1、Designation: A 266/A 266M 03a (Reapproved 2008)Standard Specification forCarbon Steel Forgings for Pressure Vessel Components1This standard is issued under the fixed designation A 266/A 266M; the number immediately following the designation indicates the yearof original adoption or, in the case of r
2、evision, 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.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 This specificat
3、ion2covers four grades of carbon steelforgings for boilers, pressure vessels, and associated equip-ment.NOTE 1Designations have been changed as follows:Current FormerlyGrade 1 Class 1Grade 2 Class 2Grade 3 Class 3Grade 4 Class 41.2 Supplementary requirements are provided for use whenadditional testi
4、ng or inspection is desired. These shall applyonly when specified individually by the purchaser in the order.1.3 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 shal
5、l be used independently of the other. Combiningvalues from the two systems may result in non-conformancewith the standard.1.4 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:3A
6、 275/A 275M Practice for Magnetic Particle Examinationof Steel ForgingsA 370 Test Methods and Definitions for Mechanical Testingof Steel ProductsA 788/A 788M Specification for Steel Forgings, GeneralRequirementsE112 Test Methods for Determining Average Grain SizeE 165 Test Method for Liquid Penetran
7、t ExaminationE 381 Method of Macroetch Testing Steel Bars, Billets,Blooms, and Forgings2.2 Other Standard:ASME Boiler and Pressure Vessel Code, Section IX, Weld-ing Qualifications43. Ordering Information and General Requirements3.1 In addition to the ordering information required bySpecification A 7
8、88/A 788M, the purchaser shall include withthe inquiry and order a detailed drawing, sketch, or writtendescription of the forging.3.2 Material supplied to this specification shall conform tothe requirements of Specification A 788/A 788M, which out-lines additional ordering information, manufacturing
9、 require-ments, testing and retesting methods and procedures, marking,certification, product analysis variations, and additional supple-mentary requirements.3.3 If the requirements of this specification are in conflictwith the requirements of Specification A 788/A 788M, therequirements of this speci
10、fication shall prevail.3.4 For hubbed flanges and tube sheets ordered for ASMEBoiler and Pressure Vessel Code application, SupplementaryRequirement S12 of Specification A 788/A 788M shall bespecified in addition to Supplementary Requirement S8 of thisspecification.4. Materials and Manufacture4.1 The
11、 steel shall be made in accordance with the MeltingProcess Section of Specification A 788/A 788M. A sufficientdiscard shall be made to secure freedom from injurious pipeand undue segregation.4.2 The material shall be forged as close as practical to thespecified shape and size.4.3 The finished produc
12、t shall be a hot-worked forging asdefined by Specification A 788/A 788M.5. Machining5.1 Surfaces shall be machined as designated by the pur-chaser. Unmachined surfaces shall be sufficiently free of scaleto permit inspection.1This specification is under the jurisdiction of ASTM Committee A01 on Steel
13、,Stainless Steel and Related Alloys and is the direct responsibility of SubcommitteeA01.06 on Steel Forgings and Billets.Current edition approved March 1, 2008. Published April 2008. Originallyapproved in 1943. Last previous edition approved in 2003 as A 266/A 266M 03a.2For ASME Boiler and Pressure
14、Vessel Code applications, see related Specifi-cation SA266/ SA266M in Section II of that code.3For 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
15、 Summary page onthe ASTM website.4Available from the American Society of Mechanical Engineers, 345 East 47thSt., New York, NY 10017.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5.2 Machining may be performed either prior to or aft
16、er heattreatment at the option of the manufacturer unless specified inaccordance with Supplementary Requirement S1.6. Heat Treatment6.1 After forging and before reheating for heat treatment,the forgings shall be cooled in such a manner as to preventinjury and to accomplish transformation.6.2 All for
17、gings shall be annealed, normalized, or normal-ized and tempered, but alternatively may be liquid quenchedand tempered when mutually agreed upon between the manu-facturer and the purchaser. When tempering is performed, itshall be at a subcritical temperature, but no less than 1100F595C.6.3 A multipl
18、e stage austenitizing procedure may be usedwhereby the forging is first fully austenitized and liquidquenched, followed by reheating within the intercritical tem-perature range to partially reaustenitize, and again liquidquenched. On completion of the austenitizing/quenchingcycles, tempering at a te
19、mperature between 1100F 595Cand the lower critical temperature shall follow.NOTE 2Although liquid quenching from the austenitizing tempera-tures is more effective in enhancing impact properties, air cooling from theaustenitizing temperatures is also beneficial and may be used instead ofthe normalizi
20、ng procedure in 6.2.7. Chemical Composition7.1 Heat AnalysisThe heat analysis obtained from sam-pling in accordance with Specification A 788/A 788M shallcomply with Table 1 except that the additional features ofSupplementary Requirements S11 and S12 shall also apply asindividually specified in the o
21、rdering information.7.2 Product AnalysisThe purchaser may use the productanalysis provision of Specification A 788/A 788M to obtain aproduct analysis from a forging representing each heat ormultiple heat.8. Mechanical Properties8.1 General RequirementsExcept when otherwise speci-fied in accordance w
22、ith Supplementary Requirement S2, thematerial shall conform to the requirements for mechanicalproperties prescribed in Table 2 when tested in accordance withthe latest issue of Test Methods and Definitions A 370. Thelargest obtainable tension test specimen as specified in TestMethods and Definitions
23、 A 370 shall be used.8.1.1 Except when otherwise specified in accordance withSupplementary Requirement S2, the longitudinal axis of thespecimens shall be parallel to the direction of major working ofthe forging. For upset-disc forgings, the longitudinal axis of thetest specimen shall be in the tange
24、ntial direction.8.1.1.1 The longitudinal axis of the specimen shall belocated midway between the parallel surfaces of the testextension if added to the periphery of disks or midway betweenthe center and surface of solid forgings. For hollow forgings,the longitudinal axis of the specimens shall be lo
25、cated midwaybetween the center and outer surfaces of the wall. Whenseparately forged test blocks are employed as defined in 8.1.3,the tension test specimens shall be taken from a location thatrepresents the midwall of the heaviest section of the productionforgings. When specimens are required from o
26、pposite ends,they shall be taken from the diagonal corners of an axial plane.8.1.2 Except as specified herein, tests for acceptance shallbe made after heat treatment has been completed. When theends of the cylindrical forgings are closed in by reforging, thecylindrical forgings may be annealed, norm
27、alized, or normal-ized and tempered and tested prior to reforging. After reforg-ing, the entire forging shall be reheat-treated in the samemanner and at the same temperature range as employed whenthe forging was heat-treated prior to certification testing.8.1.3 When mutually agreed upon between manu
28、facturerand purchaser, test specimens may be machined from aspecially forged block suitably worked and heat treated withthe production forgings. Such a special block shall be obtainedfrom an ingot, slab, or billet from the same heat used to makethe forgings it represents. This block shall receive es
29、sentiallythe same type of hot working and forging reduction as theproduction forgings; however, a longitudinally forged bar withdimensions not less than T by T by 3T may be used to representa ring forging. The dimension T shall be representative of theheaviest effective cross section of the forging.
30、 For quenchedand tempered forgings for which tests are required at both endsby 8.2.2.3 and 8.2.2.4, separately forged test blocks are notallowed.NOTE 3In using separately forged test blocks, attention is drawn tothe effect of mass differences between the production forgings and the testblocks.8.2 Sp
31、ecific RequirementsThe number and location oftests are based on forging length, weight, and heat treatment,and shall be as prescribed below. The length and weight to beused for this purpose shall be the shipped length and weight offorgings produced individually or the aggregate shipped lengthand wei
32、ght of all pieces cut from a multiple forging.8.2.1 Annealed, Normalized, or Normalized and TemperedSteel Forgings:8.2.1.1 For forgings weighing 5000 lb 2250 kg or less atthe time of heat treatment, one tension test shall be taken fromone forging per heat in each heattreatment charge. When heatTABLE
33、 1 Chemical RequirementsComposition, %Grades 1 and 2 Grade 3 Grade 4Carbon, max 0.30 0.35 0.30Manganese 0.401.05 0.801.35 0.801.35Phosphorus, max 0.025 0.025 0.025Sulfur, max 0.025 0.025 0.025Silicon 0.150.35 0.150.35 0.150.35TABLE 2 Tensile RequirementsGrade 1 Grades2 and 4Grade 3Tensile strength,
34、min, ksiMPa6085415585709548565575100515690Yield strength (0.2 % offset),min, ksi MPa302053625037.5260Elongation in 2 in. or 50mm, min, %23 20 19Reduction of area, min, % 38 33 30A 266/A 266M 03a (2008)2treatment is performed in continuous-type furnaces with suit-able temperature controls and equippe
35、d with recording pyrom-eters so that complete heat-treatment records are available, atempering charge may be considered as any continuous run notexceeding an 8-h period.8.2.1.2 For forgings and forged bars weighing over 5000 lb2250 kg at the time of heat treatment, one tension test shall betaken fro
36、m each forging.8.2.2 Quenched and Tempered Forgings:8.2.2.1 For quenched and tempered forgings weighing 5000lb 2250 kg or less at the time of heat treatment, but notexceeding 12 ft 3.7 m in length, one tension test shall betaken from one forging per heat in each heattreatment charge.When heat treatm
37、ent is performed in continuous-type furnaceswith suitable temperature controls and equipped with recordingpyrometers so that complete heat-treatment records are avail-able, a tempering charge may be considered as any continuousrun not exceeding an 8-h period.8.2.2.2 For quenched and tempered forging
38、s and forged barsweighing over 5000 lb 2250 kg to 10 000 lb 4500 kg at thetime of heat treatment, but not exceeding 12 ft 3.7 m inlength, one tension test shall be taken from each forging.8.2.2.3 For quenched and tempered forgings and forged barsthat exceed 12 ft 3.7 m in length, one tension test sh
39、all betaken from each end of each forging.8.2.2.4 For quenched and tempered forgings and forged barsweighing more than 10 000 lb 4500 kg at the time of heattreatment, two tension test specimens shall be taken from eachforging. These shall be offset 180 from each other except thatif the length of the
40、 forging, excluding test prolongations,exceeds 12 ft 3.7 m, then one specimen shall be taken fromeach end of the forging.9. Repair Welding9.1 Repair welding of forgings is permissible only at theoption of the purchaser. If repair welding is performed, weldersand weld procedures shall be qualified in
41、 accordance withSection IX of the ASME Boiler and Pressure Vessel Code.10. Certification10.1 In addition to the mandatory certification requirementsof Specification A 788/A 788M, the heat treatment cycle datashall be included.11. Product Marking11.1 Each forging shall be identified in accordance wit
42、h theMarking Section of Specification A 788/A 788M. In addition,the forging shall be marked following the grade designation bythe letter “A” for annealed, “N” for normalized, “NT” fornormalized and tempered, and “S” for liquid quenched andtempered, as applicable.12. Keywords12.1 pressure vessel serv
43、ice; steel forgingscarbonSUPPLEMENTARY REQUIREMENTSOne or more of the following supplementary requirements shall apply only when specified by thepurchaser in the inquiry, contract, or order. Details of these supplementary requirements shall beagreed upon between the manufacturer and the purchaser.S1
44、. Rough Turning and BoringS1.1 The position of the rough turning and boring in thesequence of manufacturing operations shall be as specified bythe purchaser.S2. Alternative Tension Test OrientationS2.1 In lieu of the requirements of Section 8, the longitu-dinal axis of the test specimens shall be tr
45、ansverse to thedirection of major working of the forging. The results shallconform with requirements of Table 2, with the exception ofthe ductility limits that shall be as follows:Grade 1 2 and 4 3Elongation in 2 in. 50 mm, min, % 20 19 18Reduction of area, min, % 30 25 25S3. Hydrostatic TestS3.1 Ah
46、ydrostatic pressure test shall be applied. The detailsof the test, including its position in the sequence of manufac-turing operations, shall be specified.S4. Magnetic Particle ExaminationS4.1 All accessible surfaces of the finished forging shall beexamined by a magnetic particle method. The method
47、shall bein accordance with Practice A 275/A 275M. Acceptance limitsshall be as agreed upon between the manufacturer and thepurchaser.S5. Liquid Penetrant ExaminationS5.1 After forgings have been heat treated by liquid quench-ing and tempering, all accessible surfaces shall be inspected forquench cra
48、cks by the liquid penetrant method in accordancewith Test Method E 165 as an alternative to magnetic particleexamination.S6. Macroetch TestS6.1 A sample forging shall be sectioned and etched toshow flow lines and internal imperfections. The test shall beconducted in accordance with Method E 381. Det
49、ails of the testshall be agreed upon between the manufacturer and thepurchaser.S7. Product AnalysisS7.1 A product analysis in accordance with Section 7 shallbe made from one randomly selected forging representing eachsize and shape of forging on the order. If the analysis fails toA 266/A 266M 03a (2008)3comply, each forging shall be checked or the lot rejected. Allresults shall be reported to the purchaser.S8. Specimen Location on Forged HubsS8.1 Forged hubs to be butt-welded to shells shall be forgedin such a m
