1、Designation: A320/A320M 17aA320/A320M 17bStandard 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 cas
2、e 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
4、by 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 fe
5、rritic 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 an
6、d 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,
7、additional 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 extensiv
8、ely 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 obta
9、inable.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 opt
10、ion 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) uni
11、ts, 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 sys
12、tems 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
13、the 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 May 1, 2017Oct. 1, 2017. Published May 2017November 2017. Originally approved in 1948. Last previous edition approved in 2017 asA320/A320M 17.A320/A320M 17a. DOI:
15、10.1520/A0320_A0320M-17A.10.1520/A0320_A0320M-17B.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 B
16、ook 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 tech
17、nically 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 this
18、 standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1A194/A194M Specification for Carbon Steel, Alloy Steel, and Stainless Steel Nuts for Bolts for High Pressure or HighTemperature Service, or BothA370 Test Methods and Definitions
19、 for Mechanical Testing of Steel ProductsA962/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 MetalsF436/F436M Specification for Hardened Steel Washers Inch
20、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 Washers3. Ordering Information3.1 It is the purchasers responsibil
21、ity 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, for the austenitic stainless steels, solution-treated (Class 1);
22、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 10, and3.1.5 Special requirements, in accordance with 5.1.1, 5.1
23、.3, 5.1.4, and 13.1.4. Common Requirements4.1 Bolting materials and 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, cer
24、tification, optional supplementary requirements, and others. Failure 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
25、 prevail.5. Materials and Manufacture5.1 Heat Treatment:5.1.1 Bolting 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 tempe
26、red.Grades B8, B8C, B8M, B8T, B8F, B8P, B8LN, and B8MLN shall receive 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 a
27、nd then cooling in air or in a liquid medium at a rate sufficient 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 1
28、A.5.1.2 Use of water quenching is prohibited for any ferritic grade 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 tre
29、ated is identified as Class 2.5.1.4 If scale-free bright finish is 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 roll
30、ing of the threads and any type of cutting.6. Mechanical Requirements6.1 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). Alternative
31、ly, Class 2 Strain Hardened Headed BoltingComponents shall be tested 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, fu
32、ll sizetest results shall prevail.6.1.2 Number of Tests:4 Available from American Society of Mechanical Engineers (ASME), ASME International Headquarters, Two Park Ave., New York, NY 10016-5990, http:/www.asme.org.A320/A320M 17b26.1.2.1 For heat-treated bars, one tension test and one impact test con
33、sisting 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, same size, and subjected to the same heat treatment. Not fewe
34、r 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, bolts, screws, etc., one tension test and one set of three impac
35、t 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 fractionthereofOver 134 45 to 212 65,incl6000 2700 or fractionthere
36、ofOver 212 65 100 pieces or fraction thereof6.1.2.3 Full Size Specimens, Headed Bolting ComponentsHeaded bolts, studs, bolts or screws 1 12 in. in body diameter andsmaller, with body length three times the diameter or longer, and whichthat are produced by upsetting or forging (hot or cold) shallbe s
37、ubjected to full size testing in accordance with 6.1.3. This testing shall be in addition to tensile testing as specified in 6.1.1.Wedge tensile testing shall be limited to product with socket head cap screw, hexagon, square, hex flange, or twelve point flangeheads. The lot size shall be shown in 6.
38、1.2.2. Failure shall occur in the body or threaded sectionssection with no failure, orindications of failure, such as cracks, at the junction of the head and shank.Wedge tensile testing is not required for flat countersunkhead or socket button products.6.1.3 Full Size Bolting Components, Wedge Tensi
39、le TestingWhen applicable, see 6.1.2.3. Headed bolts, studs, or screwscomponents shall be wedge tested full size in accordance with Annex A3 of Test Methods and Definitions size. A370 and shallconform to the tensile strength shown in Table 1. The minimum full size breaking strength (lbf) load applie
40、d (lbf or kN) forindividual sizes shall be as follows:Ts5UTS3As (1)W 5Ts 3At (1)where:W = minimum wedge tensile load without fracture,Ts = tensile strength specified in ksi or MPa in Tables 2 and 3, andAt = stress area of the thread section, square inches or square millimetres, as shown in the Cone
41、Proof Load Tables inSpecification A962/A962M.where:Ts = Wedge tensile strengthUTS = Tensile strength specified in Table 1, andAs = Stress area, square inches, as shown in ASME B1.1 or calculated as follows:As50.785 D20.974/n!2 (2)where:D = Nominal thread size, andn = The number of threads per inch.6
42、.2 Impact Properties:6.2.1 Requirements:6.2.1.1 Impact tests are required for the grades shown in Table 3. Class 1, 1A, and 2 austenitic steels for temperatures above325 F 200 C; Class 1 and 1Aaustenitic Grades B8, B8A, B8P, B8PA, B8C, B8CA, B8LN, and B8LNAabove 425 F 255C; and ferritic or austeniti
43、c bolting 12 in. (12.5 mm) and smaller, are exempt from impact testing, unless SupplementaryRequirement S1 is specified in the purchase order (see 1.4). All other material furnished under this specification shall be tested.Material of Grades L7, L7A, L7B, L7C, L7M, L43, L70, L71, L72, and L73 shall
44、show a minimum impact energy absorption of20 ft lbf 27 J and of Grade L1 a minimum impact energy absorption of 40 ft lbf 54 J at the test temperature when testedby the procedure specified in the applicable portions of Sections 19 to 28 of Test Methods and Definitions specified testtemperature. A370.
45、 The temperature of the coolant used for chilling the test specimens shall be controlled within 63 F 1.5 C.Test temperatures for ferritic grades are listed in Table 4. Exceptions to this requirement are permissible, and the impact tests maybe made at specified temperatures different than those shown
46、 in Table 4, provided the test temperature is at least as low as theintended service temperature and the bolting is suitably marked to identify the reported test temperature. When impact testing isrequired for austenitic grades, test criteria shall be agreed upon between the supplier and purchaser.6
47、.2.1.2 The impact test requirements for standard and subsize Charpy test specimens are prescribed in Table 2.6.2.2 Number of Tests:A320/A320M 17b3TABLE 3 Chemical Requirements (Composition, %)AType . . . . . . FerriticSteelsGradeSymbol . . . . . L7, L7M, L70 L7A, L71 L7B, L72 L7C, L73 L43 L1Descript
48、ion . . . Chromium-MolybdenumBCarbon-Molybdenum(AISI 4037)Chromium-Molybdenum(AISI 4137)Nickel-Chromium-Molybdenum(AISI 8740)Nickel-Chromium-Molybdenum(AISI 4340) Low-Carbon BoronRange,%ProductVariation,% Range,%ProductVariation,% Range,%ProductVariation,% Range,%ProductVariation,% Range,%ProductVar
49、iation,% Range,%ProductVariation,%Over orUnderOver orUnderOver orUnderOver orUnderOver orUnderOver orUnderCarbon 0.380.48C0.02 0.350.400.02 0.350.400.02 0.380.430.02 0.380.430.02 0.170.240.01Manganese 0.751.000.04 0.700.900.03 0.700.900.03 0.751.000.04 0.600.850.03 0.701.400.04Phosphorus,max0.035 0.005over0.035 0.005over0.035 0.005over0.035 0.005over0.035 0.005over0.035 0.005overSulfur, max 0.040 0.005over0.040 0.005over0.040 0.005over0.040 0.005over0.040 0.005over0.050 0.005overSilicon 0.1
