1、Designation: A668/A668M 04 (Reapproved 2009)A668/A668M 13 American Association StateHighway and Transportation Officials StandardAASHTO No.: M 102Standard Specification forSteel Forgings, Carbon and Alloy, for General IndustrialUse1This standard is issued under the fixed designation A668/A668M; the
2、number immediately following the designation 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 () indicates an editorial change since the last revision or reapproval.This
3、standard has been approved for use by agencies of the Department of Defense.1. Scope*1.1 This specification covers untreated and heat-treated carbon and alloy steel forgings for general industrial use. Other ASTMspecifications for forgings are available for specific applications such as pressure ves
4、sels, railroad use, turbine generators, gearing,and others involving special temperature requirements.1.2 Hot-rolled or cold finished bars are not within the scope of this specification.1.3 Six classes of carbon steel and seven classes of alloy steel forgings are listed (see Section 7) , ), which in
5、dicates theirrequired heat treatments, as well as mechanical properties.1.4 Provision, with the suffix H for certification and marking, for the supply of forgings after hardness testing only.1.5 Supplementary requirements, including those in Specification A788/A788M, of an optional nature are provid
6、ed. These shallapply only when specified by the purchaser.1.6 Appendix X1 lists the current classes corresponding to the various classes of Specifications A235, A237, and A243, whichhave been superseded by this specification.1.7 The values stated in either inch-poundSI units or SIinch-pound units ar
7、e to be regarded separately as the standard; withinthe text and tables, the SI units are shown in brackets. The values stated in each system are not exactly equivalent; therefore; maynot be exact equivalents; therefore, each system mustshall be used independently of the other. Combining values from
8、the twosystems may result in nonconformance with the specification. standard.1.8 Unless the order specifies the applicable “M“ specification, the forgings shall be furnished to the inch-pound unitsunits.2. Referenced Documents2.1 ASTM Standards:2A275/A275M Practice for Magnetic Particle Examination
9、of Steel ForgingsA370 Test Methods and Definitions for Mechanical Testing of Steel ProductsA388/A388M Practice for Ultrasonic Examination of Steel ForgingsA788/A788M Specification for Steel Forgings, General RequirementsE290 Test Methods for Bend Testing of Material for DuctilityE381 Method of Macro
10、etch Testing Steel Bars, Billets, Blooms, and Forgings3. Terminology3.1 The terminology section of Specification A788/A788M is applicable to this specification. The terminology section ofSpecification A788/A788M is applicable to this specification.3.2 Definitions of Terms Specific to This Standard:1
11、 This specification is under the jurisdiction ofASTM Committee A01 on Steel, Stainless Steel and RelatedAlloys and is the direct responsibility of Subcommittee A01.06on Steel Forgings and Billets.Current edition approved Oct. 1, 2009June 1, 2013. Published March 2010June 2013. Originally approved in
12、 1972. Last previous edition approved in 20042009 asA668/A668M 04.A668/A668M 04(2009). DOI: 10.1520/A0668_A0668M-04R09.10.1520/A0668_A0668M-13.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvol
13、ume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adeq
14、uately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standardCopyright ASTM
15、International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.2.1 hollow cylindrical forgingclassa forging whose length, as measured on its longitudinal axis is more than its diameter,shall be considered as a hollow cylinder within the scope of this specificati
16、on if it has been lengthened by extrusion or forged ina manner similar to that of a ring, namely, expanded in diameter on a mandrel.description of steel forgings based on heat treatment,mechanical properties and composition.3.2.2 ring-shaped or disk-shaped forgingcontrolling cross section thickness
17、(TC)a forging whose length, as measured on itslongitudinal axis, is less than its diameter or main transverse dimension is considered a ring or disk within the meaning of thisspecification. the diameter of the largest theoretical sphere which can be inscribed within the volume of the forging.3.2.3 T
18、Pdesignates prolongations which have a size other than the controlling cross section thickness (TC).4. Ordering Information and General Requirements4.1 Material supplied to this specification shall conform to the requirements of Specification A788/A788M which outlinesadditional ordering information,
19、 manufacturing requirements, testing and retesting methods and procedures, marking, certification,product analysis variations and additional supplementary requirements.4.1.1 If the requirements of this specification are in conflict with the requirements of Specification A788/A788M, therequirements o
20、f this specification shall prevail.4.2 When this specification is to be applied to an inquiry, contract, or order, the purchaser should furnish the followinginformation:4.2.1 The ordering information required by Specification A788/A788M.,4.2.2 The class of forging desired as listed in Section Table
21、1,4.2.3 Location(s) of areas of significant loading if test specimens are to be located in accordance with 7.1.4.5. ,4.2.4 The options which may be selected as found in 5.3.25.4.2, 6.17.6.3, and 7.37.7, and4.2.5 Any applicable supplementary requirements.5. Materials and Manufacture5.1 DiscardSuffici
22、ent discard shall be made from each ingot to secure freedom from piping and undue segregation.5.2 Forging ProcessProcess:5.2.1 The forging shall be brought as close as practical to finished shape and size by hot mechanical work.5.2.2 Supplementary requirements S2, S14, and S15 may be specified by th
23、e purchaser to satisfy concerns about the utility ofthe proposed forging.5.3 Heat Treatment:5.3.1 All forgings, other than Class A, shall be heat treated. See Section 7.5.3.2 Where options exist within a class, the choice of heat treatment shall be left to the discretion of the manufacturer, unlesst
24、he purchaser specifies one of the available options.6. Chemical Composition6.1 The steel shall conform to the requirements for chemical compositionrequirements prescribed in Table 1.6.2 The choice of chemical composition is left to the discretion of the manufacturer, unless otherwise specified by th
25、e purchaser.See Appendix X2.6.3 Heat Analysis:6.3.1 An analysis of each heat shall be made by the manufacturer.6.4 Product AnalysisAn analysis may be made by the purchaser according to the requirements of Specification A788/A788M.If a standard grade has been used to manufacture the forging the permi
26、ssible variations in composition of SpecificationA788/A788M shall apply. If a non-standard grade of steel has been used, and composition limits have not been supplied, theproduct analysis can be used only to confirm the type of steel supplied.TABLE 1 Chemical RequirementsElements Composition, max, %
27、Classes A to Fand AH to FHClasses G to Nand GH to NHManganese 1.35 .Phosphorus 0.050 0.040Sulfur 0.050 0.040Sulfur 0.025 0.025A668/A668M 1327. Mechanical Properties7.1 Tensile Requirements:7.1.1 The material shall conform to the tensile properties prescribed in Table 2. See Test Methods A370.7.1.2 S
28、ize ClassificationAll ForgingsThe dimensions of the controlling cross section thickness (TC) of the forging at timeof heat treatment determine the size classification mechanical properties to be met within each class (see Table 2): ) except as notedin 7.1.4.2.7.1.2.1 Solid ForgingsEither the as forg
29、ed or rough machined diameter or thickness of solid forgings, disregarding large ends,collars, flanges, and journals, at time of heat treatment shall determine the size classification.TABLE 2 Tensile RequirementsA,BClassSize, Controlling CrossSection (TC),in. mmTensile Strength, minYield Point, Yiel
30、dStrength 0.2 %Offset, minElonga-tion in 2in. or50 mm,min, %Reduc-tion ofArea,min, %BrinellHardness(HBW)Over Not Over psi MPa psi MPaCarbon SteelA (AH) (Untreated) . 20 500 47 000 325 . . . . 183 maxB (BH) (Annealed, or normalized, ornormalized and tempered). 20 500 60 000 415 30 000 205 24 36 12017
31、4C (CH) (Annealed, or normalized, or . 12 300 66 000 455 33 000 230 23 36 137183normalized and tempered) 12 300 20 500 66 000 455 33 000 230 22 34 137183D (DH) (Normalized, annealed, or normalized . 8 200 75 000 515 37 500 260 24 40 149207and tempered) 8 200 12 300 75 000 515 37 500 260 22 35 149207
32、12 300 20 500 75 000 515 37 500 260 20 32 14920720 500 75 000 515 37 500 260 19 30 149207E (EH) (Normalized and tempered or . 8 200 85 000 585 44 000 305 25 40 174217double-normalized and tempered) 8 200 12 300 83 000 570 43 000 295 23 37 17421712 300 20 500 83 000 570 43 000 295 22 35 174217F (FH)
33、(Quenched and tempered, or . 4 100 90 000 620 55 000 380 20 39 187235normalized, quenched and tempered) 4 100 7 175 85 000 585 50 000 345 20 39 1742177 175 10 254 85 000 585 50 000 345 19 37 17421710 250 20 500 82 000 565 48 000 330 19 36 174217Alloy SteelG (GH) (Annealed, or normalized, or . 12 300
34、 80 000 550 50 000 345 24 40 163207normalized and tempered) 12 300 20 500 80 000 550 50 000 345 22 38 163207H (HH) (Normalized and tempered) . 7 175 90 000 620 60 000 415 22 44 1872357 175 10 250 90 000 620 58 000 400 21 42 18723510 250 20 500 90 000 620 58 000 400 18 40 187235J (JH) (Normalized and
35、 tempered, or . 7 175 95 000 655 70 000 485 20 50 197255normalized, quenched, and tempered) 7 175 10 250 90 000 620 65 000 450 20 50 18723510 250 20 500 90 000 620 65 000 450 18 48 207255K (KH) (Normalized, quenched, and tempered) . 7 178 105 000 725 80 000 550 20 50 2122697 175 10 250 100 000 690 7
36、5 000 515 19 50 20726910 250 20 500 100 000 690 75 000 515 18 48 207269L (LH) (Normalized, quenched, and tempered) . 4 100 125 000 860 105 000 725 16 50 2553214 100 7 175 115 000 795 95 000 655 16 45 2353027 175 10 250 110 000 760 85 000 585 16 45 22329310 250 20 500 110 000 760 85 000 585 14 40 223
37、293M (MH) (Normalized, quenched, . 4 100 145 000 1000 120 000 825 15 45 293352and tempered) 4 100 7 175 140 000 965 115 000 790 14 40 2853417 178 10 254 135 000 930 110 000 758 13 40 26933110 250 20 500 135 000 930 110 000 758 12 38 269341N (NH) (Normalized, quenched, and tempered) . 4 100 170 000 1
38、175 140 000 965 13 40 3314014 100 7 175 165 000 1140 135 000 930 12 35 3314017 175 10 250 160 000 1100 130 000 900 11 35 32138810 250 20 500 160 000 1100 130 000 900 11 35 321402A Forgingswithcontrollingcrosssectionthickness(TC)inexcessof20in.508mmforallclassesotherthanclassDmaybecertifiedtoSpecific
39、ationA668/A668Mprovidedthey meet the requirements for controlling cross sections of 20 in. 508 mm listed in Table 2. Alternatively, the manufacturer and purchaser may agree upon the requiredmechanical property values as described in Supplement S9.1.B Requirements presented in Table 2 are to be met a
40、t the test locations given in 7.1.4. Tests from other locations may not exhibit the property values shown in Table 2.A668/A668M 1337.1.2.2 Ring or Hollow Cylinder Forging The size classification shall be determined by its wall thickness or width, whicheveris the smaller dimension of either the as fo
41、rged or rough machined forging at time of heat treatment.7.1.3 Number of TestsUnless the purchaser specifies that forgings shall be furnished in accordance with the requirements of7.3, the number of tension tests performed shall be as follows:7.1.3.1 For all classes of heat-treated forgings with rou
42、gh machined weights as-heat treated weights (excluding testprolongations) less than 5000 lb 2250 kg each, one test shall be made from each size classification represented in each heat ineach annealing or normalizing charge, or from each size classification in each heat in each normalizing or quenchi
43、ng chargerepresented in each tempering charge. For untreated forgings (Class A) weighing less than 5000 lb 2250 kg each, one test fromeach heat shall be made.7.1.3.2 On all classes, for forgings with rough machined weights as-heat treated weights (excluding test prolongations) of 5000lb 2250 kg or m
44、ore, at least one test from each forging shall be made.7.1.3.3 On all classes, for forgings with rough machined weights as-heat treated weights (excluding test prolongations) of 7000lb 3200 kg or more, two tests will be taken: on ring and disk forgings 180 180 apart; on shafts and long hollow cylind
45、ers (over80 in. 2.0 m in length excluding test material), one from each end and offset 180 .180. Shafts and cylinder forgings 80 in. 2.0m or less in length (excluding test material) may have both tests located at one end 180 180 apart.7.1.3.4 When forgings are made in multiple as a single forging, t
46、hat is, forged as one piece and divided after heat treatment,the multiple forging shall be considered as one forging, and the number of tests required shall be as designated in 7.1.3.1, 7.1.3.2,and 7.1.3.3.7.1.4 Prolongations:7.1.4.1 Asufficient number of the forgings shall have prolongations for ex
47、tracting specimens for testing. LocationsExamples oftest specimenslocations for various types of forgings shall be as forging configurations are shown in Fig. 1Figs. 1 and 2.NOTE 1Figures provided demonstrate the concept of controlling cross section thickness (TC) but do not encompass all possible t
48、est prolongationconfigurations which meet the requirements of Section 7.7.1.4.2 The nominal or principal outside rough machine diameter or thickness of the forgings, disregarding large ends, collars,flanges, and journals shall determine the size of the prolongations for test specimens; however, the
49、prolongations on annealed,Forall forgings of non-uniform cross section in classes A, B, C, D, E, G and H: The prolongation(s) may be extensions of sectionsother than the controlling cross section thickness (TC normalized, or normalized), that is TP and tempered TC shafts may beextensions of the small diameter end of . In this case, the dimension of TPthe shaft, as shown in shall
