1、Designation: A 788/A 788M 08aAn American National StandardStandard Specification forSteel Forgings, General Requirements1This standard is issued under the fixed designation A 788/A 788M; the number immediately following the designation indicates the yearof original adoption or, in the case of revisi
2、on, 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 Department of Defense.1. Scope*1.1 This specification2c
3、overs 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 A
4、lloy 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/A 291M Steel Forgings, Carbon and Alloy, for Pinions,Gears, and Shafts
5、 for Reduction 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 470
6、M Vacuum-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
7、forGeneral 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 S
8、teel Rolls 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
9、Toughness 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 Sup
10、eralloyForgings 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 Specif
11、ication for Continous Grain FlowForged Carbon and Alloy Steel Crankshaftsfor Medium Speed Diesel EnginesA 1021/A 1021M Martensitic Stainless Steel Forgings andForging Stock for High-Temperature Ser-vice1.2 In case of conflict in requirements, the requirements ofthe individual product specifications
12、shall prevail over 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 nego
13、tiations with the 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 1
14、6)shall reflect 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 specificat
15、ion is under the 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 Nov. 1, 2008. Published November 2008. Originallyapproved in 1984. Last previous edition appro
16、ved in 2008 as A 788/A 788M 08.2For 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, P
17、A 19428-2959, 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 e
18、xact equivalents; 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 t
19、he 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:3A 266/A 266M Specification for Carbon Steel Forgings forPressure Vessel ComponentsA 275/A 275M Practice fo
20、r Magnetic Particle Examinationof 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 S
21、teelForgings 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 Testin
22、gof Steel 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-Trea
23、ted SteelForgings 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-Tr
24、eated Carbon 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 Superstren
25、gth Alloy 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, f
26、or General 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 F
27、orgings 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, f
28、orCarburizing 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 Indus
29、trial UseA 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
30、Specification 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 E
31、nginesA 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 Materia
32、lsE112 Test 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 Fracture3For referenced ASTM standards, visit the A
33、STM 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. The last approved version of this historical standard is referencedon www.astm.org.A 788/A 7
34、88M 08a2Toughness KIcof Metallic MaterialsE 428 Practice for Fabrication and Control of Metal, Otherthan Aluminum, Reference Blocks Used in UltrasonicTestingE 1290 Test Method for Crack-Tip Opening Displacement(CTOD) Fracture Toughness MeasurementE 1820 Test Method for Measurement of Fracture Tough-
35、nessE 1916 Guide for Identification and/or Segregation ofMixed Lots of Metals3. Terminology3.1 Terminology A 941 is applicable to this specification.Additional terms and wording more applicable to forgings areas noted in this section.3.2 Forging Definitions:3.2.1 steel forging, nthe product of a sub
36、stantially com-pressive plastic working operation that consolidates the mate-rial and produces the desired shape. The plastic working maybe performed by a hammer, press, forging machine, or ringrolling machine, and must deform the material to produce anessentially wrought structure.3.2.1.1 Discussio
37、nHot rolling operations may be used toproduce blooms or billets for reforging.3.3 Forging Geometries:3.3.1 bar forging, nforging that has no bore and having anaxial length greater than its maximum cross sectional dimen-sion.3.3.1.1 DiscussionMore than one cross sectional shape orsize may be included
38、. Sometimes referred to as a solid forging.3.3.2 hollow forging, nforging (also known as a shellforging or a mandrel forging) in which (a) the axial length isequal to or greater than the diameter, and (b) the forging lengthand wall thickness are produced by hot working over a mandrel(usually water c
39、ooled) such that the bore diameter remainsessentially the same as that of the mandrel.3.3.2.1 DiscussionUnless a hollow ingot has been used,the starting slug is hot trepanned or punched after upsetting andthe bore diameter adjusted to suit the forging mandrel. Theoutside diameter may be contoured if
40、 required. The workpieceis forged between the upper die and lower dies while themandrel is supported by cranes or manipulators to facilitaterotation.3.3.3 ring forging, ntype of hollow forging in which (a)the axial length is less than the diameter, (b) the wall thicknessis reduced, and (c) the outsi
41、de diameter is increased by hotworking between the top die and a mandrel supported ontemporary saddles.3.3.3.1 DiscussionForging between the top die and themandrel enables the ring diameter to be increased whilereducing the wall thickness, without increasing the axiallength.3.3.4 ring rolling, ninvo
42、lves the use of specialized equip-ment whereby a hot punched, trepanned, or bored disk is (a)hot worked between a powered outer roller and an idling innerroller, such that the wall thickness is reduced and the outsidediameter is increased, and (b) the axial length of the ring is notintended to incre
43、ase and may be contained by a radiallyoriented tapered roller.3.3.5 disk forging, nforging, sometimes referred to as apancake forging, that has (a) an axial length appreciably lessthan its diameter, (b) may be dished on one or both faces, and(c) final forging includes upsetting operations to reduce
44、theheight of the stock and increase its diameter.3.3.5.1 DiscussionSince much of the hot working is donein axially compressing the stock, the central area may notreceive sufficient consolidation. To counter this effect, consid-eration is usually given to the initial saddening (see 3.3.7)ofthe ingot
45、or billet.3.3.6 slab forging, nforging, sometimes referred to as aforged plate, that is usually square or rectangular in shape, witha thickness appreciably smaller than the other dimension. Thehot working may include upsetting.3.3.7 saddening, nterm used in the open die forgingindustry to describe t
46、he initial hot working of an ingot forsurface compaction and flute working surface prior to fullworking of the ingot cross section.3.3.7.1 DiscussionThe term is also extended to initial hotworking intended to give consolidation of ingot central areasprior to upsetting when making products such as tu
47、rbine andgenerator rotors and tube sheets.3.4 billets and blooms, ninterchangeable terms represent-ing hot-worked semi-finished product intended as a startingstock for making forgings.3.4.1 DiscussionNo size limitations are assumed for ei-ther term. Cast shapes produced by a continuous castingproces
48、s, 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.3.5 Definitions of Terms Specific to This Standard:3.5.1 bottom pouring, nsteel from a single heat, or from amultiple
49、 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 sequence froma heat.3.5.2 ingot, nthe product obtained when molten steel,upon being cast into a mold, is subsequently capable of beingwrought in conformance with 3.1. Open-ended molds, whichare usually cooled and used, for example, in the continuouscasting of steel, are considered to be included in this definition.3.5.3 intercritical heat tre
