OUTOKUMPU - DUPLEX Stainless Steels Technical Data - 1049240

Duplex Stainless Steel

Characteristic properties• Goodtoverygoodresistancetouniformcorrosion• Goodtoverygoodresistancetopittingandcrevice

corrosion• Highresistancetostresscorrosioncracking

andcorrosionfatigue• Highmechanicalstrength• Goodabrasionanderosionresistance• Goodfatigueresistance• Highenergyabsorption• Lowthermalexpansion• Goodweldability

Applications• Pulpandpaperindustry• Desalinationplants• Flue-gascleaning• Cargotanksandpipesystemsinchemicaltankers• Seawatersystems• Firewallsandblastwallsonoffshoreplatforms• Bridges• Componentsforstructuraldesign• Storagetanks• Pressurevessels• Heatexchangers• Waterheaters• Rotors,impellersandshafts• Reinforcingbarsforconcretestructures

Steel grades

Outokumpu EN ASTM/UNS

LDX 2101® 1.4162 S321012304 1.4362 S32304LDX 2404™ 1.4662 S824412205 1.4462 S32205/S318034501 1.4501 S32760 2507 1.4410 S32750

Outokumpu International Chemical composition, % National steel designations, steel name steel No Typical values superseded by EN

EN ASTM/UNS C N Cr Ni Mo Others BS DIN NF SS

LDX 2101® 1.4162 S32101 0.03 0.22 21 1.5 0.3 5Mn – – – – 2304 1.4362 S32304 0.02 0.10 23 4.8 0.3 – – 1.4362 Z3 CN 23-04 Az 2327 LDX 2404™ 1.4662 S82441 0.02 0.27 24 3.6 1.6 3Mn – – – – 2205 1.4462 S32205* 0.02 0.17 22 5.7 3.1 – 318S13 1.4462 Z3 CND 22-05 Az 2377 4501 1.4501 S32760 0.02 0.25 25 7.0 3.8 W,Cu – – – – 2507 1.4410 S32750 0.02 0.27 25 7.0 4.0 – – – Z3 CND 25-06 Az 2328

4307 1.4307 304L 0.02 – 18 8.3 – – 304S11 1.4307 Z3 CN 18-10 2353 4404 1.4404 316L 0.02 – 17 11 2.1 – 316S11 1.4404 Z3 CND 17-11-02 2348 904L 1.4539 N08904 0.01 – 20 25 4.3 1.5Cu 904S13 1.4539 Z2 NCDU 25-20 2562 254 SMO® 1.4547 S31254 0.01 0.20 20 18 6.1 Cu – – – 2378

Chemical composition Table1

General characteristicsAustenitic-ferriticstainlesssteelalsoreferredtoasduplexstainlesssteels,combinemanyofthebeneficialpropertiesofferriticandausteniticsteels.Duetothehighcontentofchro-miumandnitrogen,andoftenalsomolybdenum,thesesteelsoffergoodresistancetolocalisedanduniformcorrosion.Theduplexmicrostructurecontributestothehighstrengthandhighresistancetostresscorrosioncracking.Duplexsteelshavegoodweldability. OutokumpuproducesawholerangeofduplexgradesfromtheleanalloyedLDX2101®uptothesuperduplexgrades2507and4501.ThispublicationpresentsthepropertiesofLDX2101®,2304,LDX2404™,2205and2507.Thepropertiesof4501isingeneraltermsverysimilartothoseof2507.Grade4501isdeliveredifspecified.

Chemical compositionThetypicalchemicalcompositionsofOutokumpugradesareshowninTable1.Thechemicalcompositionofaspecificsteelgrademayvaryslightlybetweendifferentnationalstan-dards.Therequiredstandardwillbefullymetasspecifiedontheorder.

* Also available as S31803

www.outokumpu.com

Aus

teni

tic

Dup

lex

2 Duplex Stainless Steel

MicrostructureThechemicalcompositionofduplexsteelsisbalancedtogiveapproximatelyequalamountsofferriteandausteniteinsolution-annealedcondition.Thehighertheannealingtemperaturethehighertheferritecontent. Duplexsteelsaremorepronetoprecipitationofsigmaphase,nitridesandcarbidesthancorrespondingausteniticsteels,causingembrittlementandreducedcorrosionresis-tance.Theformationofintermetallicphasessuchassigmaphaseoccursinthetemperaturerange600-950°Canddecompositionofferriteoccursintherange350-525°C(475°Cembrittlement). Exposuresatthesetemperaturesshouldthereforebeavoided.Inproperweldingandheat-treatmentoperationstheriskofembrittlementislow.However,certainrisksexist,forexampleatheattreatmentofthicksections,especiallyifthecoolingisslow. Figure1illustratestherelationbetweentimeandtem-peraturethatleadstoareductionoftheimpacttoughnesswith50%.Duetotheriskofembrittlement,theduplexsteelsshouldnotbeusedattemperaturesabove250-325°C.Themaximumtemperatureandstrengthvaluedependsongradeandthedesignrulesbeingused.

Mechanical propertiesTables2-4showthemechanicalpropertiesforflatrolledpro-ducts.DataaccordingtoEN10088andEN10028whenapplicable.LDX2404™isnotyetlistedinEN10088.Data

Fig. 1. Curves for reduction of impact toughness to 50% compared to solution annealed condition.

T emperature (°C)

1100

1000

900

800

700

600

500

400

300

0,01 0,1 1 10 100 1000

(36s) (6min) T ime (h )

2507

2205

2304

LDX 2101 ®

Mechanical properties at 20˚C Table2

Minimum values, Typical values according to EN 10088 P H C P (15mm) H (4mm) C (1mm)

LDX 2101® Proof strength Rp0.2 MPa 450 480 530 480 570 600Tensile strength Rm MPa 650 680 700 700 770 800Elongation A5 % 30 30 30/201 38 38 35Hardness HB 225 230 230

2304Proof strength Rp0.2 MPa 400 400 450 450 520 545Tensile strength Rm MPa 630 650 650 670 685 745Elongation A5 % 25 20 20 40 35 35Hardness HB 210 220 225

LDX 2404™*Proof strength Rp0.2 MPa 480 550 550 540 620 640Tensile strength Rm MPa 680 750 750 750 800 850Elongation A5 % 25 25 25/201 33 32 30Hardness HB, max 290 290 290 230



P = hot rolled plate. H = hot rolled strip. C = cold rolled coil and strip.* Mechanical properties according to AM 641. 1Refers to A80 for gauges less than 3 mm.

forLDX2404™correspondstotheinternalstandardAM641.Theallowabledesignvaluesmayvarybetweenproductforms.Theappropriatevaluesaregivenintherelevantspecifications.

3

LDX 2101® 2304 2205 2507 4404

Rp0.2 478 446 497 565 280Rm 696 689 767 802 578Fatigue strength 500 450 510 550 274


* Values from internal standard, AM 611** Values from internal standard, AM 641

LDX 2101®* 2304 LDX 2404™** 2205 2507

20°C 60 60 60 60 60 -40°C 27 40 40 40 40

Fatigue

Thehightensilestrengthofduplexsteelsalsoimplieshighfatiguestrength.Table5showstheresultofpulsatingtensilefatiguetests(R=min/max=0.1)inairatroomtempe-rature.Thefatiguestrengthhasbeenevaluatedat2million

LDX 2101®* 2304 LDX 2404™** 2205 2507 Rp0.2 Rm Rp0.2 Rm Rp0.2 Rm Rp0.2 Rm Rp0.2 Rm

100°C 380 590 330 540 385 615 360 590 450 680150°C 350 560 300 520 345 590 335 570 420 660200°C 330 540 280 500 325 575 315 550 400 640250°C 320 540 265 490 310 560 300 540 380 630

Impact toughness.Minimum values according to EN 10028, transverse direction, J Table3

Tensile properties at elevated temperatures.Minimum values according to EN 10028, MPa Table4

cyclesanda50%probabilityofrupture.Thetestwasmadeusingroundpolishedbars.Asshownbythetablethefatiguestrengthoftheduplexsteelscorrespondsapproximatelytotheproofstrengthofthematerial.

Fatique, pulsating tensile test, MPa Table5

* Values for hot rolled and cold rolled strip according to AM 611** Values from internal standard, AM 641

* Values may differ slightly between the diferent duplex gradesRT = Room temperature

Physical propertiesPhysicaldataaccordingtoEN10088applyforallourduplexsteels,seeTable6.

20°C 100°C 200°C 300°C

Density g/cm3 7.8Modulus of elasticity GPa 200 194 186 180Poissons ratio 0.3Linear expansion at (RT ➞ T)°C X10-6/°C – 13.0 13.5 14.0Thermal conductivity W/m°C 15 16 17 18Thermal capacity J/kg°C 500 530 560 590Electric resistivity µΩm 0.80 0.85 0.90 1.00

Typical values* Table6


Corrosion resistanceTheduplexsteelsprovideawiderangeofcorrosionresistanceinvariousenvironments.Foramoredetaileddescriptionoftheirresistance,seetheOutokumpuCorrosionHandbook.Abriefdescriptionfollowsbelowregardingtheirresistanceindifferenttypesofenvironments.

Uniform corrosion

Uniformcorrosionischaracterisedbyauniformattackonthesteelsurfacethathascomeintocontactwithacorrosivemedium.Thecorrosionresistanceisgenerallyconsideredgoodifthecorrosionrateislessthan0.1mm/year.Duetotheirhighchromiumcontent,duplexsteelsofferexcellentcorrosionresistanceinmanymedia. LDX2101®has,inmostcases,abetterresistancethan4307andinsomecasesasgoodas4404.2304isinmostcasesequivalentto4404,whiletheothermorehighly-alloyedduplexsteelsshowevenbetterresistance.

Sulphuric acidTheisocorrosiondiagraminsulphuricacidisshowninFigure2.Insulphuricacidcontaminatedbychlorideions,2205showsmuchbetterresistancethan4404andasimilarresistancetothatof904L,Figure3.

Hydrochloric acidStainlesssteelgradessuchas4307and4404haveverylimiteduseinhydrochloricacidbecauseoftheriskofuniformandlocalisedcorrosion.High-alloyedsteelssuchas2507andtosomeextentalso2205canbeusedindilutehydrochloricacid,Figure4.Pittingisnormallynotaproblemintheareabelowtheboundarylineintheisocorrosiondiagrambutcrevicesshouldbeavoided.

Nitric AcidInstronglyoxidisingacids,e.g.nitricacid,non-molybdenumalloyedsteelsareoftenmoreresistantthanthemolybdenumalloyedsteels.LDX2101®and2304aregoodalternativesbecauseoftheirhighchromiumcontentincombinationwithalowmolybdenumcontent.

Pitting and crevice corrosion

Theresistancetopittingandcrevicecorrosionincreaseswiththecontentofchromium,molybdenumandnitrogeninthesteel.Thisisoftenillustratedbythepittingresistanceequivalent(PRE)forthematerial,whichcanbecalculatedbyusingtheformula:PRE=%Cr+3.3x%Mo+16x%N.PREvaluesgivenfordifferentgradesarepresentedinTable7. ThePREvaluecanbeusedforaroughcomparisonbetweendifferentmaterials.Amuchmorereliablewayofrankingsteelsisaccordingtothecriticalpittingtemperature(CPT).ThereareseveralmethodsavailabletomeasureCPT.Theelectrochemicalmethod,usedbyOutokumpumakesitpossibletomeasuretheresistancetopittingwithoutinterferencefromcrevicecorrosion(ASTMG150).Theresultsaregivenasthecriticalpittingtemperature,CPT,atwhichpittingisinitiated.Thepittingcorrosionresistance

Temperature, °C

100

80

60

40

20

2507

2205

904L

4404 254 SMO

0 10 20 30 40

H2SO4 % +2000 ppm Cl-

®

Fig. 3. Isocorrosion curves, 0,1 mm/year, in sulphuric acid containing 2000 ppm chloride ions.

Fig. 2. Isocorrosion curves, 0.1 mm/year, in sulphuric acid.

Temperature, °C

140

120

100

80

60

40

20

2304

4404

2205

904L

2507

2507

4404

2205

0 20 40 60 80 100

H2SO4, weight-%

Boiling Point Curve

LDX2101

4307

®

Temperature, °C

120

100

80

60

40

200 1 2 3 4

HCI, weight-%

Boiling Point Curve

2507

2205

44042304

Fig. 4. Isocorrosion curves 0.1mm/year, in hydrochloric acid.

5

90

80

70

60

50

40

30

20

10

CPT, °C

4404 904L4307 4436 254 SMO ®2304 25072205LDX 2101 ® LDX 2404 ™


Fig. 5. Typical critical pitting corrosion temperatures (CPT) in 1M NaCl measured according to ASTM G150 using the Avesta Cell. Test surfaces wet ground to 320 mesh. CPT varies with product form and surface finish.

ofthesteelsinaground(P320mesh)conditionisshowninFigure5. Theactualvalueoftheasdeliveredsurfacemaydifferbetweenproductforms. Whenrankingtheresistancetocrevicecorrosion,itiscommontomeasureacriticaltemperatureatwhichcorrosionisinitiatedinawelldefinedsolution.Thetypicalcriticalcrevicecorrosiontemperatures(CCT)measuredin6%FeCl3+1%HClaccordingtoASTMG48MethodF,ispresentedinFigure6.Differentproductsanddifferentsurfacefinishes,e.g.millfinishsurfaces,mayshowCCTvaluesthatdifferfromthevaluesgiveninthefigure.Duetotheirdifferentalloyinglevels,thefiveduplexsteelsshowconsiderabledifferencesintheresistancetopittingandcrevicecorrosion.LDX2101®hasaresistancein-between4307and

Stress corrosion cracking

Conventionalausteniticstainlesssteelcanbeattackedbystresscorrosioncracking(SCC)inchlorideenvironmentsatelevatedtemperatures.Stainlesssteelsoftheduplextypearelesssusceptibletothistypeofcorrosion. DifferentmethodsareusedtorankstainlesssteelgradeswithregardtotheirresistancetoSCC.Theresultscanvarydependingonthemethodandtestingenvironment.Theresistancetostresscorrosioncrackinginachloridesolutionunderevaporativeconditionscanbedeterminedaccording

Steel grade PRE

4307 184404 24LDX 2101® 262304 26LDX 2404™ 33904L 342205 35254 SMO® 432507 43

PRE values for different austeniticand duplex grades. Table7

4404,2304isonalevelwithconventionalmolybdenum-alloyedsteelsofthe4404type,whileLDX2404™and2205isonalevelwith904Land2507with254SMO®.

Fig. 6. Typical critical crevice corrosion temperature (CCT) according to ASTM G48 Method F. Test surfaces dry ground to 120 mesh. CCT varies with product form and surface finish

2304 25072205LDX 2101 ® LDX 2404 ™

CCT , ° C

50

40

30

20

10

0

4404 904L4307 4436 254 SMO ®

tothedropevaporationmethod.Thismeansthatasaltsolu-tionisallowedtoslowlydripontoaheatedspecimen,whileitisbeingsubjectedtotensilestress. Bythismethodthethresholdvalueisdeterminedfortheminimumstressforfailureafter500hourstestingat80-120°C.Thethresholdvalueisusuallyexpressedasaper-centageoftheproofstrengthofthesteelat200°C.Figure7showstheresultsofsuchatest.Itisevidentthatduplexste-elsaresuperiortoconventionalausteniticstainlesssteel,suchas4307and4404.

6

100

80

70

90

60

50

40

30

20

10

0

4404

2304 2205

904L

2507 4307

<10<15

254SMO®

LDX2101®

LDX2404™

Min

imu

m s

tres

s fo

r fa

ilure

, % o

f R

at 2

00°C

p0.

2

Fig. 7. Typical threshold stresses determined using the drop evaporation test.


Sulphide induced stress corrosion cracking

Inthepresenceofhydrogensulphideandchloridestheriskofstresscorrosioncracking,atlowtemperatures,increases.Suchenvironmentscanexist,forexample,inboreholesforoilandgaswells.Duplexgrades,suchas2205and2507havedemonstratedgoodresistance,while13%chromiumsteelshaveshownatendencytowardsstresscorrosioncrack-ing.However,cautionshouldbeobservedregardingcondi-tionswithhighpartialpressureofhydrogensulphideandwherethesteelissubjectedtohighinternalstress. 2205and2507arebothapprovedmaterialsaccordingtoNACE MR0175 / ISO 1515 Petroleum and natural gas industries - Materials for use in H2S-containing environments in oil and gas production.Corrosion fatigue

Thecombinationofhighmechanicalstrengthandverygoodresistancetocorrosiongivesduplexsteelsahighcorrosionfatiguestrength.S-Ncurvesfor2205and4404insynthe-ticseawaterareshowninFigure8.Thecorrosionfatiguestrengthof2205isconsiderablyhigherthanthatof4404.

Intergranular corrosion

Duetotheduplexmicrostructureandlowcarboncontent,theduplexsteelshaveverygoodresistancetointergranularcorrosion.Thecompositionofthesteelensuresthatauste-niteisreformedintheheat-affectedzoneafterwelding.Theriskofundesirableprecipitationofcarbidesandnitridesinthegrainboundariesisthusminimised.

Erosion corrosion

Stainlesssteelingeneraloffersgoodresistancetoerosioncorrosion.Duplexgradesareespeciallygoodthankstotheircombinationofhighsurfacehardnessandgoodcorrosionresistance.Examplesofapplicationswherethisisbeneficialaresystemssubjectedtoparticlescausinghardweare.g.pipesystemscontainingwaterwithsandorsaltcrystals.

Galvanic Corrosion

Galvaniccorrosioncanoccurwhentwodissimilarmetalsareconnected.Thenoblestmaterialisprotectedwhilethelessnoblematerialismoreseverelyattacked.Aslongastheduplexstainlesssteelsarepassivetheyare,inmostenviron-ments,noblerthanothermetallicconstructionmaterials,meaningthatthestainlesssteelisprotectedwhilethecorro-sionrateofe.g.carbonsteelisincreased. Galvaniccorrosiondoesnotoccurbetweendifferentgradesofstainlesssteelsaslongasbothgradesarepassive.

Fig. 8. Corrosion fatigue of stainless steel in synthetic seawater. Rotating bending test, 1500 r/min, with smooth specimens from 15 mm plate.

Stress amplitude (S), MPa

Number of cycles to failure (N)

500

400

300

200

100

0 105 106 107

2205

4404

7

2304

4404

4301

1200

1000

800

600

400

200

0

R

R

m

p0.2

LDX 2101®

En

gin

eeri

ng

str

ess

(MP

a)

Engineering Plastic Strain (%)0 20 40 60

2507

2205

904L

1200

1000

800

600

400

200

0

LDX 2404™

En

gin

eeri

ng

str

ess

(MP

a)

Engineering Plastic Strain (%)0 20 40 60

254SMO®

14

12

1

0.8

0.6

0.4

0.2

0

r-va

lue

Angle to rolling direction0 45 90

2205

2507

904L

254SMO

™

®

LDX 2404

14

12

1

0.8

0.6

0.4

0.2

0

r-va

lue

Angle to rolling direction0 45 90

®LDX 2101

2304

4301

4404


Fig. 10. Stress-strain curves for duplex and austenitic grades with corresponding corrosion resistance.

Fig. 9. Stress-strain curves for duplex and austenitic grades with corresponding corrosion resistance.

Fig. 11. r-values for duplex and austenitic grades with corresponding corrosion resistance.

Fig. 12. r-values for duplex and austenitic grades with corresponding corrosion resistance.

Fabrication

Duplexstainlesssteelissuitableforallformingprocessesavai-lableforstainlesssteel.Thehighproofstrengthcomparedtoausteniticandferriticsstainlesssteelcanimposesomedifferen-cesinformingbehaviourdependingonchosenformingtechni-que,suchasanincreasedtendencytospringback.Thispointisparticularlyrelevanttoformingofanyhighstrengthsteel.Iftheformingprocessisnotalreadydecided,itiscertainlypossibletochoosethemostsuitableoneforduplexgrades.Moreover,anexcellentinterplaybetweenhighproofstrength,workhardeningrateandelongationpromotetheduplexgradesforlightweightandcost-efficientapplicationswithcomplexshapes. Theimpactofthehighstrengthvariesfordifferentformingtechniques.Commonforallisthattheestimatedformingforceswillbehigherthanthecorrespondingausteniticandfer-riticstainlesssteelgrades.Thiseffectwillusuallybelowerthanexpectedfromjusttheincreaseinstrengthsincethechoiceofduplexstainlesssteelisoftenassociatedwithdowngauging.Itisimportanttoconsiderthatduplexstainlesssteelmayalsobemoredemandingforthetoolmaterialsandthelubricant.Alsointhiscaseattentionshouldbegiventothedowngauging. Outokumpu,AvestaResearchCentre,cansupportcustomersindetailedcomputeranalysesoftheimpactontheformingpro-cesswhenstainlesssteelgradesaretobeselected.Cold forming

Thehighstrengthoftheduplexgradesisclearlydemonstratedwhenthestress-straincurvesofOutokumpuduplexgradesarecomparedwiththecorrespondingausteniticgrades,seeFigures9-10.TheRp0.2/Rmratioalsodemonstratesalowerdeformationhardeningrateforduplexgradesathighervaluesoftheplasticstrain. Asheetmaterial'sabilitytowithstandthinningduringfor-mingisdemonstratedbyther-value,anisotropicvalue,indiffe-renttensiledirections,andthehigherther-valuethebetter,seeFigures11-12.


Heat treatment

TemperaturessuitableforheattreatmentarepresentedinTable8.Theheattreatmentshouldbefollowedbysubse-quentrapidcoolinginwaterorair.Thistreatmentappliesforbothsolutionannealingandstressrelieving.Thelat-tercaninspecialcasesbedoneat500-550°C.FurtherinformationconcerningtheseoperationsisavailablefromOutokumpu. Fig. 14. Machinability index for duplex and some

other stainless steels.

LDX 2101® 2304 LDX 2404™ 2205 2507

Hot forming 1100-900 1100-900 1120-900 1150-950 1200-1025

Quench annealing 1020-1080 950-1050 1000-1120 1020-1100 1040-1120

Stress relief annealing 1020-1080 950-1050 1000-1120 1020-1100 1040-1120

Characteristic temperatures, °C Table8

See also ”Welding”

Machining

Duplexsteelsaregenerallymoredemandingtomachinethanconventionalausteniticstainlesssteelsuchas4404,duetothehigherhardness.HoweverLDX2101®hasshownexcel-lentmachiningproperties. Themachinabilitycanbeillustratedbyamachinabilityindex,asillustratedinFigure14.Thisindex,whichincreaseswithimprovedmachinability,isbasedonacombinationoftestdatafromseveraldifferentmachiningoperations.Itprovidesagooddescriptionofmachinabilityinrelationto4404.ForfurtherinformationcontactOutokumpu.

4404 LDX 2101® LDX 2404™ 2304 2205 2507

Relative machinability

1.5

1

0.5

0

Theformabilityofduplexstainlesssteelcanbecharacteri-zedinseveralways.Figure13showsarelativerankingofOutokumpuduplexgradesincomparisontoaselectionofausteniticgrades.Therankingresemblesthemostcriticalfailuremodeinsheetforming. Inpuredrawing,theduplexgradesarecomparabletoaus-teniticgradesinthataboutthesamelimitingdrawingratiocanbedrawn.

Hot forming

HotformingisperformedatthetemperaturesillustratedinTable8.Itshould,however,beobservedthatthestrengthoftheduplexmaterialsislowathightemperaturesandcom-ponentsrequiresupportduringfabrication.Hotformingshouldnormallybefollowedbyquenchannealing.

1.0

0.8

0.7

0.9

0.6

0.5

0.4

0.3

0.2

0.1

0.0

44042304 2205 904L2507 4301LDX 2101® 254 SMO®LDX 2404™

Form

abili

ty in

pla

ne

stra

in

Fig 13. Formability ranking of some duplex and austenitic grades in relation to grade 4301.

9Duplex Stainless Steel

Welding

Duplexsteelsgenerallyhavegoodweldabilityandcanbeweldedusingmostoftheweldingmethodsusedforausteni-ticstainlesssteel:• Shieldedmetalarcwelding(SMAW)• GastungstenarcweldingTIG(GTAW)• GasmetalarcweldingMIG(GMAW)• Flux-coredarcwelding(FCW)• Plasmaarcwelding(PAW)• Submergedarcwelding(SAW)• Laserwelding• Resistancewelding• Highfrequencewelding

Duetothebalancedcomposition,theheat-affectedzoneobtainsasufficientlyhighcontentofaustenitetomaintainagoodresistancetolocalisedcorrosion.Theindividualduplexsteelshaveslightlydifferentweldingcharacteristics.Formoredetailedinformationregardingtheweldingofindividualgrades,seetheOutokumpuWeldingHandbookorcontactOutokumpu.Thefollowinggeneralinstructionsshouldbefollowed:• Thematerialshouldbeweldedwithoutpreheating.• Thematerialshouldbeallowedtocoolbetween

passes,preferablytobelow150°C.• Toobtaingoodweldmetalpropertiesinaswelded condition,fillermaterialshallbeused.ForLDX2101®reasonablygoodpropertiescanbeobtainedalsowithout

filler.

Steel grade Consumable Typical composition, % by wt. ISO C Cr Ni Mo N Designation

LDX 2101® 23 7 NL 0.02 23.5 8.0 0.3 0.14

22 9 3 NL 0.02 22.5 8.5 3.0 0.15

2304 23 7 NL 0.02 23.5 8.0 0.3 0.14

22 9 3 NL 0.02 22.5 8.5 3.0 0.15

LDX 2404™ 22 9 3 NL 0.02 22.5 8.5 3.0 0.15

2205 22 9 3 NL 0.02 22.5 8.5 3.0 0.15

2507 25 9 4 NL 0.02 25 9.5 3.5 0.25

• Therecommendedarcenergyshouldbekeptwithincer-tainlimitstoachieveagoodbalancebetweenferriteandausteniteintheweld.Theheatinputshouldbeadaptedtothesteelgradeandbeadjustedinproportiontothethicknessofthematerialtobewelded.

• Post-weldannealingafterweldingwithfillerisnotnecessary.Incaseswhereheattreatmentisconsidered,e.g.,forstressrelieving,itshouldbecarriedoutinaccordancewiththetemperaturesstatedinTable8,butwiththeminimumtemperatureincreasedwith30-50°Ctosecurefulldissolutionofintermetallicphaseinthetheweldmetal.

• ToensureoptimumpittingresistancewhenusingGTAWandPAWmethods,anadditionofnitrogenintheshielding/purginggasisrecommended.

Post fabrication treatment

Inordertorestorethestainlesssteelsurfaceandachievegoodcorrosionresistanceafterfabrication,itisoftenneces-sarytoperformapostfabricationtreatment. Therearedifferentmethodsavailable,bothmechanicalmethodssuchasbrushing,blastingandgrindingandchemi-calmethods,e.g.pickling.Whichmethodtoapplydependonwhatconsequencesthefabricationcaused,i.e.whattypeofimperfectionstoberemoved,butalsoonrequirementswithregardtocorrosionresistance,hygienicdemandsandaestheticappearance.Formoreinformation,seetheOutokumpuWeldingHandbook.

Welding consumables Table9


Hot rolled plate, sheet and strip

Cold rolled sheet and strip

Bars and forging

Tube, Pipe and Fittings

Products Table10

EN 10028-7 Flat products for pressure purposes – Stainless steels

EN 10088-2 Stainless steels – Corrosion resisting sheet/plate/strip for general and construction purposes

EN 10088-3 Stainless steels – Corrosion resisting semi-finished products/bars/rods/wire/sections for general and construction purposes

EN 10088-4 Stainless steel flat products, technical delivery conditions, steels for construction

EN 10088-5 Stainless steel long products, technical delivery conditions, steels for construction

EN 10217-7 Welded steel tubes for pressure purposes – Stainless steel tubes

EN 10272 Stainless steel bars for pressure purposes

EN 10296-2 Welded circular steel tubes for mechanical and general engineering purposes - Stanless Steel tubes

ASTM A182 / ASME SA-182 Forged or rolled alloy-steel pipe flanges, forged fittings etc for high temperature service

ASTM A240 / ASME SA-240 Heat-resisting Cr and Cr-Ni stainless steel plate/sheet/strip for pressure purposes

ASTM A276 Stainless and heat-resisting steel bars/shapes

ASTM A479 / ASME SA-479 Stainless steel bars for boilers and other pressure vessels

ASTM A789 / ASME SA-789 Seamless and welded duplex stainless steel tubing for general purposes

ASTM A790 / ASME SA-790 Seamless and welded duplex stainless steel pipe

ASTM A815 / ASME SA-815 Wrought ferritic, duplex, martensitic stainless steel piping fittings

ASTM A928 Duplex stainless steel pipe welded with addition of filler metal

VdTÜV WB 418 Ferritisch-austenitischer Walz- und Schmiedestahl, 1.4462

VdTÜV WB 496 Ferritisch-austenitischer Walz- und Schmiedestahl, 1.4362

VdTÜV WB 556 Austenitic-ferritic steel X2CrMnNi21-5-1, Material No. 1.4162, Manufacturer designation: LDX 2101®

NACE MR0175 / ISO 1515 Petroleum and natural gas industries - Materials for use in H2S-containing environments in oil and gas production.

Norsok M-CR 630, MDS D45, MDS D55

ASME Boiler and Pressure 21Cr-5Mn-1.5Ni-Cu-N (UNS S32101), Austenitic-Ferritic Duplex Stainless SteelVessel Code Case 2418 Section VIII, Division 1

Material Standards Table11

Outokumpu 2205 corresponds in American Standards to two different steel designations; UNS S31803 and UNS S32205. The latter has closer tolerance limits for some alloying elements to further optimise properties such ascorrosion resistance and strength, the properties described in this datasheet corresponds to UNS S32205.

See www.outokumpu.com/prodprog

11Duplex Stainless Steel

Information given in this brochure may be subject to alterations without notice. Care has been taken to ensure that the contents of this publication are accurate but Outokumpu and its affiliated companies do not accept responsibility for errors or for information which is found to be misleading. Suggestions for or descriptions of the end use or application of products or methods of working are for information only and Outokumpu and its affiliated companies accept no liability in respect thereof. Before using products supplied or manufactured by the company the customer should satisfy himself of their suitability.

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www.outokumpu.com

Outokumpu Stainless AB,Avesta Research Centre

Box 74, SE-774 22 Avesta, Sweden

Tel. +46 (0)226 810 00, Fax +46 (0)226 810 77

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Outokumpu is a global leader in stainless steel. Our vision is to be the undisputed number one in stainless, with success based on operational exellence. Customers in a wide range of industries use our stainless steel and services worldwide. Being fully recyclable, maintance-free, as well as very strong and durable material, stainless steel is one of the key building blocks for sustainable future. What makes Outokumpu special is total customer focus, all the way, from R&D to delivery. You have the idea. We offer world-class stainless steel, technical know-how and support. We activate your ideas. (www.outokumpu.com)

Documents

OUTOKUMPU - DUPLEX Stainless Steels Technical Data - 1049240