1、Designation: A 291/A 291M 05Standard Specification forSteel Forgings, Carbon and Alloy, for Pinions, Gears andShafts for Reduction Gears1This standard is issued under the fixed designation A 291/A 291M; the number immediately following the designation indicates the yearof original adoption or, in th
2、e case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval.A superscript epsilon (e) 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 tem
3、pered 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,
4、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 class of mat
5、erial 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-confo
6、rmancewith 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 limitations prio
7、r to use.2. Referenced Documents2.1 ASTM Standards:A 275/A 275M Test Method for Magnetic Particle Exami-nation of Steel Forgings2A 388/A 388M Practice for Ultrasonic Examination ofHeavy Steel Forgings2A 788 Specification for Steel Forgings, General Require-ments23. Ordering Information3.1 Instructio
8、ns for purchasing forgings to this specificationshould be in accordance with Specification A 788. In addition,a detailed drawing, sketch, or written description of the forgingshould be included with the inquiry or order.3.2 Supplementary requirements are provided and shallapply only when specified i
9、n 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 sui
10、tablycooled 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 a te
11、mperature 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 temperaturess
12、hall 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 Rel
13、iefIf the manufacturer elects to heat treat formechanical properties prior to machining, the forgings shall bestress relieved after machining (see 4.5) at a temperature that is50 to 100F 30 to 55C below the last previous tempering1This specification is under the jurisdiction of ASTM Committee A01 on
14、 Steel,Stainless Steel and Related Alloys, and is the direct responsibility of SubcommitteeA01.06 on Steel Forgings and Billets.Current edition approved Sept. 1, 2005. Published September 2005. Originallyapproved in 1946. Last previous edition approved in 2003 as A 291 03.2For referenced ASTM standa
15、rds, 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.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM Intern
16、ational, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.temperature 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 Machining:4.5.1 Rough machining before heat tre
17、atment 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 heat treated for me-chanical properties
18、 and subsequently bored, shall be stressrelieved.5. General Requirements5.1 Unless otherwise specified herein, the requirements ofSpecification A 788 shall apply to forgings supplied to thisspecification.6. Chemical Requirements6.1 The steel shall conform to the requirements for chemicalcomposition
19、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 The material shall conform to the requirement
20、s 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, disregardinglarge ends, collars and flanges, or the nomin
21、al 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 shall be takenfrom each forging unless a nu
22、mber 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 also be takenfrom each end of the multiple for
23、ging. 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 test specimens shall be takenfrom an extensio
24、n 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 of the forgings, disregardinglarge ends, col
25、lars 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 shall belocated as near to the surface of the
26、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 purchaser and after stress relieving ifstress reliev
27、ing 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 180 apart and the tests on the two helices s
28、hall 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 shall be made on each end 180 apart.8.
29、 Retreatment8.1 If the results of the mechanical tests of any forging donot conform to the specified requirements, the manufacturerTABLE 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 Cla
30、ss 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 0.040 0.040 0.015SiliconA, max 0.35 0.35 0.35 0.35 0.3
31、5 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 0.050.15Copper, max 0.35 0.35 0.35 0.35 0.35 0.35 0.35Alumi
32、num . . . . . . . . . . . . . . . 0.851.30 . . .AWhen vacuum carbon deoxidation is used, silicon maximum shall be 0.10 %.BOptional with manufacturer and purchaser.A 291/A 291M 052may retreat the forging one or more times, but not more thanthree additional times without approval of the purchaser.9. D
33、imensions 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 SpecificationA 788are required and shall include the final austenitizing andtempering temperature
34、s, holding times, and methods of cool-ing.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 A 291, followedby the appropriate class number. The purchaser may
35、indicatethe 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-ings; gear shaft forgings; heat-treated; pinion forgingsSUPPL
36、EMENTARY 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 thesequence of manufacturing operations is specified.S2. Impact Te
37、stsS2.1 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)1 A 10 13 8 112 B 10 13 8 113 C 30 40 20 273A D 30 40 20 27
38、TABLE 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 ksi MPa ksi MPaLongi-tudinalTransverse(Tangential)Longi-tu
39、dinalTransverse(Tangential)1 A .1010.858058555050453453102220.164537.30. . . 170 - 2232 B .10201020.959595655655655707070485485485202018.1816454538.3430. . . 201 - 2413, 3A C, D .10201020.105105105725725725808080550550550191918.1614454538.3230. . . 223 - 2624 E .10201020.1201201158258257959595906556
40、55620161413.1210403533.3025. . . 248 - 2935 F .10201020.140135130965930905115110105795760725161412.1210403530.3025. . . 285 - 3316 G .10201020.1451401351000965930120115110825795760151412.1210403530.3025. . . 302 - 3527 H .10201020.170165160137511401105140135130960930905141210.1010353025.2525. . . 34
41、1 - 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.A 291/A 291M 053Charpy V-Notch, ftlbf J, 70 to 80F20 to 25C minGrade Class Longitudinal Transverse (Tangential)4 E 30 40 20 275 F 25 34 15 206 G 25 34 15 207 H
42、 20 27 10 138 I 811 .S3. Nondestructive ExaminationS3.1 Magnetic particle examination may be specified inaccordance with Test Method A 275/A 275M.S3.2 Ultrasonic examination may be specified in accordancewith Practice A 388/A 388M.S4. PhosphorusS4.1 Phosphorus shall not exceed 0.015 %, and sulfur sh
43、allnot 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. PREVIOUS CLASSES AND CORRESPONDING CURRENT GRADESPrevious Class
44、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 Grade 9 Class JSUMMARY OF CHANGESCommitteeA01 has identi
45、fied the location of selected changes to this standard since the last issue (A 291 02)that may impact the use of this standard (approved Apr. 10, 2003).(1) Converted standard to dual unit formatASTM International takes no position respecting the validity of any patent rights asserted in connection w
46、ith any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible tec
47、hnical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful considera
48、tion at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr H
49、arbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).A 291/A 291M 054
