given In Figure

25, where it will be noted that jewelerts flawcut was the most

severe of the notches studied. This notch terminus was usad through-

out in subsequent flat plate testing.

-18-

Of the large-scale tests the most completely explored were

the intermlly notched flat plate tests in the 12-, 24-, ~- and 72-

inch widths(ll$27). Several additional specimens 108 inches In

width were tested. A drawing of the test specimen is given in

Figure 26, and a picture of the ~.inch plate specimen in the

%ensile test machine is given In Figure 27.

The data of the original flat plate test program indicated

that the results obtained with the 12’fplate specimens are equiva-

lent to those obtained with the 72-inch plate specimens, and the

subsequent flat plate testing at Swarthmore College has been

limited to the 12.inch wide specimen in which L . ~, see Figure

26. This specimen in place in the testing machine and ready for

testing is shown In Figure 28. The Swarthmore data which are con-

sidered in this report were obtained with this specimen. This fact

is noted to eliminate confusion with the later modification of this

test specimen for the Swarthmore aspect-ratio test program. Data

from this program will not be considered in this report.

It was recognized that the data which were obtained in tha

various tests could not be applied directly to the problem of

ship failures without further testing, preferably on a ship structur~

but under controlled conditions. Full-scale ship tests meeting the

above restrictions are conceivable but hardly feasible, so the full

scale hatch corner tast was devised(29) . The objectives of the hatch

corner testing program included: (a) theht-iwtion of the ductile-

brittle transitional behavior of selected project steels fabricated

-19-

into hatch corners of the basic design$ and (b) the redesign or

modification of the basic Liberty ship hatch corner detail. This

first program was essential to the i.nteg~ationof the flat plate

testing program with structural behavior.

The test specimen based on the basic hatch corner design is

given in Figurs 29. The method of testing behavior in testing are

in some measure indicated from a consideration of Figures 30 and 31.

The basic hatch corner specimen was tested in numerous modifica-

tions and several additional new designs were also tested. Details

(29)of these design alterations must be sought in the original report .

Because of its size, it is not possible to test a full width

of shipls deck in way of the hatch opening. The specimen selec$ed,

see Figures 29, 30 and 31~ was as large as could be accommodated in

the testing machine of greatest capacity then available.

The problem of brittle ship failures was recognized as arising

from the action of stress raisers such as structural discontinuit~ss,

accidental notches, etc> The large-scale test program as outlined

above took cognizance of this fact$ and all specimens possessed

effective stress raisers. The magnitudes of these multiaxial stress?q

however, were not known; and it appeared desirable to explore the

field of multiaxial stress in structures. To this end large tube

tests were designed such that the temperature of testing could be

varied over wide controlled limits$ while the longitudinal and

hoop stresses in the shell could be varied regularly through pre-

scribed values to fracture(309● ThLs test specimen is shown in

-20-

Figure 32. (The data obtained with this type specimen have already

been discussed.)

The completed program of tests on large-scale specimens in-

dicated that the mild steels tested all experienced brittle failures

at temperatures above about 200F. Since temperatures of this order

and lower are regularly encountered in service, it appeared desir-

able that the ductile-brittle transition phenomem in certain high-

yield strength structural steels be examined. Since these Steels

were to be examined for possible merchant vessel use, the full-scale

model hatch corner test specimen would be a logical specimen to

test, but because ofth+ M@. strength properties of the steel used~

the capacity of the tensile machine would be exceeded by this speci-

men. For this reason the restrained welded specimen given in Figure

33 was designed. This specimen ready for testing is presented

in Figure 34. Comparable tests for the 12-.inchflat plate specimen,

previously described, were also run.

The specimens described above are, in all instances, large

specimens and are too large for routine laboratory testing, It

was necessary, therefore, that experimentation be undertaken to

explore the possibilities of the correlation of small-scale labora-

tory test results with those obtained in the large-scale tests. In

the course of this experimentation the specimens given in Figure 35

were variously used.

EXPU(IME NTAL RESULTS

L* Q2ilEG&QQ2i2J&.

The data obtained for the project steels will be considered

-21-

following which the further data obtained on the augmented program

will be examined. The ductile-brittle transition data are considered

first.

The Ductil,e-BrittleTransition -- Project Steels: Over a period

of many years the ductile.-brlttletransition has been extensively

studied in the impact test. For this reason one of the first steps

in the examination of the project steels consisted in the determina-

tion of the impact transition curves for standard test conditions.

Data so obtained for the standard keyhole and V-notch Gharpy test

bar are presented in Figures 36 and 37.

The impact transition curves are drawn as smooth curves which

vary regularly through a range of temperature from the maximum value

of energy absorption] or ductile condition$ to the minimum value of

energy absorption or brittle state. Comparison of transition tem-

perature ranges becomes possible from such curves, but occasional

irregularities in individual curves preclude this method of com-

parison from beihg~nerally applicable. Further, the comparison

of energy absorption--temperaturecurves is not a desirable method

of evaluating the fracture characteristics of steels, as this is

an unwieldly procedure. It has been general practice, therefore

to select some energy absorption value as a re?erence value for

evaluating impact transition temperatures. Thus a commonly used

method specifies that temperature, as the transition temperature,

at which the energy absorption for a standard keyhole Charpy

-22-

specimen equals 20 ft. lbs. Other methods hz.verequired that

1/4 maximum, 1/2 maximum or maximum energy absorption can be

specified as the reference criterion.

The impact transition temperatures as specified above may prove

fully acceptable for control purposes, but it is probable that with

the exception of the maximum energy absorption value, these arbitrar-

ily specified transition temperatures are not suitable for a funda-

mental study of the fracture problem. Thus it has been argued that

the gradual decrease of energy absorption through the transition

range, for the V-notch Charpy bar, is an effect resulting from the

fracture behavior of the metal on the compression side of the test

bar(32)C If this weretrue, the elimination of the compression side

of the test bar, as is effectively done in the Schnadt-type bar,

should eliminate the characteristic broad transition range indica-

ted, for example, in Figure 37”( as shown by the slope of the curve

in the transition range). The data in Figure 38 reveal that an

elimination of this broad transition range does obtain when the

compression zone of the impact bar is removed. The impact test

transition temperatures for the project steels, by the indicated

criteria are summarized in Table C.

It has been indicated earlier that certain of the steels which

are being considered here are especially sensitive to strain rate.

In the impact test an unknown factor due to strain rate sensitivity

pretiludesthe adjustment of the impact data to predict static notch-

bar test results. The impact test, however, can be used with this

-23-

reservation in mind, to examine steel quality, thus for example,

to indicate the effects of strain-aging, grain size, plate thick-

ness, etc., on the fracture behavior of a given steel. Groups of

data which may be compared on this basis are presented in Figures

39 to45. These data show that the ductile-brittle transition is

markedly elevated by increase in grain size (plate thickness con-

stant) and by increase in plate thickness (grain size approximately

constant). Variations from plate to plate within the heat tested

are not large as shown in Figures 41, 42 and 43.

It is needless to discuss the steps taken in the development

of suitable correlation tests, by means of which the ductile-brittle

transition in the large plate tests could be predicted. Such tests

have been developed in several directions as may be gathered from a

consideration of the data presented in Figures 46 to %. These

figures summarize all pertinent data relevant to the temperature of

the ductile-brittle transition in the project steels (see Table A).

Some few test results have not been included because of the in-

completeness of the data.

From Figures 46 and 47 it will be seen that virtually complete

agreement in the transition temperature data obtains for the large--

and small-scale tests that have been reported. By analogy this

statement can reasonably be extended to embrace all the project

steels as Figured 48 to 54 show. There is little question, there-

fore, that the ductile-brittle transition temperatures, for such

steels loaded under static conditions in structures, can be predicted

-24-

with a relatively high degree of accuracy. As will follow from a

consideration of the results reported from the 3-inch edge-notched

tension test, it is necessary to specify the criteria of the duc-

tile-brittle transition for restricted tests, with? in general,

fracture appearance being the most suitable criterion for correlating

the results of the small-scale tests with the large-scale test re-

sults.

~ Strenpth and Size Effects -- ~ w: A struc-

ture is designed to carry a prescribed load, and in the interests

of economy this load should be as great as possible ad yet safe

from failure. Experienc? has shown that in meeting these combined

needs the nominal tbnsile strength is not a suitable criterion of

the strength of a structuro but must be modified by a safety factor.

Since safety factors are regularly used in structural deslgn$

it should not, perhaps, be unsuspected to find that in the flat

plate tests a ma?’keddrop-off in tensile streng& accompanies and

increase in plate size, as shown in Figure 55. The drop-off

steels (of 55,ooO to 65,OOO lb./sq.in. tensile strength) frequently

amounts to about 1/3 of the tensile strength so that the tensile

strength value for k8-inch internally notched plate lies between

35,000 and 45~000 lb./sq. in. Hatch corner test data, however,

show that the reduction in tensile strength indicated for the flat

plates is not the maximum to be observed, for nominal tensile

strengths as low as 25,000 lb./sq. in. obse?ved, for nomiml tensile

-25-

strengths as low as 25,ooO lb/sq.in. have been reported fOr the

hatch corner tests. In other words a reduction in tensile strength

by 50$ can arise in a structure.

The reduction in the tensile strength in the hatch corner

tests is in large measure a design problem, as is indicated in

Figure 56. Redesigning is frequently relatively simple; but while

marked improvement in strength can be achieved in this manner, this

can be done only by the virtual elimination of all important local

stress raisers. Accompanying this increase in tensile strength there

is a more or less general increase in ductility which is very

desirable.

In the examination of Figure 56 it is noted that wide varia-

tions in energy absorption values have been obtained. This may be

construed as a lowering of the transition range for the steel, a

conclusion, however, that should be avoided. The model hatch cor-

ners were all made of steel C wl-ichin the large plate tests has

a transition temperature of +1009. The test data which are com-

pared in Figure 56 were all obtained at 700F., and all fractures

were by cleavage. sPeC@en 35 failed by cleavage which was initiated

at ah accidental arc strike incidental to the welding of the struc-

ture. A discussion of matters pertinent to this behavior will be

undertaken below.

~. Additional T&.

The testing program which has been X&viewed in the previous

section can be expanded in two obvious directions, the first of

-26-

which consists in an attempted correlation of the properties re-

vealed in the above tests with the properties of the same materials

in a ship structure. The second consists in the exploration of

the possibility of improved structural materials. Limited ex-

perimentation in these two directions has been completed and is

considered below.

Fractured Libert~ Shi~ Plate Tests: It was generally accepted

during the formative stages of the research program under consider-

ation that the brittle problem in Liberty Ships was directly a

size-effect problem. Thus for the small-scale tests a low transi-

tion range might be expected, and this transition range would be

displaced to increasingly higher temperatures as the size of the

test bar was increased. Figuratively then a full-size ship should

characterize a more or less definite transition range for a speci-

fied steel, and this would lie at a higher temperature than that

for a small-scale test bar. By this predicate, a ship could be

considered as safe from brittle failure as long as the operating

temperature was above that of the transition range, but it would

become highly susceptible to brittle fracture once the tempera-

ture fell below that of the transition range. By this principle

of behavior It becomes reasombly convenient to attempt suitable

correlation between the many laboratory test results and full-

scale ship behavior.

Thus, for example, of the several ships which broke In two,

a restricted few failed under well-documented cmditions of tem-

perature and loading and were accessible for experimental purposes.

-27-

From these ships, therefore, plate pertinent to the initiation,

propagation and termination of the crack could be removed for labora-

tory testing, particularly in the interests of a precise determina-

tion of the ductile-brittle transition in the small-scale tests.

Since the correlation attempted in this manner assumes that the

temperature at which the ship broke will reveal the temperature of

the ductile-brittle transition for the ship, the small laboratory

tests should allow the determination of any needed correction factor

for ship plate evaluation by means of the small-scale tests. Test

data pertinent to this correlation for the 12-inch flat plate speci-

men have been reported ?Gr two ships, the “Fierre S. Dupont” and

the “Ponaganset’’(33).

The “Pierre S. i%pontf’suffered brittle fracture during a severe

winter storm at sea on February 10, 1948, with the air/water tem-

peratures reported as 270/420F.$ respectively. Details of the loca-

tion of the plate available for testing and the specimen lay-out are

given in Figures 57 and 58. The T-2 Tank Ship “Ponaganset” broke

in two on December 9, 1947, while moored and under a hogging load,

with the air/water temperatures being reported as 3\0/410F.,re-

spectively. Details of the plate location for specimens from the

llFonagansetlrare given in Figures 59 and 60. In both the ships

studied the cracks were initiated at about air temperature which

allows fixing the apparent transition ranges at about 300F. for the

I!PierreS. Dupont~fand at about 350F. for the’!ponaganset”.

-28-

!Chechemical analyses of the plates removed from these two ships

are given in Table D and the mechanical properties are given in

Table E. The results of the 12 inch flat plate tests are given

graphically in Figure 61, while the various transition temperature

data are accumulated in Table F. The data for the 12-inch flat

plate tests on the fractured ship plate indicate the transition tem-

peratures for the plates tested lie between kO°F. and 11OOF. These

data indicate that these plates through which the crack propagated

had transition temperatures above the apparent transition tempera-

tures of the ships and hence extended fractures should have been

possible.

Jk&QQz Qtw$-: The high yield strength steels which

were studied at the University of California could not be fabricated

into full-scale hatch corner test specimens because of load restric-

tions on the available testing machine. A reduced sized specimens

called the restrained welded specimen was tested instead. For com-

parison purposes steels Br and C were tested using this specimen,

and the data obtained have already been presented. The restrained

welded specimen gives nearly the same transition temperatures for

the two steels as does the full~scale hatch corner test. The re-

sults obtained for the high yield strength structural steels using

this specimen will, therefore, be considered as equivalent to the

full-scale hatch corner tests run on the project steels.

-29-

The chemical compositions, thermal treatment, and mechanical

properties of the high yield strength structural steels studied

are presented in ‘1.ableG. The transition range data are summarized

in Figures 62 and 63, and transition temperatures are accumulated

in Table Ii.

In brief, these data reveal that much reduced transition range

is possible with selected HYS steels but that a low transition

temperature is not assured by the use of such steels. Further, it

is evident that the good correlation that obtained among the respec-

tive tests for the project steels is not ‘?,ypical~as transition

temperatures given by the 12-inch flat plate HYSS specimen are as

much as 50°F. removed from those given by the restrained welded

specimen.

The nomiml tensile strength values of the restrained welded

specimen of the HYS steels studied here may drop to as low as 35

to 40$ of standard room temperature coupon test values, but the

average nominal strength of the specimens tested was approximately

65$ of the standard test bar tensile strength.

~ Studies &-Cahn and ImbembQ: The survey of the ductile-

brittle transition phenomena in the Navy tear test by Kahn and

Imbembo(34) has been especially revealihg because of the large

number of different types of steels which have been studied with

this test. Since the transition phenomena associated with this

test have already been described for the project steels, it will

-30-

be sufficient to consider here only the transition temperature data

which have been accumulated. Details of the chemical composition

and thermal treatment of the steels studied are presented in Tables

I and J, and the transition temperature data are presented in Figures

64 to 68.

From the tabulated data it is seen that the work included the

testing of:

a. Semi-killed medium steels

1. i{ormalmanganese contents

2. Higher manganese contents

b. Fully killed medium steels

c. Vanity-type high-tensile steels

d. Medium steels of several thicknesses

e. Steels finished by non-conventioml mill practices.

k,anyof the steels were also tested after stress-relieving and

normalizing treatments.

The following generalizations,which have been stated previously,

are emphasized in a consideration of these dataz

a. The transition temperature for a given steel is lower, the

lesser is the finished plate thickness, cf., Figure 64.

b. The transition temperature for a given steel is lower, the

smaller is the ferrite grain size, and the reduction in

transition temperature by the reduction in grain size may

be of large magnitude.

-31-

C. Normalizing when accompanied by a reduction in the ferrite

grain size may reduce the transition temperature by as much

as 1500F., but when a reduction in grain size does not

accompany the normalizing treatment, the reduction in

transition temperature may not be present. In this latter

case when a reduction in transition temperature is noted,

it is normally of small magnitude.

In addition to the above generalizations, it may also be con-

cluded thatg

a. For the as-rolled condition, there is a probable slight re-

duction in the transition temperature as the deoxidation

practice varies to produce from a rimming to fully killed

class of comparable steels, This reduction is more marked

for aluminum treated steels.

b. An adjustment of the (km/C) ratio to higher values does not

ensure a reduction in transition temperature for the as-

rolled platei For such steels, however, a normalizing

treatment may produce a reduction of the transition tem-

perature by as much as \O°F., cf., Figure 65. This re-

duction seemingly is brought about by a reduction in

ferrite grain size.

c. The lighter plate for the high (kin./C)ratio steels con-

sistently shows the smaller ferrite grain size, and this

grain size is not materially reduced by normalizing. The

-32-

grain size in tieavierplate in the normalized condition

approaches that representative of the light plate, and

similarly the transition temperatures for the heavier

plate approach those of the light plate.

d. In the steels studied the McQuaid--Ehngrain size was of

minor importance in determining the transition temperature.

e. Stress-relieving treatments were not observed to improve

the fracture characteristics of the plate studied.

D~~~ussION

The experimental data which have been:presented, indicate that

much of the steel wk.ichhas been used in Liberty and Victory ship

construction may ordinarily be expected to fail with brittle frac-

tures at the temperatures at which these ships regularly operate.

That the ductile-brittle characteristics of these steels, then, do

not of necessity determine the structural behavior of the steels

must follow, since most Liberty and Victory ships continue to

operate satisfactorily. From this it follows that either the

correlation of laboratory tests with ship structural behavior is

precluded by the operation of unknown quantities, or that the factors

which modify the transition temperature of a steel are improperly

combined in the tests to simulate the conditions of ship operation.

That the second alternative is the more probable follows from

a consideration of Figure 69. Here are presented maximum nominal

strength deck stress levels, determined for ships of a type considered

-33-

here under operating conditions, and it will be noted that these

stress values are very much less, for all conditions of loading,

than the comparable stress values measured in the hatch corner

tests.

In examining the apparent incomparability of the laboratory

test results with full-scale ship behavior it becomes desirable

to examine more closely the significance of the ductile-brittle

transition as determined in the small-scale tests, and to re-examine

the conditions of loading in both the laboratory tests and in a ship

structure. Of these the d~ctlle-brittle transition will be considered

first.

The Ductile-Brittle Transitio4: The appearance of brittle

fractures in mild steel specimens has been shoxn to be possible in

unnotched tensile bars tested at a suitable low temperature. None

of the steels which have been studied are brittle in this way at

ship operating temperatures. Such brittleness in ships must result,

therefore, from the existence of effective notches in extreme tensile

structural members. Such notches may arise from design or from de-

fective workmanship, or from a variety of incidental factors such as

arc strikes, the welding of clips to the deck, etc. It is further

possible that effective notches may arise from the action of fatigue.

It is evident, therefore, that the effective notches that exist in

two ships of the same design may vary over a considerable latitude

of intensities in corresponding areas. However, the design of a ship

may be such

a case that

-34.

that the incidence of severe effective

proved to be true in the basic Liberty

notches is high,

ship design.

hhen effective notches arise in this ~ay, design changes may be

introduced to bring about a structure which then becomes as re-

sistant to brittle fracture as the structural materials will

allow.

of the

cargo,

An effective stress raiser may not be a design feature

ship but may arise fram operations involved in tying down

the welding of clips to the deck, or from fatigue action.

The significance of the ductile-brittle transition observed in the

small-scale tests with respect to ship structural behavior must

center then from the outset on a consideration of the intensities

of notch action possible in a ship structure. Such knowledge will

be informative in the design of small-scale iests to predict the

transition temperature of a ship structure under essentially static

loading conditions.

The most severe notch that can be in a ship structure will re-

sult from fatigue action. This is a notch which from earlier dis-

cussion may be considered as having attained a limiting stress

raising capacity and should characterize a limiting maximum transi-

tion range. Under static conditions of loading the ship structure

possessing a fatigue notch as the effective stress raiser would

then have its highest transition temperature.

If the effective notch is not a fatigue crack, in general

under static loading the metal in the notch may be expected to

-35-

reach the yield point and deform before the adjacent material.

Even in a relatively mild notch, however, the stress In the notch

may exceed the fracture stress of the metal before yielding takes

place in the ad&cent material. Once this happens, a crack will

form which if propagated brittlely the structure will fail with a

transition temperature characterized by this crack, thus with a

transition temperature in agreement with that determined for the

fatigue crack in the same structure.

When the effective notch in the ship structure is sufficiently

mild so that plastic flow is possible in regions outside the notch

before cracking takes place h the notch, extensive plastic distor-

tion of the structure Is possible to failure.

Under conditions of static loading it is useful to know the

maximum temperature at which brittle fracture can occur and this

is a temperature determined by the most acute notch available--the

fatigue crack. This temperature is important for it would appear

that all ship fractures originate in notches equal in intensity to

fatigue cracks, ati if this Is so that latent transition temperature

of the ship, when this ship is made of mild steel, must be high.

Under static conditions of loading to failure this high transition

temperature would be realized.

Under service conditions the ship would possess a still higher

transition temperature due to the dynamic conditions of loading,

but brittle failure thus to be expected is not normally realized.

-36-

That brittle failure does not take place must arise because of

differences in loading under the laboratory and service conditions.

These deviations in loading conditions will now be considered.

~SOndiWwti Structures: Nominal tensile stress

values of 10,000 lb./sq. in. are not regularly experienced in the

strength deck of ships in operation, whereas, the nominal stress

in the hatch corner test specimen was measured at 25,000 lb/sq. in~

at failure. In an examination of this question a consideration

of the load-elongation diagram for a 12-inch plate specimen SS given

in Figure 70 is informative. On this diagram the load is specified

at which the initial crack is formed. A consideration of the num-

erous stress-strain diagrams included in the indicated reference(28)

reveals that this crack is regularly formed very early in the course

of the test and at a load of about 5/7 the tensile strength deter-

mined in this test. The ratio of the load to initiate cracking to

the maximum load increases somewhat when the specimen fails with

low energy absorption, but in this case also the initial crack is

normally present for some time prior to failure.

In a ship structure the conditions of loading are not such

that a crack can be initiated and propagated slowly to fracture

of the structure. On the contrary the loading cycle due to wind

loading and wave aation can be expected to be quite short with

a consequent ‘Iimpact”type of loading being experienced. With

this type loading the structure may be overloaded for but a

-3’7-

relatively short time, following which the overload Is released.

The problem of fracture in the ship then is resolvsd into two

components, mmely, a loading factor and a time factor. The in-

terplay of these two factors may be quite complex and may modify

the stren~th properties of the ship steel in a way not now recog-

nized. The response of the ship steel to such loading cycles will

now be considered.

Since the loading rate experimced by the ship can be relatively

high, the transition temperature considered typical of the ship

constructed of a given steel must be elevated by a proportionate

velocity factor over that experienced under static loading conditions

If the ship is operating at a temperature that lies in the range of

brittle behavior, two conditions must now ba fulfilled before

cleavage failure will result. The ship must be overloaded; ~.g.,

the stress in the effective notch must exceed the fracture strength

of the steel, and secondly, tk.isstress must be maintained suffi-

ciently long to allow the crack to be initiated and propagated.

It 5.srecognized that all cleavage fractures are generally

preceeded by some, though slight, amounts of strain. It is alao

accepted that the crack is developed In the Initial stages of its

life at ad.ow rate but is propagated at a high rate. From this

it is concluded that a short but Important time interval must

elapse before a fast moving cleavage crack can be established.

This time interval for a given steel must depend on the temperature

and the amount of overloading experienced In the critical section.

-38-

Iiodata are now available to allow a discussion of these quantities.

However, it is expected that those steels which have the lower

transition temperatures as determined by the laboratory tests, will

be the most effective in suppressing brittle crack formation in

ships.

~ Steel Selectio~: In the consideration of steel selection

for future merchant vessel construction restricted lines of action

are possible. The extreme approaches to the ship fracture problem

are first, the relaxation of materials fracture specificationswith

the expected elimination of the fracture problem by control of design

and second, the setting up of a fully reliable fracture specification

test, with the relaxation of design restrictions.

‘thelatter approach if readily realized would probably prove

desirable from the point of view or construction, but the ductile-

brittle transition studies which have been completed to date indicate

that a construction program based on this philosophy of materials

selection wotlldlead to the rejection of a large percenta~e of the

steels which could be supplied for ship construction. This is

obviously an unacceptable solution.

The alternative approach to the ship fracture problem, that

of controlling ship fractures by design control, has been used in

the construction of the Victory ships. These ships continued to

operate satisfactorilyuntil the winter of 1951-1952, at which time

several serious failures occurred. This suggests that design’improve-

ment without consideration for the fracture characteristics of the

steel is not the final answer to the ship fracture problem.

-39-

It is not the purpose of this discussion to advance a given

test for the purposes of specification needs, but in the interests

of close coordination of such tests with service failure, two

quantities must be given much importance, and these quantities

are the intensity of the notch and the duration of loading. Since

the effective notch in determining the fracture characteristics of

a st~ncture is an extremely acute crack, the notch in a small-scale

correlation test specimen should be sharp. The relative duration

of loading of the specimen would simulate that experienced by the

structure. The testing of even a small test bar over an appropriate

range of temperature should then satisfactorily predict the location

of the ductile-brittle transition for the ship. The transition tem-

perature so determined alone will not predict the performance of the

ship and gives only one extreme value for consideration in antici-

pating ship performance. Qualitatively, however~ there can be no

question but that those steels which have the higher transition tem-

perature will fail more readily in a ship structure than will those

with the lower transition temperatures. In view of the paucity of

data pertaining to the time and loading effects on the development

of a cleavage crack in mild steels and to uncertainties about load-

ing conditions in ship service, it does not appear possible at this

time to devise a test that will provide full correlation with ship

performance.

-40-

ACKNOWLEOGMEN~

The present report is a review of the salient features of

the investigations conducted on medium ship steel under the auspices

of the ship Structure Committee. The reports which have been sub-

mitted by the many contractors of these investigations are both

numerous and voluminous, and It has not been possible tp present

here other than selected material taken from these reports. The

selection of material for inclusion In this report has been the

responsibility of the authors, but valuable suggestions indicating

appropriate deletions and/pr additions have been made by Drs. John

Low, Jr., and Finn Jonassen, both of whom were kind enough to examine

the manuscript in one or more of its early forms. The writer~t

associates at the Pennsylvania State College, notably Drs. John R.

Low, Jr.; William Lankford, Jr.; John Ransom; T. A. Prater; were

closely associated with t~e early development of the research program

that was ultimately completed at that institution.

The writers would like finally to thank Nessrs. James McNutt

and Fred Bailey for much assistance in placing the manuscript,

tabulated material and cuts in final form. Their task has been

rather a difficult one as certain of the cuts requested have not

been readily available.

(1)

(2)

(3)

(4)

(5)

(6)

(7)

(8)

(9)

(lo)

(11)

(12)

(13)

-kl-

BIBLIOGRAPHY

Final Report of the Board to Investigate the Design andMethods of Construction of Welded Steel Merchant Vessels,JUly 15, 1946.

Technical Progress ReDOrt of the ShiD Structure Committee,March 1, 1948; “

Second Technical Progress Report of the Ship StructureCommittee, July 1, i950.

M. Gensamer, E. P. Klier, T. A. Prater, F. C. Wagner, J.Mack and J. L. Fisher: !!Correlationof Laboratory Tests

00

with Full Scale Ship Plate Fracture Tests.ll Ship”StructureCommittee Report Serial No. SfX-9, March 19, 1947,

A. Le Chatelier: Rapport a la Commission francaise desMethodes d’esaais le 22 October 1392. Contrib. pp. 25/46.

P. Lukwik: ‘Elements der Technologischen Mechanik, Berlin,Julius Springer, 1909.

N. N. Davidenkov and.E. M. Shevandin: Jnl. Techn. Phy. IV,1934.

N. N. Davidenkov: “Dynamic Metal Tests.’l Second edition,1936, pp. 158 et. seq.

~. W. Vanderbeck and M. Gensamer: “Evaluating Notch Tough-ness,ttwelding Research Supplement, p. 37-s~ JanuarY 1950-

M. Gensamer:p. 30, 1946.

J. Marin. V.

,,Strengthand Ductility.” Trans. A.S.M. ~.

L. Dutton and J. H. Fauoel: !!HvdrostaticTestsof Spherical Shells,II“Weldiw Resear>h fklppl;ment,p. 593-s9December, 19Lt8.

H. E. Davi&, G. E. Troxell, E. R. Parker? A. Boodberg andM. P. O~Brien !!causesof cleavage Fracture in shiP plate:Flat Plate Tests and A&iitfonal Tests ofiLarge fibes.’!

‘&Structure Committee Report Seria,LNo. st?L8, January 17, 1 7.

H. Larson and E. P. Klier: Trans. A.S.M. ~, P. 1033, 1951

H. Neuber: “Theory of Notch Stress: Principles for ExactStress Calculation” Ann Arbor, Michigan, 1947, pp. 155-175.

-k.2-

(14) K. J. Stodden and E. P. K1.ier: ‘Brittle Failure and SizeEffect in a Mild Steel,1!welding Research supplement~ P“303-s, June 1950.

(15) E. Orowan, J. F. Nye and W. J. Cairns “Notch Brittlenessand Ductile-Fracture in Metals,” Theoretical Research,Report No. 16/45, Ministry of Supply, Armament Research.Sept.; July 1945.

(16) ~$k~chs and J. D. Lubahn, Welding Research Supplement.

(17) R. S. Zeno and J. R. Low, Jr.: “The Effect of Variationin Notch Severity on the Transition Temperature of ShipPlate Steel In the Notched Bar Im act Test,” Welding

tResearch Supplement, p. 145-s, 19 8.

(.18) A. B. Bagsar: Melding Research Supplement, p. 284-s, October1949,

(19) R. D. Stout and L. J. McGeady: llTheMeaning and Measurementof Transition Temperature,1!Welding Research sUPPle~t~p. 299-s, 1948.

(20) Osborn, Scotchbrock, Stout and Johnston, “Comparison ofNotch Tests and Brittleness CriteriaftSupplement, p. 24-s, 1949.

, Welding Research

(21) R. D. Stout and L. J. KcGeady: “Notch Sensitivity ofWelded Steel Plate”, Welding Research Supplement, p. 1-s,January 1949.

(22) N. N. Davidenkov and P. Sakharov: “On the Influence ofCold Working upon the Brittleness of Steel,” Tech. Phy.U.S.S.R. ~, p. 743, 1938.

P. Sakharov: *On the Influence of a Notch upon theCritical Temperature of Brittleness of Cold-Worked Specimens,”Tech. Phy. U.S.S.R. ~, p. 758, 1938.

(23) J. M. Lessens and H. E. Jacques: *Effect of Fatigue ohTransition Temperature of Steel,‘8Welding Rssearch Supplement,P. 74-s, February 1950.

(24) fi.H. Bruckner and N. M. Newmark: “Axial Tension ImpactTests of Structural Steels,a Welding Research Supplement,p. 67-s, 1949.

(25) F. Fettweis: I!TheNotch Impact Test - Development andCritique”, Arch. Eisenhiittenw.Q p. 625, April 1929.(A partial English translation has been published by theShip Structure Committee)

(26)

(27)

(28)

(29)

(30)

(31)

(32)

(33)

(34)

-43-

R. R. Thomas and D. F. Wixxlenberg: 11AStudy of SlottedTensile Specimens for Evaluating the.Toughness of StructuralSteel, Welding Hesearch %pplement, p. 209-s, April 1%.

W. K. Wilson and R. A. Hechtman: I!CleavageFracture ofShip Plate as Influenced by Size Effect,” Ship StructureCommittee Report Serial No. SXL1O, June 12, 1947.

S. T. Carpenter and W. P. Roop: llTensileTests of InternallyNotched Plate Specimensff,Welding Research Supplement,p. 161-s, April 1950.

E. P. DeGarmo, J. L. Weiran and M. P. OtBrien: ‘tCausesof Cleavage Fracture in Ship Plate - Hatch Corner Tests”Ship Structure Committe6 Report No. SSC-5, October 23, 1946.

H. E. Davis, G. E. Troxell, E. R. Parker and M. P. O~Brien$ItBehaviorof Steel under CorsiitionSof Multiaxial Stressand Effect of Welding ani Temperature on this Behavior;Tests of Large Tubular Specimens,” OSRD No. 6365, SerialNo. M-542, December 6, 1945.

A. Boodberg and E. R. Parker, I!Causesof Cleavage Fracturein Ship Plate; High Yield Strength Structural Steel!t,ShipStructure Committee Report Serial Xo. SSC-28, September 21,1949.

E. P. Klier, F. C. Wagner, J. L. Fisher and M. Gensamer:“correlation of Laboratory Tests with Full Scale ShipPlate Fracture Tests, A Study of Strain Gradients ShipStructure Committee Report serial No. SSC-17, l%+.

E. M. MacCutcheon, C. L. Pittiglo and R. H. Raring,IvTransitionTemperature of ship Flate in Notch-Tensile Tests”~Welding Research Supplement, D. ~8b-s, April 1950.

N. A. Kahn and E. A, Imbemboi

I!FurtherStudy of Navy TearTest”, Welding Research Supp ement, p. 84-s, February 1950.

-45-

TABLES

AND

FIGURES

—

C(J)L

A

B?r

Bn

c

Dr

Dri

E

F

G

H

N

4

u.C39

3b.~ 0

.C30

.C26

. ~~~.

.C24

!020

.931

.020

,01c.“_,

.020

3.0 0

‘LADLE. A—.

CHEllICALANALYSES OF THE STEELS———

Ni %

.02

P,~.“,

.~,~

‘2.G

.16

.15

.15

-Cl.,, 4

.98

‘5.“

3.39

,05

.03

.2’2

. (: 5

.1>’

.09

.19

.13

~

. C3

. 23

.C3

.~]

.12

.12

.Ocj

.Q3

.Ck

. C4

.06

‘3,...

~~ :;

. C03

.C1.2

.?15

.C!23

. ;23

.C25

, @+

.02i

.012

.004’

.017

.C18

};2 ,<

. 00k

.005

. C06

.C09

.006

.006

.025

.0C6

. CG6

.004

.005

.CQ6

rioter Tu:

.Q.d”ati.a

X.2,h,.kn.. s,

%

SummaryofT-t Ruulb—.20.1..1

m

N&ml Mxlm?mSt r..., b m:%%. P.,...,pi. . . Frut”r., 9 E1.ng.t, ml

mop. Ulti- .1. i. 5 i..Limit mti b% T . . . L.mg r, . . . .

So>uao 69JWQ &z,Yx g 1 16.9J

m.—P.t*.t 1*1

Q1.w.,

rr..tw~1,.-15.

—,,.s,.tio,/L

.an,mti.mllSt,..,F..i.i

Talgf - 7,.n.-,Jdical ..r. *

!6,260 62, m

r..tr,mp.‘+.—

70

70

H“trr,ati.r’t

( ma%’)

,.di~>ndi ti m,

,“*rnkl?..,, U.

.

.

AJi.1 1..(i.%. p,..,

.

.

“

.

.

.

.

AX1.1 l..t1“,. pm.,

N.t”r, .1 ,,.,,”,.

I.lti.t.d h.v thou i“P1.t8 mbo.t 4 im. frc.m.“.3 P.mll.l to ..ld . . . . nld. mtio.; alla=.h..ri% ,., .bo”t 6 in. , cr.ck Pr.PaJ.t8d. . . . .Omid. r.b, a ie,uth of tub. by .1a..-.g..

So.o

Sz. o

13S,0X

148,5.?3

2

z

2

!4,9ca 49, MX Pr..ticuly ‘.=. . . for tub. i.

C1...mg. rr..tw. entir.ly ?J.uud .lr.mr. r..-,,.1 .nd ..1,.

—

shear for 6 in. (mmtur.)) f aftar rqdr by“l’Ii*, .hur rm’ 4 in,, * ctuncd

Cl . . . . . fr.ct”r. Q?i~iLUtLIW i. ..ld .bo”t48 in. . . . . .id-...t,on -d PmP.@ti.& .P1rIllyaround tub..

cl..%. fracture oric%n.ti.g 1. ..ld Z in. Cr.mm,d-.mti.. .“d pmp.g.,ing Q=mP1. t.lr .ro”l!dtub.. No .h.ttml. c.

C1-..c. r...t”r. .,lgl.!Jt i.. i. ..16 Z* 1.. frommid-... nl.n. S,. cim.n ,h.tte r.. into my pi.,...

Cln.”r,. fr.ct”r. .ri~%c.ti% ., Lm,itudin.1“old 22-1”. frm mid-..etio” ,FO.addlW .1OW theh.., .fC.et.d zone P.%11.1 t. th. mld .“d th..,,.und the ,.,. ., b.,, ..dd .

Cl..-g. ft. ct”re .ri&u<in6 i“ ..ld 4 In. lWm

.ld-*..bi . . . sP.. ~.. .Utt..., it. MW Pi.....

‘m 1“’+”~ l= I ‘ I ““0’

-t--~5,6W 51, S00

1 I I I

4’3, C.W 54, C.00 WWi60.ce30; 0.2 3.0 S.o-42

So, wc 66, cca e. 59.5J%

sn, m 66,300 60, W. 56,0We—

W,C”M 61, EQ2 69,003 7z,@m—

40,0Ya 44: m 4* &s, w

S4,CC.5 W,om 49. Ica m,eca—

40, CO0 66, DY3 86,5C4 88, K.3—

S7’OCO 56, cC0 62. C.W 59.9CQ—

25,003 59 .Cmo 61.CC4 64, MO—

k? ,WJ 49, W3 e 25. w

[

4.4 4.,

,.5 4.0

9.2 10,6

1.6 2.,

4.2 S.8

,7,4 18.7

6.7 6.s

S.o .s.0

2.0 0.3

1

1

1

1

1

1

1

1

m

70

70

i6,1c.o 61,$03 9.0 109, WI

102, CCC

Ms,ceu

86,500

98,cca

41 ,Km

m6,cca

160, m

38. WI

>6,5$4 6S,100 7.6

m.o

3.6

6.0

I

T46,430 +*, ECC-44

-40

-s9

.42

-s8

B.f w.W,lding

.

B.C..,U.d Aft.,W.ldlng

.

no..

hi-or.Z.ldi.g

,8,7$0 4B, ecc

I62, X-J 63, 4X

58.640 64, YX

w .0

10.8

IC1..mg. fr.. t”r. OFie,imtl”, In ..ld 28 In. r.-

.id-...ti . . . %.. i... .h.tt...d into m.w Pi...?.

C1mmC. CI..t”.% ori&inati”E .t defect in @t..90. rroa ..1,, 44 i.. fro. mid . . ...%... ..d pr-p.,.tir.c .m””d ‘?..1..., M .h.tt.ri...

6.1

2.0

S9,7W 59, XC

So, e.$o 24,7CC-44

—

1“

.tion of sLrcss prcstmml k govm. f:til. r..

J F. ffurc OWurrcd :,t or new ends or end co.necticms, pre-

s.tmbly d.. to high complex skws mused by bending i.. ——

TABLE C

TRANSITI?N TWPE]?ATUiES CF PROJECT STEELS

4.S DETER!41KED BY VAR1OUS NO TCH2D TESTS

Chmpylr@ctSA. V-l:otch

T.,, Test

Kqhole Notch

Restrained Chaq

10% Tens:Keyhole Notch

tbtch,d Tension

(S/8” Fide Sectim

3“ Temi. nSheared Edge

Slov-r+emi: sch.,

Type .01”%

billed tbtch

S1ow-6end, SChnat

%. .C.XPLPressed Notch

?2” Wide TensionInt.mal Notch

W Wfle Ten.i..Inteml Natch

(.%arthm- Data!

12” Hide TensionInt.mal Notch

(Callfbnll. and

Illinois hta)

3“ T.nsiw,

[email protected]

Pre,trained ChaIT5% 7.”s , Kq+mle

Prestmined Ch, T

2% Tens: Keyhole

Cbpy Impact

Full TM cknessSawc”t Notch

Charpy Impact

Std. Keyhole !:otch

Telmemkdm *F For Qmi”t or ?l.msition kg.

En.r~ Absom ti on

CEA SnLh” DT&QK~

1CO14O1OO3O2O4OOO 0-m

1271Wm-5S554S _ SO—

9585 EO?”302020--2O -

--- --— ——- _

--- -—-— ———

110 B5 53 2S 25 25-25 <C ~5 <Q

m 72 5s E? 15 42 -15 .17 -2c —

% 953413325233c -2? 4S

89 B148171S-8— — -

% 91 251 S154C 5 0-1S-S4

-—— ——— --— —

65 m 45 045 310-45 —

55 m a o.~sd-s--u —

53 75 m 35 a -?0 19 1s o -1!)0

%fibrous Fracture

:EA m h ET~T

--- -—- .— - _

271m 62-555545 -3C—

--- --— --- _

)7 B7 55 G? 15 42 .15 -1S <0 -

)??3e x!? 7.55 -20<5

1285531715 -1?.- -—

U12C45 ?—323C 3535 7

---- -—.. —--

.— -- --— ___

— — — — — — — —-

— — —-- -—— —

&IerEY Absorption

c SA RID ID TEw QHN. .. —————

?00 200 1S0 lSC M 120 SI 70 70 3 S

Y: 5 140 70 - 70

14C 105 75 55 70

--- -—

—-- --—

.20 85 6? 35 so

? 95 65 MO 3C

m 110 45 33 SC

w !+ . . 7. 2“

--— —-

4C 10S 7S 55 70

4C 105 &3 75 70

45 175 14> 110 m

60 S0-S0-

1035—-75-

— — —-.

—-- --

m -10 0 40 -2C

690-s 0-

? S) -25-32

-14 ---

41 15 15 ,1s 4:G. s.

15

--- _-

703 S-10-

703 S-3S—

UO 85 70 70 35

m 120 m MO 12[ lzo M 3s S5 3s

~ Flhvw ham.,.

CEA BnIhtk EkQHN

--— —-— --- _

ES14070-70E0 @3- m_

——- -—— —-- -

SC 10S 110 105 40 m 40 m lCO -

226 S43 ----- 27-

2585S53SS053-10 O-20 -2.0

m9565103S0W 0-S 0-

02140 455C ? ?70 -250

161%582520-14 ---

Zo?,ws? ? S) 1565-25Q, s.

65

021.276270 -3540 S34C 2S

--— ___ ---- _

—--- ——- ___ _

--— --— ___ _

--- —--- ---- --

% of specimensfrom PIERRE S. DUPONTTable D - Chemical Analysis inand PONAGANSET

Plate C “ Mn Si

DU 0.26 0.33 0.02

PBDP 0.14 0.38 0.00

PBDS 0.15 0.40 0.00

PAD 0.22 0.47 0.04

PCDP O.lli 0.41 0.01

PJSS 0.29 0.45 0.10

* Rimmed, semikllled (S-K)

P s Cu N

0.011 0.038 . . 0. .

0.020 0.035 0.16 0.005

0.020 0.030 0.17 0.004

0.021 0.035 0.03 0.004

0.027 0.030 0.10 0.004

0.015 0.040 0.03 0.0045

Table E - Mechanical Properties of Steel from PIEHRE S. DUPONT andPONAGANSET (l-In. Wide Full-Thickness Speci::ens)

Tensile Yieldstrength point, ‘::n~::: Bend test

Specimen Gage, in. psi. psi

DU 3/4 60,200 34,400 28.2 . .

PROP 13/16 52,3oo 31,900 32.5 OK

PBDS 13/16 55,600 32,6oo 31.0 OK

PAD 13/16 59,700 30,500 25.0 OK

PCDP 13/16 54,500 34, 50G 28.0 OK

PJSS 3/4 65,200 37,100 27.5 OK

Typesteel*

..

Rim

Rim

S-K

Rim

S-K

—

Table F - Transition Temperature in “F. of Steels as Determined byVarious Tests

Steel

DU

PBDP

PBDS

PAD

PCDP

~Jss

No.Tests

7

11

11

11

11

11

T. T.,Energy torupture

37

46

60

104

9+

58

T.T.,fracture

appearance

37

46

60

102

55

60

Keyhole V-Notch1/8 in., Hack Charpy Charpyhole S?lW 15 ft.-lb.15 ft.-lb.

. . 107 . . 62

71 .. 9 ..

127 .. 18 . .

152 $. 12 . .

7+ . . -3 ,.

8’9 ,. -6 . .

NavyTeerTest

. .

90

110

150

90

90

TABLEG

PROPER’ITES AND COMPOSITIONS OF HIGH YIEID STRENGTS STRUCTURAL STSSLSUSEZIIN TSE INT’SSTIGATION

sTEEL NO. 1 2 3 4 B** c

TYPE Alloy Alloy Alloy Alloy Mild MildHEAT TF,LATMLNT Quenched & Quenched & Quenched & Quenched & Semi Killed

Drawn*Semi Xilled

Drawn Drawn Drawn as-rolled as-rolled

PHYSICAL PROPERTIES

Yield Strength Psi.Average 66,OOO 80,000 80,000 84,000 36,ooO

Ultimate Strength39,000

Psi. Av@rage 89,OOO 97,000 100,000 100,000 60,000 67,4ooElongation $ in 211

Average 26 22 20 23 26Reduction In Area $

25.5:Average 64 60 60 68 63

APPROXIMATE CHRNICAL COMPOSITION

Carbon .141::~

.16 .16 .15Manganese .?5

.241.45 .27 .77 .48

Silicon .24 .77 .21 .17 .05Molybdenum .42 .16 .48

.05.20 .005

Chromium .60 1.13 .03Zii-conium .09Phos horus .;14 .02

:jl:Olh

su~pgur .023 .02i.010 .012

.021 .029 .026VanadiumNickel .53 2.32 .02

—* Steel 1 was also used in B normalized condition for some of the tests

...——

** Mild Steel Br properties included for comparison*** + Elongation III8 v

TABLE H

APPROXIFATK TdANJITION YEMPIXATUHES OF HIGH YIELD STSENG’fESTIKICTUHALSThkLS DET’hiiNINhO BY MLLNS OF DIFFERENT SFLC11.l&Ns

_.—.._____ _____

STE.hLs1. 2 3 4 B_

TYPE OF SPECIk!hN APPROXIlib.TETSJINSITIONTE,14PL~TlF.izs

3“ Edge Notched -lo°F +18OF -l!220F -lo8°F +21°F

1211Centrally Notched .50F +20°F -95W -102°F +18‘FRestrained Welded +4Cw +75+ _500F

- 65°F +58‘F

Tea,-T..tIJ!ELu

PrOpertieOof Ship Hateneae (Mn/c<3)

Medium, Sedkiid, 48.S-5,Nom.] MiaIIg.-

—— C.m$m

0:5 0!:2 07;80.25 0.42 0.080.24 0.42 0.080.25 0.49 0.040.25 0.61 0.050.21 0.49 0.080.20 0.55 0.100.18 0.50 0.07p: ::;$ :::

0,14 0.46 0.07

tit.”, Y,—

Al N0.033 0, CF34O.rxw 0.0040.W.3 0.W140.034 0.0340.015 O.WJ0.C02 0.005

–O. D32 o.cm5-0. LW2 0.C44-0. cw 0.C04-0.036 0.!3)4-0.002 O.rm

--:,ati;,zi: ,

pip, dkm+h,.8.. m

.,..,.

34,mo 58,04035 ,bw !36,24035,X4 63,20034,9!30 w,wm82,003 67,90033,303 61,41w81,303 59,4c4332,300 57,*C4

,,..e,&——

M&:,.,

;~ :

35.530,034.531.031.0az, o

M;z&.m &&%fn%-.—Lb./i..● f,..lb./k. ● /&i%?.’:*

56,(?W 1140 75052,600 1C+30 86050,WM 1320 ‘aa~48,300 ~;~ ~1 ~51,81XI#&l ,g~ :::

53:000 1550 lgtll56,13C0 1;!:49,X4 70046,4CKl 960 780

ion, Tensile and Tear-Test Pwperties of Ship Plate0.60/0.90 (MnfC >3)

———_ -———— (... ,,,,,,,;,;,, ” O/.———.— —s,.,{, te”,ik ,7

Co.’fi. F, P. T. 3

0.2, “.,” ;:ll “’ Nt,.” c, M. (P.s.,.) (?.>s. [.)

R 0.004 0.000 40,180 88,0300.22 ,,,,0 0.01 0.UU4 0.000

R 0.’22 0.90 {,.03 0.008 0.004 38,83” 63,820N 0.,2 0.9” 0.03 0.008 “.004R ~:;; ~:~ 0:0, 0.006 0.004 .n 0 05 0.W5 0.C43: ::~: ::~ g:y, 0.006 0.003 .::

,,.007 0.00311 0.20 0.74 0.07 U.008 0.004: 0.20 0.7, 0.07 0.008 0.004 ,..

0.1, 0,72 0.08 0.’m5 0.006~ U.19 0.72 0:08 ::~ ::::: ,..

0.19 0.7, 0 o“N 0.19 <!.7? 0.08 0,005 0.005 :::

,..

R ::;; ::[; ::%.; 0, “05 0. “W 35,540 63,400N 0.005 0.004{ ::;; ::~ ::% 0.009 0.00, 40,~0iJ 65,560

0.009 0.00511 [1. Y2 0.8!4 0.07 (1.006 0.0114N “.00C 0.004R 0.22 0.!,,, 0.0, “. 006 0.006 :3,,900 70,470~ 0’22 0’8” ::: o.mM ,,.006 ,..::;; ::}; O.m

–O. W6 0.005 31,370 57, Y70p; :::: p~ 0.028 0.005 31,600 58,000

# –;:;~fi 0.004 37,w” 68,30[1n 0,22 0.81 0..7 0.004 3R,70” 66,40Ll11 0,20 0.75 0.0s –~:~16 0.00, 34,200 C6,200R ,,.,() “.75 0.00 0. W+ 34,0”0 62,000: ::;; g:yj p; –o’m* (1.005 31,780 58,720

0.006 0.004 34,200 60,2000.,7 0.68 ,,.0, 0. w 0. (XM 34,1(10 G0,60U

; [>.1!1 O 77 11.09 -~:;~G 0,00% 35,000 6?,8000.19 0.77 0.07

;0,.0+ 34,70U 64,100

p: ::;; :::; –~:~~ 0.004 S4,500 W2,100

R0.004 36,600 62,000

0.1!) 0.78 [1.00 – 0.006 0. 0[15 35,200 64,900R 0.17 0.73 0.05 –0.000 0.0.5 33,500 02,100R :,:; ::0: :::; 0.[101 0,005 32,750 56,70’9k .&l:& 0. (“M M,m] ,50,000R 0.1? 0.!,(, 0.10 0001 :36.%(, L!5,1OU: 0.3:3 (1.70 0.08 0.005 0.006 87,160 67,120

::;; 0.7, 0.08 0.005 0.006 38,700 05,%00R o,,ti 0.08 0.00!! <>.01J5 38,410 68,800: :::; :]:;j 0,08 0.00, 0.005 ,..

0,{,,, 0.0[)7 0.005N ::fl ::;: 0.00 0.007 0.0[15 ,..R (,.00N

0.014 0.00$g:~ g:;] ::OIJ :::;: 0:00,

E o 005 39,410 87,620N 0.22 “,7, O., g 11.nM 0.00s: 0.19 0.6, 0.06 0.009 ,, 00%

0.19 <,. (;$) 0.06 0.009 0.004 .:0.1” 0.6, 0.00 0.014 0.003 38,580 64,020

~ 0.1, “.69 0.[1(, 0.014 0.003 ,..R 0. M? O. 0[1.$ 36,580 66,780k, 0“4 “’7” “o’ 0.007 ().004::~ ::y: :::;R 0.012 0.004 ,..

0,012 0.00!: u.,, 0.70 (1:03 o. m!, o, m?, .38;1’1o 04;4%: :::: ::: :.: (mom 0.”04

0.2, 0.87 0.”, 0.000 ,,.004V 0.24 (1 87 0.”7 0.008 0.004R 0.24 [1.87 O.”, 0,007 0,004

~:fi ~:~ ~:~~ 0.007 “.004 .: 0.017 0.000 40,140 66,800N g:;: :.7: 0.ol 0.017 000(!: “,20 ~,v, ::): “.00!3 0.00,

(,.000 0.00{: 0.20 0.75 [1.0, <,.012 0.008 ,:: .:

0.20 0.75 O.lm ,,.012 0,008R O.lg “.7% 009 0.016 0.005 “:

0.19 (,.72 0.0!1 0.01, 0.00J: 0.18 ,,.75 0.08 0.012 0.00:

0.1” 0.75 0.08 0.012 0.005R ml: ::?; 0.0,! 0.009 [,.00: ,..x “,21 ~,8, ~:~? 0.00!4 0:005 ,..R 0021 0 “08 38,850 63,820N 0.21 0.81 0.07 0.02, “.006R 0.18 ..71 0.02 0.004 0.00: 33,3io 6i, iio

0.18 0,7, 0.0, 0.004 0.005[ 0.21 0.86 0.08 0.007 0.005 30,390 67,:20

0.21 O.M 0.08 O.(M7 0.005R 0.21 ,.7, 0.0,

,..0.007 0.006 38,260 65,710

N 0.21 0.7s 0.06 0.007 0.00;~ ;:;[ ~:~ ~:~~ 0:007 0.007 37,160 66,130

0007 0.007 ,..R 0.21 0.90 0.08 U. IIIIQ, 0.Ll)5N 0.21 0.90 0.08 0.CWi o.CKM

Steels, Medium, Sernil.il.

0.6,,,,.—. ~ —8T::,,;y

El## load,. ,. 8t.rf*L*../<n, ,,. lb,,)<”.

27.6 55,700 ;j~~,8,900

31.7 57,100 1530

:g,jl: ;:;:,..

57:000 ;~f~g}~:: ,280

5a:1uo y};54.1(1053,800 :;32~52,QO054,000 ;;~~

31.7 5,,800,.. ,5,100 ,420

30., F&mm logo,.. 64,800 1130

J4,1OO y:52,400

28.0 57,000 114057,500 ~~~~

32.6 52,!70031.8 53,000 1360:::j 58,200 1190

56,W0 ;L4g30.0 m:;::31.0 105032.4 51,500 117033.5 53,600 1360:::: 51,50” y&

W,rloo28.0 67,200 123033.0 53,900 122033.5 53,600 1210:32.0 55,100 1190:<2.0 52,100 [Z&33,6 52,70029, .5 ‘5,,300 ,0,020,8 56,000 1080X.7 55,300 p::4:X2”) ,5,200

E2,600 122053, s00 ]::354,30053,800 14605:3,200 140054,000 1700

3,,, 55,200 1:{30.,. 56,700 15s0

52,000 1Z405,,700 y:,..

27.5 ,0,90050,200 1410

30. s 54,300 126054,700 147054,7G+l ::;:54,400

.0,2 53,700 ; :Oy:$::: ,360

,..F’2,9~ 127051,900 :j;:

30.() 53,700w900 ; :;[50,00050,900 ;;:::#OJ ,40”

54:200 1s105?,80” [ ~o~49,800

,.. 51,200 y:53, 10[1

,.. ,.. ,..33.5 52,600 1420

51,300 134032.7 :$yll) : :;:

30.5 67,000 157054,300 ;~;~

28.0 54,60053,400 ~~~

31.0 55,600p;:g :4&g

56:2.Xl %640

i:.rnno.ition, Te.sile and Tear.lcst Properties of Ship I>laLe Steels, Medium, Fully IGlled (Si or .41)

40 -

30 .z

ii -mma>20 .w KK muz

E

III #

I0.

Oa ..

FIG. 1. The transition.in ...vJ absorptionand

fracture.w?ar.nce in the Ch:wpykeyholeinpct q!echen. steel Dr

.-200 –160 -120 ’80 -4U u *U Ou

TEMPERATURE, “ C

FIG. 2. The per cent md.ction in area versustemperatureof testing.steelE.

. ..43. w, ..,,,

,,6.,,,’” .,.., r,, mm,., Mm,

.25

●.

!

●●

x to -

~❑

3:.15

z

6

$~ .C6-

Klw , I ( , 1-200 ’160 -120 ’80 -40 0 40

TEMPERATURE, - C

se.),.,. ,.

,0—————

i

,//

%/,6+ ‘ ‘~’J7 ‘ ,,.

3,,.L“

,,,,.,.,,,.,,,..=,,

-. I

‘?.

- ,,.,.,.,;,,.,”,, ,,, >”4

.<,,..: ( ,) m “1, {,,,4””. “.ri..l r“!!., U..-io!o!.. O.WJ, ., , ,0 “.504”. . O.w .*II 1!- .I.. d-.

~:;xl:,i,:,:: :: , :+3,, ~u“,, ,1,,...,,... ..,!..1 (-!!!! 11.=-i-. - O.W .! . ~“ 0.-,”. - ..- ., ~,,) ,,,...,,,,.,,. 1. 2 “ml 3: , . ..e,m. . 0,002, .L-A”.mo 4. s .-4

.! 1 = “.ul-h. . O.IW

FIG. 7. t’ahew..fnominol biariat pmpernie. with tempenza.re

F’Irl. Ii, Slow bend test result,s.

\.

\’h

‘o \ (●\O\A

\*

’98

[

O\

\

● 9 \<

NOlldtiOS6V A9WNI

b

+

NOlldHOSW A9WN3

—

—

I

;,.

\

<

)’8’V) H91ONMO13E NOllWUINOO%+

(3) 39VAV313 % +

1 I I

‘-’20‘ =++21-

-200*

F200

:

160m-1

4L

>J20wawzw~ 80~~

4

.:0

o 100 200

PER CENT ELONGATION

ABc

—D

/

-’j

FIG. 1’7.

UNSTRISPEClkSPEClhSPECIN

;SED SPECIMENS:NS STRESSED AT 29,700 PSI:NS STRESSED AT 10,000 WI.NS PRESTRAINED IN TENSION

I I I) 120 160 200 5

TEMPERATURE, ●F

:cffect.of fatiguecm n.t.he<i1~.pmctst:ength.(Znd,,,tnce

% 000 p.s.i.)limitof notcl,cdspecimeneappr.x.. ,C,. TV. B - 105,000CYC1.CSof stress.Curvez - l,OLX!,000cycles.

120

6 1? 1,

IMPACTING VE;OCITY, FT/ S;C

FIG 18. The transition teroperature versms impacting velocityfor selected pm ject steels 1“ tension Impact.

AdaPted from Bmckner and Nekmark, (24).

6 12 18 24IMPACTING VELOCITY, FT/SEC

FIG. 19. A Sll~Eested extrapolation of the curves of F>g . 18.

ILo

130

1-

50

.-

1 I I

6 12 18

IMPACTING VELOCITY. FT/ SEC

FIG. 20. Suggestealvariation of transition temperature in theCharpy V-notch impact test with impacting velocity.The two experimental points were determined reSpectivelyin slow bending and impact bending.

“s:

—-----77’- -!? @zz1-IL

SCATTER!! REGION ,1,

/VAI –~

W IDTH

FIG. 21. Influence of specimen width on absorbed energy atconstant temperature.

I

1 I*.,,S,cc,m,.s ..,,24 !.ch.s b.,

HW,s.. . . .

%r-H3/4

,. --- 3/4

I I [I2. I I I

1

FIG. 22. Form of Taylor Model Basintensile test :;pecimens.

3.3

20

10

0

.%,. L/wFIG. Z&.211scid R#IOd bngib.!%1 10Width d Plateon

berg, AhM2bd. Re~b Am for Steel E Spxime,r., Notchd

With a Jeweler,, Sw

r-LeT‘--iFIG.23. Detailsof slot-T.ylor

Model Basin specimen

60

/ “ 314,, Di.5

50.

1 1 +

: 0.08. Dim7—

J . %w /

10

J,.,!w, S.2. c., - . “1 I

r .L/w - 0.24

-% “ m . . --- ,=

}----------+ --l------i

Lm

IL

I

b-u

=ii+- . ..

?-:. -= . . .. . Z;;:.::+,;,,~: 4!IRMB

=~’-’ ‘“l’ ‘“’”- ; - “ 1’:’” ~“~” ~ =—-----’s:. ,

.-,.

~-c.. :;4uiiiiE - w...::; ..-..._.,&-,... .._9>. ,...&L..._..,!% -,,::.%.-.=.----=:,,,: ,,.;&%-,..........*.“__J@Ei:

.=.s_.,..,

!,.

.

4! II II ‘“”””-“““ iA%;z—---[..N\,,

</?055 SECTION Of SPfC1l’fEN 5u8J[CT[D TO

RXIRL LORD nND IN TEKNRL ,-efs5uf[-,. ,,CC,M.N

~...;

CROSS SECTION OF SPECiP7FN B 5UEU[CTED

TO lNTIRfl#L PRE55URE ONLY (SPECIMEN

HORIZONTJI)

LON61TUDIN.LU SEC770N W 5&EClP7CN SUBJECTED

TO @Xl??L LO.QO RND INTERN17L PRESSURE

FIG. 32. Sections of apparatus for tests of 201’ I)iaiwtertubesat low teriperatures.

UD-7,

,,. ...,.. ,,,.,:,,, ., .,..

STAN DARD LH SPECIMEN

KEYHOLE NOTCH SUMMARY60 - —> QH

/ /“/

/

:’ 50

J

;.z 40Q(-aK0~ 30

<

$

: 20 Q/

I I ,,_-_— ——El I I 1

-200 -160 -120 -80 -40 0 40 80 120 160

TEMPERATURE OF

FIG. :3(,. r,,r,ol!, ,,,,. )! !lu. T,lry,

/“ -’-..120 / ,/---

——.

3TANOARD LH SPECIMEN

100 V-NOTCH SUM MARY

timA

a/

$

m<> 40 –- , -LJ /Wz.

/20

-. —-120 -80 -40 0 40 eo 120 160 200 240

TEMPERATURE 8F

,:,. ?:. ,-!:.!.<:1. ‘2:$:..=,<

FIG. 38. L~wgy absorption, fracture appetiramce, and

l:1ter21 contraction w. testing temperature forV-no.ch milled and V-n~~*.chpr=sed (bothSchn:adtmodific;a’.ion) L’harpy imp:~ctspecimens.;Milclsteel. (Ref. (14))

1:101010101010

;810

~tiwTreatment

R. T., 1 h,.R.T., 6 hr.R,T.. 12 b.R.T,, 36 hr.R.T.. 1 wk.R,T., 4 wk.R.T., 1 hr.R.T., 6 hr.R, T., 12br.R. T., 36 hr.R. T., 1 wk.R.T, 4 wk.250” c., ~1,hr.250 °C., ltl, hr.2Xi” C.,4hr.2W” C.,30 hr.

Steel A257. 50$!%

30– 1: 35

20 3535

:40204015 4515 35

45:46

451:70 1%55 ‘a555m70 106

TransitionTan:, :F.

257. 50%40

k! 4010 3510 45

352 4536 502025 2m 45

35 ““65 Ew 95

6; 05

FIG. 39. ~hdrF”~\~_I,LJtChinip:,c~trdns iLion Lerhperature

inOF at 2,5 ~,rla 5~~nlmi[llU,lenergy~itwrpticmfor

specimens preslr:,ined in compression. ROT. is

room temperature. (Ref. (35))

10

t-200 -1

Ah’ Co)led f,-,1650 F. X 16.

*Z.*+

*.,..,.-m >....--

“ ..i--——-......- m ,...+ ,*_. ... ....— ----- . <.*L<*4?$:#=awJr-.?+,.:,;,-,;,.,

--a.~.-..:...r —.

c Furn.ce cooledf,.,, 1850 F.x 100

,. Air U,.ld . . .1?5J !:. x 100

, .-

U. Furnace cooledf,.. 1850 F.x 600

STEEL N +

.-d

So)

(2)(3)/

.

I

l—

+

Ill~u~

-120 -80 -4U o )

FIG. Q.

FIG. 1+2.

FIGS. Q-45. The influence of plate thickness ~tndvariationsfrom plate to plate of constimt thickness on notchedbar test results. :11 steel from one heat. ProjectSteel C. R=specimens from plate surface. Uthersat mid-thickness.

STE

7

J12’’PLATE

1

3“PLATE.

/’

JRESTRAINEDWELDED

-40 -20 0 20 40 60

4AVYrEARrEST

● 4

4

;LOWIEND

OHARPY v

KEYHOLE

v

1

+ATCH20RNER

/

[

●

● ☛

) -40 -20 0 20 40 60TEMPERATURE, “F

FIG. 46

sTEEL C

‘2” PLATE

,J●

‘PLATE

[

●

●

●

~

PLATE

[

●

/EsTRAINEDMELDED ‘

NY /[ARisT

f

I I

iARPY

KEYHOLE

iATCH;oRNER

/

1201! )0=6090120 I

-30 0 30 Go ‘0TEMPERATURE, 0 F

FIG, 47

STEEL A

J72’’PLATE

2“PLATE

J,

5“PLATE

J,

{ESTRAINEDNELDED

NOT TESTED

) O 40 80 120 160 20C

NAVYTEAR m“

3“TEST

●●

●

go

● ,

)LOW3END

l!!

;HARPY

~~

●KEYllCt

A V-NOTCH

:’

A 0°L

k●

iATCH:ORNER

NOT TESTED

o 40 80 120 160 200TEMPERATURE, “F

FIG. 48

STEEL B.

72’’PLATE

I I

12’’PLATE

?ESTRAINEDWELDED

NOT TESTED

1 1 I I

I -40 0 40 80-

tiAVYTEARTEST

NOT TESTED

iLOWIEND A...*

IiiF

iATCH;ORNER

NOT TESTED

1 I 1 1

) -40 0 40 80TEMPERATURE, 0 F

FIG.49

STE

72’’PLATE

J’12’’PLATE

o-a

3“PLATE

NOT TESTED

,

?ESTRAINEDMELDED

NOT TESTED

~80 -40 80 120 1(

Ih

SLOWIEND ●

;HARPY +. KEYHOLE

4v

Y WV●

6

●Vv

V-nolcn

+ATCH;ORNER

NO- TESTED

-80 -40 0 40 80 120 I

Lzwoofwn

TEMPERATURE, “F

, FIG, 50

2“PLATE

?“PLATE

J

●

1 I

!UPLATE

NOT TESTED

1 ,

?ESTRAINEDWELDED

NOT TESTED

, I

-3o 0 30 60 90 -60 30 0 30 60 90TEMPERATURE, 0 F

FIG. 51

WYEAREST

v’●

● V-m’rctl

●

,

+ATCHCORNER

NOT TESTED

L

.,-S72’’ PLATE

12”PLATE

7-

1 ,

“PLATE

NOT TESTED

ESTRAINEDlELDED

NOT TESTED

o 30 60 90 120 150.

.L L

NAVYTEARTEST

(

●

SLOWBEND

,?!.

● e●

i ●

●

>HARPY

w

IATCHORNER

NOT TESTED

1

0 30 60 90 120 15CTEMPERATuRE, “F

FIG. 52

STEEL H

2“PLATE

1

/’PLATE

?ESTRAINEDNELDED

NOT TESTED

90 -60 -30 0 30 60TEMPEF

IAVY“EAR‘EST

L ●

$

;HARPY

T●ee

T-●

●●

LL●●●:

d ,

KEYHOLE

T

Y

*

-IATCHCORNER

NOT TESTED

-90 -60 -30 0 30 60URE, “F

FIG. 53

ST

72’’ PLATE

2“ PLATE

r-’

f’PLATE

(

ESTRAINED/ELDED

NOT TESTED

-200 -150 -loo -5(3 () 50+

NAVYTEARTEST

NOT TESTED

;LOW3END

● OO

,,,1,

●

●

●

●

;HARPY

sIATCH;ORNER

NOT TESTED

-200 -150 -100 -50 0 50TEMPERATURE, “F

FIG. 54

UV48MTONIN KWLWL ‘STRESSWtltl WIDTH06

..-.

U4RUTU2V IN W STSt39 WITH WIOTH OF PLATE- TESTS AT 327

FIG.55. Wide plate test results.

HATCH CORNER TESTSMAXIMUM NOMINAL STRESS AND ENERGY ABSORPTION

(ill teSts ~t 70°F.)

3Pf:l- CESIGN MAXIMUM NOMINAL STRESj -PSI

FEATURE t’ , ‘?m” I “’r’”” I ‘P I I “Y I ‘“~

5 BAslc CEslai

CCWTINUWS27 LCNGITUCSNAL

GIRDERWSSET FtATE

28 RHNFC6CEMENTU.SC.G, CCOE 5

,E4MZ AS 3029 EXCEPT NO

CX2UBLER

30 US,C.G COOE I

31 BRITISHMODIFICATION Z///H/////H/// fl/Z!!%ZA

JBASIC DESIGN

32 +&&&i

I ~ANGLE BRACES~ I,.. ..——b- ‘ Wl!coo 1 2W+xa ( 3.C9J!’X.3 ‘ 4,C43XI I 5W4X0

I6&

1’

ENERGY ABSORPTION - IN LB.

vH%z+zzzz22vzz23MAXIM NCMINAL STRESS ENERGY ABSORPTION

FIG. 56.

[PUN .IJWER OEM

FW57. Pierre S. DwwIt,,-Pkm tiew Of the upper deckdww% the plate rern.oedrfmk testing and the .djacertc

The ma.k SE-L.. i. . weld . . . . ,.. comer ., N.. , ,.,., .md w“..= ., ..”.3,., !,,*. . . . . . . i..o,”d . . . . . .“..,,,

n

ana STANDARD TENSILE BARS

;jikkb.,8..,, ,6 ,, M,.,.

,,. ”...,, 0,,.

STEEL OU

Fig. 58 .“Pierre S. Dqwmt,,—Smr@e from deck plate C-10aowillg IOc.=tion of t.., ,pe.i ?neru

40Key to Fracture Appearance

.= Fibrous.4

0 Gron.lor ●I 2~. _ e Mixed

%’Steel DU

o@

40

20

0

FIG. 61. Twelve-inch wide specimens. Results of tests of

samples removed from fractured ships. 3/L m 13/16inch thick pl; ,te.

lCMPC,AT”,E o, ,,,, -,,

FIG, 62a ENERGY TO MAXIMUM LOAD vS. TEMPERATURE FIG.626 ENERGY TO FAILURE VS TEMPERATURE

RELATION FUR RESTRAINED WELDEO SPECIMENS RELATION FOR RESTR AlNEO WELDSO SFECIMENSOF HIGH YIELO STRENGTH STRUCTURAL STEELS. OF HI(3I YIELD STRENGTH STRUCTURAL STEELS.

RESULTS w ,,,,s w ,,..,.,.s MA., m.. .,,, Sr...,,,”,,s ,, ,.s,, 0, ,,,,, !4,., MADE m.. ML. ,,,,, .,..WI,. ..6020 ELECTRODE ARE s“,.. ,,, ,..,.., s0..,.602, .Umnoo. AR. ,.0.. m. .,?4,.,,,0..

~j.j~~r-~j

~~~~’wu- “-: ]::““, .

;’y;,~ &

~’~’”k ~l’mr+-y~j

“.” s,. ‘::7:,; “4”s”=..

“,.. ‘~~

X::o”::,,o

. . . . .

.+

.,,. . . . .4,

,6.,,.,,%., ., .. . . !m. ,-.10. 63 T..WT,ON TEM.ER.WRCS ,,. “,,,.s s,,,., 8 .,,. m,., B

.s .,,,.. !... ❑“ ,2. GE.,,..., mm.., ,,,,,.,.,

D E

!00

,..

,2.

~m

~;,

350

300

MA X, LOADFRACTURE 270,800 LB5,

250A I I

8-- ...1.... I-V IS. CRACK 240,000 LBS.

! I I1I

J

2W , - -.

. Ia 1.

; ‘!I “ , ,

150 —,

,

,

I

100 !

-#T=

ENERGY TO V15. CRACK 7,700 lN, L6S. 1

ENERGY TO MAX. LOAD

ENERGY TO FRACTURE }32,900 IN. LBS.

.— ——,

1 , II50 -—

,

,,

0 ~.1 .2 .3 ,4 .5 .6 ,, .8 ,9 ,,~ ,,, ! .2

ELONGATION- INCHES

LOAD-ELONGATION CURVE

SPECIMEN BN 21-I (l°F, O% SHEAR)

350 1 1 I

MAX. LOAD 324,800 LBS.

~

300I

v I \\

,

d250 + \

V15. cRACK 235,500 LBS.

I \

200 ~-- —.

)

: ;

: T

150 :

~

100 — —ENERGY TO VI S. CRACK 4,900 IN. LBS. \

ENERGY To MA X. LOAD 110,000 IN. LBS.1

I IENERGY To FRAcT”R~ 290,000 {N. LBS,

- — I

I 11111111II

50 ; I

1 FRACTURE (

40,000 LBS. ?

1 I

Ii ( I

0 ‘I

1.2 ,3 ,4 .5 ,6 ., ,B ,9 ,,~ ,,, ,2

EL0NGA710N - INCHES

LOAD-ELONGATION CURVE

SPECIMEN BN 21-20 (30° F,10070 SHEAR)

FIG. 70. Twelve-inch wide flat plate tests. (Ref. (28))

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CORRELATION OF LABORATORY TESTS WITH FULL SCALE SHIP …