1、Designation: A291/A291M 17Standard 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 gearsrings, disks, cylinders or rectangular bars hav-ing gear teeth.3.1.2 pinionscircular cross section forgings of multiplediameter with gear teeth on one or more diameters.3.1.3 shaftscircular cross section forgings of one or morediameters which do not have integral gear teeth
10、.4. Ordering Information4.1 Instructions 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.4.2 Supplementary requirements are pro
11、vided 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 preliminary heattreatment as is proper for the design and composition. Theforgings shall be heated to a suitable temperature for asufficient length of
12、 time for austenitization and shall be suitablycooled to bring about complete transformation.5.1.2 Forgings may be immediately treated for mechanicalproperties after preliminary heat treatment or may be roughturned prior to treatment for mechanical properties.1This specification is under the jurisdi
13、ction of ASTM Committee A01 on Steel,Stainless Steel and Related Alloys and is the direct responsibility of SubcommitteeA01.06 on Steel Forgings and Billets.Current edition approved Nov. 1, 2017. Published November 2017. Originallyapproved in 1946. Last previous edition approved in 2016 as A291/A291
14、M 16a.DOI: 10.1520/A0291_A0291M-17.2For 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 sect
15、ion appears at the end of 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
16、 Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.15.2 Heat Treatment for Mechanical PropertiesThe forg-ing shall be reheated to a temperature above the upper criticaltemperature an
17、d held a sufficient length of time for completeaustenitization. Grade 1 shall be air cooled while Grades 2through 9 shall be liquid quenched.5.3 TemperingThe forgings shall be tempered to developthe specified properties. Minimum tempering temperaturesshall be as follows:Minimum Tempering Temperature
18、Grade 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 100 F 55 C per h to 600 F315 C.5.4 Stress ReliefIf the manufacturer elects to heat treat
19、formechanical properties prior to machining, the forgings shall bestress relieved after machining (see 5.5) at a temperature that is50 to 100 F 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 thefurnac
20、e at a maximum rate of 100 F 55 C h to 600 F315 C.5.5 Machining:5.5.1 Rough machining before heat treatment for mechani-cal properties may be performed at the option of the manufac-turer.5.5.2 If the producer elects to heat treat for mechanicalproperties prior to machining, the forgings shall be str
21、essrelieved after machining.5.5.3 BoringForgings, after being heat treated for me-chanical properties and subsequently bored, shall be stressrelieved.6. General Requirements6.1 Unless otherwise specified herein, the requirements ofSpecification A788/A788M shall apply to forgings supplied tothis spec
22、ification.7. Chemical Requirements7.1 The steel shall conform to the requirements for chemicalcomposition prescribed in Table 1.7.2 The limits for elements other than carbon, manganese,phosphorus, sulfur, and silicon in Grade 2 alloy shall be agreedupon between the manufacturer and purchaser.8. Mech
23、anical Requirements8.1 Tensile and Impact Requirements:8.1.1 The 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.8.1.2 ClassificationThe nominal or specified rough-m
24、achined diameter or thickness of solid forgings, disregardinglarge ends, collars and flanges, or the nominal rough-machinedwall thickness of bored forgings shall determine the sizeclassification.8.1.3 Number, Location, and Orientation of Test Specimens:8.1.3.1 At least one tension test specimen eith
25、er 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 specimenshall be taken from each end of the multiple forging. Whenimpact tests are specified in accordance with
26、 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 than 500 lb 225 kg each (rough-machined weight)may be tested in lots; the number of forgings to make up
27、a lotshall be 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 each individualforging or on both ends of the multiple forging if the forgingsare made in multiple. The nomi
28、nal or specified outside rough-machined diameter or thickness of the forgings, disregardinglarge ends, collars and flanges, shall determine the size ofprolongations for test specimens.TABLE 1 Chemical RequirementsElement Composition, %Grade 1 Grade 2 Grade 3 Grade 3A Grades 4 to 7 Grade 8 Grade 9Cla
29、ss 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 0.250.39Manganese 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
30、.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 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.
31、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, silicon maximum shall be 0.10 %.BOptional with manufacturer and purchaser.A291/A291M 1728.1.3.3 The axis of the longitudinal tension test specimenshall be loc
32、ated 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 practicable.8.2 Brinell Hardness:8.2.1 The material shall conform to the requirements for
33、hardness 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.8.2.2 Number and Location of TestsOn each forging 8 in.200 mm and over in diameter,
34、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 forging under 8 in. 200 mm in diameter, twoBrinell hardness tests shall be made,
35、 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, the manufacturermay retreat the forging one or more times, but not more thanthree a
36、dditional 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 Reports11.1 Material test reports as specified in Specification A788/A788M are required and
37、 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 manufacturers name or trademark, the manu-facturers serial number, ASTM designation A291/
38、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 the purchaser.13. Keywords13.1 alloy steel forgings; carbon steel forgings; gear
39、forg-ings; gear shaft forgings; heat-treated; pinion forgingsTABLE 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 JBrinellHardnessNumberRangeOverNotOv
40、er 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.
41、3230. . . 223 - 2624 E .10201020.120120115825825795959590655655620161413.1210403533.3025. . . 248 - 2935 F .10201020.140135130965930905115110105795760725161412.1210403530.3025. . . 285 - 3316 G .10201020.1451401351000965930120115110825795760151412.1210403530.3025. . . 302 - 3527 H .10201020.17016516
42、0137511401105140135130960930905141210.1010353025.2525. . . 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 173SUPPLEMENTARY REQUIREMENTSThe following supplementary requirements shall apply only
43、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 thesequence of manufacturing operations is specified.S2. Impact TestsS2.1 Impact tests shall be made. The specimens shall bemachined and tested w
44、ith minimum properties and test tem-peratures specified as follows.Charpy V-Notch, ftlbf J, 70 to 80 F20 to 25 C minGrade Class Longitudinal 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. Nond
45、estructive 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. PhosphorusS4.1 Phosphorus shall not exceed 0.015 %, and sulfur shallnot exceed 0.018 % for all classe
46、s.S5. Vacuum DegassingS5.1 The molten steel shall be vacuum treated prior to, orduring, pouring of the ingot, to remove objectionable 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
47、 made on the outside surface of that portion of theforging on which teeth will be cut, two tests being made oneach helix 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. H
48、ardness tests shall be performed at the quarter-face width of the tooth portion diameter. On shaft forgings, twohardness tests shall 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
49、the location of the required hardness tests.APPENDIX(Nonmandatory Information)X1. PREVIOUS 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 Cl
