1、Designation: A757/A757M 15Standard 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 U.S. Depa
3、rtment of Defense.1. Scope*1.1 This specification covers carbon and alloy steel castingsfor pressure-containing and other applications intended primar-ily for petroleum and gas pipelines in areas subject to low-ambient temperatures. Castings shall be heat treated by nor-malizing and tempering or liq
4、uid quenching and tempering.Allclasses are weldable under proper conditions. Hardenability ofsome 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; the
5、refore, 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
6、 thesafety 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:2A488/A488M Practice for
7、Steel Castings, Welding, Qualifi-cations of Procedures and PersonnelA703/A703M Specification for Steel Castings, GeneralRequirements, for Pressure-Containing PartsA985/A985M Specification for Steel Investment CastingsGeneral Requirements, for Pressure-Containing PartsA1067/A1067M Specification for T
8、est Coupons for SteelCastings2.2 American Society of Mechanical Engineers:3ASME Boiler and Pressure Vessel Code2.3 Manufacturers Standardization Society of the Valve andFittings Industry Standards:4MSS SP-55 Quality Standard for Steel Castings for Valves,Flanges, Fittings, and Other Piping Component
9、s - VisualMethod for Evaluation of Surface Irregularities3. Terminology3.1 Definitions:3.1.1 Definitions in Specification A703/A703M are appli-cable to this specification.3.1.2 Definition of nominal thickness, T, applies toquenched and tempered castings with a thickness exceeding 2in. 50 mm. Nominal
10、 thickness, T, is the maximum thicknessof the pressure-containing wall of the casting exclusive ofpadding added for directional solidification, flanges,appendages, and sections designated by the designer as non-critical.4. General Conditions for Delivery4.1 Except for investment castings, castings f
11、urnished tothis specification shall be in accordance with the requirementsof Specification A703/A703M, including any supplementaryrequirements that are indicated in the purchase order. Failure tocomply with the general requirements of Specification A703/A703M constitutes nonconformance with this spe
12、cification. Incase of conflict between the requirements of this specificationand Specification A703/A703M, this specification 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 Subcommitte
13、eA01.18 on Castings.Current edition approved July 1, 2015. Published August 2015. Originallyapproved in 1978. Last previous edition approved in 2010 as A757/A757M 10.DOI: 10.1520/A757_A757M-15.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at se
14、rviceastm.org. For Annual Book of ASTMStandards volume 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
15、 from Manufacturers Standardization Society of the Valve and FittingsIndustry (MSS), 127 Park St., NE, Vienna, VA 22180-4602, http:/www.mss-.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-
16、2959. United States14.2 Steel investment castings furnished to this specificationshall conform to the requirements of Specification A985/A985M, including any supplementary requirements that areindicated in the purchase order. Failure to comply with thegeneral requirements of Specification A985/A985M
17、 consti-tutes nonconformance with this specification. In case of con-flict between the requirements of this specification and Speci-fication A985/A985M, A985/A985M shall prevail.5. Ordering Information5.1 Orders for material to this specification should includethe following, as required, to describe
18、 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 drawingnumber. (Dimensional tolerances and machined surfacesshould be indicated on the casting drawing).5.1.5 Options in the specificat
19、ion,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.6. Materials and Manufacture6.1 Melting ProcessThe steel shall be made by the electricfurnace process or other primary processes
20、approved by thepurchaser. The primary melting may incorporate separatedegassing or refining and may be followed by secondarymelting.6.2 Heat Treatment:6.2.1 All castings shall be heat treated by either normalizingand tempering or quenching and tempering. Tempering tem-perature shall be 1100F 595C mi
21、nimum, 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 to 200F 95Cmaximum before any optional intermediate temper, but shallcool to 100F 40C maximum before the final temper, whichshall b
22、e 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 transfor-mation range directly after pouring and solidification beforethey are reheated for normalizing or liquid quenching.7. Chemi
23、cal 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 castings shall conform to the require-ments as to the tensile properties prescribed in Table 2.9. Impact Requirements9.1 Impact prop
24、erties 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 of theCharpy specimens shall be parallel to the longitudinal axis ofthe tensile bar.TAB
25、LE 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 NickelNickelMolybdenumChromiumMolybdenumNickelChromiumMolybdenumNickelChromiumMolybdenumMartensi
26、ticChromiumNickelCarbon 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 0.025 0.020 0.030Si
27、licon 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 0.50 0.50 0.50 0.50
28、 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 increase of 0.04 % manga
29、nese over the maximum specified will be permitted up to 1.40 %.BTotal residuals includes phosphorus and sulfur.A757/A757M 1529.2 Test temperature and absorbed energy requirements forthe grade shall be as specified in Table 3. Impact properties attemperatures other than specified in Table 3 shall be
30、agreedupon between the manufacturer and the purchaser and Supple-mentary Requirement S8 shall be specified. 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
31、fall below the minimum specified for a singlespecimen. Supplementary Requirement S52 may be specified iflateral 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 t
32、hewelding procedure qualification test. Test temperature, energyabsorption, specimen type, and test method 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 fou
33、rth 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 shall be normal to the surface of the weld(see Fig. 1).9.3.2 C
34、oupons Representing the Heat-Affected Zone:9.3.2.1 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 thickness. Heat-affected zone coupons forimpact specimens shall be t
35、aken transverse to the weld andetched to define the heat-affected zone. The notch shall be cutnormal to the material surface in the heat-affected zone toinclude as much heat-affected zone as possible in the resultingfracture (see Fig. 2).9.3.2.2 Where the material thickness permits, the axis of aspe
36、cimen may be inclined to allow the root of the notch to alignparallel to the fusion line (see Fig. 2).9.4 Test temperature and impact values for section thicknessin excess of those specified in Table 3 may be agreed uponbetween the manufacturer and the purchaser, in which case,Supplementary Requirem
37、ent S8 shall be specified. Castingsshall be marked with this test temperature in accordance with14.1.10. Workmanship, Finish, and Appearance10.1 Castings shall conform to the shapes, tolerances, andsizes indicated by patterns or drawings submitted by thepurchaser.10.2 The castings shall not be peene
38、d, plugged, or impreg-nated to stop leaks or disguise rejectable indications.11. Quality11.1 The surface of the casting shall be examined visuallyand shall be free of adhering sand, scale, cracks, and hot tears.Other surface discontinuities shall meet the visual acceptancestandards specified in the
39、order. Visual Method MSS SP-55 orother visual standards may be used to define acceptable surfacediscontinuities and finish. Unacceptable visual surface discon-tinuities shall be removed and their removal verified by visualexamination of the resultant cavities. When methods involvinghigh temperatures
40、 are used in the removal of discontinuities,the casting shall be preheated to at least the minimumtemperatures in Table 4.TABLE 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,
41、%A1Q QT 65 450 35 240 24 35A2Q QT 70 485 40 275 22 35B2N, B2Q NT/QTD70 485 40 275 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 1
42、5 30135 930E1Q QT 90 620 65 450 22 40E2N1, E2Q1 NT/QT 90 620 70 485 18 35120 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
43、 QT indicates that either a normalized and tempered or quenched and tempered heat treatment may be used.A757/A757M 15311.2 When additional inspection is desired, SupplementaryRequirements S4, S5, and S10 may be ordered.TABLE 3 Charpy V-Notch Energy Requirements for Standard Size (10 mm by 10 mm) Spe
44、cimensAGrade 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 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
45、 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 73 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
46、 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; martensitic stainless steel; pressurecontaining; stainless steel; steel castingsFIG. 5 Thermal Buffer PadsLongitudina
47、l 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 ZoneA757/A757M 157SUPPLEMENTARY REQUIREMENTSAlist of standardized supplementary requirements for use at the option
48、 of the purchaser is describedin Specification A703/A703M. Those that are considered suitable for use with this specification arelisted below by title only. Additional supplementary requirements suitable for use with thisspecification at the option of the purchaser are described below. One or more of the supplementaryrequirements indicated below may be included in the purchasers order or contract. When so included,a supplementary requirement shall have the same force as if it were in the body of the specification.Supplementary requirements details not fully described shall be agreed upon b
