1、Designation: A291/A291M 18Standard 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 adoption or, in the ca
2、se 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 normalized and tempered car-bon steel and quenched and tempered
3、 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, andGrade 9, Class
4、 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 class of material
5、 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 in non-conformanc
6、ewith 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, health, and environmental practices and deter-mine the applicability of regulatory limit
7、ations prior to use.1.6 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization
8、TechnicalBarriers to Trade (TBT) Committee.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. Terminology3
9、.1 Definitions:3.1.1 controlling cross section thickness (TC)the diameterof the largest theoretical sphere which can be inscribed withinthe volume of the forging.3.1.2 gearsrings, disks, cylinders or rectangular bars hav-ing gear teeth.3.1.3 pinionscircular cross section forgings of multiplediameter
10、 with gear teeth on one or more diameters.3.1.4 shaftscircular cross section forgings of one or morediameters which do not have integral gear teeth.4. Ordering Information4.1 Instructions for purchasing forgings to this specificationshould be in accordance with Specification A788/A788M.Inaddition, a
11、 detailed drawing, sketch, or written description ofthe forging should be included with the inquiry or order.4.2 Supplementary requirements are provided and shallapply only when specified in the purchase order.5. Heat Treatment5.1 Preliminary Heat Treatment:5.1.1 The forgings shall be given such pre
12、liminary 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 suitablycooled to bring about complete transformation.1This specification is under the jurisdiction of ASTM Commit
13、tee A01 on Steel,Stainless Steel and Related Alloys and is the direct responsibility of SubcommitteeA01.06 on Steel Forgings and Billets.Current edition approved June 1, 2018. Published June 2018. Originallyapproved in 1946. Last previous edition approved in 2017 as A291/A291M 17.DOI: 10.1520/A0291_
14、A0291M-18.2For referenced ASTM standards, 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.*A Summary of Changes section appears at the end of
15、 this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelo
16、pment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.15.1.2 Forgings may be immediately treated for mechanicalproperties after preliminary heat treatment or they may bepreliminarily machined prior to treatment
17、 for mechanicalproperties.5.2 Heat Treatment for Mechanical PropertiesThe forg-ing shall be reheated to 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.5.3
18、 TemperingThe forgings shall be tempered to developthe specified properties. Minimum tempering temperaturesshall 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
19、cooled under uniform conditions in thefurnace at a maximum rate of 100 F 55 C per h to 600 F315 C.5.4 Stress ReliefIf the manufacturer elects to heat treat formechanical properties prior to machining, the forgings shall bestress relieved after machining (see 5.5) at a temperature that is50 to 100 F
20、30 to 55 C below the last previous temperingtemperature but in no case below 1000 F 540 C. Theforgings shall be cooled under uniform conditions in thefurnace at a maximum rate of 100 F 55 C h to 600 F315 C.5.5 Machining:5.5.1 Machining before heat treatment for mechanical prop-erties may be performe
21、d at the option of the manufacturer.5.5.2 If the producer elects to heat treat for mechanicalproperties prior to machining, the forgings shall be stressrelieved after machining.5.5.3 BoringForgings, after being heat treated for me-chanical properties and subsequently bored, shall be stressrelieved.6
22、. General Requirements6.1 Unless otherwise specified herein, the requirements ofSpecification A788/A788M shall apply to forgings supplied tothis specification.7. Chemical Requirements7.1 The steel shall conform to the requirements for chemicalcomposition prescribed in Table 1.7.2 The limits for elem
23、ents other than carbon, manganese,phosphorus, sulfur, and silicon in Grade 2 alloy shall be agreedupon between the manufacturer and purchaser.8. Mechanical Requirements8.1 Tensile and Impact Requirements:8.1.1 The material shall conform to the requirements fortensile and impact properties prescribed
24、 in Table 2 and impactproperties (see S2) when agreed upon between the purchaserand the supplier.8.1.2 ClassificationThe dimensions of the controllingcross section thickness (TC) of the forging at the time of heattreatment determine the mechanical properties to be met withineach class (see Table 2).
25、8.1.3 Number, Location, and Orientation of Test Specimens:8.1.3.1 At least one tension test specimen either longitudinalor tangential at the option of the manufacturer shall be takenfrom each forging unless a number of forgings are forged andtreated in multiple, in which case one tension test specim
26、enshall be taken from each end of the multiple forging. Whenimpact tests are specified in accordance with SupplementaryRequirement S2, one set of impact tests shall also be takenfrom each end of the multiple forging. When agreed uponbetween the manufacturer and the purchaser, forgings weigh-ing less
27、 than 500 lb 225 kg each at time of heat treatment maybe tested in lots; the number of forgings to make up a lot shallbe by mutual agreement.8.1.3.2 Tension and impact test specimens shall be takenfrom an extension of the main body of the forging, or from afull-size prolongation left on one end of e
28、ach individualforging or on both ends of the multiple forging if the forgingsTABLE 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
29、 0.350.50 0.380.45 0.250.39Manganese 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
30、0.30 max 3.254.00Chromium 0.25 maxB1.25 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
31、vacuum carbon deoxidation is used, silicon maximum shall be 0.10 %.BOptional with manufacturer and purchaser.A291/A291M 182are made in multiple. The dimensions of the controlling crosssection thickness (TC) of the forging at the time of heattreatment shall determine the size of prolongations for tes
32、tspecimens.8.1.3.3 The axis of the longitudinal tension test specimenshall be located at any point 114 in. 32 mm below the surfaceof the forging or mid-radius if 5 in. 127 mm diameter andunder. The axis of the tangential test specimen shall be locatedas near to the surface of the forging as practica
33、ble.8.2 Brinell Hardness:8.2.1 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 purchaser and after stress relieving ifstress relieving is required.8.2
34、.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 end 180 apart and the tests on the two ends shall be 90apart. On each
35、 forging under 8 in. 200 mm in diameter, twoBrinell hardness tests shall be made, one on each end 180apart. On shaft forgings, two hardness tests shall be made oneach end 180 apart.9. Retreatment9.1 If the results of the mechanical tests of any forging donot conform to the specified requirements, th
36、e manufacturermay retreat the forging one or more times, but not more thanthree additional times without approval of the purchaser.10. Dimensions and Tolerance10.1 The forgings shall conform to the dimensions andtolerances specified on the purchasers drawing or order.11. Certification and Reports11.
37、1 Material test reports as specified in Specification A788/A788M are required and shall include the final austenitizingand tempering temperatures, holding times, and methods ofcooling.12. Marking, Packaging, and Loading12.1 Each forging shall be legibly stamped by the manufac-turer with the manufact
38、urers name or trademark, the manu-facturers serial number, ASTM designation A291/A291M,followed by the appropriate class number. The purchaser mayindicate the desired location of such identification information.12.2 Packaging and loading shall be done so the forging isnot damaged during shipment to
39、the purchaser.13. Keywords13.1 alloy steel forgings; carbon steel forgings; gear forg-ings; gear shaft forgings; heat-treated; pinion forgingsTABLE 2 Mechanical PropertiesGrade ClassSize, SolidDiameter orThickness, in.ATensile Strength, minYield Strength, 0.2%Offset, minBElongation in 2 in. 50mm, mi
40、n, %Reduction of Area,min, %CharpyV-notchFtlb JBrinellHardnessNumberRangeOverNotOver ksi MPa ksi MPaLongi-tudinalTransverse(Tangential)Longi-tudinalTransverse(Tangential)1 A .1010.858058555050453453102220.164537.30. . . 170 - 2232 B .10201020.959595655655655707070485485485202018.1816454538.3430. . .
41、 201 - 2413, 3A C, D .10201020.105105105725725725808080550550550191918.1614454538.3230. . . 223 - 2624 E .10201020.120120115825825795959590655655620161413.1210403533.3025. . . 248 - 2935 F .10201020.140135130965930905115110105795760725161412.1210403530.3025. . . 285 - 3316 G .10201020.14514013510009
42、65930120115110825795760151412.1210403530.3025. . . 302 - 3527 H .10201020.170165160137511401105140135130960930905141210.1010353025.2525. . . 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.BFor Grade 1, th
43、e yield point may be reported in lieu of the 0.2 % offset yield strength.A291/A291M 183SUPPLEMENTARY 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 ro
44、ugh turning and boring in thesequence 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 80 F20 to 25 C minGrade Class L
45、ongitudinal Transverse (Tangential)1 A 10 13 8 112 B 10 13 8 113 C 30 40 20 273A D 30 40 20 274 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 e
46、xamination may be specified in accordancewith Practice A388/A388M.S4. PhosphorusS4.1 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 objection
47、able gases,particularly hydrogen.S6. Hardness TestingS6.1 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 180 apar
48、t 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 tests sh
49、all be made on each end 180 apart. When thissupplement is required, the purchaser shall supply detaileddrawings indicating the location of gear teeth, the helix angle,and the location of the required hardness tests.APPENDIX(Nonmandatory Information)X1. PREVIOUS CLASSES AND CORRESPONDING CURRENT GRADESPrevious Class Current Grade Current ClassClass 1 G
