1、Designation: A723/A723M 10 (Reapproved 2015)Standard 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 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 () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This specification2covers requirements for high-strength quenched and tempered alloy s
3、teel forgings for pres-sure vessels, isostatic presses, shock tubes, and similar com-ponents.1.2 These materials are not intended for welded construc-tion.1.3 Three grades of nickel-chromium-molybdenum steelsand six classes of increasing tensile strength are included. Thestrength class, section size
4、, and configuration of the forgingwill 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 the text and tables, the SI units are shown in brackets.The values stated in each system ar
5、e not exact equivalents;therefore, each system must be used independently of the other.Combining values from the two systems may result in noncon-formance with the specification.1.5 Unless the order specifies the applicable “M” specifica-tion designation, the material shall be furnished to the inch-
6、pound units.2. Referenced Documents2.1 ASTM Standards:3A275/A275M Practice for Magnetic Particle Examination ofSteel ForgingsA370 Test Methods and Definitions for Mechanical Testingof Steel ProductsA388/A388M Practice for Ultrasonic Examination of SteelForgingsA788/A788M Specification for Steel Forg
7、ings, General Re-quirements2.2 Other Standards:ASME Boiler and Pressure Vessel Code43. Ordering Information and General Requirements3.1 In addition to the ordering information required bySpecification A788/A788M, the purchaser shall include withthe inquiry and order a detailed drawing, sketch, or wr
8、ittendescription of the forging and the method of selecting testlocation (see 6.2). When appropriate, the areas of significantloading in the forging shall be designated. The purchaser mayalso include appropriate supplementary requirements fromSpecification A788/A788M as well as from this specificati
9、on.3.2 Material supplied to this specification shall conform tothe requirements of Specification A788/A788M, which out-lines additional ordering information, manufacturingrequirements, testing and retesting methods and procedures,marking, certification, product analysis variations, and addi-tional s
10、upplementary requirements.3.3 If the requirements of this specification are in conflictwith the requirements of Specification A788/A788M, therequirements of this specification shall prevail.3.4 When forgings are required to be in compliance withDivision 3 of the ASME Boiler and Pressure Vessel Code,
11、Supplementary Requirement S6 should be specified.4. Materials and Manufacture4.1 Melting PracticeThe steel melting procedures ofSpecification A788/A788M shall apply except that the open-hearth process shall not be used, and that the steel shall bevacuum degassed prior to or during the pouring of the
12、 ingot, inorder to remove objectionable gases, particularly hydrogen.4.1.1 Use of secondary remelting or refining operations maybe considered for particularly demanding applications.4.2 DiscardSufficient discard shall be taken from eachingot to secure freedom from piping and excessive segregation.1T
13、his specification is under the jurisdiction 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 March 1, 2015. Published March 2015. Originallyapproved in 1975. Last previous e
14、dition approved in 2010 as A723/A723M 10.DOI: 10.1520/A0723_A0723M-10R15.2For ASME Boiler and Pressure Vessel Code applications see related Specifi-cation SA723/SA723M in Section II of that Code.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at
15、serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.4Available from American Society of Mechanical Engineers (ASME), Two ParkAve., New York, NY 10016-5990, http:/www.asme.org.*A Summary of Changes section appears at th
16、e end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States14.3 Heat Treatment:4.3.1 Forgings shall be rough-machined prior to final heattreatment if it is necessary to reduce the mass to ensure fullhardening or to meet the
17、requirements of 6.2. The risk ofcracking during heat treatment with high-hardenability steelsof the type covered by this specification should be borne inmind when deciding on the degree of surface preparationbefore heat treatment.4.3.2 Heat Treatment for Mechanical PropertiesHeattreatment shall cons
18、ist of normalizing (which may be part ofthe preliminary treatment), reaustenitization, liquid quenching,and tempering. The forgings shall be quenched in a suitableliquid medium by spraying or immersion. Quenching shall befollowed by tempering at a minimum temperature of 1000F540C. The minimum time a
19、t tempering temperature shall be12 h/in. 12 h/25 mm of maximum section thickness, unlessotherwise agreed between supplier and purchaser.5. Chemical Composition5.1 Heat AnalysisThe heat analysis obtained from sam-pling in accordance with Specification A788/A788M shallcomply with Table 1.5.1.1 Temper
20、Embrittlement ControlThe purchasers at-tention is drawn to Supplementary Requirement S24 in Speci-fication A788/A788M for application of the J Factor whichmay be of assistance in the control of temper embrittlement inforgings produced to Specification A723/A723M.5.2 Product AnalysisThe manufacturer
21、shall use the prod-uct analysis provision of Specification A788/A788M to obtaina product analysis from a forging representing each heat ormultiple heat. The purchaser may also make this determinationin accordance with Specification A788/A788M.6. Mechanical Properties6.1 General RequirementsThe forgi
22、ng shall conform tothe requirements of Table 2 and Table 3. The largest obtainabletension test specimen as specified in Test Methods and Defi-nitions A370 (that is, standard round 0.500-in. 12.5-mmdiameter specimen) shall be used. Charpy V-notch Type Aimpact specimens, as shown in Test Methods and D
23、efinitionsA370, shall be used.6.2 SamplingThe mid-point of the gage length of tensiontest specimens and the area under the notch of impact speci-mens shall be located in accordance with one of the followingmethods as specified by the purchaser, or suggested by thesupplier and approved by the purchas
24、er. Wherever practical, alltesting shall be from integral prolongations of the forging.6.2.1 Method 1This method shall always be used whenthe maximum quenched thickness does not exceed 4 in. 100mm. Datum points of the specimens, as described in 6.2, shallbe located in the forging or test forging (6.
25、2.4) at mid-thicknessand at least23 T (T is the maximum heat-treated thickness)from the quenched end surface or nearest adjacent surfaces.6.2.2 Method 2t by 2t, where t is the distance from thearea of significant loading (3.1) to the nearest quenchedsurface. However, the datum points of the specimen
26、s asdescribed in 6.2 shall not be nearer to one quenched surfacethan34 in. 20 mm and to the second quenched surface than 112 in. 40 mm. When this method of testing is employed,forgings are usually manufactured in accordance with apurchaser-approved drawing showing prequenched dimensionsand the locat
27、ion of mechanical test specimens. It is commonlyused for disk-type forgings such as tube sheets and covers.6.2.3 Method 3For maximum quenched thicknesses inexcess of 4 in. 100 mm as heat treated. Where this method oftesting is employed, the datum points of the test specimen, asdescribed in 6.2, shal
28、l be removed14 T from the nearestquenched surface and23 T from the quenched end surface ornearest adjacent surface.6.2.4 Method 4Test specimens shall be taken from arepresentative separate test forging made from the same heat ofsteel, which shall receive substantially the same reduction andtype of h
29、ot working, and have a cross section not less than theproduction forgings which it represents. It shall be heat treatedin the same furnace charge and under the same conditions asthe production forgings. The test specimen shall be removedusing the Method 3 procedure.6.3 Thermal Buffers:6.3.1 Thermal
30、buffer rings, at least T by T in cross section orsections of such a ring at least 3 T in length, shall be welded tothe test end(s) of a forging prior to heat treatment formechanical properties. The buffer material may be any weld-able carbon or low-alloy steel and shall be joined to the forgingwith
31、a partial penetration-type weld which completely seals thebuffered surface. The test coupons shall be removed from theforging in the region buffered by the ring or ring segments. Ifthe latter are used, the test coupons shall be removed from theforging in the area under the center13 of the buffer rin
32、gsegment length. In either case, the test specimens shall belocated at a minimum distance of12 in. 13 mm from thebuffered surface of the forging and at least14 T from aquenched surface of the forging. Buffered weld areas must beat least 1 in. 25 mm from any finished machining surface ofthe complete
33、forging.6.3.2 Bearing in mind the characteristics of the base mate-rials included in this specification, precautions should be taken,such as the use of pre- and post-weld heating and austeniticweld metal, to minimize the occurrence of crack-like defects.6.3.3 Approval of the purchaser should be obta
34、ined for theuse of this method.6.4 Samples shall be removed from the forgings afterquenching and tempering.TABLE 1 Chemical RequirementsComposition, %Grade 1 Grade 2 Grade 3Carbon, max 0.35 0.40 0.40Manganese, max 0.90 0.90 0.90Phosphorus, max 0.015 0.015 0.015Sulfur, max 0.015 0.015 0.015Silicon, m
35、ax 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 0.80Vanadium, max 0.20 0.20 0.20A723/A723M 10 (2015)26.5 OrientationFor upset disk forgings, the longitudinalaxis of all test specimens shall be orient
36、ed in the tangential orradial direction. For all other forgings, the longitudinal axis ofthe specimens shall be oriented in the direction of maximumworking of the forging, or as agreed between manufacturer andpurchaser.6.6 Number of Tests:6.6.1 For forgings weighing 1000 lb 455 kg or less, as heattr
37、eated but not exceeding 80 in. 2030 mm in length, exclud-ing test material, one tension test and one set of impact tests(three specimens) shall be taken to represent each heat in eachheat-treatment charge. This testing shall be repeated at theopposite end of the same test forging, if the heat-treate
38、d lengthexcluding test material exceeds 80 in. 2030 mm. When heattreatment is performed in continuous-type furnaces with suit-able temperature control and equipped with recording pyrom-eters so that complete heat-treatment records are available, aheat-treatment charge shall be considered as any cont
39、inuousrun not exceeding8hinduration.6.6.2 Forgings weighing over 1000 lb 455 kg but not over5000 lb 2270 kg as heat treated and not over 80 in. 2030mm in length excluding test material, one tension test and oneset of three impact tests shall be removed from each forging.When the length of the forgin
40、g exceeds 80 in. 2030 mm thistesting shall be repeated at the opposite end of the forging.6.6.3 Forgings exceeding 5000 lb 2270 kg and not over 80in. 2030 mm in length, excluding test material, shall have onetension test and one set of three impact tests removed fromeach of two locations, 180 apart.
41、 For forgings with lengthsexceeding 80 in. 2030 mm this testing shall be repeated at theopposite end of the forging. Supplementary Requirement S6 isapplicable for forgings intended for use under the rules ofSection VIII, Division 3 of the ASME Boiler and PressureVessel Code.7. Nondestructive Examina
42、tion Requirements7.1 Ultrasonic Examination:7.1.1 Forgings shall be ultrasonically examined in accor-dance with the procedures of Practice A388/A388M.7.1.1.1 Straight-Beam Examination: (a)Unless otherwisespecified, the back-reflection method of tuning shall be used inaccordance with Practice A388/A3
43、88M.(b) In addition to the reportable conditions of PracticeA388/A388M, indications exceeding the resultant back-reflection shall be recorded.(c) A forging shall be unacceptable when one or morereflections are present producing indications accompanied by acomplete loss of back-reflection, not attrib
44、utable to nor asso-ciated with the geometric configuration. For this purpose, aback-reflection of less than 5 % of full screen height shall beconsidered complete loss of back-reflection.7.1.1.2 Angle-Beam Examination: (a) Calibration notchesshall be cut into the inside diameter and outside diameters
45、urfaces in accordance with Practice A388/A388M.(b)Aforging that contains a discontinuity which results in anindication exceeding the amplitude of the reference line issubject to rejection.(c) The report of the ultrasonic test shall be in compliancewith Practice A388/A388M.(d) Additional nondestructi
46、ve examination or trepanningmay be employed to resolve questions of interpretation ofultrasonic indications. The manufacturer shall accept respon-sibility for injurious defects that will not be removed in finalmachining.7.2 Magnetic Particle Examination:7.2.1 Each forging shall be examined by magnet
47、ic particlemethods described in Practice A275/A275M. Acceptance andrejection standards shall be as follows: Only indications withmajor dimensions greater than116 in. 1.6 mm shall beconsidered relevant. The following relevant indications areunacceptable:7.2.1.1 Any linear indications greater than116
48、in. 1.6 mmlong for materials less than58 in. 16 mm thick; greater than18 in. 3.2 mm long for materials from58 in. to under 2 in. 50TABLE 2 Tensile RequirementsClass 1 Class 2 Class 2a Class 3AClass 4BClass 5CTensile strength, min, ksi MPa 115 795 135 930 145 1000 155 1070 175 1205 190 1310Yield stre
49、ngth, 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 30ATypical maximum section size of 10 in. 255 mm for open-ended vessels, or 7 in. 180 mm for blind-ended vessels.BTypical maximum section size of 6 in. 150 mm for open-ended vessels, or 4 in. 100 mm for blind-ended vessels.CTypical maximum section size of 4 in. 100 mm.TABLE 3 Charpy V-Notc
