Designation: A 890/A 890M– 99

An American National Standard

Standard Specication for

Castings, Iron-Chromium-Nickel-Molybdenum CorrosionResistant, Duplex (Austenitic/Ferritic) for General Application1This standard is issued under the xed designation A 890/A 890M; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscript epsilon (e) indicates an editorial change since the last revision or reapproval.

1. Scope 1.1 This specication covers a group of cast duplex stainless steels (austenitic/ferritic). 1.2 The duplex stainless steel alloys offer a combination of enhanced mechanical properties and corrosion resistance when properly balanced in composition and properly heat treated. Ferrite levels are not specied, but these alloys will develop a range of approximately 30 to 60% ferrite with the balance austenite. 1.3 The values stated in either inch-pound units or metric (SI) units are to be regarded separately as standard. Within the text the metric (SI) units are shown in brackets. The values stated in each system are not exact equivalents; therefore, each system must be used independently of the other. Combining values from the two systems may result in nonconformance with the specication. 2. Referenced Documents 2.1 ASTM Standards: A 370 Test Methods and Denitions for Mechanical Testing of Steel Products2 A 732/A732M Specication for Castings, Investment, Carbon and Low-Alloy Steel for General Application, and Cobalt Alloy for High Strength at Elevated Temperatures3 A 781/A781M Specication for Castings, Steel and Alloy, Common Requirements, for General Industrial Use3 E 29 Practice for Using Signicant Digits in Test Data to Determine Conformance With Specications4 E 562 Practice for Determining Volume Fraction by Systematic Manual Point Count5 E 1245 Practice for Determining the Inclusion or SecondPhase Constituent Content of Metals by Automatic Image Analysis5

3. Ordering Information 3.1 Orders for material to this specication shall include the following, as required, to describe the material adequately: 3.1.1 Description of casting by pattern or drawing number (dimensional tolerance shall be included on the casting drawing), 3.1.2 Specication designation and grade including year of issue, 3.1.3 Options in the specication (See 9.1), and 3.1.4 Supplementary requirements desired, including the standards of acceptance. 4. Process 4.1 The steel shall be made by the electric furnace process with or without separate rening such as argon-oxygendecarburization (AOD). 5. Heat Treatment 5.1 Castings shall be heat treated in accordance with the requirements in Table 1.NOTE 1—Proper heat treatment of these alloys is usually necessary to enhance corrosion resistance and in some cases to meet mechanical properties. Minimum heat-treat temperatures are specied; however, it isTABLE 1 Heat Tr

eatment RequirementsGrade 1A, 1B, 1C Heat Treatment Heat to 1900°F[1040°C] minimum, hold for sufficient time to heat casting uniformly to temperature, quench in water or rapid cool by other means. Heat to 2050°F[1120°C] minimum, hold for sufficient time to heat casting uniformly to temperature, quench in water or rapid cool by other means. Heat to 1950°F[1070°C] minimum, hold for sufficient time to heat casting uniformly to temperature, quench in water or rapid cool by other means. Heat to 2050°F[1120°C] minimum for sufficient time to heat casting uniformly to temperature and water quench, or the casting may be furnace cooled to 1850°F[1010°C] minimum, hold for 15 min minimum and then water quench. A rapid cool by other means may be employed in lieu of water quench. Heat to 2050°F[1120°C] minimum, hold for sufficient time to heat casting to temperature, furnace cool to 1910°F[1045°C] minimum, quench in water or rapid cool by other means. Heat to 2010°F[1100°C] minimum, hold for sufficient time to heat casting uniformly to temperature, quench in water or cool rapidly by other means.

2A

3A

4A1 This specication is under the jurisdiction of ASTM Committee A-1 on Steel, Stainless Steel, and Related Alloysand is the direct responsibility of Subcommittee A01.18 on Castings. Current edition approved Dec. 10, 1999. Published January 2000. Originally published as A 890– 88. Last previous edition A 890/A 890M– 98. 2 Annual Book of ASTM Standards, Vol 01.03. 3 Annual Book of ASTM Standards, Vol 01.02. 4 Annual Book of ASTM Standards, Vol 14.02. 5 Annual Book of ASTM Standards, Vol 03.01.

5A

6A

Copyright ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.

sometimesnecessarytoheat-treatathighertemperatures,holdforsome

minimumtimeattemperatureandthenrapidlycoolthecastingsinorder

toenhancethecorrosionresistanceandmeetmechanicalproperties.

6.ChemicalComposition

6.1Thesteelshallconformtotherequirementsasto

chemicalcompositionprescribedinTable2.

7.GeneralRequirements

7.1Materialfurnishedtothisspeci cationshallconformto

therequirementsofSpeci cationA781/A781M,including

anysupplementaryrequirementsthatareindicatedinthe

purchaseorder.Failuretocomplywiththegeneralrequire-

mentsofSpeci cationA781/A781Mconstitutesnonconfor-

mancewiththisspeci cation.Incaseofcon ictbetweenthe

requirementsofthisspeci cationandSpeci cationA781/

A781M,thisspeci cationshallprevail.

8.RepairbyWelding

8.1Thecompositionofthedepositedweldmetalmaybe

similartothatofthecastingormaybesuitablyalloyedto

achievethedesiredcorrosionresistanceandmechanicalprop-

erties.8.2Weldrepairsshallbesubjecttothesamequalitystandardsasareusedtoinspectthecastings.8.3Whenpostweld/heattreatmentisbelievednecessaryforadequatecorrosionresistanceorimpactresistance,Sup-plementaryRequirementS33PostWeld/HeatTreatmentshallbeincludedinthepurchaseorder.9.ProductMarking9.1Castingsshallbemarkedformaterialidenti cationwiththespeci cationdesignationandgrade.Inaddition,themanu-facturer’snameoridenti cationmarkandthepatternnumbershallbecastorstampedusinglow-stressstampsonallcastings.Small-sizecastingsmaybesuchthatmarkingmustbelimitedconsistentwiththeavailablearea.Themarkingofheatnumbersonindividualcastingsshallbeagreeduponbetweenthemanufacturerandthepurchaser.Markingshallbeinsuchpositionasnottoinjuretheusefulnessofthecasting.10.Keywords10.1austenite;duplexstainlesssteel;ferrite;stainlesssteel;steelcastings

TABLE2ChemicalRequirements

Grade

Type

UNS

ACI

Composition:

Carbon,max

Manganese,max

Silicon,max

Phosphorus,max

Sulfur,max

Chromium

Nickel

Molybdenum

Copper

Tungsten

Nitrogen

Grade

Type

UNS

ACI

Composition:

Carbon,max

Manganese,max

Silicon,max

Phosphorus,max

Sulfur,max

Chromium

Nickel

Molybdenum

Copper

Tungsten

Nitrogen

A1A25Cr-5Ni-Mo-CuJ93370CD4MCu0.041.001.000.0400.04024.5–26.54.75–6.001.75–2.252.75–3.25...1B25Cr-5Ni-M0-Cu-NJ93372CD4MCuN0.041.01.00.040.0424.5–26.54.7–6.01.7–2.32.7–3.3...0.10–0.254A22Cr-5Ni-Mo-NJ92205CD3MN0.031.501.000.040.02021.0–23.54.5–6.52.5–3.51.00,max...0.10–0.301CA25Cr-6Ni-Mo-Cu-NJ93373CD3MCuN0.0301.201.100.0300.03024.0-26.75.6-6.72.9-3.81.40-1.90...0.22-0.335AA25Cr-7Ni-Mo-NJ93404CE3MN0.031.501.000.040.0424.0–26.06.0–8.04.0–5.0......0.10–0.302A24Cr-10Ni-Mo-NJ93345CE8MN0.081.001.500.040.0422.5–25.58.0–11.03.0–4.5......0.10–0.306AA25Cr-7Ni-Mo-NJ93380CD3MWCuN0.031.001.000.0300.02524.0–26.06.5–8.53.0–4.00.5–1.00.5–1.00.20–0.303A25Cr-5Ni-Mo-NJ93371CD6MN0.061.001.000.0400.04024.0–27.04.0–6.01.75–2.5......0.15–0.25%Cr+3.3%Mo+16%N$

40.

SUPPLEMENTARYREQUIREMENTS

Thefollowingsupplementaryrequirementsshallnotapplyunlessspeci edinthepurchaseorder.AlistofstandardizedsupplementaryrequirementsforuseattheoptionofthepurchaserisincludedinSpeci cationA781/A781M.Thosethatareordinarilyconsideredsuitableforusewiththis

speci cationarelistedbelowbytitleonly.OthersenumeratedinSpeci cationA781/A781Mmaybeusedwiththisspeci cationuponagreementbetweenthemanufacturerandpurchaser.

S2.RadiographicExamination

S3.LiquidPenetrantExamination

S5.ExaminationofWeldPreparation

S6.Certi cation

S7.PriorApprovalofMajorWeldRepairs

S9.CharpyImpactTest

S10.HardnessTest

S12.TestReport

S13.Unspeci edElements

S31.EstimatingFerriteContent

S31.1Ferritecontentsshallbedeterminedbypointcount

(PracticeE562),byotherquantitativemetallographicmethods

suchasimageanalysis(PracticeE1245),bymeasurementof

magneticresponse,orbyothermethodsuponagreement

betweenthemanufacturerandthepurchaser.Frequencyof

testingandlocationoftestsshallbebyagreementbetweenthe

manufacturerandthepurchaser.

S32.TensileRequirements

S32.1Onetensiletestshallbemadefromeachheatand

shallconformtothetensilerequirementsspeci edinTable

S32.1.Testbarsshallbepouredinspecialblocksfromthe

sameheatasthecastingsrepresented.(SeeS32.4.)

S32.2Thebarfromwhichthetestspecimenisremoved

shallbeheat-treatedinproductionfurnacestothesame

procedureasthecastingsitrepresents.

S32.3Testspecimensmaybecutfromheat-treatedcastings,

attheproducer’soption,insteadoffromtestbars.

S32.4Testcouponsmaybecastintegrallyorasseparate

castblocksinaccordancewithFigs.1and2ofSpeci cationA781/A781M.TensioncouponsshallbemachinedtotheformanddimensionsofFig.4ofTestMethodsandDe nitionsA370,exceptwheninvestmentcastingsareordered.Wheninvestmentcastingsareordered,themanufacturermaypreparetestspecimensinaccordancewithS3.2ofSpeci cationA732/A732M.TestingshallbeinaccordancewithTestMethodsandDe nitionsA370.S32.5Ifanyspecimenshowsdefectivemachiningordevel-ops aws,itmaybediscardedandanothersubstitutedfromthesameheat.S32.6Todetermineconformancewiththetensiontestrequirements,anobservedvalueorcalculatedvalueshallberoundedoffinaccordancewithPracticeE29tothenearest500psi[5MPa]foryieldandtensilestrengthandtothenearest1%forelongationandreductionofarea.S33.PostWeld/HeatTreatmentS33.1Castingsshallbeheat-treatedaftermajorweldre-pairs,butheattreatmentafterminorweldrepairsisnotrequiredexceptuponagreementbetweenthemanufacturerandthepurchaser.S33.2Weldrepairsshallbeconsideredmajorinthecaseofacastingthathasleakedonhydrostatictestingorwhenthedepthofthecavityafterpreparationforrepairexceeds20%oftheactualwallthickness,or1in.[25mm],whicheverissmaller,orwhentheextentofthecavityexceedsapproxi-mately10in.2[65cm2].Allotherweldrepairsshallbeconsideredminor.S33.3PostweldheattreatmentshallbeinaccordancewithTable1.S34.PriorApprovalofWeldMaterialS34.1Thepurchasermustgiveapprovalofallweld llermaterialstobeusedpriortoanyweldrepairs.S35.HeatTreatmentofTestMaterialS35.1Testmaterialforeachheatshallbeheat-treatedwiththecastingsitrepresents.

TABLES32.1TensileRequirements

Grade

Type

Tensilestrength,ksi[MPa],min

Yieldstrength(0.2%offset),ksi

[MPa],min

Elongationin2in.[50mm],%,

minA

Grade

Type

Tensilestrength,ksi[MPa],min

Yieldstrength(0.2%offset),ksi

[MPa],min

Elongationin2in.[50mm],%,

minA

A1A25Cr-5Ni-Mo-Cu100[690]70[485]162A24Cr-10Ni-Mo-N95[655]65[450]253A25Cr-5Ni-Mo-N95[655]65[450]254A22Cr-5Ni-Mo-N90[620]60[415]255A25Cr-7Ni-Mo-N100[690]75[515]186A25Cr-7Ni-Mo-N100[690]65[450]251B25Cr-5Ni-Mo-Cu-N100[690]70[485]161C25Cr-6Ni-Mo-Cu-N100[690]65[450]25WhenICItestbarsareusedintensiletestingasprovidedforinthisspeci cation,thegagelengthtoreducedsectiondiameterratioshallbe

4:1.

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