Parr Zirconium Corrosion Info

7/24/2019 Parr Zirconium Corrosion Info

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Corrosion Resistance of Zircadynelloys In Specific Media

Hydrochloric cid One of the earliest applications for Aeration does not affectzirconium was in the handling of zirconium’s behavior in hydrochlorichydrochloric acid. Zirconium is still acid. However, oxidizing impuritieswidely used in this area. The corro- such as cupric or ferric chlorides insion rate of zirconium is less than 5 relatively small amounts willmpy at all concentrations and decrease the corrosion resistance oftemperatures well in excess of the zirconium in hydrochloric acid. Theseboiling point. Even in 37% HCI, zir- oxidizing ions should be avoided orconium does not corrode appreciably electrochemical protection methodsuntil temperatures of 130°C are should be used to counteract thereached (see Figure 1). Zirconium’s effect of oxidizing impurities. Pleasecorrosion-resistant behavior in pure contact our Technical Services

hydrochloric acid is superior to any Department for more information onother engineering metal. this technique.

Concentration (Weight Percent) *Avoid Fe + ’ ‘, Cu + + ions

FIGURE 1. Corrosion of Zircadyne 702 in hydrochloric acid solutions.

Solution

32 HCI

10% HCI + 100 ppm FeCI,




*Severe pitting and stress cracking observed.

Temperature“C

3030303030

Duration ofTest (Days)

91

91

91

91

91

Average Corrosion

702RaWTpy)

705

0.03 0.03

0.9 0.7



pplications Ofrconium Inydrochloric Acid

ulfuric Acid

Current applications of zirconiumequipment in hydrochloric acid in-clude pumps, valves, piping, con-densers, and evaporators. Zirconiumheat exchangers, pumps, andagitators have been used for over 20years in an azo dye coupling reaction.Besides being very corrosion resis-tant in this environment, zirconiumdoes not plate out undesirable saltswhich would change the color andstability of the dyes. Heat exchangers

The corrosion resistance of zir-conium in sulfuric acid is excellent attemperatures well above boiling andat acid concentrations up to 70%.

Figure 2 shows the isocorrosioncurves of zirconium in H,SO, soiu-tions. Upon exposure to sulfuric acid,a film is formed on the zirconium sur-face which is resistant to furtherattack by the acid.

Tests conducted in our corrosionlaboratory have shown that weldedand non-welded coupons of Zir-cadyne alloys are about equally cor-rosion resistant in lower concentra-tions. These corrosion data, collectedfor three grades of Zircadyne zir-

conium (702, 704 and 705) areillustrated in the isocorrosiondiagrams shown in Figures 3-5. Thediagrams are separated into areas ofacid temperature and concentrationwith the expected corrosion ratesshown within each area outlined by asolid line. The dashed lines separatethe graph into two regions, where atlower concentrations the weld wouldbe expected to behave similarly to thenon-welded metal, and where athigher concentrations the welds

would be preferentially attacked.Comparing Figures 3-5, the Zir-cadyne 702 and Zircadyne 704 areapproximately equivalent in theirresistance to sulfuric acid, and bothare more resistant to sulfuric acidthan Zircadyne 705. It is important tonote that the data are representativeof a pure acid system, and thepresence of oxidizing halide con-taminants can accelerate the rate ofattack.

At temperatures above 200°C and

made of zirconium are used bychemical companies in the produc-tion of polymers. Other hydrochloricapplications where zirconium hasbeen used are phthalic-hydrochloricacid and wet hydrogen chloride-chlorine atmospheres. A very impor-

tant application for zirconium is inprocesses that cycle betweenhydrochloric or sulfuric acid andalkaline solutions.

at the higher concentrations (shownin the area above the dashed lines)the welds and heat-affected zones(HAZ) were found to be much more

susceptible to corrosion attack thanthe base metal. This corrosion attackin the welds and HAZ in Zircadyne702 and Zircadyne 704 occurs in thealpha phase grain boundaries exceptin the area of the prior beta grainboundaries which are not attacked.Heat-treating the weldments at thestress-relieving temperatures of500 “C to 600 “C does not significantlyimprove their corrosion resistance.However, heat treatment ofweldments in the temperature range

of 630°C to 788°C does improve thecorrosion resistance. The optimumheat treatment for improving Zir-cadyne 702’s corrosion resistancewas determined by experimentationto be % to 1 hour at 730-788°C(1400 f 50°F). Lower-temperatureheat treatments down to 630°C canbe used to balance the improvementsin corrosion resistance, strength, andfabricability.

In welded coupons of Zircadyne705, intragranular attack of both the

weld and HAZ was observed in 65%sulfuric acid. Annealing thezirconium-welded coupons between550°C and 1000°C greatly improvesthe corrosion resistance of the weldin 65% H&O,. For the lower end ofthis temperature range, a heatingtime of two hours is recommended.Half an hour is sufficient at 1000°C.Lower temperatures are normally used(550-600 “C) to minimize dimensionalchanges caused by oxide film growth.For details, call TWCA.

‘continued on page 8.



Sulfuric Acid*

Concentration (Weight Percent)

FIGURE 2. Corrosion of Zircadyne 702 in sulfuric acid solutions.

60

1



50

I00

450



260

220

6(

2(

FIGURE 5.


Corrosion of Zircadyne 705 in sulfuric acid solutions.

*continued from page 7.



Effect of Impurities From studies on oxidizingimourities in H.SO,. it was found thatfeiric, cupric, 2nd nitrate ionimpurities in H,SO, affect the corro-sion resistance properties of zir-conium and its alloys at concentra-

tions above 65% H&O,. This isshown by the isocorrosion curves inFigures 6 and 7. For example, 200ppm cupric ions reduce the 0.125mm/y (5 mpy) isocorrosion curve byless than 5 weight percent acid. Inless than 65% H,SO,, 200 ppmimpurity levels of these ions forZircadyne grades 702 and 704, and60% H,SO, for grade 705, have noeffect on their corrosion resistance.In fact below 65%, grade 702 did notexperience accelerated attack even

with 1 additions of cupric or ferricions. Chloride ions were found tohave no effect on the corrosion-resistant properties of zirconium insulfuric acid.

Zirconium can tolerate only very

small amounts of fluoride ions inH,SO, even at low-acid concentra-tions. At concentrations greater than50% H&30,, the corrosion rate will behigh even with 1 ppm fluoride ions.Figures 8 and 9 show the effect of thefluoride ion in sulfuric acid.Therefore, fluoride ions have to becomplexed, using inhibitors such aszirconium sponge and phosphorouspent-oxide, when zirconium equip-ment is used to handle fluoride ion-contaminated H,SO, solutions.

FIGURE 6. Effect of 200ppm impurity levels inHA04 on the 0.125 mm/yisocorrosion curve ofZircadyne 702.

FIGURE 7. Effect of 200ppm impurity levels inH&04 on the 1.125 mm/yisocorrosion curve ofZircadyne 705.

FIGURE 8. Effect offluoride ions in boilingHA04 on the corrosionrate of Zircadyne 702.

FIGURE 9. Effect offluoride ions in boilingH&i04 on the 0.125 mm/yand 1.25 mm/y corrosionlines for Zircadyne 702.

Figure 6 Figure 7

H&O, Concentration (wt %)

Flumde IO” concentration @pm)

Figure 8H,SO, concenfraf~on wl %)

Figure 9



Applications OfZirconium In

ulfuric Acid

hosphoric Acid

Nitric Acid

Zirconium is used extensively in40-70 weight percent sulfuric acid atelevated temperatures. Zirconiumhas been used to replace imperviousgraphite heat exchangers and leadheating coils in an environment con-taining sulfuric acid, zinc and sodiumsulfates, hydrogen sulfide, and

carbon disulfide. Zirconium has beenused in these applications for overten years without corrosion problems.Some other examples of sulfuric acidapplications include ester manufac-turing, steel pickling, alcoholstripping towers and hydrogenperoxide manufacturing.

Zirconium is corrosion resistant in and temperature (see Figure 10). Thephosphoric acid at concentrations up corrosion rate of zirconium is still lessto 55% and temperatures exceeding than 5 mpy at 60°C and concentra-the boiling point. Above 55% H,PO, tions up to 85%. Fluoride ion im-concentrations, the corrosion rate purities in phosphoric acid can causerises with increasing concentration attack of zirconium.

Zirconium exhibits excellent corro-sion resistance to nitric acid in allconcentrations up to 90% andtemperatures up to 200°C. Only oneother metal, platinum, is equal to zir-conium for this service (see Figure11). Welded zirconium and its alloysretain this high corrosion resistance.For example, welded Zircadyne 702,704, and 705 corrode at rates lessthan .05 mpy in 70% HNO, at boiling.

In concentrated nitric acid, stress-corrosion cracking (SCC) may occurabove 70% concentration if hightensile stresses are present. Forexample, the critical stress to causeSCC in Zircadyne alloys 702 and 704is about 100% of the yield stress at90% concentration and roomtemperature. This compares to Zir-

cadyne 705 where about 50% of theyield stress may cause stress-corrosion cracking at the same con-centration and temperature.

It is inevitable to have theimpurities of iron, chromium, andchlorides in many HNO, processesresulting, for example, from the corro-sion of stainless steels or the con-tamination of chloride-containingcooling water. Tests have been per-formed at TWCA to determine the cor-rosion rates of zirconium in HNO,containing ferric chloride, naturalseawater, sodium chloride, iron,stainless steel, sodium fluoride, andhydrofluoric acid.

Ferric chloride is a well-knownpitting agent of zirconium. However,nitrate ions are effective inhibitors of

(Continued on Page 11)

FIGURE 10. Corrosion of zirconium inphosphoric acid solutions.

26OC -I

HNO, Concentration (Weight Percent)

FIGURE 11. Corrosion of zirconium innitric acid solutions.

0



itric Acidinued from Page 10)

pitting in zirconium. Test resultsshowed that zirconium did not cor-rode or pit in boiling 30% to 70%HNO, with up to 1% Fe&. Similarly,the presence of up to 1% seawater or1 % NaCl did not degrade zirconium’scorrosion resistance to aqueousHNO,. However, welded specimenscould exhibit minor pitting in HNO,vapors if a sufficient amount ofchloride (e.g., 1% NaCl but not 1%seawater) was present in solutions.This corrosion problem can beattributed to the chlorine gasgenerated upon the addition of NaClinto HNO,. It is suggested that areasthat can accumulate chlorine gas beavoided for zirconium equipmentwhen chlorides are present in HNO,.

Iron-or stainless-steel (Type 304)-containing HNO, solutions wereprepared, first, by dissolving iron orstainless steel in 70% HNO, at 204 “Cusing an autoclave. Under these con-ditions, corrosion rates of iron andstainless steel were estimated to begreater than 25.4 mm/y. Thirty per-cent to 70% HNO, solutions with 1%Fe or 1.45% stainless steel wereprepared from the master solution.These solutions contained varying

amounts of Fe3 +, Cr3+ and Cr6+. Non-welded and welded coupons weretested in 30%, 50% and 70% HNO,with 1% Fe or 1.45% stainless steelat boiling temperatures, and in 65%HNO, with 1% Fe or 1.45% stainless

steel at 204°C. Test results indicatedthat the presence of heavy-metal ionshad little effect on the corrosionresistance of zirconium.

The presence of fluoride ions inacidic solutions can significantlyincrease the corrosion rate of zir-conium. In mixtures of HNO, and HF,the corrosion rate of zirconium isdirectly proportional to the HF con-centration. In one-day tests, the cor-rosion rates of zirconium in 30%,50% and 70% containing 10 ppm F-

(as HF) at 80°C were determined tobe 0.20, 0.31 and 0.62 mm/y, respec-tively. Again, the corrosion of zir-conium in HNO, - F- solutions can becontrolled by adding an inhibitor toconvert fluoride ions into noncor-rosive complex ions. Zirconiumsponge, zirconium powder, zirconiumcompounds (such as zirconiumnitrate), and phosphorous pentoxidecan be used as inhibitors.

ydrofluoric Acid Zirconium has no corrosion tions as low as .OOl .resistance in hydrofluoric acid and is Acid solutions containing HF arerapidly attacked even at concentra- commonly used to etch zirconium.

austics Zirconium is resistant to virtuallyall :I;:aline solutions, either fused orirr solution, to the boiling temperature.Zirconium is resistant in sodiumhydroxide and potassium hydroxidesolutions even under anhydrous con-ditions. It is also resistant to calciumhydroxide and ammonium hydroxideat concentrations to 28% andtemperatures to boiling. This corro-sion resistance makes zirconiumdistinctly different from some otherhighly corrosion-resistant materials,such as tantalum, glass, graphite,and PTFE, which are attacked bystrong alkalis. Moreover, steels andstainless alloys, which have good cor-rosion resistance to alkalis, are sub-ject to cracking in certain concentra-tions and temperatures.

Zirconium U-bends were tested in

concentrated NaOH at boiling. Duringthe test period, concentration changedfrom 50% to about 85%, and temper-ature increased from 149°C to300 “C. PTFE washers and tubes usedin making U-bends dissolved. However,zirconium U-bends remained ductileand did not show any cracks after 20days.

Zirconium coupons were tested ina white liquor paper-pulping solution,which contained NaOH and Na,S, at120X, 177°C and 227°C. Allcoupons had corrosion rates of lessthan 1 mpy. In the same solution, bothgraphite and glass corroded rapidly at100 “C.

A very important application for zir-conium is in processes that cyclebetween HCI or H,SO, and alkalinesolutions.

11



Natural Andolluted Waters

Molten Salts

iquid Metals

Organics AndOrganic Acids

Zirconium has excellent corrosion heat exchangers, condensers, andresistance to seawater, fresh water, other equipment used in these media.polluted water, and brackish water, Zircadyne alloys are replacing Ti-which makes it a natural choice for Pd alloys in this type of service.

Zirconium is resistant to attack in greater than 1000°C. Zirconium issome molten salts. Zirconium is resis- also fairly resistant to potassiumtant to corrosive attack in molten hydroxide.sodium hydroxide through temperatures

Zirconium is resistant to some than 1 mpy in liquid lead to 600°Ctypes of molten metals, but the corro- lithium to 8OO”C, mercury to lOO”C,sion rate is affected by trace im- and sodium to 600°C. Molten metals

purities such as oxygen, hydrogen, or which are known to severely attacknitrogen in the specific molten metal. zirconium are molten zinc, bismuth,Zirconium has a corrosion rate of less and magnesium.

Zirconium is very resistant to mostorganics. It is commonly used in theproduction of acetic acid and aceticanhydride where the corrosion rate isless than 2 mpy in all concentrationsand temperatures. Zirconium also

shows a high resistance to corrosionin citric, lactic, formic, oxalic,tartaric, tannic, and chlorinatedorganic acids.

Zirconium’s excellent corrosion

resistance in the nitrogen fertilizerenvironment has led to its use inmany applications in plants pro-ducing fertilizers and urea. With azirconium lining in a urea-synthesisprocess, the reaction can take place

at higher temperatures and pressurespermitting greater conversion of CO,to urea and thereby avoiding the cor-rosive intermediate products.



Types Of Corrosion

alvanic Corrosion

revice Corrosion

Due to the protective oxide filmwhich normally forms on zirconium inair, highly reactive zirconiumassumes a noble potential similar tosilver and passivated stainless steel.If this passive film is removed, zir-conium will become activated andconsequently will corrode when incontact with other more noble metals(see Table 1).

Other less noble metals will cor-rode when in contact with zirconiumcoated with its oxide film intact Forexample, in seawater or acid solu-tions, carbon steel, aluminum, andzinc will corrode rapidly in electrrcalcontact with zirconium. Therefore,care should be taken to keep themelectrically insulated.

TableGalvanic Series In Seawater

Cathodic(Most Noble) Platinum

GoldGraphiteTitaniumSilverZirconiumType 316, 317 Stainless Steel (passive)Type 304 Stainless Steel (passive)Type 410 Stainless Steel (passive)Nickel (passive)Silver SolderCupro Nickels (70-30)Bronzes

CopperBrassesNickel (active)Naval BrassTinLeadType 316, 317 Stainless Steels (active)Type 304 Stainless Steel (active)Cast IronSteel or IronAluminum 2024CadmiumAluminum (commercially pure)

ZincMagnesium and Magnesium AlloysAnodic(Active)

Of all the corrosion-resistant deposits, and crevices under fastenermetals, zirconium and tantalum are heads, For instance, in chlorine ser-the most resistant to crevice corro- vice, many metals are subject tosion. Crevice or contact corrosion is a crevice attack; zirconium is resistantform of localized corrosion usually to dry chlorine and is, therefore,associated with small volumes of unaffected.stagnant solutions caused by lap Zirconium can replace Ti-Pd alloysjoints, gasket surfaces, surface in chloride-containing media.

13



Pitting Corrosion Zirconium is quite resistant to becomes greater than the pittingpitting corrosion in chloride, bromide, potential, pits will be initiated. Zirand iodide solutions. Electrochemical conium will also pit in perchloratemeasurements, however, can reveal solutions if oxidizing impurities arezirconium’s pitting tendency in these present. Nitrate and sulfate ions willhalide solutions. The reason zir- inhibit pitting of zirconium in certainconium does not pit in most halide concentrations. TWCA laboratory per-environments is that the corrosion sonnel will continue to generate newpotential is lower than the pitting data on the pitting corrosion of zir-potential. The presence of oxidizing conium. For more detailed informa-ions (such as Fe3+ or Cu’+) in halide tion on zirconium’s pitting behavior,solutions will increase the corrosion contact TWCA’s Technical Servicespotential and when the potential Department at (503) 926-4211.

Fretting Corrosion Fretting corrosion takes place cannot be eliminated mechanically) iswhen vibrational contact is made at to apply a heavy oxide coating on thethe interface of tight-fitting, highly zirconium which drastically reducesloaded surfaces as between the the frictional resistance and preventsleaves of a spring, or parts of ball and the removal of passive protectiveroller bearings. The best way to over- oxide (see zirconium oxide films).come this type of corrosion (if it

Stress CorrosionZirconium and its alloys are resis-

tant to stress-corrosion cracking(SCC) in many environments (such asNaCl, HCI, MgCI,, NaOH, H,S), whichwould induce SCC in other alloys. Zir-conium service failures due to SCCare few in the chemical applications.The high SCC resistance of zirconiumcan probably be attributed to its highrepassivation rate. Any break in thesurface film will be quickly healedprovided there is sufficient oxygencontent. Even in dehydrated systems,

there is generally sufficient oxygenpresent for repassivation.Environments known to cause SCC

of zirconium alloys include FeCI, or

CuCI, solutions, CH,OH + HCICH,OH + i2, concentrated HNO, andliquid mercury or cesium. Stress cor-rosion cracking in zirconium alloyscan be successfully prevented by:

1. Avoiding high sustained tensilestress.

2. Modifying the environment.3. Achieving a texture with the hex-

agonal basal planes perpendicularto the cracking path.

4. Maintaining a high quality surfacefilm, i.e. low in impurities, defects,and mechanical damage.

High Temperature ‘Zirconium will react with oxygen in barrier to hydrogen up to 760°C. In anthe air at temperatures above 54O”C, all-hydrogen atmosphere, hydrogen

Reaction With Gases producing a white zirconium oxide absorption will begin at 31O”C, andfilm that is very refractory, brittle, and the metal will ultimately become em-porous. At temperatures above brittled. Hydrogen can be removed700°C zirconium will absorb oxygen from zirconium by vacuum annealingand become embrittled after pro- for prolonged times at temperatureslonged exposure. The oxide film on above 750 “C.zirconium provides an effective



Corrosion By HighTemperature WaterAnd Steam

Zirconium’s resistance to air, hot increased resistance to highwater, and steam makes it a logical temperature water and steam. Inchoice for power generation applica- comparison, the Zircadyne 705 alloytions. The metal can be exposed for with 2.5% columbium additionprolonged periods in steam without possesses higher R.T. and elevatedpronounced attack below 425 “C. tensile strengths than Zircadyne 704

Zircadyne 704, a zirconium alloy and also exhibits good resistance incontaining 1.5% tin with small addi- steam applications.tions of iron and chromium, shows an

Zirconium Oxide One of the unique properties of zir-

Films For Corrosionconium which makes it attractive forchemical usage is the protectivenature of its oxide film. This film gives

Resistance And Low excellent corrosion resistance in

Friction Surfaces spite of the metal’s reactive nature.

Should it be mechanically destroyed,this oxide barrier will regenerate itselfin many environments. Aluminum andtitanium exhibit similar characteristicsexcept that the film on zirconium isconsiderably more corrosion resistant.

Several methods of oxide forma-tion are possible, depending on theproperties desired. Normal methodsinclude:

1. Anodizing.2. Autoclaving in high-

temperature water or steam.

3. Formation in air.Anodizing forms a film that is verythin, but may be useful in someapplications. Since it is formed nearroom temperature, it does not havethe coherence to the underlyingmetal that the other, thermallyproduced coatings do.

Autoclave film formation is a prac-tice common to the nuclear reactorindustry. In this process, the uniformfilm of high integrity which is formedis superior to that formed at the lower

operating temperatures. In addition tothe slower corrosion rate, the rate ofhydrogen absorption is drasticallyreduced. Films can be formed in 14days in 360°C pressurized (2700 psi)deionized water or in l-3 days at400°C (1500 psi) in high-purity steam.

The most common film used in thechemical industry is one formed inair. Often, this film is formed during

the final stress relief of a componentat about 550°C for times of I/Z to 4hours at temperature. This film willrange in color from a straw yellowthrough an iridescent blue or purple,to a powdery tan or light grey. Such

films need not be taken as a sign ofmetal contamination. This Iow-temperature stress relief does notcause significant penetration ofoxygen into the metal; it does,however, form an oxide layer which isdiffusion-bonded to the base metal.

In addition to the corrosionresistance imparted by the oxide film,Atomic Energy of Canada Limited hasfound that a properly formed filmserves as an excellent bearing sur-face against a variety of materials in

several environments and over abroad temperature range (CanadianPatent No. 770,080 and AECLPublication CRE-996).

This treatment consists of cleaningthe surface followed by 4-6 hours at550°C in air.

The resultant oxide layer, approx-imately .0002” thick, is equivalent tosapphire in hardness and is diffusion-bonded to the base metal. The oxidelayer can be damaged by strikingaction, but serves as an excellent

bearing surface for sliding contacts.Oxidized zirconium pump shafts arean example of a common application.

For more detailed information onthis subject, send for a paper entitled,“Improved Wear Resistance of Zir-conium by Enhanced Oxide Films”,by John Haygarth and Lloyd Fenwickof TWCA.

15



Zirconium ForHeat TransferApplications

Health And Safety

In process heat transfer, the rate ofexchange of heat between the sourceand the receiver is critical. Thedriving force is the temperature dif-ference across an impedance. Thisimpedance consists of source and

receiver film coefficients, theresistance due to a metal barrier andany scale which may have formed onthis metal barrier.

The actual design of a shell andtube heat exchanger, followingpreliminary sizing, entails selectionsof a suitable material of constructionand determination of the minimumallowable tubing wall thickness. Theideal corrosion-resistant material willallow continuous operation withoutscale formation and accompanying

degradation of film coefficients. In-creased flow rates are possible dueto the dimensional stability present in

Zirconium is non-toxic and conse-quently does not require seriouslimitations on its use because ofhealth hazards.

Finely divided zirconium is

pyrophoric because of its heat-producing reaction with oxidizingelements such as oxygen. Largepieces of sheet, plate, bar, tube andingot can be heated to hightemperatures without excessiveoxidation or burning. However, smallpieces with a high surface-area-to-mass ratio, such as machine chipsand turnings, are easily ignited andburn at extremely high temperatures.It is recommended that large accu-mulations of chips and other finely

divided material be avoided. Also, instoring the chips and turnings, careshould be taken to place the materialin non-flammable containers andisolated areas.

One effective storage method is tokeep the material covered with water

References

the tubing diameter, yielding higherand constant film coefficients. Sincezirconium is corrosion resistant, acorrosion allowance is seldom re-quired thus minimizing the actual wallthickness and resistance to heat

transfer.These factors all contribute to astable, dependable heat transfersurface which allows equipment tooperate for extended periods of timein numerous media. Fouling problemsare often eliminated with a change tozirconium tubes.

Zirconium tubing is also availablewith a finned surface for increasedheat transfer rates. Finned tube ex-changers are typically much smallerthan smooth tubed exchangers for

the same total heat transfer require-ment.

in the containers and in turn, use oilon the water to keep it fromevaporating. If a fire accidentallystarts in zirconium, do not attempt toput it out with water or ordinary fire

extinguishers. Use dry sand,powdered graphite, or commerciallyavailable Metal-X* powder. Largequantities of water can be used tocontrol and extinguish fires in otherflammables in the vicinity of zirconium fire.

In somes cases when the corrosion-resistance of zirconium is exceeded,a finely divided corrosion product,which may be very pyrophoric, canform on the surface of the metal. Thisfilm can be rendered non-pyrophoric

by simple oxidation treatments withhot steam.

Please contact us for more detailedinformation on this subject.*Metal-X is a registered trademark for

powder produced by Ansul Manu-facture in Marinette, Wisconsin.

Dillon, C.P., Pyrophoric Surfaces on Zirconium Equipment: A Potentialignition Hazard MTI Publication No. 19, The Materials Technology Institute

of the Chemical Process Industries, Inc., 1986Yau, T.L., “Methods to Treat Pyrophoric Film on Zirconium ” IndustrialApplications of Titanium and Zirconium: Third Conference, ASTM STP.830,R.T. Webster and C.S. Young, Eds., American Society for Testing andMaterials, 1984.



The CorrosionResistance ofZircadyne” 702

?3ti;

$C

EI-

200 ,392O

150. 302 O

100 1 21200

50 . , 122025, . 77O

0 25 50 75 100

Percent Concentration

0 < 2 mpy (.002” per yr.)

20 mpy (.020” per yr.)

0 < 50 mpy (.050” per yr.)

n 50 mpy (.050” per yr.)

V Weight gain

ACETALDEHYDE

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TRI CHLOROETHYLENE

ZI NC CHLORI DE

5



Zirconium Corrosion DataCONCENTRATION TEMPERATURE

CORROSIVE MEDIA REMARKS

Acetic Acid + 2% HI,

Acetic Acid + 2% HI,1% methanol, 500 ppmformic, 100 ppm Cu 80 150 <l - <l

Acetic Acid + 2% HI,1% methanol, 500 ppmformic, 100 ppm Fe 80 150 <l <l

Acetic Acid + 2% HI 98 150 <l - <l

Acetic Acid + 2% HI+ 200 ppm Cl-(Fe Cl,) 80 100 <l - <l

Acetic Acid +2% HI+ 200 ppm Fe+3(Fe,(so.,)3) 80 100 <l - <l

Acetic Acid + 2% I- (KI) 98 150 <l <l

Acetic Acid + 2% HI+ 1% CH, OH + 500 ppm 80 150 (1 (1HCOOH



CORROSION RATE, mpyCONCENTRATION TEMPERATURE

RROSIVE MEDIA % “C Zr 702 Zr 704 Zr 705 REMARKS

cetic Acid + 2% HI+ 200 ppm Cl- (NaCI) 80 100 <l - cl

cetic Acid + 50% AceticAnhydride 50 Boiling <l cl

cetic Acid + 50%48% HBr 50 115 <l cl

cetic Acid + Saturatedgaseous HCI and Cl, 100 Boiling >200 - >200

cetic Acid + Saturatedgaseous HCI and Cl, 100 40 <1 - -

cetic Acid + 10% CH, OH 90 200 <l - -

uminum Chlorate 30 100 <2 - -

uminum Chloride 5, 10, 25 35- 100 <l - -

25 Boiling <l - <l40 100 (2 - -

uminum Chloride (aerated) 5, 10 60 <2 - -

uminum Fluoride 20 Room >50 - - pH = 3.2

uminum Potassium Sulfate 10 Boiling nil - nil pH = 3.2

uminum Sulfate 25 Boiling nil - nil60 100 <2 - -

mmonia (wet) + water 38 <5 - -

mmonium Carbamate - 193 (1 - - 58.4% Urea,16.8% Ammonia,14.8% CO*, 9.9% Hz0at 3,200-3,500 psi

mmonium Chloride 1 lO, saturated 35-l 00 <l - -

mmonium Hydroxide 28 Room-l 00 ==l - -

mmonium Fluoride 20 28 >50 - - pH = 820 98 >50 - - pH = 8

mmonium Oxalate 100 100 <2 -

mmonium Sulfate 5, 10 100 <5 -

niline Hydrochloride 5, 20 35- 100 <l - -

5, 20 100 <2 - -

qua Regia 3:l Room >50 - 3 parts HCI / 1 part HNO:

7



CORROSIVE MEDIA


O/O “C Zr 702 Zr 704 Zr 705 REMARKS

Barium Chloride

Bromine

Bromochloromethane

Cadmium Chloride

Calcium Bromide

Calcium Chloride

5, 2025

loo-LiquidVapor

100

100

100

5, 10, 25

7075

Mixture

35-100 < 1Boiling 5-l 0 -

20 (10 20-50 Pitting20 - >50 Pitting

100 12

Room < 2 -

100 <2 -

35-100 < 1 -

Boiling < 1 == 1 B.P. = 162°CBoiling < 5 -

79 < 1 - 14% CaCI, 8% NaCl0.2% Ca(OH),

Calcium Fluoride Saturated 28 nil - pH=5Saturated 90 nil - pH = 5

Calcium Hypochlorite 2, 6, 20 100 <5

Carbonic Acid Saturated 100 <5

Carbon Tetrachloride o-1 00 Room-100 < 2

Chlorine Room >50 -(water saturated) 75 >50 -

Chlorine Gas 100 94 >50 -(more than 0.13% HpO)

Chlorine Gas (dry)

Chlorinated Water

Chloroacetic Acid

Chromic Acid

Citric Acid

Chrome PlatingSolution

Cupric Chloride

100

100

1 O-50

1 O-5010, 25, 5050

5, 10, 2020, 40, 50

Room < 5 -

100 <2 -

Boiling < 1

Boiling < 1

35-100 < 1100 < 1

Boiling < 5 -

66 >50 >50 M + T ChemicalsCR-1 00

35- 100 >50 150 150Boiling >50 >50 >50



CORROSIVE MEDIA


% “C Zr 702 Zr 704 Zr 705 REMARKS

Cupric Cyanide

Cupric Nitrate

Dichloroacetic Acid

Ethylene Dichloride

erric Chloride

erric Sulfate

ormaldehyde

luoboric Acid

luosilicic Acid

ormic Acid

ormic Acid (aerated)

ydrazine

Saturated Room

40 Boiling

100 Boiling

100 Boiling

O-50 Room- 100O-50 Boiling

10 o-1 00

6-37 BoilingO-70 Room- 100

5-20 Elevated

10 Room

1 O-90 35-Boiling

1 O-90 Room- 100

Mixture 109

Mixture 130

>50 -

W.G. - W.G. B.P. = 115°C

<20 -

c.5 -

>50 >50 >50>50 >50 >50

<2 -

< 1 < 1(2

>50 -

>50 -

<5

<5

< 1 - 2 Hydrazine + saturatedNaCl + 6 NaOH

nil - - 2% Hydrazine + Saturated

NaCl + 6 NaOH

ydrobromic Acid 48

Mixture

Boiling

Boiling

<5

< 1

< 5 B.P. = 125°C (shallow pits)

cl 24% HBr + 50%Acetic Acid (glacial)

ydrochloric Acid 2 225 < 1 < 15 Room < 1 -

10 35 < 120 35 < 132 30 < 1 -

32 82 < 1 -

0% HCI + Cl2 gas 58 5-10’ - - *Pitting

7% HCI + Cl* gas - 58 (5 -

0% HCI + 100 ppm FeCI, - 30 < 1 <2 < 1 SCC observed

0% HCI + 100 ppm FeCI, - 105 (5 - - *Pitting Rate

9



CORROSIVE MEDIA


% “C Zr 702 Zr 704 Zr 705 REMARKS

20% HCI + 100 FeCI,pm - 105 <5 - -

37% HCI + 100 FeCI,pm - 53 5-10 - SCC Observed

Hydrochloric Acid Mixture Room Dissolved - - 20% HCI + 20% HN03

Mixture Room Dissolved - - 10% HCI + 10% HN03

Hydrofluoric Acid o-1 00 Room >50 - -

Hydrogen Peroxide 50 100 (2 -

Hydroxyacetic Acid - 40 (5

Lactic Acid 10-100 148 -=z 1 -1 O-85 35-Boiling < 1 -

Magnesium Chloride 5-40 Room-l 00 (247 Boiling nil nil

Manganese Chloride 5, 20 Room-l 00 ==z1 -

Mercuric Chloride 1 -Saturated 35- 100 < 1 -

Saturated Boiling < 1 - < 1

Nickel Chloride 5, 20 35- 100 -=z 1 - -5-20 100 < 1 - -

30 Boiling nil - nil

Nitric Acid 20 103 < 1 < 1 < 170 121 < 1 < 1 < 11 O-70 Room-260 < 1 -

70-98 Room-Boiling < l* - - ‘SCC Observed

Nitric Acid + 1% Fe 65 120 < 1 - -

Nitric Acid + 1% Fe 65 204 < 1

Nitric Acid + 1.45% 304 SS. 65 204 nil -

Nitric Acid + 1 O/O I- 70 120 nil -(as NaCI)

Nitric Acid + 1 O/O eawater 70 120 nil -

Nitric Acid + 1 O O FeCI, 70 120 nil

Oxalic Acid o-1 00 100 < 1 -

Perchloric Acid 70 100 <2

Phenol Saturated Room <5

0




RROSIVE MEDIA % “C Zr 702 Zr 704 Zr 705 REMARKS

osphoric Acid 5-30 Room (5 -5-35 60 (55-50 100 <5 -

35-50 Room <5 -45 Boiling (5 -

50 Boiling (5 5-10 lo-15 B.P. = 108°C65 100 5-10 - <2070 Boiling >50 - ~50 B.P. = 123-l 26°C85 38 5-20 -85 80 20-50 - 20-5085 Boiling >50 >50 B.P. = 156°CMixture Room nil - 88% H,PO, + 0.5% HN03Mixture Room W.G. - - 88% H,PO, + 5% HN03Mixture 89 >50 >50 85% H3P04 + 4% HN03

assium Chloride Saturated 60 < 1-

Saturated Room < 1 -

assium Fluoride 20 28 nil - - pH=8.920 90 >50 - - pH=8.90.3 Boiling < 1 - -

assium Hydroxide 50 27 < 110 Boiling < 1 -

25 Boiling < 1 -

50 Boiling (5 -

50-anhydrous 241-377 >50Mixture 29 < 1 - 13% KOH, 13% KCI

assium Iodide O-70 Room-l 00 <2 -

assium Nitrite O-100 Room- 100 (2 -

ver Nitrate 50 Room (5

dium Bi-Sulfate 40 Boiling < 1 < 1 B.P. = 107°C

dium Chloride 3-Saturated 35-Boiling < 1 - < 129 Boiling < 1 - -

Saturated Room < 1 -

Saturated Boiling < 1 < 1 Adjusted to pH = 1Saturated 107 nil - Adjusted to pH = 0

dium Chloride + 3.5 80 nil -urated SOS

dium Chloride + 25 80 nil -urated SO,

dium Chloride + Saturated 80 nilurated SO,

11




CORROSIVE MEDIA O/O “C Zr 702 Zr 704 Zr 705 REMARKS

Sodium Chloride Mixture 215 nil nil nil 25% NaCl + 0.5% AceticAcid + 1 O/O + saturatedHS

Sodium Fluoride Saturated 28 nilSaturated 90 >50 - -

Sodium Formate O-80 100 <2

Sodium Hydrogen Sulfite 40 Boiling < 1 - < 1

Sodium Hydroxide 5-10 21 < 128 Room < 1 - -

1 O-25 Boiling < 140 100 < 1 -

50 38-57 < 1 - -50-73 188 20-50 - -73 11 o-1 29 (273 to anhydrous 212-538 20-50 - -Mixture 82 < 1 - 9-l 1 O/O aOH, 15% NaClMixture 1 O-32 < 1 - 10% NaOH, 10% NaCl &

wet CoCI,Mixture 129 < 1 - 0.6% NaOH, 2% NaCIO,

+ trace of NH,

Mixture 191 < 1 - - 7% NaOH, 53% NaCI,7% NaCIO,, 80-l 00 ppm

NH3Mixture 138 (5 - - 52% NaOH + 16% NH3

Sodium Hydroxide 20 60 10-20 -(Suspended salt-violentboiling)

Sodium Hydroxide 50 38 < 1+ 750 ppm Free Cl, 50 38-57 < 1

Sodium Hypochlorite 6 100 (5 - as received super chlor.6 50 nil - nil

Sodium Iodide O-60 100 <2 -

Sodium Peroxide o-1 00 Room- 100 (2 -

Sodium Silicate o-1 00 Room- 100 (2

2




ORROSIVE MEDIA O/O “C Zr 702 Zr 704 Zr 705 REMARKS

odium Sulfate O-20 Room-l 00 (2

odium Sulfide 33 Boiling nil nil

annic Chloride 5 100 <l24 Boiling (1

uccinic Acid O-50 100 <2100 150 (2 -

lfuric Acid o-75 20 (1 <l (180 20 (5 >50 - -80 30 20-50 >50 >50

77.5 60 10-20 - <lo75 50 <l - -

77 50 5-l 0 >5080 50 >50 >50 >5075 80 (5 (565 100 <l <570 100 <2 <575 100 <5 <576 100 <lo77 100 <20

77.5 100 >50 >50 >5060 130 - (565 130 (170 140 <5 <lo58 Boiling (1 <5 B.P. = 140°C62 Boiling <5 1 O-20 B.P. = 146°C

64 Boiling <5 20-50 B.P. = 152°C68 Boiling (5 - B.P. = 165°C69 Boiling (5 B.P. = 167°C71 Boiling (5 B.P. = 171 “C

72-74 Boiling 5-10 >5075 Boiling 1 O-20 >50 B.P. = 189°C

lfuric Acid1000 ppm Fe3- 60 Boiling (1 - B.P. = 138-142°C10,000 ppm Fe3- 60 Boiling <5 - Added as Fe,(SO,),

lfuric Acid

200-l 000 ppm Fe3- 65 Boiling <5 - B.P. = 152-l 55°C10,000 ppm Fez- 65 Boiling 5-10 - Added as Fe,(SOJ,

lfuric Acid4ppm-141 ppmFe3- 70 Boiling 5-10 - - B.P. = 167-l 71 “C200 ppm 70 Boiling 10-20 - - Added as Fe,(S04),1410 ppm-10,000 ppm Fez- 70 Boiling >50

lfuric Acid1000 ppm FeCI, 60 Boiling (5 15 ~20 B.P. = 138-l 42°C10,000 ppm FeCI, 60 Boiling c.5 (20 20-5020,000 ppm FeCI, 60 Boiling 20-50 20-50 >50

13




O/O “C Zr 702 Zr 704 Zr 705 REMARKSORROSIVE MEDIA

Sulfuric Acid+ 200 ppm FeCI,+ 1000 ppm FeCI,+ 10,000 ppm FeCI,

Sulfuric Acid+ 10 ppm FeCI,+ 100 ppm FeCI,+ 200 ppm FeCI,+ 1000 ppm FeCI,+ 10,000 ppm FeCI,

B.P. = 152-l 55°Coiling (5Boiling (5Boiling (5

(20(20<20

<5<5<5

<20<20(20<20>50

656565

7070707070

Boiling <20Boiling (20Boiling (20Boiling <20Boiling 20-50

>50>50>50>50>50

3.P. = 167-l 71 “C

Sulfuric Acid+ 200 ppm cU*’

+ 1000-l 0,000 ppm Cu*+60 Boiling60 Boiling

- Added as CuSO,

Added as CuS04

Added as CuS04

Added as NaNOa

<5< 1

<5Sulfuric Acid+ 200-l 0,000 ppm Cu2+ 65 Boiling

Sulfuric Acid+ 3 ppm ClJ”’

+ 27-226 ppm Cu’+70 Boiling 5-1070 Boiling >50

Sulfuric Acid+ 1000-l 0,000 ppm N03-+ 50,000 ppm N03-

Sulfuric Acid+ 200-l 000 ppm NO,-

+ 10,000 ppm N03-+ 50,000 ppm NOa-

60 Boiling60 Boiling

65 Boiling


<5>50

<5

1 O-20>50

Added as NaNO,

-

Sulfuric Acid+ 200 ppm N03-+ 6000 ppm NO,-

70 Boiling 5-1070 Boiling 20-50

Added as NaNO,

Added as HN03

Added as HN03

1O/oH&30,. 99% HN0310% H,SO?, 90% HNO,14% H,SOI. 14% HN0325% H,SOa, 75% HN0350% H,SO,, 50% HNO,68% H,SOJ, 5% HNO,

<51 O-20>50

<5>50

-

Sulfuric Acid+ 1000 ppm NO,-+ 10,000 ppm N03-+ 50,000 ppm N03-

60 Boiling60 Boiling60 Boiling

Sulfuric Acid+ 1000 ppm NO,-+ 1 O,OOO-50,000 ppm NO,-


Sulfuric Acid Mixture Room- 100 < 1Mixture Room-l 00 nilMixture Boiling < 1Mixture 100 >50Mixture Room < 1Mixture Boiling >50

>50

>50

>50

>50

4



CORROSION RATE, mpyCONCENTRATION TEMPERATlJRE

ORROSIVE MEDIA O/O “C Zr 702 Zr 704 Zr 705 REMARKS

lfuric Acid (Cont.) Mixture Boiling-l 35 1 O-20 1 O-20 ~50 68% H,SO,, 1 O/o HN03Mixture Room >50 >50 ~50 75% HS04, 25% HN03Mixture Boiling < 1 - - 7.5% HzSOzj, 19% HCIMixture Boiling < 1 - 34% H,SO,, 17% HCIMixture Boiling < 1 - - 40% H,SO,, 14% HCIMixture Boiling l-5 - 56% H,SO,, 10% HCIMixture Boiling < 1 - - 60% HS04, 1.5% HCIMixture Boiling <5 - - 69% H$SOd, 1 5% HCIMixture Boiling 10-20 - - 69% H,SO,, 4% HCIMixture Boiling (20 - - 72% HzS04, 1.5% HCIMixture Boiling >50 - >50 20% H2S04, 7% HCI with

50 ppm F impurities

lfurous Acid 6 Room (5 - -

Saturated 192 5-50 -

lfamic Acid 10 Boiling nil - nil B.P. = 101 “C

nnic Acid 25 35- 100 < 1 -

rtaric Acid 1O-50 35- 100 < 1 -

chloroacetic Acid 1 O-40 Room (2 -

100 Boiling >50 -

100 100 >50 - B.P. = 195°C

trachloroethane 100 Boiling (5 B.P. = 146’C symmetricalB.P. = 129°C unsymmetrica

chloroethylene 99 Boiling (5 - - B.P. = 87°C

sodium Phosphate 5-20 100 <5

ea Reactor Mixture Mixture 193 < 1 - 58 Urea17NH,15co*10 H,O

ater - Sea (Pacific) Boiling nil nil200 nil - pH = 7.6

nc Chloride 70 Boiling nil nil5-20 35-Boiling < 140 180 < 1 < 1

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Parr Zirconium Corrosion Info