1、Designation: A291/A291M 05 (Reapproved 2015)Standard Specification forSteel Forgings, Carbon and Alloy, for Pinions, Gears andShafts for Reduction Gears1This standard is issued under the fixed designation A291/A291M; the number immediately following the designation indicates the yearof original adop
2、tion 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. Scope1.1 This specification covers normalized and tempered car-bon steel and quen
3、ched and tempered alloy steel forgings forpinions, gears, and shafts.1.2 Several grades of steel are covered as follows:1.2.1 Grade 1, Class A, is normalized and tempered carbonsteel.1.2.2 Grade 2, Class B, Grade 3, Class C, Grade 3A, ClassD, Grades 4 to 7, Classes E, F, G, and H, Grade 8, Class I,
4、andGrade 9, Class J, are liquid quenched and tempered alloy steel.1.3 All grades and classes are considered weldable underproper conditions. Welding technique is of fundamental impor-tance and it is presupposed that welding procedure andinspection shall be in accordance with approved methods forthe
5、class of material used.1.4 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 equivalents; therefore, eachsystem shall be used independently of the other. Combiningvalues from the two systems may result
6、in non-conformancewith the standard.1.5 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limi
7、tations prior to use.2. Referenced Documents2.1 ASTM Standards:2A275/A275M Practice for Magnetic Particle Examination ofSteel ForgingsA388/A388M Practice for Ultrasonic Examination of SteelForgingsA788/A788M Specification for Steel Forgings, General Re-quirements3. Ordering Information3.1 Instructio
8、ns for purchasing forgings to this specificationshould be in accordance with Specification A788/A788M.Inaddition, a detailed drawing, sketch, or written description ofthe forging should be included with the inquiry or order.3.2 Supplementary requirements are provided and shallapply only when specifi
9、ed in the purchase order.4. Heat Treatment4.1 Preliminary Heat Treatment:4.1.1 The forgings shall be given such preliminary heattreatment as is proper for the design and composition. Theforgings shall be heated to a suitable temperature for asufficient length of time for austenitization and shall be
10、 suitablycooled to bring about complete transformation.4.1.2 Forgings may be immediately treated for mechanicalproperties after preliminary heat treatment or may be roughturned prior to treatment for mechanical properties.4.2 Heat Treatment for Mechanical PropertiesThe forg-ing shall be reheated to
11、a temperature above the upper criticaltemperature and held a sufficient length of time for completeaustenitization. Grade 1 shall be air cooled while Grades 2through 9 shall be liquid quenched.4.3 TemperingThe forgings shall be tempered to developthe specified properties. Minimum tempering temperatu
12、resshall be as follows:Minimum Tempering TemperatureGrade Class F C1 and 2 A and B 1150 6203, 3A, and 4 C, D, and E 1075 5805, 6, 7 F, G, and H 1050 5658 I 1100 5959 J 1000 540The charge shall be cooled under uniform conditions in thefurnace at a maximum rate of 100F 55C per h to 600F315C.4.4 Stress
13、 ReliefIf the manufacturer elects to heat treat formechanical properties prior to machining, the forgings shall be1This 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 a
14、nd Billets.Current edition approved June 1, 2015. Published June 2015. Originallyapproved in 1946. Last previous edition approved in 2010 as A291/A291M 05(2010). DOI: 10.1520/A0291_A0291M-05R15.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at s
15、erviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.*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. Un
16、ited States1stress relieved after machining (see 4.5) at a temperature that is50 to 100F 30 to 55C below the last previous temperingtemperature but in no case below 1000F 540C. Theforgings shall be cooled under uniform conditions in thefurnace at a maximum rate of 100F 55C/h to 600F315C.4.5 Machinin
17、g:4.5.1 Rough machining before heat treatment for mechani-cal properties may be performed at the option of the manufac-turer.4.5.2 If the producer elects to heat treat for mechanicalproperties prior to machining, the forgings shall be stressrelieved after machining.4.5.3 BoringForgings, after being
18、heat treated for me-chanical properties and subsequently bored, shall be stressrelieved.5. General Requirements5.1 Unless otherwise specified herein, the requirements ofSpecification A788/A788M shall apply to forgings supplied tothis specification.6. Chemical Requirements6.1 The steel shall conform
19、to the requirements for chemicalcomposition prescribed in Table 1.6.2 The limits for elements other than carbon, manganese,phosphorus, sulfur, and silicon in Grade 2 alloy shall be agreedupon between the manufacturer and purchaser.7. Mechanical Requirements7.1 Tensile and Impact Requirements:7.1.1 T
20、he material shall conform to the requirements fortensile and impact properties prescribed in Table 2 and impactproperties (see S2) when agreed upon between the purchaserand the supplier.7.1.2 ClassificationThe nominal or specified rough-machined diameter or thickness of solid forgings, disregardingl
21、arge ends, collars and flanges, or the nominal rough-machinedwall thickness of bored forgings shall determine the sizeclassification.7.1.3 Number, Location, and Orientation of Test Specimens:7.1.3.1 At least one tension test specimen either longitudinalor tangential at the option of the manufacturer
22、 shall be takenfrom each forging unless a number of forgings are forged andtreated in multiple, in which case one tension test specimenshall be taken from each end of the multiple forging. Whenimpact tests are specified in accordance with SupplementaryRequirement S2, one set of impact tests shall al
23、so be takenfrom each end of the multiple forging. When agreed uponbetween the manufacturer and the purchaser, forgings weigh-ing less than 500 lb 225 kg each (rough-machined weight)may be tested in lots; the number of forgings to make up a lotshall be by mutual agreement.7.1.3.2 Tension and impact t
24、est specimens shall be takenfrom an extension of the main body of the forging, or from afull-size prolongation left on one end of each individualforging or on both ends of the multiple forging if the forgingsare made in multiple. The nominal or specified outside rough-machined diameter or thickness
25、of the forgings, disregardinglarge ends, collars and flanges, shall determine the size ofprolongations for test specimens.7.1.3.3 The axis of the longitudinal tension test specimenshall be located at any point 114 in. 32 mm below the surfaceof the forging. The axis of the tangential test specimen sh
26、all belocated as near to the surface of the forging as practicable.7.2 Brinell Hardness:7.2.1 The material shall conform to the requirements forhardness as prescribed in Table 2. Brinell hardness tests shallbe made on prepared areas on the forgings after machining tothe sizes ordered by the purchase
27、r and after stress relieving ifstress relieving is required.7.2.2 Number and Location of TestsOn each forging 8 in.200 mm and over in diameter, four Brinell hardness testsshall be made on the outside surface of that portion of theforging on which teeth will be cut, two tests being made oneach helix
28、180 apart and the tests on the two helices shall be90 apart. On each forging under 8 in. 200 mm in diameter,two Brinell hardness tests shall be made, one on each helix180 apart. Hardness tests shall be performed at the quarter-face width of the tooth portion diameter. On shaft forgings, twohardness
29、tests shall be made on each end 180 apart.TABLE 1 Chemical RequirementsElement Composition, %Grade 1 Grade 2 Grade 3 Grade 3A Grades 4 to 7 Grade 8 Grade 9Class A Class B Class C Class DClasses E, F, G,and H Class I Class JCarbon 0.55 max 0.50 max 0.45 max 0.45 max 0.350.50 0.380.45 0.250.39Manganes
30、e 0.600.90 0.400.90 0.400.90 0.400.90 0.400.90 0.400.70 0.200.60Phosphorus, max 0.040 0.040 0.040 0.040 0.040 0.040 0.015Sulfur, max 0.040 0.040 0.040 0.040 0.040 0.040 0.015SiliconA, max 0.35 0.35 0.35 0.35 0.35 0.40 0.35Nickel 0.30 maxB0.50 max 1.003.00 1.65 min 0.30 max 3.254.00Chromium 0.25 maxB
31、1.25 max 1.50 max 0.60 min 1.401.80 1.251.75Molybdenum 0.10 maxB0.15 min 0.15 min 0.200.60 0.300.45 0.300.70Vanadium, max 0.06 0.10 0.05 0.10 0.10 0.03 0.050.15Copper, max 0.35 0.35 0.35 0.35 0.35 0.35 0.35Aluminum . . . . . . . . . . . . . . . 0.851.30 . . .AWhen vacuum carbon deoxidation is used,
32、silicon maximum shall be 0.10 %.BOptional with manufacturer and purchaser.A291/A291M 05 (2015)28. Retreatment8.1 If the results of the mechanical tests of any forging donot conform to the specified requirements, the manufacturermay retreat the forging one or more times, but not more thanthree additi
33、onal times without approval of the purchaser.9. Dimensions and Tolerance9.1 The forgings shall conform to the dimensions andtolerances specified on the purchasers drawing or order.10. Certification and Reports10.1 Material test reports as specified in Specification A788/A788M are required and shall
34、include the final austenitizingand tempering temperatures, holding times, and methods ofcooling.11. Marking, Packaging, and Loading11.1 Each forging shall be legibly stamped by the manufac-turer with the manufacturers name or trademark, the manu-facturers serial number, ASTM designation A291/A291M,f
35、ollowed by the appropriate class number. The purchaser mayindicate the desired location of such identification information.11.2 Packaging and loading shall be done so the forging isnot damaged during shipment to the purchaser.12. Keywords12.1 alloy steel forgings; carbon steel forgings; gear forg-in
36、gs; gear shaft forgings; heat-treated; pinion forgingsSUPPLEMENTARY REQUIREMENTSThe following supplementary requirements shall apply only when specified by the purchaser on theorder and agreed to by the manufacturer.S1. Rough Turning and BoringS1.1 The position of rough turning and boring in thesequ
37、ence of manufacturing operations is specified.S2. Impact TestsS2.1 Impact tests shall be made. The specimens shall bemachined and tested with minimum properties and test tem-peratures specified as follows.Charpy V-Notch, ftlbf J, 70 to 80F20 to 25C minGrade Class Longitudinal Transverse (Tangential)
38、1 A 10 13 8 112 B 10 13 8 113 C 30 40 20 273A D 30 40 20 27TABLE 2 Mechanical PropertiesGrade ClassSize, SolidDiameter orThickness, in.ATensile Strength, minYield Strength, 0.2%Offset, minElongation in 2 in. 50mm, min, %Reduction of Area,min, %CharpyV-notchFtlb JBrinellHardnessNumberRangeOverNotOver
39、 ksi MPa ksi MPaLongi-tudinalTransverse(Tangential)Longi-tudinalTransverse(Tangential)1 A .1010.858058555050453453102220.164537.30. . . 170 - 2232 B .10201020.959595655655655707070485485485202018.1816454538.3430. . . 201 - 2413, 3A C, D .10201020.105105105725725725808080550550550191918.1614454538.32
40、30. . . 223 - 2624 E .10201020.120120115825825795959590655655620161413.1210403533.3025. . . 248 - 2935 F .10201020.140135130965930905115110105795760725161412.1210403530.3025. . . 285 - 3316 G .10201020.1451401351000965930120115110825795760151412.1210403530.3025. . . 302 - 3527 H .10201020.1701651601
41、37511401105140135130960930905141210.1010353025.2525. . . 341 - 4158 I . 10 120 825 85 585 15 . 40 . 255 - 3029 J 20 . . . 170 1175 140 960 10 10 30 30 25 30 352 - 401A10 in. = 250 mm. 20 in. = 500 mm.A291/A291M 05 (2015)3Charpy V-Notch, ftlbf J, 70 to 80F20 to 25C minGrade Class Longitudinal Transve
42、rse (Tangential)4 E 30 40 20 275 F 25 34 15 206 G 25 34 15 207 H 20 27 10 138 I 811 .S3. Nondestructive ExaminationS3.1 Magnetic particle examination may be specified inaccordance with Practice A275/A275M.S3.2 Ultrasonic examination may be specified in accordancewith Practice A388/A388M.S4. Phosphor
43、usS4.1 Phosphorus shall not exceed 0.015 %, and sulfur shallnot exceed 0.018 % for all classes.S5. Vacuum DegassingS5.1 The molten steel shall be vacuum treated prior to, orduring, pouring of the ingot, to remove objectionable gases,particularly hydrogen.APPENDIX(Nonmandatory Information)X1. PREVIOU
44、S CLASSES AND CORRESPONDING CURRENT GRADESPrevious Class Current Grade Current ClassClass 1 Grade 1 Class AClass 2 Grade 2 Class BClass 3 Grade 3 Class CClass 3A Grade 3A Class DClass 4 Grade 4 Class EClass 5 Grade 5 Class FClass 6 Grade 6 Class GClass 7 Grade 7 Class HClass 8 Grade 8 Class IClass 9
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