1、Designation: A983/A983M 06 (Reapproved 2011)1Standard 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
2、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.1NOTEEditorial correction was made in Table 2 in March 2014.1. Scope*1.
3、1 This specification covers continuous grain flow forgedcarbon 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 norm
4、ally made by the forging supplier, unlessotherwise specified 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 Speci
5、fication A788/A788M apply.1.6 Unless the order specifies the 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 th
6、e SI units are shown in brackets. Thevalues stated in each system are not exact equivalents;therefore, 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
7、Methods and Definitions for Mechanical Testingof Steel ProductsA503/A503M Specification for Ultrasonic Examination ofForged CrankshaftsA788/A788M Specification for Steel Forgings, General Re-quirementsA966/A966M Practice for Magnetic Particle Examination ofSteel Forgings Using Alternating CurrentA98
8、6/A986M Specification for Magnetic Particle Examina-tion of 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 Struc
9、tural Welding Code3DIN 50 6024JIS G 0555 Microscopic Testing 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
10、 Choice of chemical composition Grade from Table 2 ifthis purchaser option is exercised (4.1.3).3.4 Whether surface hardening in designated areas isrequired, referencing Supplementary Requirements S10, S11,or S12, and providing the necessary instructions.3.5 For crankshafts designed to include welde
11、d counter-weights the purchaser may specify an alternate welding code toAWS D1.1 Structural Welding Code.3.6 For alternate tensile and hardness test requirementsspecify Supplementary Requirement S2.1This specification is under the jurisdiction of ASTM Committee A01 on Steel,Stainless Steel and Relat
12、ed Alloys and is the direct responsibility of SubcommitteeA01.06 on Steel Forgings and Billets.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-06R11E01.2For referenced ASTM stan
13、dards, 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.3Available from American Welding Society, 550 NW Le Jeune Rd., Miami, FL33126.Availabl
14、e from American Welding Society (AWS), 550 NW LeJeune Rd.,Miami, FL 33126, http:/www.aws.org.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 Or
15、ganization (JSA), 4-1-24Akasaka Minato-Ku, Tokyo, 107-8440, Japan, http:/www.jsa.or.jp.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States14. Materials and Manufacture4.1 Me
16、lting Practice:4.1.1 The steel making section of Specification A788/A788M shall apply together with mandatory vacuum degas-sing.4.1.2 Supplementary Requirement S1 may be used if non-metallic inclusion rating of the steel is required.4.1.3 Unless otherwise specified by the purchaser (3.2), theforging
17、 supplier shall select the chemical composition grade tobe 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 ro
18、lled barwill follow the centerline contour of the main bearings, 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 forgi
19、ng facility. This need not be repeated for othercrankshafts 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 centerlinelongi
20、tudinal section of the main bearing-web-crankpin-web-main 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
21、 Heat Treatment for Mechanical Properties:4.3.1 Heat treatment 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 counter
22、weights are to be attached to the crank-shaft by welding (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 prop
23、erties shall consistof normalizing followed by tempering at a subcriticaltemperature, or austenitizing, liquid quenching and subcriticaltempering. A normalizing cycle may precede the austenitizingstage.4.3.3.1 The minimum tempering temperature shall be1100F 595C.4.3.4 If the crankshaft design includ
24、es attaching counter-weights to the webs by welding, 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-tio
25、n of heat treatment, then the stress relieving temperatureshall 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 t
26、hewebs, then the welding shall be done to a written, 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 hea
27、ttreatment requirements.5. Chemical Composition5.1 Heat AnalysisThe heat analysis obtained after sam-pling in accordance with Specification A788/A788M shallcomply with Table 2 for the chosen grade, and the require-ments agreed upon by Supplementary Requirement S4 if thiswas selected.TABLE 1 Tensile
28、and Hardness RequirementsClass 1 Class 2 Class 3 Class 4 Class 5 Class 6 Class 7Tensile Strength, ksi Mpa min 80 550 100 690 110 760 120 830 130 900 140 965 150 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 62.5
29、mm (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 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 G
30、rade 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 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.
31、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 maxSilicon 0.15-0.40 0.15-0.40 0.15-0.40 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 . . . . . . . . . . . . . . . . . . . . . . .
32、 . 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 . . . 0.10 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 m
33、ax 0.15 max 0.15 maxA983/A983M 06 (2011)126. Mechanical Requirements6.1 Tension Testing:6.1.1 The heat treated forging shall comply with the require-ments of Table 1 for the selected grade when tested inaccordance with this section. See also Test Methods andDefinitions A370. It should be noted that
34、when the SI systemis specified the gauge length for the tension test shall bemeasured over 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 Sampling
35、The longitudinal axis of the axially ori-ented tension 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 Supplem
36、entary Requirement S6 provides for testing ofeach crankshaft 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
37、 both, are specified, one tension testspecimen shall be 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 S
38、ize7.1 The grain size of the forging following heat treatmentshall 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 harden
39、ed indesignated areas for purposes of wear resistance and, 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
40、-ing of the bearing journals), or S11 (full induction hardening 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. Theexam
41、ination shall be in accordance with Test Method A966/A966M.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
42、 is required.10. Workmanship10.1 In addition to the specific 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 certific
43、ation of a crankshaft includes inspectionby a classification 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 A7
44、88/A788M, the purchaser shall notify the producer on any 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, con
45、tinuous grain flow; medium speeddiesel engines; steel forgings; 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 upon
46、by the manufacturer and the purchaser.S1. Nonmetallic Inclusion 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, o
47、r JIS G 0555.S1.2 The acceptance criteria for the nonmetallic 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.A983/A983M 06 (2011)13S2
48、.2 The alternate tensile strength values shall be interpo-lated from the values 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
49、 in Table 1, but shall be in increments of0.05 mm.S3. Machining Before Heat TreatmentS3.1 Forgings shall be rough machined to agreed upondimensions prior to heat treatment for mechanical properties.S4. 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 certi
