1、Designation: A320/A320M 17bA320/A320M 18Standard Specification forAlloy-Steel and Stainless Steel Bolting for Low-TemperatureService1This standard is issued under the fixed designation A320/A320M; the number immediately following the designation indicates the yearof original adoption or, in the case
2、 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.This standard has been approved for use by agencies of the U.S. Department of Defense.1. Scope*1.1 This
3、specification2 covers alloy steel bolting materials and bolting components for pressure vessels, valves, flanges, andfittings for low-temperature service. See Specification A962/A962M for the definition of bolting. The bars shall be hot-wroughtand may be further processed by centerless grinding or b
4、y cold drawing. Austenitic stainless steel may be solution annealed orannealed and strain-hardened. When strain hardened austenitic stainless steel is ordered, the purchaser should take special care toensure that Appendix X1 is thoroughly understood.1.2 Several grades are covered, including both fer
5、ritic and austenitic steels designated L7, B8, etc. Selection will depend ondesign, service conditions, mechanical properties, and low-temperature characteristics. The mechanical requirements of Table 1indicate the diameters for which the minimum mechanical properties apply to the various grades and
6、 classes, and Table 2 stipulatesthe requirements for Charpy impact energy absorption. The manufacturer should determine that the material can conform to theserequirements before parts are manufactured. For example, when Grade L43 is specified to meet the Table 2 impact energy valuesat 150 F 101 C, a
7、dditional restrictions (such as procuring a steel with lower P and S contents than might normally besupplied) in the chemical composition for AISI 4340 are likely to be required.NOTE 1The committee formulating this specification has included several grades of material that have been rather extensive
8、ly used for the presentpurpose. Other compositions will be considered for inclusion by the committee from time to time as the need becomes apparent. Users should note thathardenability of some of the grades mentioned may restrict the maximum size at which the required mechanical properties are obtai
9、nable.1.3 The following referenced general requirements are indispensable for application of this specification: SpecificationA962/A962M.1.4 Nuts for use with bolting are covered in Section 10 and the nut material shall be impact tested.1.5 Supplementary Requirements are provided for use at the opti
10、on of the purchaser. The supplementary requirements shallapply only when specified in the purchase order or contract.1.6 This specification is expressed in both inch-pound units and SI units; however, unless the purchase order or contractspecifies the applicable M specification designation (SI) unit
11、s, the inch-pound units shall apply.1.7 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in eachsystem may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from thetwo syst
12、ems may result in non-conformance with the standard.1.8 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 t
13、he World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:31 This specification is under the jurisdiction ofASTM Committee A01 on Steel, Stainless Steel and RelatedAlloys and is the direct responsibility of Subcommittee A01.22on Steel Forgings
14、and Wrought Fittings for Piping Applications and Bolting Materials for Piping and Special Purpose Applications.Current edition approved Oct. 1, 2017June 1, 2018. Published November 2017June 2018. Originally approved in 1948. Last previous edition approved in 2017 asA320/A320M 17a.A320/A320M 17b. DOI
15、: 10.1520/A0320_A0320M-17B.10.1520/A0320_A0320M-18.2 For ASME Boiler and Pressure Vessel Code applications, see related Specification SA-320 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
16、Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.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 to the previous version. Becauseit may not be tec
17、hnically 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 Summary of Changes section appears at the end of thi
18、s standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1TABLE 1 Mechanical RequirementsClass and Grade, Diameter, in. mm Heat TreatmentMinimumTemperingTemperature,F CTensileStrength,min, ksiMPaYield Strength,min, ksiMPa (0.2 %offset
19、)Elongationin 2 in.or 50mm, min, %Reductionof Area,min, %Hardness,maxFerritic SteelsL7, L7A, L7B, L7C, L70, L71, L72, L73 125 105 16 50 321 HBW or 35HRC212 65 and underA quenched and tempered 1100593860 725L43 125 105 16 50 321 HBW or 35HRC4 100 and underA quenched and tempered 1100593860 725L7M 100
20、 80 18 50 235 HBWB or99 HRB212 65 and underA quenched and tempered 1150620690 550L1 125 105 16 50 . . .1 25 and underA quenched and tempered 860 725Austenitic SteelsCClass 1: B8, B8C, B8M, B8P,B8F, B8T, B8LN, B8MLN, all diameterscarbide solution treated 755153020530 50 223 HBWD or96 HRBClass 1A: B8A
21、, B8CA, B8MA, B8PA,B8FA, B8TA, B8LNA,B8MLNA, all diameterscarbide solution treated in thefinished condition755153020530 50 192 HBW or 90HRBClass 2: B8, B8C, B8P, B8F, B8T: carbide solution treated and strainhardened34 20 and under 12586010069012 35 321 HBW or 35HRCover 34 to 1 20 to 25, incl 1157958
22、055015 30 321 HBW or 35HRCover 1 to 114 25 to 32, incl 1057256545020 35 321 HBW or 35HRCover 114 to 112 32 to 40, inclA 1006905034528 45 321 HBW or 35HRCClass 2: B8M: carbide solution treated and strainhardened34 20 and under 1107609565515 45 321 HBW or 35HRCover 34 to 1 20 to 25, incl 1006908055020
23、 45 321 HBW or 35HRCover 1 to 114 25 to 32, incl 956556545025 45 321 HBW or 35HRCover 114 to 112 32 to 40, inclA 906205034530 45 321 HBW or 35HRCA These upper diameter limits were established on the basis that these were the largest sizes commonly available that consistently met specification proper
24、ty limits. They are not intended as absolute limits beyond whichbolting materials could no longer be certified to the specification.B To meet the tensile requirements, the Brinell hardness shall not be less than 200 HBW or 93 HRB.C Class 1 products are made from solution-treated material. Class 1Apr
25、oducts are solution treated in the finished condition for corrosion resistance; heat treatment is critical for enhancing this physical property and meetingthe mechanical property requirements. Class 2 products are made from solution-treated material that has been strain hardened. Austenitic steels i
26、n the strain-hardened condition may not show uniform propertiesthroughout the cross section, particularly in sizes over 34 in. 20 mm in diameter.D For sizes 34 in. 20 mm in diameter and smaller, a maximum hardness of 241 HBW (100 HRB) is permitted.A320/A320M182A194/A194M Specification for Carbon Ste
27、el, Alloy Steel, and Stainless Steel Nuts for Bolts for High Pressure or HighTemperature Service, or BothA962/A962M Specification for Common Requirements for Bolting Intended for Use atAny Temperature from Cryogenic to theCreep RangeE566 Practice for Electromagnetic (Eddy Current) Sorting of Ferrous
28、 MetalsF436/F436M Specification for Hardened Steel Washers Inch and Metric DimensionsF606/F606M Test Methods for Determining the Mechanical Properties of Externally and Internally Threaded Fasteners,Washers, Direct Tension Indicators, and Rivets2.2 ASME Standards:4B1.1 Screw ThreadsB18.22.1 Plain Wa
29、shers3. Ordering Information3.1 It is the purchasers responsibility to specify in the purchase order all information necessary to purchase the neededmaterials. Examples of such information include, but are not limited to, the following:3.1.1 Quantity and size,3.1.2 Heat-treated condition, that is, f
30、or the austenitic stainless steels, solution-treated (Class 1); solution-treated after finishing(Class 1A); and annealed and strain-hardened (Class 2),3.1.3 Description of items required (bars, bolts, screws, or studs),3.1.4 Nuts and washers, if required by the purchaser, in accordance with Section
31、10, and3.1.5 Special requirements, in accordance with 5.1.1, 5.1.3, 5.1.4, and 13.1.4 Available from American Society of Mechanical Engineers (ASME), ASME International Headquarters, Two Park Ave., New York, NY 10016-5990, http:/www.asme.org.TABLE 4 Recommended Test Temperature for Stock PartsGrade
32、Test TemperatureF CL7M, L70,L71, L72, L73100 73L7, L7A, L7B, L7C 150 101L43 150 101L1 100 73TABLE 2 Impact Test Temperatures and PropertiesGradeTest Temperature CVN Specimen SectionSize, mmMin Average ImpactToughness of Three TestSpecimens, ft-lbf JMin Impact Value of a SingleSpecimen of Set of Thre
33、e,ft-lbf JF C10 10 20 27 15 20L7M, L70, L71, L72, L73 100 73 10 7.5 16 22 12 1610 10 20 27 15 20L7, L7A, L7B, L7C, L43 150 101 10 7.5 16 22 12 1610 10 40 54 30 41L1 100 73 10 7.5 32 44 24 32TABLE 2 Impact Energy Absorption RequirementsSize ofSpecimen, mmMinimum Impact ValueRequired for Averageof Eac
34、h Set of ThreeSpecimens, ftlbf JMinimum ImpactValue Permitted forOne Specimen Onlyof a Set, ftlbf JAll Grades Except L1A10 by 1010 by 7.520 2716 2215 2012 16Grade L110 by 1010 by 7.540 5432 4430 4124 32A See 6.2.1.1 for permitted exemptions.A320/A320M 1834. Common Requirements4.1 Bolting materials a
35、nd bolting components supplied to this specification shall conform to the requirements of SpecificationA962/A962M. These requirements include test methods, finish, thread dimensions, macroetch (carbon and alloy steels only)marking, certification, optional supplementary requirements, and others. Fail
36、ure to comply with the requirements of SpecificationA962/A962M constitutes nonconformance with this specification. In case of conflict between the requirements in this specificationand Specification A962/A962M, this specification shall prevail.5. Materials and Manufacture5.1 Heat Treatment:5.1.1 Bol
37、ting materials shall be allowed to cool to room temperature after rolling or forging. Grades L7, L7A, L7B, L7C, L7M,L43, L1, L70, L71, L72, and L73 shall be reheated to above the upper critical temperature and liquid quenched and tempered.Grades B8, B8C, B8M, B8T, B8F, B8P, B8LN, and B8MLN shall rec
38、eive a carbide solution treatment. Products made from suchmaterial are described as Class 1. This shall consist of holding the bolting material for a sufficient time at a temperature at whichthe chromium carbide will go into solution and then cooling in air or in a liquid medium at a rate sufficient
39、 to preventreprecipitation of the carbide. Bolting material thus treated is described as Class 1. If specified in the purchase order, boltingmaterial shall be solution treated in the finished condition and shall be described as Class 1A.5.1.2 Use of water quenching is prohibited for any ferritic gra
40、de when heat treatment is performed after heading or threading.5.1.3 When increased mechanical properties are desired, austenitic bolting shall be solution annealed and strain hardened ifspecified in the purchase order; material so treated is identified as Class 2.5.1.4 If scale-free bright finish i
41、s required, this shall be specified in the purchase order.5.1.5 For L7M bolting, the final heat treatment, which may be the tempering or stress-relieving operation conducted at 1150 F620 C minimum, shall be done after machining or rolling of the threads and any type of cutting.6. Mechanical Requirem
42、ents6.1 Tensile Properties:6.1.1 Bolting material as represented by the tension specimens shall conform to the requirements as to tensile propertiesprescribed in Table 1 at room temperature after heat treatment (see 5.1.1). Alternatively, Class 2 Strain Hardened Headed BoltingComponents shall be tes
43、ted full size after strain hardening to determine tensile strength and yield strength and shall conform tothe requirements prescribed in Table 1. Should the results of full size tests conflict with results of tension specimen tests, full sizetest results shall prevail.6.1.2 Number of Tests:6.1.2.1 F
44、or heat-treated bars, one tension test and one impact test consisting of three specimens shall be made for each diameterof each heat represented in each tempering charge. When heat treated without interruption in continuous furnaces, the material ina lot shall be the same heat, same prior condition,
45、 same size, and subjected to the same heat treatment. Not fewer than two tensiletests and two impact tests are required for each lot containing 20 000 lbs 9000 kg or less. Every additional 10 000 lbs 4500kg or fraction thereof requires an additional tensile test and impact test.6.1.2.2 For studs, bo
46、lts, screws, etc., one tension test and one set of three impact specimens shall be made for each diameterof each heat involved in the lot. Each lot shall consist of the following:Diameter, in. mm Lot Size, lb kg118 30 and under 1500 680 or fraction thereofOver 118 30 to 134 45,incl4500 2040 or fract
47、ionthereofOver 134 45 to 212 65,incl6000 2700 or fractionthereofOver 212 65 100 pieces or fraction thereof6.1.2.3 Full Size Specimens, Headed Bolting ComponentsHeaded bolts or screws 1 12 in. in body diameter and smaller, withbody length three times the diameter or longer, and that are produced by u
48、psetting or forging (hot or cold) shall be subjected tofull size testing in accordance with 6.1.3. This testing shall be in addition to tensile testing as specified in 6.1.1. Wedge tensiletesting shall be limited to product with socket head cap screw, hexagon, square, hex flange, or twelve point fla
49、nge heads. The lotsize shall be shown in 6.1.2.2. Failure shall occur in the body or threaded section with no failure, or indications of failure, suchas cracks, at the junction of the head and shank. Wedge tensile testing is not required for flat countersunk head or socket buttonproducts.6.1.3 Full Size Bolting Components, Wedge Tensile Test
