1、Designation: A983/A983M 06 (Reapproved 2011)Standard Specification forContinuous Grain Flow Forged Carbon and Alloy SteelCrankshafts for Medium Speed Diesel Engines1This standard is issued under the fixed designation A983/A983M; the number immediately following the designation indicates the yearof o
2、riginal 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.1. Scope*1.1 This specification covers continuous grain flow forgedcarbo
3、n and alloy steel crankshafts for medium speed diesel andnatural gas engines.1.2 The steel used in the manufacture of the forgings isrequired to be vacuum degassed.1.3 The choice of steel composition grade for a givenstrength class is normally made by the forging supplier, unlessotherwise specified
4、by the purchaser.1.4 Provision is made for treatment of designated surfacesof the crankshaft to provide enhanced fatigue strength, or wearresistance, or both.1.5 Except as specifically required in this specification, allprovisions of Specification A788/A788M apply.1.6 Unless the order specifies the
5、applicable “M” specifica-tion designation, the material shall be furnished to the inch-pound units.1.7 The values stated in either inch-pound units or SI(metric) units are to be regarded separately as standard. Withinthe text and tables the SI units are shown in brackets. Thevalues stated in each sy
6、stem are not exact equivalents; there-fore, each system shall be used independently of the other.Combining values from the two systems may result in noncon-formance with the specification.2. Referenced Documents2.1 ASTM Standards:2A370 Test Methods and Definitions for Mechanical Testingof Steel Prod
7、uctsA503/A503M Specification for Ultrasonic Examination ofForged CrankshaftsA788/A788M Specification for Steel Forgings, General Re-quirementsA966/A966M Practice for Magnetic Particle Examinationof Steel Forgings Using Alternating CurrentA986/A986M Specification for Magnetic Particle Examina-tion of
8、 Continuous Grain Flow Crankshaft ForgingsE45 Test Methods for Determining the Inclusion Content ofSteelE112 Test Methods for Determining Average Grain SizeE340 Test Method for Macroetching Metals and Alloys2.2 Other Standards:AWS D1.1 Structural Welding Code3DIN 50 6024JIS G 0555 Microscopic Testin
9、g Method for the Non-Metallic Inclusions in Steel53. Ordering Information3.1 In addition to the ordering requirements of SpecificationA788/A788M, the following items should be included:3.2 Choice of mechanical property class from Table 1.3.3 Choice of chemical composition Grade from Table 2 ifthis p
10、urchaser option is exercised (4.1.3).3.4 Whether surface hardening in designated areas is re-quired, referencing Supplementary Requirements S10, S11, orS12, and providing the necessary instructions.3.5 For crankshafts designed to include welded counter-weights the purchaser may specify an alternate
11、welding code toAWS D1.1 Structural Welding Code.3.6 For alternate tensile and hardness test requirementsspecify Supplementary Requirement S2.4. Materials and Manufacture4.1 Melting Practice:4.1.1 The steel making section of Specification A788/A788M shall apply together with mandatory vacuum degas-si
12、ng.4.1.2 Supplementary Requirement S1 may be used if non-metallic inclusion rating of the steel is required.1This specification 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 Bil
13、lets.Current edition approved April 1, 2011. Published June 2011. Originallyapproved in 1998. Last previous edition approved in 2006 as A983/A983M 06.DOI: 10.1520/A0983_A0983M-06R11.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.o
14、rg. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from American Welding Society, 550 NW Le Jeune Rd., Miami, FL33126.Available from American Welding Society (AWS), 550 NW LeJeune Rd.,Miami, FL 33126, http:/www.aws.org.
15、4Available from Verlag Stahleisen mbh, Postfach 8229, D-4000 Dusseldorf,Germany.5Available from Japanese Standards Association, 1-24 Akasaka 4, Minato-Ku,Tokyo 107, Japan.Available from Japanese Standards Organization (JSA), 4-1-24Akasaka Minato-Ku, Tokyo, 107-8440, Japan, http:/www.jsa.or.jp.1*A Su
16、mmary 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, United States.4.1.3 Unless otherwise specified by the purchaser (3.2), theforging supplier shall select the chemical composition grade tobe
17、 used from Table 2.4.2 Forging:4.2.1 The use of bar from starting stock produced by slittinga rectangular section is not permitted.4.2.2 The procedure used in forging the crankshaft shallensure that the centerline of the starting forged or rolled barwill follow the centerline contour of the main bea
18、rings, webs,and crankpins of the crankshaft.4.2.3 The grain flow present between adjacent main bearingjournals, webs, and the intervening crankpin shall be demon-strated for the first article testing of a new crankshaft design bya given forging facility. This need not be repeated for othercrankshaft
19、s of the same design that differ from the first articlecrankshaft by the number of crankpin throws or, by agreementwith the purchaser, for V-Cylinder configurations of the sameengine. The axial grain flow shown after etching a centerlinelongitudinal section of the main bearing-web-crankpin-web-main
20、bearing section shall be approved by the purchaser.Etching shall be done in accordance with Test Method E340.Using Supplementary Requirement S2, additional grain flowsections may be taken by agreement between the manufacturerand purchaser.4.3 Heat Treatment for Mechanical Properties:4.3.1 Heat treat
21、ment of crankshaft forgings may be doneeither before or after rough machining, at the manufacturersoption. By the use of Supplementary Requirement S3 thepurchaser can specify that heat treatment be done after roughmachining.4.3.2 When counterweights are to be attached to the crank-shaft by welding (
22、see 4.3.4), then the heat treatment formechanical properties shall follow after completion of thewelding. Intermediate post weld heat treatment may be appliedto the assembly at the manufacturers option.4.3.3 Heat treatment for mechanical properties shall consistof normalizing followed by tempering a
23、t a subcritical tempera-ture, or austenitizing, liquid quenching and subcritical temper-ing. A normalizing cycle may precede the austenitizing stage.4.3.3.1 The minimum tempering temperature shall be1100F 595C.4.3.4 If the crankshaft design includes attaching counter-weights to the webs by welding,
24、then the manufacturer shallqualify the weld procedure and welders in accordance with awritten procedure acceptable to the purchaser. The procedureshall incorporate AWS specifications.4.3.5 If forgings receive thermal stress relief after comple-tion of heat treatment, then the stress relieving temper
25、atureshall not exceed (T-50)F (T-30)C where T is the temperingtemperature. If this stress relieving temperature is exceeded,then the mechanical testing required in Section 6 shall berepeated.4.3.6 If crankshaft counterweights are to be welded to thewebs, then the welding shall be done to a written,
26、and qualifiedprocedure conforming to AWS D1.1 Structural Welding Codeor another similar welding code acceptable to the purchaser.This procedure shall contain instructions concerning repair ofcounterweight welds, including preheat and post weld heattreatment requirements.5. Chemical Composition5.1 He
27、at AnalysisThe heat analysis obtained after sam-pling in accordance with Specification A788/A788M shallcomply with Table 2 for the chosen grade, and the requirementsagreed upon by Supplementary Requirement S4 if this wasselected.6. Mechanical Requirements6.1 Tension Testing:6.1.1 The heat treated fo
28、rging shall comply with the require-ments of Table 1 for the selected grade when tested inaccordance with this section. See also Test Methods andTABLE 1 Tensile and Hardness RequirementsClass 1 Class 2 Class 3 Class 4 Class 5 Class 6 Class 7Tensile Strength, ksi Mpa min 80 550 100 690 110 760 120 83
29、0 130 900 140 965 150 1035Yield Strength, (0.2% offset), ksi Mpa min 45 310 70 485 80 550 90 620 100 690 110 760 120 830Elongation, min % in 2 in. (4D) % in 62.5mm (5D)20 18 18 16 18 16 17 15 16 14 15 13 14 12Reduction of Area, % min 45 45 45 45 40 40 40Brinell Hardness, min 163 207 229 248 262 285
30、302Brinell Hardness, max 217 255 269 293 302 331 341TABLE 2 Chemical Requirements Composition %Grade 1 Grade 2 Grade 3 Grade 4 Grade 5 Grade 6 Grade 7 Grade 7A Grade 8 Grade 8ACarbon 0.43-0.53 0.43-0.52 0.28-0.33 0.38-0.48 0.30-0.48 0.35-0.45 0.28-0.35 0.380.48 0.30-0.35 0.380.48Manganese 0.60-1.10
31、0.75-1.10 0.40-1.00 0.75-1.10 0.65-1.00 0.65-1.00 0.40-1.00 0.401.00 0.40-0.80 0.400.80Phosphorous 0.025 max 0.025 max 0.025 max 0.025 max 0.025 max 0.025 max 0.025 max 0.025 max 0.025 max 0.025 maxSulfur 0.025 max 0.025 max 0.025 max 0.025 max 0.025 max 0.025 max 0.025 max 0.025 max 0.025 max 0.025
32、 maxSilicon 0.15-0.40 0.15-0.40 0.15-0.040 0.15-0.40 0.15-0.40 0.15-0.40 0.15-0.40 0.150.40 0.15-0.40 0.150.40Nickel . . . . . . . . . . . . . . . . . . . . . . . . 1.30-1.70 1.301.70Chromium . . . 0.20-0.35 0.80-1.20 0.80-1.20 0.80-1.20 0.80-1.20 2.8-3.3 2.83.3 1.00-1.40 1.001.40Molybdenum . . . 0.
33、10 max 0.15-0.25 0.15-0.25 0.15-0.25 0.30-0.50 0.30-0.50 0.300.50 0.20-0.35 0.200.35Vanadium 0.10 max 0.10 max 0.10 max 0.10 max 0.10 max 0.10 max 0.10 max 0.10 max 0.15 max 0.15 maxA983/A983M 06 (2011)2Definitions A370. It should be noted that when the SI system isspecified the gauge length for the
34、 tension test shall be measuredover a length of 5D.6.1.2 Test MaterialAn integral test prolongation equal indiameter to that of the starting bar diameter shall be providedat one end of each crankshaft subject to mechanical testing.6.1.3 SamplingThe longitudinal axis of the axially ori-ented tension
35、test specimen shall be located at the mid-radiusposition in the integral crankshaft test prolongation. Supple-mentary Requirement S5 provides for a tension test prolonga-tion to be provided at both ends of the heat treated crankshaft,and Supplementary Requirement S6 provides for testing ofeach crank
36、shaft in lieu of the test frequency specified inSupplementary Requirement S5.6.1.4 OrientationLongitudinal tension test specimensshall be taken from the crankshaft prolongation.6.1.5 Number of TestsUnless Supplementary Require-ments S5 or S6, or both, are specified, one tension testspecimen shall be
37、 tested to the requirements of Table 1, for theselected grade, at a frequency of one test per heat treatmentload.6.2 Impact TestingIf Charpy impact testing of the crank-shaft is required, Supplementary Requirement S7 shall bespecified.7. Grain Size7.1 The grain size of the forging following heat tre
38、atmentshall be ASTM 5 or finer when tested at the tension testlocation(s) in accordance with Test Methods E112.8. Surface Hardening8.1 When required by the purchaser, and indicated in thecrankshaft drawing, the crankshaft shall be surface hardened indesignated areas for purposes of wear resistance a
39、nd, when thebearing fillets are included, enhanced fatigue strength.8.2 The method and extent of the surface hardening shall bespecified by the purchaser by including reference to Supple-mentary Requirements S9 (nitriding), S10 (induction harden-ing of the bearing journals), or S11 (full induction h
40、ardening ofbearing journals and fillets).9. Nondestructive Examination9.1 Because ac magnetizing equipment is required to beused, the magnetic particle examination of the crankshaft shallbe done on completion of all machining operations. Theexamination shall be in accordance with Test Method A966/A9
41、66M.9.1.1 Acceptance criteria for the magnetic particle exami-nation shall be in accordance with Specification A986/A986M.9.2 Supplementary Requirement S8 shall be specified ifultrasonic examination of the crankshaft bar or the crankshaftforging is required.10. Workmanship10.1 In addition to the spe
42、cific order or drawing require-ments for surface finish, the general appearance with respect tosoundness and finish shall be consistent with good crankshaftpractice, as determined by ordinary visual inspection.11. Certification11.1 When certification of a crankshaft includes inspectionby a classific
43、ation agency, the manufacturer shall be notified ofthis provision, so that arrangements can be made to allow forwitnessing of such manufacturing and testing operations asneeded.12. Delivery12.1 In addition to the requirements of Specification A788/A788M, the purchaser shall notify the producer on an
44、y specialcorrosion protection and packing instructions. SupplementaryRequirement S12 may be used to call for specific packinginstructions, otherwise the producers normal product protec-tion practices shall apply.13. Keywords13.1 crankshafts, continuous grain flow; medium speeddiesel engines; steel f
45、orgings; surface hardeningSUPPLEMENTARY REQUIREMENTSOne or more of the following supplementary requirements shall apply only when specified by thepurchaser in the inquiry or order. Details of these supplementary requirements shall be agreed uponby the manufacturer and the purchaser.S1. Nonmetallic I
46、nclusion RatingS1.1 The nonmetallic inclusion rating for steel bars orbillets to be used for making CGF crankshafts shall be done inaccordance with an agreed upon practice, or one of thefollowing standards: Test Methods E45Method D, DIN 50602, or JIS G 0555.S1.2 The acceptance criteria for the nonme
47、tallic inclusionrating shall be specified by the purchaser.S2. Alternate Tensile and Hardness RequirementsS2.1 The purchaser shall specify alternate tensile strengthand hardness requirements to those specified in Table 1.S2.2 The alternate tensile strength values shall be interpo-lated from the valu
48、es given in Table 1. For strength levelshigher than Class 7 in Table 1 the requirements shall be agreedbetween the purchaser and the manufacturer.S2.3 The alternate hardness values shall be interpolatedfrom the values given in Table 1, but shall be in increments of0.05 mm.S3. Machining Before Heat T
49、reatmentS3.1 Forgings shall be rough machined to agreed upondimensions prior to heat treatment for mechanical properties.A983/A983M 06 (2011)3S4. Additional Chemical ElementsS4.1 In addition to the elements specified in Table 2 for aspecific grade, additional elements shall be added to the steelwithin ranges agreed upon between manufacturer and pro-ducer.S4.2 The chemical analysis of the modified grade shall bereported as required by the certification section.S5. Mechanical TestingS5.1 For each cranksha
