1、Designation: A 909/A 909M 06Standard Specification forSteel Forgings, Microalloy, for General Industrial Use1This standard is issued under the fixed designation A 909/A 909M; the number immediately following the designation indicates the yearof original adoption or, in the case of revision, the year
2、 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 wrought, microalloyed carbonsteel forgings for industrial use. Microalloyed steels dev
3、eloptheir properties by the addition of small amounts of microal-loying elements such as vanadium, columbium, titanium, ormolybdenum. The properties may be influenced also by controlof the hot working process and temperature and by control ofthe subsequent cooling rate.1.2 The forgings shall be furn
4、ished to chemical compositionand mechanical property requirements as specified herein.Chemical composition is based on standard carbon steel gradesmodified to include microalloying elements. Strength level isspecified based on desired mechanical properties in the forg-ings. Depending on the forging
5、process, different strengthclasses may be attainable from a single chemical composition.Conversely, mechanical properties of a given strength classmay be achieved using different chemical compositions. Themanufacturer should be consulted if development of chemicalcomposition is necessary.1.3 For the
6、 purpose of this specification, forgings withmaximum section thickness of 4 in. 100 mm are to beconsidered.1.4 Supplementary Requirements S1 to S8 are provided foruse when additional controls or requirements are desired.These shall apply only when specified on the purchase order.1.5 The values state
7、d in either inch-pound units or SI(metric) units are to be regarded separately as standard. Withinthe text and tables, SI units are shown in brackets. The valuesstated in each system are not exact equivalents; therefore, eachsystem shall be used independently of the other. Combiningvalues from the t
8、wo systems may result in nonconformancewith this specification.1.6 Unless the order specifies the applicable “M” specifica-tion designation, the material shall be furnished to the inch-pound units.2. Referenced Documents2.1 ASTM Standards:2A 29/A 29M Specification for Steel Bars, Carbon andAlloy,Hot
9、-Wrought, General Requirements forA 275/A 275M Test Method for Magnetic Particle Exami-nation of Steel ForgingsA 370 Test Methods and Definitions for Mechanical Testingof Steel ProductsA 576 Specification for Steel Bars, Carbon, Hot-Wrought,Special QualityA 751 Test Methods, Practices, and Terminolo
10、gy forChemical Analysis of Steel ProductsA 788/A 788M Specification for Steel Forgings, GeneralRequirementsA 921/A 921M Specification for Steel Bars, Microalloy,Hot-Wrought, Special Quality, for Subsequent Hot ForgingE10 Test Method for Brinell Hardness of Metallic Materi-alsE18 Test Methods for Roc
11、kwell Hardness and RockwellSuperficial Hardness of Metallic MaterialsE45 Test Methods for Determining the Inclusion Contentof Steel3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 microalloy forgingsforgings from microalloyedsteels produced by effectively controlling the thermo
12、mechani-cal components of the forging process to achieve requiredmechanical properties with no post-forging heat treatment.3.1.2 microalloy forging procedurethe written thermo-mechanical processing parameters to be followed during theproduction of a microalloy forging. It would include, but is notli
13、mited to: starting stock size; chemical composition, includingany optional microalloying additions; reheat practice; forgingtemperature range; method of heating; cooling methods; andlot size definition.1This specification is under the jurisdiction of ASTM Committee A01 on Steel,Stainless Steel and R
14、elated Alloys and is the direct responsibility of SubcommitteeA01.06 on Steel Forgings and Billets.Current edition approved Dec. 1, 2006. December 2006. Originally approved in1992. Last previous edition approved in 2003 as A 909 03.2For referenced ASTM standards, visit the ASTM website, www.astm.org
15、, 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 International, 100 Barr Harbor Drive, PO Box C7
16、00, West Conshohocken, PA 19428-2959, United States.4. Ordering Information4.1 Orders for material supplied to this specification shouldinclude the information specified in 4.1 of Specification A 788/A 788M. The purchaser should refer to Specification A 788/A 788M for information not contained in th
17、is specification.4.1.1 The type (see 6.1), grade (see 6.1), and the remainderof the chemical composition (see 6.2 to 6.5) should beincluded.4.2 The information contained in 4.2 of SpecificationA 788/A 788M should be specified, as necessary, to adequatelydescribe the desired material.4.3 In addition
18、to the requirements of 4.1 and 4.2 ofSpecification A 788/A 788M, the following should be includedin the purchase order, as applicable:4.3.1 From Table 1, strength class or method of testing, orboth, including test location on the forging.4.3.2 Definition of lot size including the number of me-chanic
19、al tests to be performed per lot.4.3.3 Any supplementary requirements.5. Materials and Manufacture5.1 Melting PracticeThe steel shall be produced in accor-dance with the applicable methods for primary and secondarymelting outlines in Specification A 788/A 788M.5.2 The steel shall be killed.5.3 Hot F
20、orgingThe forging shall be brought as close aspractical to finish size by hot mechanical working. Controlledhot working and cooling practices shall be applied to developspecified mechanical properties.5.4 Microalloy Forge ProcedureWhen requested by thepurchaser, a written forge procedure shall be ma
21、de available tothe purchaser by the manufacturer.6. Chemical Composition6.1 Carbon, manganese, phosphorus, and sulfur analysesshall conform to the table on Grade Designations and ChemicalRequirements of Hot-Wrought Carbon Steel Bars in Specifi-cation A 576 for the grade specified, to such other limi
22、ts thatmay be specified using the ranges and limits in the table onGrade Designations and Chemical Requirements of Hot-Wrought Carbon Steel Bars in Specification A 576,ortotheranges and limits set forth in Table 1 of Specification A 921/A 921M.NOTE 1For improved machinability, alternative sulfur ran
23、ges may bespecified by agreement between the purchaser and the producer. Addi-tional machinability-enhancing elements such as lead, bismuth, selenium,or tellurium may also be specified by agreement.6.2 Silicon analysis shall be 0.15/0.35 %. Silicon content upto 0.80 % maximum may be furnished by agr
24、eement betweenpurchaser and producer.6.3 Vanadium, columbium (niobium), titanium, or molyb-denum may be specified singly or in combination, subject tothe limits shown in Table 2. The elements and ranges specifiedshall be by agreement between the purchaser and the producer.6.4 Nitrogen may be specifi
25、ed as a supplement to vanadium,columbium, or titanium. When nitrogen is specified as asupplement to vanadium, the minimum ratio of vanadium tonitrogen shall be 4 to 1. The nitrogen content shall not exceed0.03 % and shall be reported.6.5 Sampling for heat and product analysis shall be inaccordance w
26、ith the requirements of Specification A 788/A 788M. Chemical Analyses shall be in accordance withSpecification A 751.7. Metallurgical Requirements7.1 Grain SizeThe steel shall conform to the fine grainsize requirement of Specification A 29/A 29M. The grainrefining element may be specified in accorda
27、nce with one ofthe following types:7.1.1 Type AAluminumThe total aluminum analysisshall be 0.020 % or greater, and shall be reported.7.1.2 Type BThe grain refining element shall be specifiedin accordance with 5.1.2.3 of Specification A 29/A 29M.7.2 MicrostructureThe microstructure shall consist of a
28、minimum of 90 % ferrite-pearlite or 90 % bainite as agreedbetween producer and purchaser.8. Mechanical Properties8.1 The mechanical properties of the forgings shall conformto the requirements listed in Table 1 for the strength classspecified.8.2 Test specimens shall be prepared for testing from thef
29、orging in its as forged condition unless otherwise specified.8.3 Test specimens shall be oriented parallel to the longitu-dinal axis of the forging and removed from a full thicknesssection or may be removed and produced in accordance withthe requirements of Test Methods and Definitions A 370.Ifconfo
30、rming to Test Methods and Definitions A 370, test speci-mens shall be removed from a position midway between thecenter and the surface of the forging.8.4 Test specimens for shapes and flats may be machined inaccordance with the requirements of Test Methods and Defi-nitions A 370 or with both edges p
31、arallel. Test specimens formaterial over 1.5 in. 40 mm in thickness or diameter may bemachined to a thickness or diameter of at least34 in. 20 mmfor a length of at least 9 in. 230 mm, or they may conform torequirements of Test Methods and Definitions A 370.TABLE 1 Mechanical Property RequirementsCla
32、ssYield Strength,minTensile Strength,minElongation,min, %BrinellHardness,minksi MPa ksi MPain8in.200 mmin2in.50 mm60 60 415 75 515 16 18 16780 80 550 95 655 13 15 201100 100 690 125 860 8 10 269120 120 825 150 1030 6 8 321TABLE 2 Chemical Requirements (Microalloy Elements)ElementChemical Ranges and
33、Limits, %Heat Analysis Product AnalysisVanadium 0.02 to 0.20 0.01 to 0.21Columbium (Niobium) 0.005 to 0.07 0.004 to 0.08Molybdenum 0.01 to 0.30 0.31 maxTitanium 0.030 max 0.040 maxA 909/A 909M 0628.5 At least two tension tests shall be made from each heatand forging lot.8.6 If so specified by the pu
34、rchaser, forgings may bespecified on the basis of hardness tests alone. If this option isexercised, the class shall be identified with the letter “H,” thatis, “60H,” “80H,” and so on. Hardness testing shall beperformed in accordance with Test Method E10 or TestMethods E18.9. Workmanship, Finish, and
35、 Appearance9.1 The forgings shall conform to the requirements specifiedon the purchasers drawing and shall have a good, workman-like appearance, free of any injurious imperfections.10. Retreatment10.1 Forgings above the specified hardness range or withductility values below specified limits may be t
36、empered andretested, upon approval by purchaser or in accordance with theapproved forging procedure. Forgings below specified hard-ness minimums or tensile and yield requirements may be heattreated upon approval by the purchaser.11. Certification and Test Reports11.1 When specified by the purchaser,
37、 the manufacturerscertification that the material was manufactured and tested inaccordance with this specification together with a report of theheat analysis for the specified elements and for copper,chromium, nickel, molybdenum, vanadium and columbiumshall be furnished. When the amount of an elemen
38、t present isless than 0.02 %, the heat analysis may be reported as 0.02 %except for titanium and nitrogen. When specified, these ele-ments shall be reported to three decimal places. The certifica-tion requirements of Specification A 788/A 788M shall alsoapply.11.2 The report shall include the result
39、s of any mechanicaltests performed in accordance with this specification, includingsupplementary requirements, if any.12. Keywords12.1 forging procedure; microalloyed; steel forgingsSUPPLEMENTARY REQUIREMENTSOne or more of the following supplementary requirements shall apply only when specified by t
40、hepurchaser.S1. Restricted Chemical CompositionS1.1 Restricted heat analysis limits or ranges or restrictedproduct analysis tolerances on one or more elements shall bespecified by the purchaser.S2. Restricted Incidental ElementsS2.1 The steel shall not exceed the limits for copper, nickel,chromium,
41、molybdenum, or other elements as shown on thepurchase order.S3. Nonmetallic InclusionsS3.1 A microscopical examination of longitudinal sectionsto determine the nature and frequency of nonmetallic inclu-sions shall be made as prescribed in Test Methods E45. Theacceptance limits shall be specified by
42、the purchaser.NOTE S1In resulfurized steels, much of the sulfur is present as sulfideinclusions. For this reason, maximum sulfide inclusion level should not bespecified.S4. Calcium TreatmentS4.1 The steel shall be calcium treated.S5. Stress RelievingS5.1 The steel shall be stress relieved by a cycle
43、 specifiedby the purchaser or selected by the manufacturer.NOTE S2Stress relieving may affect mechanical properties and thisshould be considered when specifying this requirement.S6. Notch Toughness TestsS6.1 Charpy V-notch tests shall be performed in sets ofthree. The absorbed energy requirement and
44、 the test tempera-ture shall be agreed upon between producer and purchaser.S6.2 Testing frequency shall be as for tension testing (see8.5). The specimens shall be taken adjacent to the tension testspecimen and shall be located as near as practicable midwaybetween surface and center of the forging di
45、ameter or thicknessand width. The longitudinal axis of specimen shall be parallelto the longitudinal axis of the forging. The length of the notchshall be perpendicular to the nearest surface of the forging.Testing procedure and acceptance criteria shall be in accor-dance with Test Methods and Defini
46、tions A 370.S7. CleaningS7.1 The surface of the forgings shall be descaled bypickling or shot blasting or other suitable means.S8. Magnetic Particle TestingS8.1 Magnetic particle testing of the forgings shall bespecified in accordance with Test Method A 275/A 275M.Acceptance requirements shall be as
47、 agreed upon between thepurchaser and the producer.A 909/A 909M 063SUMMARY OF CHANGESCommitteeA01 has identified the location of selected changes to this standard since the last issue (A 909 03)that may impact the use of this standard. (Approved Dec. 1, 2006.)(1) Changed standard designation from si
48、ngle to dual units.(2) Revised 1.3, 8.4, and Table 1 to comply with guidelines fora combined inch-pound and SI units standard.(3) The heading for hardness requirements in Table 1 has beenchanged from “Hardness, BHN min” to “Brinell Hardness,min.”ASTM International takes no position respecting the va
49、lidity of any patent rights asserted in connection with 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 technical 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
