1、Designation: A 788/A 788M 06An American National StandardStandard Specification forSteel Forgings, General Requirements1This standard is issued under the fixed designationA 788/A 788M; the number immediately following the designation indicates the yearof original adoption or, in the case of revision
2、, 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 specification2co
3、vers a group of common require-ments that, unless otherwise specified in the individual productspecification, shall apply to steel forgings under any of thefollowing specifications issued by ASTM:ASTMDesignation TitleA 266/A 266M Carbon Steel Forgings for Pressure VesselComponentsA 288 Carbon and Al
4、loy Steel Forgings for MagneticRetaining Rings for Turbine GeneratorsA 289/A 289M Alloy Steel Forgings for Nonmagnetic Retain-ing Rings for GeneratorsA 290/A 290M Carbon and Alloy Steel Forgings for Rings forReduction GearsA 291 Steel Forgings, Carbon and Alloy, for Pinions,Gears, and Shafts for Red
5、uction GearsA 336/A 336M Alloy Steel Forgings for Pressure and High-Temperature PartsA 372/A 372M Carbon and Alloy Steel Forgings for Thin-Walled Pressure VesselsA 427 Wrought Alloy Steel Rolls for Cold and HotReductionA 469/A 469M Vacuum-Treated Steel Forgings for GeneratorRotorsA 470/A 470M Vacuum
6、-Treated Carbon and Alloy SteelForgings for Turbine Rotors and ShaftsA 471 Vacuum-Treated Alloy Steel Forgings for Tur-bine Rotor Disks and WheelsA 508/A 508M Quenched and Tempered Vacuum-TreatedCarbon and Alloy Steel Forgings for Pres-sure VesselsA 521 Steel, Closed-Impression Die Forgings forGener
7、al Industrial UseA 541/A 541M Quenched and Tempered Carbon and AlloySteel Forgings for Pressure Vessel Compo-nentsA 579/A 579M Superstrength Alloy Steel ForgingsA 592/A 592M High-Strength Quenched and Tempered Low-Alloy Steel Forged Fittings and Parts forPressure VesselsA 649/A 649M Forged Steel Rol
8、ls Used for Corrugating Pa-per MachineryA 668/A 668M Steel Forgings, Carbon and Alloy, for GeneralIndustrial UseA 723/A 723M Alloy Steel Forgings for High-Strength Pres-sure Component ApplicationA 765/A 765M Carbon Steel and Low-Alloy Steel Pressure-Vessel-Component Forgings with Manda-tory Toughnes
9、s RequirementsA 768/A 768M Vacuum-Treated 12 % Chromium Alloy SteelForgings for Turbine Rotors and ShaftsA 837/A 837M Steel Forgings, Alloy, for Carburizing Applica-tionsA 859/A 859M Age-Hardening Alloy Steel Forgings for Pres-sure Vessel ComponentsA 891 Precipitation Hardening Iron Base SuperalloyF
10、orgings for Turbine Rotor Disks andWheelsA 909 Steel Forgings, Microalloy, for General Indus-trial UseA 940 Vacuum Treated Steel Forgings, Alloy, Differ-entially Heat Treated, for Turbine RotorsA 965/A 965M Steel Forgings, Austenitic, for Pressure andHigh Temperature PartsA 983/A 983M Specification
11、for Continous Grain FlowForged Carbon and Alloy Steel Crankshaftsfor Medium Speed Diesel EnginesA 1021 Martensitic Stainless Steel Forgings andForging Stock for High-Temperature Ser-vice1.2 In case of conflict in requirements, the requirements ofthe individual product specifications shall prevail ov
12、er those ofthis specification.1.3 The purchaser may specify additional requirements (see4.2.3) that do not negate any of the provisions of either thisspecification or of the individual product specifications. Theacceptance of any such additional requirements shall bedependent on negotiations with th
13、e supplier and must beincluded in the order.1.4 If, by agreement, forgings are to be supplied in apartially completed condition, that is, all of the provisions ofthe product specification have not been filled, then the materialmarking (see Section 17) and certification (see Section 16)shall reflect
14、the extent to which the product specificationrequirements have been met.1.5 As noted in the Certification Section (16), the numberand year date of this specification, as well as that of the productspecification, are required to be included in the productcertification.1This specification is under the
15、 jurisdiction of ASTM Committee A01 on Steel,Stainless Steel and Related Alloys and is the direct responsibility of SubcommitteeA01.06 on Steel Forgings and Billets.Current edition approved Sept. 1, 2006. Published September 2006. Originallyapproved in 1984. Last previous edition approved in 2005 as
16、 A 788/A 788M 05c.2For ASME Boiler and Pressure Vessel Code applications, see related Specifi-cation SA788 in Section II of that code.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,
17、 United States.1.6 When the SI version of a product specification isrequired by the purchase order, Specification A 788/A 788Mshall be used.1.7 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 equivale
18、nts; therefore, eachsystem shall be used independently of the other. Combiningvalues from the two systems may result in non-conformancewith the standard.1.8 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of th
19、is 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:3A 266/A 266M Specification for Carbon Steel Forgings forPressure Vessel ComponentsA 275/A 275M Test Method for Magnetic
20、 Particle Exami-nation of Steel ForgingsA 288 Specification for Carbon and Alloy Steel Forgingsfor Magnetic Retaining Rings for Turbine GeneratorsA 289/A 289M Specification for Alloy Steel Forgings forNonmagnetic Retaining Rings for GeneratorsA 290/A 290M Specification for Carbon and Alloy SteelForg
21、ings for Rings for Reduction GearsA 291/A 291M Specification for Steel Forgings, Carbonand Alloy, for Pinions, Gears and Shafts for ReductionGearsA 336/A 336M Specification for Alloy Steel Forgings forPressure and High-Temperature PartsA 370 Test Methods and Definitions for Mechanical Testingof Stee
22、l ProductsA 372/A 372M Specification for Carbon and Alloy SteelForgings for Thin-Walled Pressure VesselsA 388/A 388M Practice for Ultrasonic Examination ofHeavy Steel ForgingsA 427 Specification for Wrought Alloy Steel Rolls for Coldand Hot ReductionA 469/A 469M Specification for Vacuum-Treated Stee
23、lForgings for Generator RotorsA 470/A 470M Specification for Vacuum-Treated Carbonand Alloy Steel Forgings for Turbine Rotors and ShaftsA 471 Specification for Vacuum-Treated Alloy Steel Forg-ings for Turbine Rotor Disks and WheelsA 508/A 508M Specification for Quenched and TemperedVacuum-Treated Ca
24、rbon and Alloy Steel Forgings forPressure VesselsA 521 Specification for Steel, Closed-Impression Die Forg-ings for General Industrial UseA 541/A 541M Specification for Quenched and TemperedCarbon and Alloy Steel Forgings for Pressure VesselComponentsA 579/A 579M Specification for Superstrength Allo
25、y SteelForgingsA 592/A 592M Specification for High-Strength Quenchedand Tempered Low-Alloy Steel Forged Fittings and Partsfor Pressure VesselsA 649/A 649M Specification for Forged Steel Rolls Usedfor Corrugating Paper MachineryA 668/A 668M Specification for Steel Forgings, Carbonand Alloy, for Gener
26、al Industrial UseA 723/A 723M Specification for Alloy Steel Forgings forHigh-Strength Pressure Component ApplicationA 751 Test Methods, Practices, and Terminology forChemical Analysis of Steel ProductsA 765/A 765M Specification for Carbon Steel and Low-Alloy Steel Pressure-Vessel-Component Forgings
27、withMandatory Toughness RequirementsA 768/A 768M Specification for Vacuum-Treated 12 %Chromium Alloy Steel Forgings for Turbine Rotors andShaftsA 833 Practice for Indentation Hardness of Metallic Mate-rials by Comparison Hardness TestersA 837/A 837M Specification for Steel Forgings, Alloy, forCarbur
28、izing ApplicationsA 859/A 859M Specification for Age-Hardening AlloySteel Forgings for Pressure Vessel ComponentsA 891 Specification for Precipitation Hardening Iron BaseSuperalloy Forgings for Turbine Rotor Disks and WheelsA 909 Specification for Steel Forgings, Microalloy, forGeneral Industrial Us
29、eA 939 Practice for Ultrasonic Examination from BoredSurfaces of Cylindrical ForgingsA 940 Specification for Vacuum Treated Steel Forgings,Alloy, Differentially Heat Treated, for Turbine RotorsA 941 Terminology Relating to Steel, Stainless Steel, Re-lated Alloys, and FerroalloysA 965/A 965M Specific
30、ation for Steel Forgings, Austenitic,for Pressure and High Temperature PartsA 966/A 966M Practice for Magnetic Particle Examinationof Steel Forgings Using Alternating CurrentA 983/A 983M Specification for Continuous Grain FlowForged Carbon and Alloy Steel Crankshafts for MediumSpeed Diesel EnginesA
31、991/A 991M Test Method for Conducting TemperatureUniformity Surveys of Furnaces Used to Heat Treat SteelProductsA 1021/A 1021M Specification for Martensitic StainlessSteel Forgings and Forging Stock for High-TemperatureServiceE23 Test Methods for Notched Bar Impact Testing ofMetallic MaterialsE112 T
32、est Methods for Determining Average Grain SizeE 165 Test Method for Liquid Penetrant ExaminationE 380 Practice for Use of the International System of Units(SI) (The Modernized Metric System)4E 399 Test Method for Linear-Elastic Plane-Strain FractureToughness KIcof Metallic Materials3For referenced A
33、STM 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.4Withdrawn.A 788/A 788M 062E 428 Practice for Fabrication and Control of Metal
34、, Otherthan Aluminum Reference, Blocks Used in UltrasonicExaminationE 1290 Test Method for Crack-Tip Opening Displacement(CTOD) Fracture Toughness MeasurementE 1820 Test Method for Measurement of Fracture Tough-nessE 1916 Guide for Identification and/or Segregation ofMixed Lots of Metals3. Terminolo
35、gy3.1 Terminology A 941 is applicable to this specification.Additional terms and wording more applicable to forgings areas noted in this section.3.1.1 Definitions:3.2 steel forgingthe product of a substantially compres-sive plastic working operation that consolidates the materialand produces the des
36、ired shape. The plastic working may beperformed by a hammer, press, forging machine, or ring rollingmachine, and must deform the material to produce an essen-tially wrought structure. Hot rolling operations may be used toproduce blooms or billets for reforging. Forgings may besubdivided into the fol
37、lowing three classes on the basis of theirforging temperatures:3.2.1 coldworked forgingsforgings produced by plasticworking well below the temperature range at which recrystal-lization of the material occurs. Cold-worked forgings must bemade from material previously hot worked by forging orrolling.3
38、.2.2 hot-coldworked forgingsforgings worked at el-evated temperatures slightly below the recrystallization rangeto increase mechanical strength. Hot-cold-worked forgingsmust be made from material previously hot worked by forgingor rolling. A hot-cold-worked forging may be produced in onecontinuous o
39、peration wherein the material is first hot workedand then cold worked by control of the finishing temperature.3.2.3 DiscussionBecause of differences in manufacture,hot-rolled, or hot-rolled and cold-finished bars (semi-finishedor finished), billets, or blooms are not considered to beforgings.3.2.4 h
40、ot-worked forgingsforgings produced by workingat temperatures above the recrystallization temperature for thematerial.3.3 Billets and BloomsInterchangeable terms representinghot-worked semi-finished product intended as a starting stockfor making forgings.3.3.1 DiscussionNo size limitations are assum
41、ed for ei-ther term. Cast shapes produced by a continuous castingprocess, without subsequent work, are considered to be ingotsfor the purposes of this specification, and if supplied as billetsor blooms must carry the descriptor Cast Billet or Cast Bloom.3.4 Definitions of Terms Specific to This Stan
42、dard:3.4.1 bottom pouringsteel from a single heat, or from amultiple heat tapped into a common ladle (see 8.1.1 and 8.1.2),introduced into ingot mold(s) such that they are filled from thebottom up. One or more molds can be set up on an individualplate, and more than one plate may be poured in sequen
43、ce froma heat. The plate is generally constructed such that the moltensteel can be ducted through refractory channels to the bottomof each mold on the plate. The steel is poured into a centralsprue that is high enough to permit filling the ingot molds to therequired level.3.4.2 ingotthe product obta
44、ined when molten steel, uponbeing cast into a mold, is subsequently capable of beingwrought in conformance with 3.1. Open-ended molds, that areusually cooled and used, for example, in the continuous castingof steel, are considered to be included in this definition.3.4.3 intercritical heat treatmentu
45、se of a multi-stage heattreatment procedure in which the material is first austenitized ata temperature above the upper critical temperature (Ac3)followed by cooling below the lower critical temperature(Ac1). The material is then reheated to a temperature in theintercrtical range between the Ac1 and
46、 the Ac3 and againcooled below the Ac1, followed by subcritical tempering in therange specified in the material specification.3.4.3.1 DiscussionThis procedure is generally applicableto low hardenability carbon and low alloy steels that wouldusually have a microstructure of ferrite and pearlite in th
47、e heattreated section size of the component being heat treated.3.4.4 killed steelsteel deoxidized, either by the addition ofstrong deoxidizing agents or by vacuum treatment, to reducethe oxygen content to such a level that essentially no reactionoccurs between carbon and oxygen during solidification
48、3.4.4.1 DiscussionVacuum carbon deoxidation (VCD) isa steelmaking process in which primary deoxidation occursduring vacuum treatment as a result of the carbon-oxygenreaction. In order for primary deoxidation to occur duringvacuum treatment, deoxidizing agents such as aluminum orsilicon are not to be
49、 added to the melt in any significant amountprior to the vacuum treatment operation.3.4.4.2 DiscussionPrecipitation deoxidation is a steel-making process in which primary deoxidation is achieved bythe addition of strong deoxidizing agents, such as aluminum,early in the process, and holding the steel in the molten statefor sufficient time for the products of deoxidation to separatefrom the melt to the slag.3.4.5 sequential or continuous strand castingsteel fromseveral heats poured consecutively into a cooled open-endedmold to form a continuous cast product with a cha
