1、Designation: A 744/A 744M 06Standard Specification forCastings, Iron-Chromium-Nickel, Corrosion Resistant, forSevere Service1This standard is issued under the fixed designationA 744/A 744M; the number immediately following the designation indicates the yearof original adoption or, in the case of rev
2、ision, 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.This standard has been approved for use by agencies of the Department of Defense.1. Scope*1.1 This specificati
3、on covers 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-
4、treatment is not considered mandatory for retention of accept-able corrosion resistance, refer to SpecificationA 743/A 743M.NOTE 1For general corrosion-resistant alloy castings, referenceshould be made to SpecificationA 743/A 743M. For general heat-resistantalloy castings, reference should be made t
5、o Specification A 297/A 297M.For nickel-base alloy castings, refer to Specification A 494/A 494M.1.3 The values stated in either inch-pound units or SI unitsare to be regarded separately as standard. Within the text, theSI units are shown in brackets. The values stated in eachsystem are not exact eq
6、uivalents; therefore, each system mustbe used independently of the other. Combining values from thetwo systems may result in nonconformance with the specifi-cation. Inch-pound units are applicable for material ordered toSpecification A 744 and SI units for material ordered toSpecification A 744M.2.
7、Referenced Documents2.1 ASTM Standards:2A 262 Practices for Detecting Susceptibility to Intergranu-lar Attack in Austenitic Stainless SteelsA 297/A 297M Specification for Steel Castings, Iron-Chromium and Iron-Chromium-Nickel, Heat-Resistant,for General ApplicationA 370 Test Methods and Definitions
8、for Mechanical Testingof Steel ProductsA 494/A 494M Specification for Castings, Nickel andNickel AlloyA 732/A 732M Specification for Castings, Investment, Car-bon and Low-Alloy Steel for General Application, andCobalt Alloy for High Strength at Elevated TemperaturesA 743/A 743M Specification for Cas
9、tings, Iron-Chromium,Iron-Chromium-Nickel, Corrosion-Resistant, for GeneralApplicationA 781/A 781M Specification for Castings, Steel and Alloy,Common Requirements, for General Industrial UseA 957 Specification for Investment Castings, Steel andAlloy, Common Requirements, for General Industrial UseE2
10、9 Practice for Using 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.
11、 Terminology3.1 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 A 781/A 7
12、81M, including any supplementary require-ments that are indicated on the purchase order. Failure tocomply with the general requirements of Specification A 781/A 781M constitutes nonconformance with this specification. Incase of conflict between the requirements of this specificationand Specification
13、 A 781/A 781M, this specification shall pre-vail.4.2 Steel investment castings furnished to this specificationshall conform to the requirements of Specification A 957,including any supplementary requirements that are indicated in1This specification is under the jurisdiction of ASTM Committee A01 on
14、Steel,Stainless Steel, and Related Alloys and is the direct responsibility of SubcommitteeA01.18 on Castings.Current edition approved March 1, 2006. Published March 2006. Originallyapproved in 1977. Last previous edition approved in 2004 as A 744/A 744M 00(2004).2For referenced ASTM standards, visit
15、 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 onthe ASTM website.3Available from The American Welding Society (AWS), 550 NW LeJeune Rd.,Miami, FL 33126.1*A Summary
16、 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.the purchase order. Failure to comply with the general require-ments of Specification A 957 constitutes nonconformance withthis sp
17、ecification. In case of conflict between the requirementsof this specification and Specification A 957, Specification A957 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 Descriptio
18、n of the 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
19、Supplementary 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 therequire
20、ments in 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
21、 time at 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
22、ends shall 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 A5.1
23、4 ER NiCrMo-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 is
24、required.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 thede
25、posited weld 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 f
26、or repair 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 ins
27、pect the 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 th
28、e following 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 minim
29、um, hold for sufficient time to heat casting to temperature, quench in wateror rapid cool by other means.CN7M (N08007) 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, 2150F 1180C
30、 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 sufficie
31、nt 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.A 744/A 744M 062TABLE 2 Chemical RequirementsG
32、rade 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,10 Nick
33、el 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 with Moly
34、bdenum0.03B1.50 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 9.013.0 3.04
35、.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 Nickel wit
36、h 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 . . . . . . . . . . . . 0.1800.240AGrade CF8C
37、 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 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
38、content and shall not exceed 1.1 %.BFor purposes of determining conformance with this specification, the observed or calculated value for carbon content shall be rounded to the nearest 0.01 % in accordance with the rounding method of Practice E29.A744/A744M063NOTE 3The maximum wetted surface tempera
39、ture of 800F 425Cpermitted on minor weld repairs without subsequent heat treatment for theaustenitic grades is necessary to avoid sensitization to intergranularcorrosion. Minor repairs of this type can be made by using a low heatinput (example, 50 000 J/in.) welding process or by cooling wettedsurfa
40、ces with water during welding, or both. Wetted surface temperaturemeasurement can be accomplished with temperature-indicating crayon orcontact pyrometer.11. Rejection and Rehearing11.1 Samples that represent rejected material shall be pre-served for two weeks from the date of transmission of thereje
41、ction report. In case of dissatisfaction with the results of thetests, the manufacturer may make claim for a rehearing withinthat time.12. Product Marking12.1 Castings shall be marked for material identificationwith the ASTM specification number (A 744/A 744M) andgrade symbol, that is, CF8, CN7M, et
42、c. In addition, themanufacturers name or identification mark and the patternnumber shall be cast or stamped using low-stress stamps on allcastings. Small-size castings may be such that marking must belimited consistent with the available area. The marking of heatnumbers on individual castings shall
43、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 stainless steel; corrosion; stainless steel;steel castingsSUPPLEMENTARY REQUIREMENTSThe following supplementary requirements shall not appl
44、y unless specified in the purchase order. Alist of standard supplementary requirements for use at the option of the purchaser is included inSpecificationA 781/A 781M. Those which are ordinarily considered for use with this specification aregiven below. Others enumerated in Specification A 781/A 781M
45、 may be used with this specificationupon agreement between the manufacturer and the purchaser.S2. Radiographic ExaminationS3. Liquid Penetrant ExaminationS5. Examination of Weld PreparationS6. CertificationS7. Prior Approval of Major Weld RepairsS21. Intergranular Corrosion TestS21.1 An intergranula
46、r corrosion test shall be performed inaccordance with the appropriate practice for the grade in-volved, as listed in Practices A 262, or as agreed upon with thepurchaser. Intergranular corrosion tests on stabilized or 0.03 %carbon maximum grades (CF3, CF3M, CF8C, CG3M,CK3MCuN, and CN3MN) shall be ma
47、de 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-shipped condition.S22. Tension TestS22.1 Tensile properties shall be determined from materialrepresenting each heat. The bar from which the
48、test specimenis taken shall be heat-treated in production furnaces to the sameprocedure as the casting it represents. The results shall conformto the requirements specified in Table S22.1.S22.2 Test bars shall be poured in separately cast keelblocks similar to Fig. 1 or Fig. 2 of Specification A 781
49、/A 781M.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 in Fig. 6 of Test Methods and DefinitionsA 370, unless the purchase order is for investment castings, inwhich case, the specimens shall be prepa
