1、Designation: A757/A757M 10Standard Specification forSteel Castings, Ferritic and Martensitic, for Pressure-Containing and Other Applications, for Low-TemperatureService1This standard is issued under the fixed designation A757/A757M; the number immediately following the designation indicates the year
2、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 () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Departmen
3、t of Defense.1. Scope*1.1 This specification covers carbon and alloy steel castingsfor pressure-containing and other applications intended prima-rily for petroleum and gas pipelines in areas subject tolow-ambient temperatures. Castings shall be heat treated bynormalizing and tempering or liquid quen
4、ching and tempering.All classes are weldable under proper conditions. Hardenabil-ity of some grades may limit usable section size.1.2 The values stated in either inch-pound units or SI unitsare to be regarded separately as standard. The values stated ineach system are not exact equivalents; therefor
5、e, each systemmust be used independently of the other. Combining valuesfrom the two systems may result in non-conformance with thestandard.1.2.1 Unless the order specifies an “M” designation, thematerial shall be furnished to inch-pound units.1.3 This standard does not purport to address all of thes
6、afety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2A370 Test Methods and Definit
7、ions for Mechanical Testingof Steel ProductsA488/A488M Practice for Steel Castings, Welding, Quali-fications of Procedures and PersonnelA703/A703M Specification for Steel Castings, General Re-quirements, for Pressure-Containing PartsA941 Terminology Relating to Steel, Stainless Steel, Re-lated Alloy
8、s, and FerroalloysA985/A985M Specification for Steel Investment CastingsGeneral Requirements, for Pressure-Containing Parts2.2 American Society of Mechanical Engineers:3ASME Boiler and Pressure Vessel Code2.3 Manufacturers Standardization Society of the Valve andFittings Industry Standards:4MSS SP-5
9、5 Quality Standard for Steel Castings for Valves,Flanges, Fittings, and Other Piping Components - VisualMethod for Evaluation of Surface Irregularities3. Terminology3.1 Definitions:3.1.1 Definitions in Test Methods and Definitions A370 andTerminology A941 are applicable to this specification.3.1.2 D
10、efinition of nominal thickness, T, applies toquenched and tempered castings with a thickness exceeding 2in. 50 mm. Nominal thickness, T, is the maximum thicknessof the pressure-containing wall of the casting exclusive ofpadding added for directional solidification, flanges, append-ages, and sections
11、 designated by the designer as noncritical.4. General Conditions for Delivery4.1 Except for investment castings, castings furnished tothis specification shall be in accordance with the requirementsof Specification A703/A703M, including any supplementaryrequirements that are indicated in the purchase
12、 order. Failure tocomply with the general requirements of Specification A703/A703M constitutes nonconformance with this specification. Incase of conflict between the requirements of this specificationand Specification A703/A703M, this specification shall pre-vail.4.2 Steel investment castings furnis
13、hed to this specificationshall conform to the requirements of Specification A985/1This 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 Nov. 1, 2010. P
14、ublished December 2010. Originallyapproved in 1978. Last previous edition approved in 2004 as A757/A757M 00(2004). DOI: 10.1520/A757/A757M-10.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards vol
15、ume information, refer to the standards Document Summary page onthe ASTM website.3Available from American Society of Mechanical Engineers (ASME), ASMEInternational Headquarters, Three Park Ave., New York, NY 10016-5990, http:/www.asme.org.4Available from Manufacturers Standardization Society of the
16、Valve and FittingsIndustry (MSS), 127 Park St., NE, Vienna, VA 22180-4602, http:/www.mss-.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.A985M, including any suppleme
17、ntary requirements that areindicated in the purchase order. Failure to comply with thegeneral requirements of SpecificationA985/A985M constitutesnonconformance with this specification. In case of conflictbetween the requirements of this specification and Specifica-tion A985/A985M, A985/A985M shall p
18、revail.5. Ordering Information5.1 Orders for material to this specification should includethe following, as required, to describe the material adequately:5.1.1 Quantity,5.1.2 ASTM designation and date of issue,5.1.3 Grade designation (Table 1),5.1.4 Description of casting by part, pattern, or drawin
19、gnumber. (Dimensional tolerances and machined surfacesshould be indicated on the casting drawing).5.1.5 Options in the specification,5.1.6 Whether the castings are to be produced using invest-ment casting process, and5.1.7 Supplementary requirements desired, if any, includingstandards of acceptance.
20、6. Materials and Manufacture6.1 Melting ProcessThe steel shall be made by theelectric furnace process or other primary processes approvedby the purchaser. The primary melting may incorporate sepa-rate degassing or refining and may be followed by secondarymelting.6.2 Heat Treatment:6.2.1 All castings
21、 shall be heat treated by either normalizingand tempering or quenching and tempering. Tempering tem-perature shall be 1100F 595C minimum, except gradesB4N and B4Q, which shall be tempered at 1050F 565Cminimum.6.2.2 E3N castings shall be heat treated by heating to1850F 1010C minimum, and air cooling
22、to 200F 95Cmaximum before any optional intermediate temper, but shallcool to 100F 40C maximum before the final temper, whichshall be between 1050 and 1150F 565 and 620C.6.2.3 Furnace temperatures for heat treating shall be con-trolled by pyrometers.6.2.4 Castings shall be allowed to cool below the t
23、ransfor-mation range directly after pouring and solidification beforethey are reheated for normalizing or liquid quenching.7. Chemical Composition7.1 The steel shall be in accordance with the requirementsas to chemical composition prescribed in Table 1.8. Tensile Requirements8.1 Steel used for the c
24、astings shall conform to the require-ments as to the tensile properties prescribed in Table 2.9. Impact Requirements9.1 Impact properties shall be determined on each heat bytesting a set of three Charpy V-notch specimens. The bar fromwhich the impact specimens are machined shall be prepared inaccord
25、ance with Section 12. The longitudinal axis of theCharpy specimens shall be parallel to the longitudinal axis ofthe tensile bar. Testing shall be in accordance with TestMethods and Definitions A370.9.2 Test temperature and absorbed energy requirements forthe grade shall be as specified in Table 3, e
26、xcept for thoseTABLE 1 Chemical Requirements (Maximum Percent Unless Range is Given)Grade A1Q A2Q B2N B2Q B3N B3Q B4N B4Q C1QD1N1 D1Q1D1N2 D1Q2D1N3 D1Q3E1Q E2N, E2Q E3NType CarbonCarbon-Manga-nese212 Nickel 312 Nickel 412 NickelNickelMolybdenumChromiumMolybdenumNickelChromiumMolybdenumNickelChromium
27、MolybdenumMartensiticChromiumNickelCarbon 0.30 0.25A0.25 0.15 0.15 0.25 0.20 0.22 0.20 0.06Manganese 1.00 1.20A0.50/0.80 0.50/0.80 0.50/0.80 1.20 0.40/0.80 0.50/0.80 0.40/0.70 1.00Phosphorus 0.025 0.025 0.025 0.025 0.025 0.025 0.025 0.025 0.020 0.030Sulfur 0.025 0.025 0.025 0.025 0.025 0.025 0.025 0
28、.025 0.020 0.030Silicon 0.60 0.60 0.60 0.60 0.60 0.60 0.60 0.60 0.60 1.00Nickel 2.0/3.0 3.0/4.0 4.0/5.0 1.5/2.0 2.5/3.5 2.75/3.90 3.5/4.5Chromiu 2.0/2751.35/1.851.50/2.1.5/14.0Molybdenum 0.15/0.391.00064600Specified ResidualElements:Vanadium 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 Copper 0.50 0
29、.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50Nickel 0.50 0.50 0.50Chromiu 0.40.40.40.40.40.4Molybdenum 0.25 0.25 0.25 0.25 0.25 Tungsten 0.100.10.1Totalresiduals (maxi-mum %)B1.00 1.00 1.00 1.00 1.00 1.00 1.00 0.70 0.70 0.50AFor each 0.01 % of reduction in carbon below the maximum specified, an increa
30、se of 0.04 % manganese over the maximum specified will be permitted up to 1.40 %.BTotal residuals includes phosphorus and sulfur.A757/A757M 102grades that have no values specified, in which case, impactenergy values and test temperatures shall be agreed uponbetween the manufacturer and the purchaser
31、. The averageenergy value of three specimens shall not be less than theminimum average specified, with only one value permittedbelow the minimum average specified and this value notpermitted to fall below the minimum specified for a singlespecimen. Supplementary Requirement S8 may be specified iflat
32、eral expansion or percent shear area, or both, are desired bythe purchaser.9.3 Impact properties shall also be determined on both theheat-affected zone of the base metal and the weld metal of thewelding procedure qualification test. Test temperature, energyabsorption, specimen type, and test method
33、shall be the same asspecified for the base material.9.3.1 Coupons Representing the Weld DepositsImpactspecimens shall be located so that the longitudinal axis of thespecimen is at least one fourth of the thickness of the weld testplate, t, from the surface of the test assembly and is transverseto th
34、e longitudinal axis of the weld with the area of the notchlocated in the weld metal. The length of the notch of theCharpy specimen shall be normal to the surface of the weld(see Fig. 1).9.3.2 Coupons Representing the Heat-Affected Zone:9.3.2.1 Impact specimens in test plate thicknesses greaterthan58
35、 in. 16 mm shall be from coupons removed from aTABLE 2 Tensile RequirementsGrade Heat TreatmentA,BTensile Strength,Cmin, ksiMPaYield Strength(0.2 % offset),min, ksi MPaElongation in 2 in.50 mm, min, %Reduction of Area, min, %A1Q QT 65 450 35 240 24 35A2Q QT 70 485 40 275 22 35B2N, B2Q NT/QTD70 485 4
36、0 275 24 35B3N, B3Q NT/QT 70 485 40 275 24 35B4N, B4Q NT/QT 70 485 40 275 24 35C1Q QT 75 515 55 380 22 35D1N1, D1Q1 NT/QT 85 585 55 380 20 35115 795D1N2, D1Q2 NT/QT 95 655 75 515 18 35125 860D1N3, D1Q3 NT/QT 105 725 85 585 15 30135 930E1Q QT 90 620 65 450 22 40E2N1, E2Q1 NT/QT 90 620 70 485 18 35120
37、 825E2N2, E2Q2 NT/QT 105 725 85 585 15 30135 930E2N3, E2Q3 NT/QT 115 795 100 690 13 30145 1000E3N NT 110 760 80 550 15 35AQT = Quenched and tempered.BNT = Normalized and tempered.CMinimum ksi (MPa), unless range is given.DNT/QT indicates that either a normalized and tempered or quenched and tempered
38、 heat treatment may be used.TABLE 3 Charpy V-Notch Energy Requirements for Standard Size (10 mm by 10 mm) SpecimensAGrade Heat TreatmentB,CEffective Section Size,max, in. mmTest Temperature Energy value, ftlbf J,min value for twospecimens and minaverage of threespecimensEnergy Value, ftlbf J,min for
39、 single specimenF CA1Q QT 114 32 50 46 13 17 10 14A2Q QT 3 75 50 46 15 20 12 16B2N, B2Q NT/QTD5 125 100 73 15 20 12 16B3N, B3Q NT/QT 114 32 150 101 15 20 12 16B4N, B4Q NT/QT 114 32 175 115 15 20 12 16C1Q QT 5 125 50 46 15 20 12 16D1N1, D 1Q1 NT/QTEEE E ED1N2, D 1Q2 NT/QTD1N3, D 1Q3 NT/QTE1Q QTE100 7
40、3 30 41 25 34E2N1, E 2Q1 NT-QT 5 125 100 73 30 41 25 34E2N2, E 2Q2 NT-QT 114 32 100 73 20 27 15 20E2N3, E 2Q3 NT/QT 114 32 100 73 15 20 12 16E3N NT 114 32 100 73 20 27 15 20AHardenability and residual elements (primarily P carbon steel; ferritic; investment castings;low temperature service; martensi
41、tic stainless steel; pressurecontaining; stainless steel; steel castingsFIG. 5 Thermal Buffer PadsLongitudinal Axis and Gage Length of Test Specimen Must be Within Cross-Hatched ZoneFIG. 6 Prolongation Test SpecimenLongitudinal Axis and Gage Length of Test Specimen Must Be Within Cross-Hatched ZoneA
42、757/A757M 107SUPPLEMENTARY REQUIREMENTSAlist of standardized supplementary requirements for use at the option of the purchaser is describedin SpecificationA781/A781M andA985/A985M. Those that are considered suitable for use with thisspecification are listed below by title only. Additional supplement
43、ary requirements suitable for usewith this specification at the option of the purchaser are described below. One or more of thesupplementary requirements indicated below may be included in the purchasers order or contract.When so included, a supplementary requirement shall have the same force as if
44、it were in the bodyof the specification. Supplementary requirements details not fully described shall be agreed uponbetween the purchaser and the supplier, but shall not negate any of the requirements in the body ofthe specification.S1. Unspecified ElementsS4. Magnetic Particle ExaminationS5. Radiog
45、raphic ExaminationS8. Lateral Expansion and Percent Shear AreaS8.1 The test temperature, specimen location, and methodof testing shall be as stated in Section 9.S8.2 Lateral Expansion:S8.2.1 Lateral expansion shall be determined and reportedfor information, if no minimum is specified.S8.2.2 The late
46、ral expansion value shall be agreed upon.The value determined shall meet the specified value and shallbe reported to the purchaser.S8.3 Percent Shear Area:S8.3.1 Percent shear area shall be determined and reportedfor information, if no minimum is specified.S8.3.2 The percent shear area value shall b
47、e agreed upon.The value determined shall meet the specified value and shallbe reported to the purchaser.S9. Drop Weight TestS10. Examination of Weld PreparationS12. Prior Approval of Major Weld RepairsS13. Hardness TestS14. Tension Test from Each Heat and Heat-TreatmentChargeS17. Tension Test from C
48、astingsS20. Weld Repair ChartsS21. Heat-Treatment Furnace RecordsS22. Heat TreatmentS51. Magnetic Particle Inspection after Liquid QuenchS51.1 Castings that are liquid quenched shall be examinedby magnetic particle inspection for quench cracks. Examina-tion shall be in accordance with Supplementary RequirementS4.S52. Charpy Impact TestS52.1 Impact properties at temperatures other than specifiedin Table 2, or impact properties for grades that do not havespecified test temperatures or impact values, shall be deter-mined on each heat by testing a set of three Charpy V-notchspecimens. It is prefe
