1、Designation: A744/A744M 10Standard Specification forCastings, Iron-Chromium-Nickel, Corrosion Resistant, forSevere Service1This standard is issued under the fixed designation A744/A744M; the number immediately following the designation indicates the yearof original adoption or, in the case of revisi
2、on, the year of last revision. A number in parentheses indicates the year of last reapproval.A superscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope*1.1 This specification c
3、overs iron-chromium-nickel alloy,stainless steel castings intended for particularly severe corro-sive applications.1.2 This specification requires postweld heat-treatment ofall weld repairs affecting surfaces intended to be wetted by thecorrosive medium. For applications for which postweld heat-trea
4、tment is not considered mandatory for retention of accept-able corrosion resistance, refer to Specification A743/A743M.NOTE 1For general corrosion-resistant alloy castings, referenceshould be made to Specification A743/A743M. For general heat-resistantalloy castings, reference should be made to Spec
5、ification A297/A297M.For nickel-base alloy castings, refer to Specification A494/A494M.1.3 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard. The values stated ineach system may not be exact equivalents; therefore, eachsystem shall be used independentl
6、y of the other. Combiningvalues from the two systems may result in non-conformancewith the standard.1.3.1 Within the text, the SI units are shown in brackets.1.3.2 Inch-pound units are applicable for material ordered toSpecification A744 and SI units for material ordered toSpecification A744M.2. Ref
7、erenced Documents2.1 ASTM Standards:2A262 Practices for Detecting Susceptibility to IntergranularAttack in Austenitic Stainless SteelsA297/A297M Specification for Steel Castings, Iron-Chromium and Iron-Chromium-Nickel, Heat Resistant, forGeneral ApplicationA370 Test Methods and Definitions for Mecha
8、nical Testingof Steel ProductsA494/A494M Specification for Castings, Nickel and NickelAlloyA732/A732M Specification for Castings, Investment, Car-bon and Low Alloy Steel for General Application, andCobalt Alloy for High Strength at Elevated TemperaturesA743/A743M Specification for Castings, Iron-Chr
9、omium,Iron-Chromium-Nickel, Corrosion Resistant, for GeneralApplicationA781/A781M Specification for Castings, Steel and Alloy,Common Requirements, for General Industrial UseA957 Specification for Investment Castings, Steel and Al-loy, Common Requirements, for General Industrial UseE29 Practice for U
10、sing Significant Digits in Test Data toDetermine Conformance with Specifications2.2 American Welding Society Standards:3AWS A5.11 Specification for Nickel and Nickel Alloy Cov-ered Welding ElectrodesAWS A5.14 Specification for Nickel and Nickel Alloy BareWelding Rods and Electrodes3. Terminology3.1
11、Definitions of Terms Specific to This Standard:3.1.1 wetted surface, none that contacts a corrosive envi-ronment.4. General Conditions for Delivery4.1 Except for investment castings, castings furnished tothis specification shall conform to the requirements of Speci-fication A781/A781M, including any
12、 supplementary require-ments that are indicated on the purchase order. Failure tocomply with the general requirements of Specification A781/A781M constitutes nonconformance with this specification. Incase of conflict between the requirements of this specificationand Specification A781/A781M, this sp
13、ecification shall pre-vail.1This specification is under the jurisdiction of ASTM Committee A01 on Steel,Stainless Steel and Related Alloys and is the direct responsibility of SubcommitteeA01.18 on Castings.Current edition approved May 1, 2010. Published June 2010. Originallyapproved in 1977. Last pr
14、evious edition approved in 2006 as A744/A744M 06.DOI: 10.1520/A0744_A0744M-10.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page on
15、the ASTM website.3Available from The American Welding Society (AWS), 550 NW LeJeune Rd.,Miami, FL 33126.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4.2 Steel inves
16、tment castings furnished to this specificationshall conform to the requirements of Specification A957,including any supplementary requirements that are indicated inthe purchase order. Failure to comply with the general require-ments of Specification A957 constitutes nonconformance withthis specifica
17、tion. In case of conflict between the requirementsof this specification and Specification A957, SpecificationA957 shall prevail.5. Ordering Information5.1 Orders for material to this specification should includethe following, as required, to describe the material adequately:5.1.1 Description of the
18、casting by pattern number ordrawing (dimensional tolerances shall be included on thecasting drawing),5.1.2 Grade,5.1.3 Heat treatment,5.1.4 Identify wetted surface(s),5.1.5 Options in the specification,5.1.6 Whether casting are to be produced using the invest-ment casting process, and5.1.7 Supplemen
19、tary requirements desired, including thestandards of acceptance.6. Process6.1 Alloys shall be melted by the electric furnace processwith or without separate refining, such as argon-oxygen-decarburization (AOD).7. Heat Treatment7.1 Castings shall be heat treated in accordance with therequirements in
20、Table 1.NOTE 2Proper heat treatment of these alloys is usually necessary toenhance corrosion resistance and in some cases to meet mechanicalproperties. Minimum heat-treat temperatures are specified; however, it issometimes necessary to heat treat at higher temperatures, hold for someminimum time at
21、temperature and then rapidly cool the castings in orderto enhance the corrosion resistance and meet mechanical properties.8. Chemical Requirements8.1 The materials shall conform with the chemical require-ments prescribed in Table 2.9. Workmanship, Finish, and Appearance9.1 Machined welding ends shal
22、l be suitably protectedagainst damage during shipping.10. Repair by Welding10.1 The composition of the deposited weld metal shall besimilar to that of the casting except in grade CK3MCuN. In thecase of Grade CK3MCuN, the composition of the depositedmetal shall be similar to that of AWS A5.14 ER NiCr
23、Mo-3(UNS NO6625) or AWS A5.11 E NiCrMo-3 (UNS W 86112)when postweld heat treatment is not required, and the compo-sition of the deposited metal shall be either similar to that of thebase metal or similar to that of AWS A5.14 ER NiCrMo-3 orAWS A5.11 E NiCrMo-3 when postweld heat treatment isrequired.
24、10.1.1 The composition of the deposited weld metal shall besimilar to that of the casting except in grade CN3MN. In thecase of grade CN3MN, the composition of the deposited weldmetal shall be similar to that of AWS A5.14 ER NiCrMo-3 orER NiCrMo-4 or ER NiCrMo-10, or the composition of thedeposited w
25、eld metal shall be similar to that of AWS A5.11 ENiCrMo-3 or E NiCrMo-4 or E NiCrMo-10 when postweldheat treatment is or is not required.10.2 Weld repairs shall be considered major in the case of acasting that has leaked on hydrostatic test or when the depth ofthe cavity after preparation for repair
26、 exceeds 20 % of theactual wall thickness, or 1 in. 25 mm, whichever is smaller,or when the extent of the cavity exceeds approximately 10in.265 cm2. All other weld repairs shall be considered minor.Major and minor weld repairs shall be subject to the samequality standards as are used to inspect the
27、castings. Whenmethods involving high temperatures are used in the removalof discontinuities, castings shall be preheated to 50F 10Cmin.10.3 Castings shall be postweld heat treated in accordancewith Table 1 after all major weld repairs and after those minorweld repairs involving either of the followi
28、ng conditions: (1)welding on a wetted surface, or (2) welding that heats a wettedsurface to or above 800F 425C.TABLE 1 Heat Treatment RequirementsGrade Heat TreatmentCF8 (J92600), CG8M (J93000), CF8M (J92900),CF8C (J92710), CF3 (J92500), CF3M (J92800),CG3M (J92999)AHeat to 1900F 1040C minimum, hold
29、for sufficient time to heat casting to temperature, quench in wateror rapid cool by other means.CN7M (N08007), CN3MCu (J80020) Heat to 2050F 1120C minimum, hold for sufficient time to heat casting to temperature, quench in wateror rapid cool by other means.CN7MS (J94650) Heat to 2100F 1150C min, 215
30、0F 1180C max, hold for sufficient time (2 h min) to heat casting totemperature, and quench in water.CN3MN J94651 Heat to 2100F 1150C minimum, hold for sufficient time to heat casting to temperature, quench in wateror cool rapidly by other means.CK3MCuN (J93254) Heat to 2100F 1150C minimum, hold for
31、sufficient time to heat casting to temperature, quench in wateror rapid cool by other means.AFor optimum tensile strength, ductility, and corrosion resistance, the solution annealing temperatures for Grades CF8M, CG8M, and CF3M should be in excess of1900F 1040C.A744/A744M 102TABLE 2 Chemical Require
32、mentsGrade TypeComposition, %Car-bon,maxManga-nese,maxSilicon,maxPhos-phorus,maxSul-fur,maxChromium NickelMolyb-denumCo-lum-biumCopperSele-niumTung-sten,maxVana-dium,maxIron,maxNitro-genCF8(J92600)19 Chromium,9 Nickel0.08 1.50 2.0 0.04 0.04 18.021.0 8.011.0 . . . . . . . . .CF8M(J92900)19 Chromium,1
33、0 Nickel with Molybdenum0.08 1.50 2.0 0.04 0.04 18.021.0 9.012.0 2.03.0 . . . . . .CF8C(J92710)19 Chromium,10 Nickel, with Columbium0.08 1.50 2.0 0.04 0.04 18.021.0 9.012.0 . . .A.CF3(J92500)19 Chromium,9 Nickel0.03B1.50 2.0 0.04 0.04 17.021.0 8.012.0 . . . . . .CF3M(J92800)19 Chromium,10 Nickel wit
34、h Molybdenum0.03B1.50 1.50 0.04 0.04 17.021.0 9.013.0 2.03.0 . . . . .CG3M(J92999)19 Chromium,11 Nickel, with Molybdenum0.03 1.50 1.50 0.04 0.04 18.021.0 9.013.0 3.04.0 . . . . . . . . . . . . . . . . . . . . .CG8M(J93000)19 Chromium,11 Nickel, with Molybdenum0.08 1.50 1.50 0.04 0.04 18.021.0 9.013.
35、0 3.04.0 . . . . . .CN7M(N08007)20 Chromium,29 Nickel, with Copperand Molybdenum0.07 1.50 1.50 0.04 0.04 19.022.0 27.530.5 2.03.0 . . . 3.04.0CN7MS(J94650)19 Chromium,24 Nickel, with Copperand Molybdenum0.07 1.0 2.503.50 0.04 0.03 18.020.0 22.025.0 2.53.0 . . . 1.52.0CN3MN(J94651)21 Chromium,24 Nick
36、el with Molybdenumand Nitrogen0.03 2.00 1.00 0.040 0.010 20.022.0 23.525.5 6.007.00 . . . 0.75 max . . . . . . . . . . . . 0.180.26CK3MCuN(J93254)20 Chromium,18 Nickel with Molybdenumand Copper0.025 1.20 1.00 0.045 0.010 19.520.5 17.519.5 6.07.0 . . . 0.501.00 . . . . . . . . . . . . 0.1800.240CN3MC
37、u(J80020)20 Chromium, 29 Nickel, withCopper and Molybdenum0.03 1.50 1.0 0.030 0.015 19.0 22.0 27.5 30.5 2.0 3.0 . . . 3.0 3.5 . . .AGrade CF8C shall have a columbium content of not less than eight times the carbon content and not more than 1.0 %. If a columbium-plus-tantalum alloy in the approximate
38、 Cb:Ta ratio of 3:1 is used for stabilizingthis grade, the total columbium-plus-tantalum content shall not be less than nine times the carbon content and shall not exceed 1.1 %.BFor purposes of determining conformance with this specification, the observed or calculated value for carbon content shall
39、 be rounded to the nearest 0.01 % in accordance with the rounding method of Practice E29.A744/A744M103NOTE 3The maximum wetted surface temperature of 800F 425Cpermitted on minor weld repairs without subsequent heat treatment for theaustenitic grades is necessary to avoid sensitization to intergranul
40、arcorrosion. Minor repairs of this type can be made by using a low heatinput (example, 50 000 J/in.) welding process or by cooling wettedsurfaces with water during welding, or both. Wetted surface temperaturemeasurement can be accomplished with temperature-indicating crayon orcontact pyrometer.11. R
41、ejection and Rehearing11.1 Samples that represent rejected material shall be pre-served for two weeks from the date of transmission of therejection report. In case of dissatisfaction with the results of thetests, the manufacturer may make claim for a rehearing withinthat time.12. Product Marking12.1
42、 Castings shall be marked for material identificationwith the ASTM specification number (A744/A744M) andgrade symbol, that is, CF8, CN7M, etc. In addition, themanufacturers name or identification mark and the patternnumber shall be cast or stamped using low-stress stamps on allcastings. Small-size c
43、astings may be such that marking must belimited consistent with the available area. The marking of heatnumbers on individual castings shall be agreed upon by themanufacturer and the purchaser. Marking shall be in suchposition as not to injure the usefulness of the casting.13. Keywords13.1 austenitic
44、 stainless steel; corrosion; stainless steel;steel castingsSUPPLEMENTARY REQUIREMENTSThe following supplementary requirements shall not apply unless specified in the purchase order. Alist of standard supplementary requirements for use at the option of the purchaser is included inSpecification A781/A
45、781M. Those which are ordinarily considered for use with this specification aregiven below. Others enumerated in Specification A781/A781M may be used with this specificationupon agreement between the manufacturer and the purchaser.S2. Radiographic ExaminationS3. Liquid Penetrant ExaminationS5. Exami
46、nation of Weld PreparationS6. CertificationS7. Prior Approval of Major Weld RepairsS21. Intergranular Corrosion TestS21.1 An intergranular corrosion test shall be performed inaccordance with the appropriate practice for the grade in-volved, as listed in Practices A262, or as agreed upon with thepurc
47、haser. Intergranular corrosion tests on stabilized or 0.03 %carbon maximum grades (CF3, CF3M, CF8C, CG3M,CK3MCuN, and CN3MN) shall be made on sensitized speci-mens. On all other grades of chromium-nickel steels, inter-granular corrosion tests shall be made on specimens represen-tative of the as-ship
48、ped condition.S22. Tension TestS22.1 Tensile properties shall be determined from materialrepresenting each heat. The bar from which the test specimenis taken shall be heat-treated in production furnaces to the sameprocedure as the casting it represents. The results shall conformto the requirements s
49、pecified in Table S22.1.S22.2 Test bars shall be poured in separately cast keelblocks similar to Fig. 1 or Fig. 2 of Specification A781/A781M.S22.3 Tension test specimens may be cut from heat-treatedcastings, or from as-cast castings if no heat treatment isspecified for the castings, instead of from test bars, whenagreed upon by the manufacturer and the purchaser.S22.4 Test specimens shall be machined to the form anddimensions of the standard round 2-in. 50-mm gage lengthspecimen shown i
