1、Designation: A723/A723M 10 (Reapproved 2015)A723/A723M 18Standard Specification forAlloy Steel Forgings for High-Strength Pressure ComponentApplication1This standard is issued under the fixed designation A723/A723M; the number immediately following the designation indicates the yearof original adopt
2、ion or, in the case 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 Scope*1.1 This specification2 covers requirements for high-strength quenched
3、 and tempered alloy steel forgings for pressure vessels,isostatic presses, shock tubes, and similar components.1.2 These materials are not intended for welded construction.1.3 Three grades of nickel-chromium-molybdenum steels and six classes of increasing tensile strength are included. Thestrength c
4、lass, section size, and configuration of the forging will largely dictate the applicable type(s) of steel.1.4 The values stated in either inch-pound units or SI (metric) units are to be regarded separately as the standard. Within thetext and tables, the SI units are shown in brackets. The values sta
5、ted in each system are not exact equivalents; therefore, eachsystem must be used independently of the other. Combining values from the two systems may result in nonconformance with thespecification.1.5 Unless the order specifies the applicable “M” specification designation, the material shall be fur
6、nished to the inch-poundunits.1.6 This international standard was developed in accordance with internationally recognized principles on standardizationestablished in the Decision on Principles for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organiz
7、ation Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:3A275/A275M Practice for Magnetic Particle Examination of Steel ForgingsA370 Test Methods and Definitions for Mechanical Testing of Steel ProductsA388/A388M Practice for Ultrasonic Examination of Steel Forgin
8、gsA788/A788M Specification for Steel Forgings, General Requirements2.2 Other Standards:Standard:ASME Boiler and Pressure Vessel Code 443. Ordering Information and General Requirements3.1 In addition to the ordering information required by Specification A788/A788M, the purchaser shall include with th
9、e inquiryand order a detailed drawing, sketch, or written description of the forging and the method of selecting test location (see 6.2). Whenappropriate, the areas of significant loading in the forging shall be designated. The purchaser may also include appropriatesupplementary requirements from Sp
10、ecification A788/A788M as well as from this specification.3.2 Material supplied to this specification shall conform to the requirements of Specification A788/A788M, which outlinesadditional ordering information, manufacturing requirements, testing and retesting methods and procedures, marking, certi
11、fication,product analysis variations, and additional supplementary requirements.1 This specification is under the jurisdiction ofASTM Committee A01 on Steel, Stainless Steel and RelatedAlloys and is the direct responsibility of Subcommittee A01.06on Steel Forgings and Billets.Current edition approve
12、d March 1, 2015July 1, 2018. Published March 2015August 2018. Originally approved in 1975. Last previous edition approved in 20102015 asA723/A723M 10.A723/A723M 10(2015). DOI: 10.1520/A0723_A0723M-10R15.10.1520/A0723_A0723M-18.2 For ASME Boiler and Pressure Vessel Code applications see related Speci
13、fication SA723/SA723M in Section II of that Code.3 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standardsstandards Document Summary page on the ASTM website.4 A
14、vailable from American Society of Mechanical Engineers (ASME), ASME International Headquarters, Two Park Ave., New York, NY 10016-5990, http:/www.asme.org.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made t
15、o the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Summ
16、ary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.3 If the requirements of this specification are in conflict with the requirements of Specification A788/A788M, therequirements
17、 of this specification shall prevail.3.4 When forgings are required to be in compliance with Division 3 of the ASME Boiler and Pressure Vessel Code,Supplementary Requirement S6 should be specified.4. Materials and Manufacture4.1 Melting PracticeThe steel melting procedures of Specification A788/A788
18、M shall apply except that the open-hearthprocess shall not be used, and that the steel shall be vacuum degassed prior to or during the pouring of the ingot, in order to removeobjectionable gases, particularly hydrogen.4.1.1 Use of secondary remelting or refining operations may be considered for part
19、icularly demanding applications.4.2 DiscardSufficient discard shall be taken from each ingot to secure freedom from piping and excessive segregation.4.3 Heat Treatment:4.3.1 Forgings shall be rough-machined prior to final heat treatment if it is necessary to reduce the mass to ensure full hardeningo
20、r to meet the requirements of 6.2. The risk of cracking during heat treatment with high-hardenability steels of the type coveredby this specification should be borne in mind when deciding on the degree of surface preparation before heat treatment.4.3.2 Heat Treatment for Mechanical PropertiesHeat tr
21、eatment shall consist of normalizing (which may be part of thepreliminary treatment), reaustenitization, liquid quenching, and tempering. The forgings shall be quenched in a suitable liquidmedium by spraying or immersion. Quenching shall be followed by tempering at a minimum temperature of 1000F540C
22、.1000 F 540 C. The minimum time at tempering temperature shall be 12 h/in. 12 h/25 mm of maximum sectionthickness, unless otherwise agreed between supplier and purchaser.5. Chemical Composition5.1 Heat AnalysisThe heat analysis obtained from sampling in accordance with Specification A788/A788M shall
23、 comply withTable 1.5.1.1 Temper Embrittlement ControlThe purchasers attention is drawn to Supplementary Requirement S24 in SpecificationA788/A788M for application of the J Factor which may be of assistance in the control of temper embrittlement in forgingsproduced to Specification A723/A723M.5.2 Pr
24、oduct AnalysisThe manufacturer shall use the product analysis provision of Specification A788/A788M to obtain aproduct analysis from a forging representing each heat or multiple heat. The purchaser may also make this determination inaccordance with Specification A788/A788M.6. Mechanical Properties6.
25、1 General RequirementsThe forging shall conform to the requirements of Table 2 and Table 3. The largest obtainabletension test specimen as specified in Test Methods and Definitions A370 (that is, standard round 0.500-in. 12.5-mm diameterspecimen) shall be used. Charpy V-notch TypeAimpact specimens,
26、as shown in Test Methods and Definitions A370, shall be used.6.2 SamplingThe mid-point of the gage length of tension test specimens and the area under the notch of impact specimensshall be located in accordance with one of the following methods as specified by the purchaser, or suggested by the supp
27、lier andapproved by the purchaser. Wherever practical, all testing shall be from integral prolongations of the forging.6.2.1 Method 1Method 1This method shall always be used when the maximum quenched thickness does not exceed 4 in.100 mm. Datum points of the specimens, as described in 6.2, shall be
28、located in the forging or test forging (6.2.4) at mid-thicknessand at least 23 T (T is the maximum heat-treated thickness) from the quenched end surface or nearest adjacent surfaces.TABLE 1 Chemical RequirementsComposition, %Grade 1 Grade 2 Grade 3Carbon, max 0.35 0.40 0.40Manganese, max 0.90 0.90 0
29、.90Manganese, max 1.00 0.90 0.90Phosphorus, max 0.015 0.015 0.015Sulfur, max 0.015 0.015 0.015Silicon, max 0.35 0.35 0.35Nickel 1.5 to 2.25 2.3 to 3.3 3.3 to 4.5Chromium 0.80 to 2.00 0.80 to 2.00 0.80 to 2.00Molybdenum 0.20 to 0.40 0.30 to 0.50 0.40 to 0.80Molybdenum 0.20 to 0.50 0.30 to 0.60 0.40 t
30、o 0.80Vanadium, max 0.20 0.20 0.20A723/A723M 1826.2.2 Method 2t Method 2t by 2t, where t is the distance from the area of significant loading (3.1) to the nearest quenchedsurface. However, the datum points of the specimens as described in 6.2 shall not be nearer to one quenched surface than 34 in.20
31、 mm and to the second quenched surface than 1 12 in. 40 mm. When this method of testing is employed, forgings are usuallymanufactured in accordance with a purchaser-approved drawing showing prequenched dimensions and the location of mechanicaltest specimens. It is commonly used for disk-type forging
32、s such as tube sheets and covers.6.2.3 Method 3Method 3For maximum quenched thicknesses in excess of 4 in. 100 mm as heat treated. Where thismethod of testing is employed, the datum points of the test specimen, as described in 6.2, shall be removed 14T from the nearestquenched surface and 23T from t
33、he quenched end surface or nearest adjacent surface.6.2.4 Method 4Method 4Test specimens shall be taken from a representative separate test forging made from the same heatof steel, which shall receive substantially the same reduction and type of hot working, and have a cross section not less than th
34、eproduction forgings which it represents. It shall be heat treated in the same furnace charge and under the same conditions as theproduction forgings. The test specimen shall be removed using the Method 3 procedure.6.3 Thermal Buffers:6.3.1 Thermal buffer rings, at least T by T in cross section or s
35、ections of such a ring at least 3 T in length, shall be welded tothe test end(s) of a forging prior to heat treatment for mechanical properties. The buffer material may be any weldable carbon orlow-alloy steel and shall be joined to the forging with a partial penetration-type weld which completely s
36、eals the buffered surface.The test coupons shall be removed from the forging in the region buffered by the ring or ring segments. If the latter are used, thetest coupons shall be removed from the forging in the area under the center 13 of the buffer ring segment length. In either case,the test speci
37、mens shall be located at a minimum distance of 12 in. 13 mm from the buffered surface of the forging and at least14T from a quenched surface of the forging. Buffered weld areas must be at least 1 in. 25 mm from any finished machining surfaceof the complete forging.6.3.2 Bearing in mind the character
38、istics of the base materials included in this specification, precautions should be taken, suchas the use of pre- and post-weld heating and austenitic weld metal, to minimize the occurrence of crack-like defects.6.3.3 Approval of the purchaser should be obtained for the use of this method.6.4 Samples
39、 shall be removed from the forgings after quenching and tempering.6.5 OrientationFor upset disk forgings, the longitudinal axis of all test specimens shall be oriented in the tangential or radialdirection. For all other forgings, the longitudinal axis of the specimens shall be oriented in the direct
40、ion of maximum working ofthe forging, or as agreed between manufacturer and purchaser.6.6 Number of Tests:6.6.1 For forgings weighing 1000 lb 455 kg or less, as heat treated but not exceeding 80 in. 2030 mm in length, excludingtest material, one tension test and one set of impact tests (three specim
41、ens) shall be taken to represent each heat in eachheat-treatment charge. This testing shall be repeated at the opposite end of the same test forging, if the heat-treated length excludingtest material exceeds 80 in. 2030 mm. When heat treatment is performed in continuous-type furnaces with suitable t
42、emperaturecontrol and equipped with recording pyrometers so that complete heat-treatment records are available, a heat-treatment charge shallbe considered as any continuous run not exceeding 8 h in duration.TABLE 2 Tensile RequirementsClass 1 Class 2 Class 2a Class 3A Class 4B Class 5CTensile streng
43、th, min, ksi MPa 115 795 135 930 145 1000 155 1070 175 1205 190 1310Yield strength, 0.2 % offset, min, ksi MPa 100 690 120 825 130 895 140 965 160 1105 180 1240Elongation in 2 in. or 50 mm, min, % 16 14 13.5 13 12 10Reduction of area, min, % 50 45 43 40 35 30A Typical maximum section size of 10 in.
44、255 mm for open-ended vessels, or 7 in. 180 mm for blind-ended vessels.B Typical maximum section size of 6 in. 150 mm for open-ended vessels, or 4 in. 100 mm for blind-ended vessels.C Typical maximum section size of 4 in. 100 mm.TABLE 3 Charpy V-Notch Impact Requirements at 40F 4.5C40 F 4.5 C maxACl
45、ass 1 Class 2 Class 2aA Class 3B Class 4C Class 5DMinimum average value of set of threespecimens, ftlbfE J35 47 30 41 28 38 25 34 20 27 12 16Minimum value of one specimen, ftlbf J 30 41 25 34 23 31 20 27 15 20 10 14A Or such other lower temperature as is specified when supplementary requirementSuppl
46、ementary Requirement S3 is involved.B Typical maximum section size of 10 in. 255 mm for open-ended vessels, or 7 in. 180 mm for blind-ended vessels.C Typical maximum section size of 6 in. 150 mm for open-ended vessels, or 4 in. 100 mm for blind-ended vessels.D Typical maximum section size of 4 in. 1
47、00 mm.E Not more than one specimen from a set may be below this value.A723/A723M 1836.6.2 Forgings weighing over 1000 lb 455 kg but not over 5000 lb 2270 kg as heat treated and not over 80 in. 2030 mmin length excluding test material, one tension test and one set of three impact tests shall be remov
48、ed from each forging. When thelength of the forging exceeds 80 in. 2030 mm this testing shall be repeated at the opposite end of the forging.6.6.3 Forgings exceeding 5000 lb 2270 kg and not over 80 in. 2030 mm in length, excluding test material, shall have onetension test and one set of three impact
49、 tests removed from each of two locations, 180 apart. For forgings with lengths exceeding80 in. 2030 mm this testing shall be repeated at the opposite end of the forging. Supplementary Requirement S6 is applicablefor forgings intended for use under the rules of Section VIII, Division 3 of the ASME Boiler and Pressure Vessel Code.7. Nondestructive Examination Requirements7.1 Ultrasonic Examination:7.1.1 Forgings shall
