Influence of Storage Conditions on Aluminum 4043A Welding ... · PDF fileeter of a freed single winding on a flat plane) ... very position of the inspected ... and surfacing welds

Introduction Aluminum gas metal arc welding(GMAW), without pores, is certainly achallenging task (Ref. 1). Pores are al-most exclusively formed by hydrogenduring the fast solidification of alu-minum weld pools because aluminumhas no liquid solubility for other gases(Refs. 1–3). The most common sourcesof hydrogen in the process zone areimperfections regarding the shieldinggas cover and contaminations of theworkpiece surfaces. Yet, the aluminumwelding wires must also be taken intoconsideration (Refs. 2, 4–6). When aluminum is exposed to theenvironmental air, a thin oxide layerforms on the surface immediately(Refs. 7–10). Its existence is wellknown to all professional welders whoare working with aluminum. This layer

is built up of two parts: the barrier lay-er consisting of amorphous Al2O3 andan additional surface layer. If atmos-pheric moisture is taking effect, thissurface layer comes into existence byabsorbing hydrogen from the environ-mental air (Refs. 11, 12). Thus, thestorage conditions and storage dura-tion affect the hydrogen content ofaluminum surfaces and those of weld-ing wires. The total thickness of thenatural oxide layer is within a range of12 nm (4.73E-7 in.). Furthermore, the sliding propertiesof the welding wire from the unwindingdevice up to the contact tip can deterio-rate, which may be associated with adecreasing winding diameter (the diam-eter of a freed single winding on a flatplane) and a change of the properties ofthe antifriction agent that is applied tothe welding wire surface by manufac-

turers. This may lead to perturbationsof the welding process due to a fluctu-ating wire feed speed, which, after all,promotes pore formation in the weldpool if the fluctuations affect the inertgas cover (Ref. 13). In contrast to the surfaces of theworkpieces, welding wires cannot becleaned directly before processingstarts. Assuming a constant produc-tion quality, the properties of thewelding wire are, at the very time ofprocessing, solely dependent on theenvironmental effects and their dura-tion during transport and storage.Still, there are no plain methods avail-able to easily determine the very thinaluminum-oxide layers on cylindricallyshaped specimen such as weldingwires with a small diameter. A visualexamination of the welding wire sur-faces will only grant informationabout obvious aging phenomena andis subjected to subjective evaluation.Moreover, the properties of the weld-ing wire may vary, depending on thevery position of the inspected weldingwire section on the coil. There are hints to be found in litera-ture that point to the significance of thestorage conditions for aluminum weld-ing wires (Ref. 14): A maximum storageduration of three to twelve months isrecommended (Ref. 15), and a deterio-ration of the welding wire, which givesrise to porosity, is to be expected aftersix months of storage even in unopenedpackaging (Ref. 1). Yet, both statementsare given without reason and they arehard to comprehend. A slight deteriora-tion of the weld metal quality by meansof pore formation after a storage timeof eight to twelve months of the weld-ing wires in natural ambient climate wasdiscovered (Ref. 6). However, these re-

WELDING RESEARCH

Influence of Storage Conditions on Aluminum 4043A Welding Wires

The change of wire properties, process stability of gas metal arc welding, and pore formation were investigated

BY U. REISGEN, K. WILLMS, AND S. WIELAND

ABSTRACT Spools with aluminum 4043A welding wire were stored without packaging in an unfavorable warm and humid constant climate for extended periods of time to investigatethe effects of storage on welding wire properties, welding process characteristics, andthe amount of pores in the weld metal. Among other things, the quantity of hydrogen ofthe filler material was determined using the inert gas fusion (IGF) method, and surfacingwelds were produced using gas metal arc welding (GMAW) in the overhead welding position. As a result, longterm storage of aluminum welding wires in unfavorable butconstant conditions does not increase the hydrogen content of the welding wiresufficiently to cause pores in the weld metal. Additionally, a welding wire was exposed toan atmosphere of individual condensation cycles. The hydrogen content of this weldingwire increased rapidly with each condensation cycle, which resulted in subsequent poreformation in the weld metal. Furthermore, the aging of a welding wire varied, either because the considered wire section surface was aligned with the environment or becauseit was enclosed by neighboring windings.

KEYWORDS • Aluminum Oxide Layer • Aluminum Welding Wire • Hydrogen Pore • Gas Metal Arc Welding (GMAW) • Process Stability • Storage Condition

WELDING JOURNAL / JUNE 2017, VOL. 96220-s

Research - Wielandnew.qxp_Layout 1 5/11/17 1:38 PM Page 220

sults are not correlated with the processbehavior. Altogether, the relationship be-tween the welding wire aging behavior,the process stability during welding,and the resulting amount of pores inthe weld metal were, so far, not thor-oughly investigated since there are al-most no comprehensible conclusionsavailable. This led to the investigation.

Experimental Methods All results presented in the follow-ing refer to the topmost winding levelof the welding wire on the spool. Thiswinding level was mostly exposed tothe storage climate, thus it was sup-posed to age fastest. In other words,the winding levels beneath the top-most winding level were not affectedby the ambient climate in the sameway since they were sheltered by thewinding level above, as well as depend-ent on the closeness of each neighbor-ing winding. Therefore, this approachwas necessary for comparability.

Material

In accordance with EN ISO 18273 SAl 4043A (AlSi5(A)), 1.2-mm (4.7E-2-in.)-diameter aluminum welding wire,coiled on several spools with an outerdiameter of 300 mm (11.8 in.) was in-vestigated. All welding wires originat-ed from an identical batch to assurethe comparability. Table 1 depicts thechemical composition of a 4043Awelding wire (Ref. 16).

Definition of the Storage Conditions

Two different climate conditionswere defined and performed using aventilated climate cabinet (Table 2).The “warm and humid constant cli-mate” (Ref. 17) was chosen to be anunfavorable tropical condition, whichusually should be avoided when stor-ing aluminum welding wires. The “con-densation climate” was a humid alter-nating atmosphere with the possibilityto execute single condensation cycles.

Both programs were implementedwith a slope-in to avoid accidental con-densation when placing the weldingwires into the climate cabinet. Eleven coils designated to the warmand humid constant climate were placedin storage without packaging all at thesame time. During a year of research,they were taken out of the climate cabi-net separately on 11 dates of investiga-tion. The remainders were discarded. One spool designated to the conden-sation climate was placed into the cli-mate cabinet where it was subjected tosingle condensation cycles each. Afterthe spool was dried in ambient air, theinvestigations were performed and thespool was put back into the climate cab-inet. This way, the welding wire on thespool was subjected to a total of fivecondensation cycles, until the topmostwinding level was consumed.

Measurement Methods

The hydrogen content of the weld-ing wires after various periods of stor-age was determined using the inert gasfusion (IGF) method, according to amethod described in Ref. 18. For thispurpose, three samples of each weld-ing wire were retrieved by cutting eachinto 12 pieces with a length of 8 mm(3.9E-2 in.), which was equivalent to aweight of 0.3 g. They were placed intoa carbon crucible and heated in a fur-nace. The outgassing hydrogen was absorbed by a carrier gas. By compar-ing the thermal conductivity of themixture of outgassed hydrogen andcarrier gas with a reference gas, thequantity of hydrogen was determined.The unit of the values is “parts per

WELDING RESEARCH

JUNE 2017 / WELDING JOURNAL 221-s

Fig. 1 — Change of the winding diameter. Fig. 2 — Change of the adhesion factor µ.

Table 1 — Chemical Composition of a 4043A Welding Wire (Ref. 16)

Si Fe Cu Mn Mg Zn Ti Al

Al 4043A (AlSi5(A)) 4.5–6.0 0.6 0.30 0.15 0.20 0.10 0.15 rest

Table 2 — Definition of the Test Climates (Ref. 17)

T (°C) (°F) φ (% rel.)

Warm and Humid Constant Climate 30 (86) 93 Condensation Climate 5 / +40 (23/104) 98


million” (ppm), the weight of hydro-gen in micrograms in relation to theweight of the specimen in grams. The friction behavior between thewelding wire and a polytetrafluoroethyl-ene (PTFE) wire guidance core, inner di-ameter of 2.0 mm (7.9E-2 in.), was in-vestigated by use of a nonstandardizedtest bench. For this purpose, a PTFEwire guidance core was coiled in a de-fined angle of 3 around a cylinderwith a radius of 250 mm (9.8 in.). Thisradius was assumed to be reasonable forarrangements of hose packages. A weld-ing wire section was contrived andcharged with a defined load on the oneend (FL). The other end was connectedto a load cell. It was pulled until thewelding wire started to move so themeasured force (FP) corresponded to thetransition from static to dynamic fric-tion. This way, the damping by meansof dynamic welding wire deformationcan almost be neglected. The adhesionfactor was determined using the forceratio by means of the Euler-Eytelweinformula, Equation 1. However, is acomparative value in the context of thisinvestigation, not an absolute value. Tosuppress the influence of abrasion, thePTFE wire guidance core was replacedafter each measurement.

The quantity of vaporable contami-nation on the welding wire surface wasdetermined using a smokepuff test(Refs. 14, 19). A section of welding wirewith a length of approximately 250 mm(9.84 in.) was clamped by two elec-trodes. A current impulse (302 A, 0.3 s)heated up this section until it almost

reached melting temperature. The evap-orating smoke was sucked off and meas-ured over a period of 30 s. The meas-ured value for the smoke can hint to thesum of all substances on the weldingwire surface, for example, includingresidual drawing lubricant or antifric-tion agent. Furthermore, the winding diameterof the welding wire was determined bymeasuring a single winding that liesuninfluenced on a flat plane.

Welding Process

The welding wires were used to pro-duce a surfacing weld in the overheadwelding position, so that it was possi-ble to trap occurring pores at the weldinterface when welling up (Refs. 1,13). Etched AlMg4.5Mn plates of thesize 250 100 5 mm³ (9.8 3.9 0.2in.³) were used as base material. Theplates were clamped onto a water-cooled copper block to increase the

μ = ln FPFL

11( )

WELDING RESEARCH


Fig. 3 — Change of cumulated vaporable contamination. Fig. 4 — Change of the hydrogen content by means of IGF.

Fig. 5 — Change of the average current and voltage.

Table 3 — GMAW Process Parameter

Parameter Unit Value

Welding position Overhead Welding speed m/min (in./min) 0.75 (29.5) Wire feed speed m/min (in./min) 7.0 (27.6) Shielding gas flow L/min 18 Contact tip distance mm (in.) 13 (0.5) Electrode polarity DCEP Weld bead length mm (in.) 200 (7.87) Weld bead type Stringer bead


cooling rate of the weld pool to freezeemerging pores. A standard GMAWpower source with a push-pull wirefeeder and a conventional synergicpower characteristic was used. In thecourse of this mechanized weldingprocess, the torch was moved towardthe static plate. Table 3 depicts the welding parame-ter of low power. The stochasticdroplet detachment developed as aglobular transfer. An argon shieldinggas with a common purity ≥ 99.996%for welding applications was chosenbecause this shielding gas is supposedto contain very little amounts of hy-drogen and is commonly used in this

field of application. To suppress sources of hydrogenother than the filler material, exten-sive action was taken, such as Flushing of the gas hose withshielding gas for 15 min at 5 L/min gasflow after longer pauses. This methodwas supposed to be more effective forobtaining a very low hydrogen contentin the shielding gas flowing out of thegas nozzle than using a shielding gaswith higher purity since the gas hoseemits absorbed humidity to the shield-ing gas. Frequent replacement of parts inmechanical contact to the weldingwire, especially the contact tip and

wire guidance core. Cleaning of the welding wiretransport rolls with alcohol. Handling of all related parts andwelding wires with clean latex gloves. Usage of etched base material. During the welding process, the cur-rent and the voltage were measured byuse of a digital scope with a sample ratioof 20 kHz. The voltage was measured asclose as possible between the contact tipin the torch and the workpiece.

Results

Effects of Warm and HumidConstant Climate

Figure 1 depicts the change in thewinding diameter. Within just a fewdays, it decreased from a diameter ofmore than 600 mm (23.6 in.) at thetime of manufacture to a final diame-ter close to the spool diameter. The adhesion factor at the transi-tion from static to dynamic friction be-tween the welding wire and a PTFE wireguidance core increased gradually, ascan be recognized using a linear trendline — Fig. 2. Still, maintained thesame proportions. Figure 3 depicts the change of thequantity of vaporable contamination.The measured values fluctuated con-siderably, so each point was generatedfrom ten measurements. Yet, it can besaid that the amount of vaporable con-tamination changed. Initially, high val-ues were measured, but within onemonth of storage, a nearly constant fi-nal value was reached. The hydrogen contents of the weld-

WELDING RESEARCH


Fig. 6 — Transient current and voltage process characteristic: A — Wire aged 2 days; B — wire aged 349 days.

A B

Fig. 7 — Transverse and longitudinal microsection of weld metals, wires aged to the following: A — 2 days; B — 349 days.

A B


ing wires were generally very low —Fig. 4. During constant storage, theyincreased only very slightly so that af-ter one year of storage in warm andhumid constant climate, a gain of ap-proximately 26% was detected with re-spect to the trend line and a startingvalue of 0.75 ppm. Still, the highestmeasured value was only 1.12 ppm hy-drogen, which might be close to thedetection threshold of the method.However, the results seem reliable. The average voltage and current ofthe welding process changed slightly— Fig. 5. The voltage remained al-most constant and the current slight-ly increased, which corresponds to anincreasing depth of fusion (comparedto Fig. 7). Process instabilities, espe-

cially by means of short circuits orsignificant current fluctuations, couldnot be detected. A comparison be-tween the transient current and volt-age characteristics of the weldingprocesses for the welding wires, aged2 and 349 days, revealed that the av-erage current shifted completely to aslightly higher level — Fig. 6. Figure 7 depicts a transverse and alongitudinal microsection of surfacingwelds at selected states of storage. Nopores were visible, neither when using anew welding wire, aged 2 days, norwhen a welding wire that had beenstored for 349 days in the warm and hu-mid constant climate was used. This re-sult was verified using 3D micro-focusCT scanning throughout the whole

length of the surfacing weld metal —Fig. 8.

Effect of Condensation

Since the long-term storage of thewelding wires in a warm and humidconstant climate did not result in an ef-fectual change of the welding wire prop-erties, especially the quantity of hydro-gen inside the oxide surface layer orpore formation in the weld metal, a newwelding wire was exposed to the con-densation climate. It was successivelycondensed with single condensation cy-cles in the climate cabinet. After thewelding wire had dried in ambient air, itwas investigated and processed. Figure 9 shows the hydrogen quan-

WELDING RESEARCH


Fig. 8 — 3D microfocus CT scan of the weld metal (transverse/longitudinal section) for the welding wire aged 292 days.

Fig. 9 — Hydrogen quantity for the wire dependent of the condensation cycles.

Fig. 10 — Transverse and longitudinal microsection of weld metals where the wires condensed: A — 0 times; B — 1 time; C — 2 times.

A B C


tity for the welding wire in depend-ence of the number of condensationcycles it was exposed to. The hydrogenquantity increased from a reverencevalue of a new welding wire from 0.9ppm almost linear to 2.2 ppm. Becauseof these plausible results, the low val-ues measured with the same methodduring the above mentioned long-term investigation seem reliable. Transverse and longitudinal sec-tions of the surface weld are depictedin Fig. 10. The first pores in the weldmetal occured right after the secondcondensation cycle of the weldingwire, which is easily detectable. Theywere small and numerous, and somepores agglomerate to macroscopicpores, which were trapped at the topof the weld metal near the weld inter-face (marked with red arrows). The change of the average processvoltage and process current is depictedin Fig. 11. The tendency of slightly in-creasing current can be seen here aswell as in the long-term investigation(compared to Fig. 5). After condensa-tion, the welding wires were extremelyhard to feed, yet the transiently meas-ured process voltage and current didnot reveal stutter of the welding wiremovement — Fig. 12. Thus, the poresin the weld metal resulted from thehydrogen content on the welding wires

alone, lest from process instabilities orproblems with the shielding gas covercoming along with it. Figure 13A and B depict scanningelectron microscopy (SEM) pictures ofa welding wire without condensation,aged 2 days, and the welding wire thatwas condensed five times. The axes ofthe welding wires are depicted hori-zontally in the pictures. The black re-gions on the bottom and top of thepictures are the background. The near-ly unaged welding wire (Fig. 13A)shows no oddness on its surface, whilethe surface of the condensed weldingwire is clearly divided into two differ-ent regions, a blank area on the upperside and an area changed by the con-densation at the lower side. The twoareas are separated from one anotherby a sharp line. This line was the con-tact line of this particular winding tothe neighbor winding of the topmostwinding level on the spool. The con-densed surface of the welding wire wasthe outer surface, directly exposed tothe ambient climate. An energy-dispersive X-ray spec-troscopy analysis (EDX) of different ar-eas of the condensed welding wire sur-face was executed — Fig. 13C. The re-sults are listed in Table 4 showing thatthe area directly exposed to the conden-sation climate has a qualitatively much

higher oxygen content than the area en-closed by neighbor windings. The EDXanalysis results are only valid for quali-tative matters here since the maximumthickness of the natural aluminum ox-ide layer is presumably just within 12nm (4.7E-7 in.) (Ref. 11), while the pen-etration depth of the electron beam iswithin a range of about 1 m (3.9E-5in.). The thickness of the oxides on thesurface areas exposed to the condensa-tion climate were found to be muchgreater than 12 nm (4.7E-7 in.) becausethe edges of the oxides become visibleusing SEM — Fig. 13D.

Discussion The winding diameter decreasedwithin the time from production to de-livery to a value close to the spool diam-eter. However, since the welding wirematerial aluminum 4043A is compara-tively soft, this change did not seem toaffect the welding process at all. Vaporable contamination can resultfrom various sources such as unwantedresidues of a drawing agent but also of aantifriction agent that improves thesliding of the welding wire in the wireguidance core. Thus, it is being referredto as a cumulative value. Unfortunately,no universal threshold values are avail-able for this measuring method, sincethe composition of the involved sub-stances varies with different manufac-turers. On the one hand, a diminutivevalue can point to a poor welding wirefeeding behavior; on the other hand,high values can indicate pore formationas shown in Refs. 14 and 19. Assumingthe good quality of a new welding wire,the change of the vaporable contamina-tion as a result of storage suggests a de-terioration of the filler material. Thus,the observed drop of the values maysuggest an unwanted loss of the an-tifriction agent. A direct correlation tothe change of the adhesion factor could not be determined due to the vari-ation of the measured values. However,the trends are matching. During the long-term investigation,pores did not develop in the weld metal.This indicates that a reproducible weld-ing process condition could be actual-ized over a period of one year by takingthe above mentioned extensive action. Pores occurring in the condensationexperiments derived from the hydro-gen content of the welding wire only

WELDING RESEARCH


Table 4 — Relative Chemical Composition by EDX (mass. %)

Areas O Al Si

Ø A1 and A2 0.8 93.2 6.0 Ø A3 and A4 12.4 82.9 4.8 Ø A5 and A6 18.1 77.6 4.3 Ø A7 and A8 23.9 72.9 3.2

Fig. 11 — Change of the average current and voltage dependent of the condensation cycles.


because welding process instabilitieswere not observed either. Yet, feedingcondensed wires required a skilledhandling of the wire feeding system.Pores caused by the welding wire weresmall and evenly distributed over thelength of the weld metal, which seemsreasonable at a constant wire feedspeed. The small pores can agglomer-ate to pores with a greater diameter.

The increase of the welding currentwas not fully comprehensible. It wassupposed that oxygen and hydrogenfrom the welding wire surface affectedthe composition of the shielding gas,leading to a change of electric andthermal conductivity of the arc col-umn. An accidental change of the dis-tance between the torch and the work-piece may also affect the electric char-

acteristics, but this would rather leadto a random deviation. Only the welding wire, which was ex-posed to a condensation climate, led toa detectable or rather unacceptable poreformation in the weld metal. Weldingwires that were stored for almost oneyear in the unfavorable warm and hu-mid constant climate did not evoke poreformation in the weld metal. Thus, stor-

WELDING RESEARCH


Fig. 12 — Transient current and voltage characteristic with the wires condensed: A – 0 times; B — 2 times.

Fig. 13 — Scanning electron microscopy (SEM) pictures of wire surfaces: A — Aged 2 days; B — condensed five times; C — position of EDXmapping areas on condensed wire surface; D — zoom in on condensed wire surface.

A

A

B

B

C D


age in a quite unfavorable environmentis not too critical as long as the climateremains constant, whereas a changingclimate with the possibility of conden-sation seems to have a much greater ef-fect. The amount of pores in the weldmetal increases with the measuredquantity of hydrogen on the wire sur-faces. Still, it is comprehensible thatwith increasing storage time the proba-bility of unwanted condensation in-creases as well, which, in turn, leads tothe common recommendation to limitthe storage time for filler materials(Refs. 1, 6, 15). The alignment of the surface of awelding wire section determines thestate of the aluminum oxide layer. Itcould be shown that condensation af-fects the welding wire surface areas ofthe topmost winding level that is direct-ly exposed to the environment. Furtherresearch may be conducted to investi-gate the growth of the oxide layer in anoncondensing climate on different sur-face area. It might be possible to discardthe topmost winding level of a con-densed welding wire spool and obtaingood welding wire properties at thewinding levels below. The effect of dif-ferent aging behavior might also occurwith respect to other welding wire prop-erties, for example, the quantity of va-porable contamination. The development of condensationof atmospheric humidity under certaincircumstances is quite simple. Dewpoint diagrams point out that onlysmall differences of temperature be-tween a welding wire and the environ-ment can be sufficient to provoke con-densation if there is a high relative hu-midity in the ambient air.

Conclusions The following conclusions may beobtained: 1) A long-term storage of alu-minum filler material up to one year inan unfavorable climate is comparative-ly harmless, when focusing on the hy-drogen content and pore formation inthe weld metal, as long as condensa-tion does not take place. 2) The aging of the welding wires

may lead to a change of the vaporablesubstances on the wire surfaces. 3) Processing an aged welding wireleads to slightly increasing weldingcurrent and thus to an increase of thedepth of fusion. 4) Condensation on the wire surfacesleads to pores in the weld metal even ifthe wire is dry at the moment of pro-cessing. To welders who are workingwith aluminum, this investigation sug-gests that fast climate changes, especial-ly caused by transport of the weldingwires, even within the factory premises,are to be avoided since they bear therisk of condensation. 5) The aging of the welding wire,coiled on a spool, takes place in differ-ent ways, depending on whether a wiresection is enclosed by other windingsor not. The topmost winding level ismost affected by the ambient climate,and the surface properties of a weldingwire section may even vary stronglywithin its own circumference.

This research was carried out for theproject no. IGF 17.524N within theframework of the Research Associationon Welding and Allied Processes (FV) ofthe German Welding Society (DVS) andthe German Federation of Industrial Re-search Associations. The authors grate-fully acknowledge the financial supportby the German Federal Ministry of Eco-nomic Affairs and Energy and the pro-ductive cooperation with the project-ac-companying enterprises.

1. Mathers, G. 2002. The Welding of Alu-minium and Its Alloys. Boca Raton, Fla., Cam-bridge, England, CRC Press; Woodhead Pub. 2. Coe, F. R. 1968. The quality assess-ment of gas metal arc welding wire. WeldingJournal 47(8): 355-s to 363-s. 3. N. N. 1963. The Arc Welding of Alumini-um. Information Bulletin 19, London, Eng-land, Aluminium Federation. 4. Kammer, P. A., Randall, M. D., Mon-roe, R. E., and Groth, W. G. 1963. The rela-tion of filler wire hydrogen to aluminium-weld porosity. Welding Journal 42(10): 433-

s to 441-s. 5. Reisgen, U., and Stein, L. 2016. Funda-mentals of Joining Technology — Welding,Brazing and Adhesive Bonding. Düsseldorf,Germany, DVS-Media GmbH. 6. Uchida, A. 1970. The Influence of Stor-age of Electrode Wire on the Quality of MIG-Welded Joint of Aluminium Alloy. Japan Insti-tute of Light Material Welding Paper No. 4. 7. Hatch, J. E. 1984. Aluminum: Proper-ties and Physical Metallurgy. Metals Park,Ohio, ASM. 8. N. N. 1953. Handling, Storing andTransporting Aluminium and its Alloys. Infor-mation Bulletin 15, London, England, Alu-minium Federation. 9. Vargel, C. 2004. Corrosion of Alumini-um. Paris, Elservier, Ltd. 10. Zähr, J., Ulrich, H.-J., Oswald, S.,Türpe, M., and Füssel, U. 2013. Analysesabout the influence of the natural oxide lay-er of aliminium on the brazeability in ashielding gas furnace. Weld World 57(4):449–455. 11. Hunter, M. S., and Fowle, P. 1956.Natural and thermally formed oxide films onaluminum. Journal of the Electrochemical Soci-ety 103(9): 482–486. 12. Kubaschewski, O., Cibula, A., andMoore, D. C. 1970. Gases and Metals. Lon-don, New York: Iliffe; American Elsevier forthe Metals and Metallurgy Trust. 13. Baum, L., and Fichter, V. 1986. MIG-,MAG-Schweissen. Die schweisstechnische Prax-is. 131, Düsseldorf, Germany, DVS-Verlag. 14. Lemyre, J. R. 1968. Production, in-spection, quality & packaging of aluminiumfiller metal in wire form. Wire & Wire Prod-ucts 3: 61–65. 15. N. N. 2008. MIG-Schweißen von Alu-minum. Geräte, Prozesse, Hilfsstoffe. DVS-Merkblatt 0913-2, 5, Düsseldorf, Germany,DVS-Verlag. 16. N. N. 2004. DIN EN ISO 18273Welding Consumables — Wire Electrodes,Wires and Rods for Welding of Aluminiumand Aluminium Alloy — Classification.Berlin, Germany, Beuth. 17. N. N. 2004. DIN 40046-721-1 Guid-ance for the Correlation and Transformationof Environmental Condition Classes of IED60721-3 to the Environmental Tests of IEC60068 — Storage. Berlin, Germany, Beuth. 18. N. N. 2014. Methode zur Bestim-mung des Wasserstoffgehaltes von Massiv-drähten und — stäben aus Aluminum-legierungen für das Lichtbogen — oderStrahlschweißen. DVS-Merkblatt 0947, 1,Düsseldorf, Germany, DVS-Verlag. 19. Eichhorn, E. G. 1968. Tests for eval-uating the cleanliness of aluminum weldwire. Welding Journal 47(11): 875–880.

WELDING RESEARCH


Acknowledgments

References

STEPHAN WIELAND ([email protected]aachen.de) is the research engineer for arc welding, KONRAD WILLMS ([email protected]aachen.de)is the head of the arc welding department, and UWE REISGEN ([email protected]aachen.de) is the head of the Welding and Joining Instituteof RWTH Aachen University, Germany.


Documents

Influence of Storage Conditions on Aluminum 4043A Welding ... · PDF fileeter of a freed single winding on a flat plane) ... very position of the inspected ... and surfacing welds