1、Designation: A 757/A 757M 00 (Reapproved 2004)Standard Specification forSteel Castings, Ferritic and Martensitic, for Pressure-Containing and Other Applications, for Low-TemperatureService1This standard is issued under the fixed designation A 757/A 757M; the number immediately following the designat
2、ion indicates the yearof 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.This standard has been approved for use by ag
3、encies of the Department of Defense.1. Scope1.1 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 te
4、mpering or liquid quenching 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. Within the text, theSI units are shown in bra
5、ckets. The values stated in eachsystem are not exact equivalents; 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 757 and S
6、I units for material ordered toSpecification A 757M.2. Referenced Documents2.1 ASTM Standards:2A 370 Test Methods and Definitions for Mechanical Testingof Steel ProductsA 488/A 488M Practice for Steel Castings, Welding, Quali-fications of Procedures and PersonnelA 703/A 703M Specification for Steel
7、Castings, GeneralRequirements, for Pressure-Containing PartsA 919 Terminology Relating to Heat Treatment of Metals3E 29 Practice for Using Significant Digits in Test Data toDetermine Conformance with SpecificationsE 30 Test Methods for Chemical Analysis of Steel, CastIron, Open-Hearth Iron, and Wrou
8、ght Iron3E 38 Methods for Chemical Analysis of Nickel-Chromiumand Nickel-Chromium-Iron Alloys3E 94 Guide for Radiographic ExaminationE 125 Reference Photographs for Magnetic Particle Indica-tions on Ferrous CastingsE 142 Method for Controlling Quality of RadiographicTesting3E 165 Test Method for Liq
9、uid Penetrant ExaminationE 186 Reference Radiographs for Heavy-Walled (2 to 412-in. 51 to 114-mm) Steel CastingsE 208 Test Method for Conducting Drop-Weight Test toDetermine Nil-Ductility Transition Temperature of FerriticSteelsE 280 Reference Radiographs for Heavy-Walled (412 to12-in. 114 to 305-mm
10、) Steel CastingsE 350 Test Methods for Chemical Analysis of Carbon Steel,Low-Alloy Steel, Silicon Electrical Steel, Ingot Iron, andWrought IronE 353 Test Methods for Chemical Analysis of Stainless,Heat-Resisting, Maraging, and Other Similar Chromium-Nickel-Iron AlloysE 390 Reference Radiographs for
11、Steel Fusion WeldsE 446 Reference Radiographs for Steel Castings up to 2 in.51 mm in ThicknessE 709 Guide for Magnetic Particle Examination2.2 American Society of Mechanical Engineers:4ASME Boiler and Pressure Vessel Code2.3 Manufacturers Standardization Society of the Valve andFittings Industry Sta
12、ndards:5MSS SP-53 Quality Standard for Steel Castings for Valves,Flanges and Fittings, and Other Piping Components (DryPowder Magnetic Particle Inspection Method)MSS SP-54 Quality Standard for Steel Casting for Valves,Flanges and Fittings, and Other Piping Components (Ra-diographic Inspection Method
13、)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 Oct. 1, 2004. Published October 2004. Originallyapproved in 1978. Last previous edition approv
14、ed in 2000 as A 757/A 757M 00.2For 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 onthe ASTM website.3Withdrawn.4Available from Amer
15、ican Society of Mechanical Engineers (ASME), ASMEInternational Headquarters, Three Park Ave., New York, NY 10016-5990.5Available from Manufacturers Standardization Society of the Valve and FittingsIndustry (MSS), 127 Park St., NE, Vienna, VA 22180-4602.1Copyright ASTM International, 100 Barr Harbor
16、Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.MSS SP-55 Quality Standard for Steel Castings for Valves,Flanges and Fittings, and Other Piping Components (Vi-sual Method)3. Terminology3.1 Definitions:3.1.1 Definitions in Test Methods and Definitions A 370 andTerminology A 919 ar
17、e applicable to this specification.3.1.2 Definition 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 solidifi
18、cation, flanges, append-ages, and sections designated by the designer as noncritical.4. Ordering Information4.1 Orders for material to this specification should includethe following, as required, to describe the material adequately:4.1.1 Description of the casting by pattern number ordrawing (dimens
19、ional tolerances shall be included on thecasting drawing),4.1.2 Grade,4.1.3 Options in the specification,4.1.4 Detailed drawing, including areas that are suitable formarking, the proposed nondestructive testing techniques andareas to be so tested, and the test dimension, T (see 3.1.2), and4.1.5 Supp
20、lementary requirements desired, if any, includingstandards of acceptance.5. Materials and Manufacture5.1 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
21、may be followed by secondarymelting.5.2 Heat Treatment:5.2.1 All castings 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.5.2.2 E3N castings
22、 shall be heat treated by heating to1850F 1010C minimum, and air cooling 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.5.2.3 Furnace temperatures for heat treating shall be con-
23、trolled by pyrometers.5.2.4 Castings shall be allowed to cool below the transfor-mation range directly after pouring and solidification beforethey are reheated for normalizing or liquid quenching.6. Chemical Composition6.1 Heat AnalysisAn analysis of each heat shall be madeby the manufacturer to det
24、ermine the percentages of theelements specified in Table 1. The analysis shall be made froma test sample preferably taken during the pouring of the heat.When drillings are used, they shall be taken not less than14 in.6.4 mm beneath the surface. The chemical composition thusdetermined shall be report
25、ed to the purchaser or his represen-tative, and shall conform to the requirements specified in Table1 for the grade being poured.6.2 Product AnalysisA product analysis may be made bythe purchaser from material representing each heat, lot, orTABLE 1 Chemical Requirements (Maximum Percent Unless Range
26、 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 NickelNickelMolybdenumChromiumMolybdenumNickelChromiumMolybdenumNickelChromiumMolybdenumMartensiticChromiumNickelCarbon 0.30 0.25A0.25 0.15 0.15 0.25 0.
27、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 0.025 0.020 0.030Silicon 0.60 0.60 0.60 0.60 0.60 0.60 0.60 0.60 0.60 1.00N
28、ickel 2.0/3.0 3.0/4.0 4.0/5.0 1.5/2.0 2.5/3.5 2.75/3.90 3.5/4.5Chromium 2.0/2.75 1.35/1.85 1.50/2.0 11.5/14.0Molybdenum 0.15/0.30 0.90/1.20 0.35/0.60 0.40/0.60 0.40/1.0Specified ResidualElements:Vanadium 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 Copper 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50
29、 0.50Nickel 0.50 0.50 0.50 Chromium 0.40 0.40 0.40 0.40 0.40 0.40 Molybdenum 0.25 0.25 0.25 0.25 0.25 Tungsten 0.10 0.10 0.10Totalresiduals (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 increase of 0.04 % mangane
30、se over the maximum specified will be permitted up to 1.40 %.BTotal residuals includes phosphorus and sulfur.A 757/A 757M 00 (2004)2casting. The analysis shall be made on representative material.Due to the possibility of decarburization, samples for carbonanalysis shall be taken no closer than14 in.
31、 6.4 mm to a castsurface, except that castings too thin for this shall be analyzedon representative material. When a product analysis is per-formed, the chemical composition thus determined may varyfrom the specified limits in Table 1 by the amounts shown inTable 2. When the analysis exceeds the per
32、mitted variancespecified in Table 2, the material shall be subject to rejection bythe purchaser.6.3 Referee AnalysisTest Methods E 350 or E 353 shall beused for referee purposes. Test Methods E 30 or E 38 shall beused if Test Methods E 350 or E 353 do not include a methodfor some element present in
33、the material. When a comparisonis made between the heat analysis and the referee analysis, thereproducibility data, R 2, in the precision statement of TestMethods E 350 or E 353 shall be used as a guide.6.4 RoundingChemical analysis results shall be rounded,in accordance with Practice E 29, to the n
34、earest unit in the lastright-hand place of values in the table of chemical require-ments.7. Tensile Requirements7.1 One tension test shall be made from each heat. Themechanical properties thus determined shall conform to therequirements specified in Table 3. The bar from which thetension specimen is
35、 machined shall be in accordance withSection 12.7.2 Tension test specimens shall be machined to the formand dimensions shown in Fig. 2 of Test Methods and Defini-tions A 370 and tested in accordance with Test Methods andDefinitions A 370.7.3 If a specimen is machined improperly or flaws arerevealed,
36、 the specimen may be discarded and another substi-tuted from the same heat.7.4 To determine conformance with the tension test require-ments, an observed value or calculated value shall be roundedoff in accordance with Practice E 29 to the nearest 500 psi 5MPa for yield and tensile strengths and to t
37、he nearest 1 % forelongation and reduction of area.8. Impact Requirements8.1 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 inaccordance with Section 12. The longitudinal axis
38、 of theCharpy specimens shall be parallel to the longitudinal axis ofthe tensile bar. Testing shall be in accordance with TestMethods and Definitions A 370 using the Charpy V-notch TypeA specimen.8.2 Test temperature and absorbed energy requirements forthe grade shall be as specified in Table 4, exc
39、ept for thosegrades that have no values specified, in which case, impactenergy values and test temperatures shall be agreed uponbetween the manufacturer and the purchaser. The averageenergy value of three specimens shall not be less than theminimum average specified, with only one value permittedbel
40、ow the minimum average specified and this value notpermitted to fall below the minimum specified for a singlespecimen. Supplementary Requirement S8 may be specified iflateral expansion or percent shear area, or both, are desired bythe purchaser.8.3 Impact properties shall also be determined on both
41、theheat-affected zone of the base metal and the weld metal of thewelding procedure qualification test. Test temperature, energyabsorption, specimen type, and test method shall be the same asspecified for the base material.8.3.1 Coupons Representing the Weld DepositsImpactspecimens shall be located s
42、o 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 the longitudinal axis of the weld with the area of the notchlocated in the weld metal. The length of the notch of theCharpy specimen
43、 shall be normal to the surface of the weld(see Fig. 1).8.3.2 Coupons Representing the Heat-Affected Zone:8.3.2.1 Impact specimens in test plate thicknesses greaterthan58 in. 16 mm shall be from coupons removed from alocation as near as practical to a point midway between thesurface and center thick
44、ness. Heat-affected zone coupons forimpact specimens shall be taken transverse to the weld andetched to define the heat-affected zone. The notch shall be cutTABLE 2 Product Analysis TolerancesElement Range,A% TolerancesB,COver Maximum or Under MinimumLimit, %C up to 0.65above 0.650.03 3 %CL+ 0.020.0
45、4Mn up to 1above 10.08 3 %MnL+ 0.010.09Si up to 0.60above 0.600.22 3 %SiL 0.010.15P all 0.13 3 %PL+ 0.005S all 0.36 3 %SL+ 0.001Ni up to 2above 20.10 3 %NiL+ 0.030.25Cr up to 2above 20.07 3 %CrL+ 0.040.18Mo up to 0.6above 0.60.04 3 %MoL+ 0.030.06V up to 0.25above 0.250.23 3 %VL+ 0.0040.06W up to 0.1
46、0above 0.100.08 3 %WL+ 0.020.02Cu up to 0.15above 0.150.18 3 %CuL+ 0.020.05A1 up to 0.10above 0.100.08 3 %AlL+ 0.020.03AThe range denotes the composition limits up to which tolerances are computedby the equation and above which the tolerances are given by a constant.BThe subscript L for the elements
47、 in each equation indicates that the limits ofthe element specified by the applicable specification are to be inserted into theequation to calculate the tolerance for the upper limit and the lower limit (ifapplicable), respectively. Examples of computing tolerances are presented in theFootnote C bel
48、ow.CTo illustrate, consider the manganese limits 0.50 to 0.80 % of E 1Q. Accordingto Table 4, the maximum permissible deviation of a product analysis below thelower limit 0.50 is 0.05 % = (0.08 3 0.50 + 0.01). The lowest acceptable productanalysis of E 1Q, therefore, is 0.45 %. Similarly, the maximu
49、m permissibledeviation above the upper limit of 0.80 % is 0.074 % = (0.08 3 0.80 + 0.01). Thehighest acceptable product analysis of E 1Q, therefore, is 0.874 %. For A 2Q, themaximum manganese content is 1.40 % if the carbon content is 0.20 % or lower.In this case, the highest acceptable product analysis is 1.49 % = (1.40 + 0.09).A 757/A 757M 00 (2004)3normal to the material surface in the heat-affected zone toinclude as much heat-affected zone as possible in the resultingfrac
