1、Designation: A320/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 case of revision,
2、 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 specification
3、2covers alloy steel bolting materialsand bolting components for pressure vessels, valves, flanges,and fittings for low-temperature service. See SpecificationA962/A962M for the definition of bolting. The bars shall behot-wrought and may be further processed by centerlessgrinding or by cold drawing. A
4、ustenitic stainless steel may besolution annealed or annealed and strain-hardened. Whenstrain hardened austenitic stainless steel is ordered, the pur-chaser should take special care to ensure that Appendix X1 isthoroughly understood.1.2 Several grades are covered, including both ferritic andaustenit
5、ic steels designated L7, B8, etc. Selection will dependon design, service conditions, mechanical properties, andlow-temperature characteristics. The mechanical requirementsof Table 1 indicate the diameters for which the minimummechanical properties apply to the various grades and classes,and Table 2
6、 stipulates the requirements for Charpy impactenergy absorption. The manufacturer should determine that thematerial can conform to these requirements before parts aremanufactured. For example, when Grade L43 is specified tomeet the Table 2 impact energy values at 150 F 101 C,additional restrictions
7、(such as procuring a steel with lower Pand S contents than might normally be supplied) in thechemical composition for AISI 4340 are likely to be required.NOTE 1The committee formulating this specification has includedseveral grades of material that have been rather extensively used for thepresent pu
8、rpose. Other compositions will be considered for inclusion bythe committee from time to time as the need becomes apparent. Usersshould note that hardenability of some of the grades mentioned mayrestrict the maximum size at which the required mechanical properties areobtainable.1.3 The following refe
9、renced general requirements are in-dispensable for application of this specification: SpecificationA962/A962M.1.4 Nuts for use with bolting are covered in Section 10 andthe nut material shall be impact tested.1.5 Supplementary Requirements are provided for use at theoption of the purchaser. The supp
10、lementary requirements shallapply only when specified in the purchase order or contract.1.6 This specification is expressed in both inch-pound unitsand SI units; however, unless the purchase order or contractspecifies the applicable M specification designation (SI) units,the inch-pound units shall a
11、pply.1.7 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 shall be used independently of the other. Combiningvalues from the two systems may result in non-conformance
12、with the standard.1.8 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization Te
13、chnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:3A194/A194M Specification for Carbon Steel, Alloy Steel,and Stainless Steel Nuts for Bolts for High Pressure orHigh Temperature Service, or BothA962/A962M Specification for Common Requirements forBolting Intended for
14、Use at Any Temperature from Cryo-genic to the Creep RangeE566 Practice for Electromagnetic (Eddy Current) Sorting ofFerrous Metals1This specification is under the jurisdiction of ASTM Committee A01 on Steel,Stainless Steel and Related Alloys and is the direct responsibility of SubcommitteeA01.22 on
15、Steel Forgings and Wrought Fittings for PipingApplications and BoltingMaterials for Piping and Special Purpose Applications.Current edition approved Oct. 1, 2017. Published November 2017. Originallyapproved in 1948. Last previous edition approved in 2017 as A320/A320M 17a.DOI: 10.1520/A0320_A0320M-1
16、7B.2For ASME Boiler and Pressure Vessel Code applications, see related Specifi-cation SA-320 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
17、 to the standards Document Summary page onthe ASTM website.*A Summary 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 StatesThis international standard was developed in accordance with in
18、ternationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1TABLE1MechanicalRequirementsClassandGrade,Dia
19、meter,in.mmHeatTreatmentMinimumTemperingTemperature,FCTensileStrength,min,ksiMPaYieldStrength,min,ksiMPa(0.2%offset)Elongationin2in.or50mm,min,%ReductionofArea,min,%Hardness,maxFerriticSteelsL7,L7A,L7B,L7C,L70,L71,L72,L731251051650321HBWor35HRC21265andunderAquenchedandtempered1100593860725L431251051
20、650321HBWor35HRC4100andunderAquenchedandtempered1100593860725L7M100801850235HBWBor99HRB21265andunderAquenchedandtempered1150620690550L11251051650.125andunderAquenchedandtempered860725AusteniticSteelsCClass1:B8,B8C,B8M,B8P,B8F,B8T,B8LN,B8MLN,alldiameterscarbidesolutiontreated75515302053050223HBWDor96
21、HRBClass1A:B8A,B8CA,B8MA,B8PA,B8FA,B8TA,B8LNA,B8MLNA,alldiameterscarbidesolutiontreatedinthefinishedcondition75515302053050192HBWor90HRBClass2:B8,B8C,B8P,B8F,B8T:carbidesolutiontreatedandstrainhardened3420andunder1258601006901235321HBWor35HRCover34to120to25,incl115795805501530321HBWor35HRCover1to114
22、25to32,incl105725654502035321HBWor35HRCover114to11232to40,inclA100690503452845321HBWor35HRCClass2:B8M:carbidesolutiontreatedandstrainhardened3420andunder110760956551545321HBWor35HRCover34to120to25,incl100690805502045321HBWor35HRCover1to11425to32,incl95655654502545321HBWor35HRCover114to11232to40,incl
23、A90620503453045321HBWor35HRCATheseupperdiameterlimitswereestablishedonthebasisthatthesewerethelargestsizescommonlyavailablethatconsistentlymetspecificationpropertylimits.Theyarenotintendedasabsolutelimitsbeyondwhichboltingmaterialscouldnolongerbecertifiedtothespecification.BTomeetthetensilerequireme
24、nts,theBrinellhardnessshallnotbelessthan200HBWor93HRB.CClass1productsaremadefromsolution-treatedmaterial.Class1Aproductsaresolutiontreatedinthefinishedconditionforcorrosionresistance;heattreatmentiscriticalforenhancingthisphysicalpropertyandmeetingthemechanicalpropertyrequirements.Class2productsarem
25、adefromsolution-treatedmaterialthathasbeenstrainhardened.Austeniticsteelsinthestrain-hardenedconditionmaynotshowuniformpropertiesthroughoutthecrosssection,particularlyinsizesover34in.20mmindiameter.DForsizes34in.20mmindiameterandsmaller,amaximumhardnessof241HBW(100HRB)ispermitted.A320/A320M 17b2F436
26、/F436M Specification for Hardened Steel Washers Inchand Metric DimensionsF606/F606M Test Methods for Determining the MechanicalProperties of Externally and Internally ThreadedFasteners, Washers, Direct Tension Indicators, and Rivets2.2 ASME Standards:4B1.1 Screw ThreadsB18.22.1 Plain Washers3. Order
27、ing Information3.1 It is the purchasers responsibility to specify in thepurchase order all information necessary to purchase theneeded materials. Examples of such information include, butare not limited to, the following:3.1.1 Quantity and size,3.1.2 Heat-treated condition, that is, for the austenit
28、ic stain-less steels, solution-treated (Class 1); solution-treated afterfinishing (Class 1A); and annealed and strain-hardened (Class2),3.1.3 Description of items required (bars, bolts, screws, orstuds),3.1.4 Nuts and washers, if required by the purchaser, inaccordance with Section 10, and3.1.5 Spec
29、ial requirements, in accordance with 5.1.1, 5.1.3,5.1.4, and 13.1.4. Common Requirements4.1 Bolting materials and bolting components supplied tothis specification shall conform to the requirements of Speci-fication A962/A962M. These requirements include testmethods, finish, thread dimensions, macroe
30、tch (carbon andalloy steels only) marking, certification, optional supplemen-tary requirements, and others. Failure to comply with therequirements of Specification A962/A962M constitutes non-conformance with this specification. In case of conflict be-tween the requirements in this specification and
31、SpecificationA962/A962M, this specification shall prevail.5. Materials and Manufacture5.1 Heat Treatment:5.1.1 Bolting materials shall be allowed to cool to roomtemperature after rolling or forging. Grades L7, L7A, L7B,L7C, L7M, L43, L1, L70, L71, L72, and L73 shall be reheatedto above the upper cri
32、tical temperature and liquid quenchedand tempered. Grades B8, B8C, B8M, B8T, B8F, B8P, B8LN,and B8MLN shall receive a carbide solution treatment. Prod-ucts made from such material are described as Class 1. Thisshall consist of holding the bolting material for a sufficient timeat a temperature at whi
33、ch the chromium carbide will go intosolution and then cooling in air or in a liquid medium at a ratesufficient to prevent reprecipitation of the carbide. Boltingmaterial thus treated is described as Class 1. If specified in thepurchase order, bolting material shall be solution treated in thefinished
34、 condition and shall be described as Class 1A.5.1.2 Use of water quenching is prohibited for any ferriticgrade when heat treatment is performed after heading orthreading.5.1.3 When increased mechanical properties are desired,austenitic bolting shall be solution annealed and strain hard-ened if speci
35、fied in the purchase order; material so treated isidentified as Class 2.5.1.4 If scale-free bright finish is required, this shall bespecified in the purchase order.5.1.5 For L7M bolting, the final heat treatment, which maybe the tempering or stress-relieving operation conducted at1150 F 620 C minimu
36、m, shall be done after machining orrolling of the threads and any type of cutting.6. Mechanical Requirements6.1 Tensile Properties:6.1.1 Bolting material as represented by the tension speci-mens shall conform to the requirements as to tensile propertiesprescribed in Table 1 at room temperature after
37、 heat treatment(see 5.1.1). Alternatively, Class 2 Strain Hardened HeadedBolting Components shall be tested full size after strainhardening to determine tensile strength and yield strength andshall conform to the requirements prescribed in Table 1.Should the results of full size tests conflict with
38、results oftension specimen tests, full size test results shall prevail.6.1.2 Number of Tests:6.1.2.1 For heat-treated bars, one tension test and oneimpact test consisting of three specimens shall be made foreach diameter of each heat represented in each temperingcharge. When heat treated without int
39、erruption in continuousfurnaces, the material in a lot shall be the same heat, same priorcondition, same size, and subjected to the same heat treatment.Not fewer than two tensile tests and two impact tests arerequired for each lot containing 20 000 lbs 9000 kg or less.Every additional 10 000 lbs 450
40、0 kg or fraction thereofrequires an additional tensile test and impact test.6.1.2.2 For studs, bolts, screws, etc., one tension test andone set of three impact specimens shall be made for eachdiameter of each heat involved in the lot. Each lot shall consistof the following:4Available from American S
41、ociety of Mechanical Engineers (ASME), ASMEInternational Headquarters, Two Park Ave., New York, NY 10016-5990, http:/www.asme.org.TABLE 2 Impact Energy Absorption RequirementsSize ofSpecimen, mmMinimum Impact ValueRequired for Averageof Each Set of ThreeSpecimens, ftlbf JMinimum ImpactValue Permitte
42、d 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 32ASee 6.2.1.1 for permitted exemptions.A320/A320M 17b3Diameter, in. mm Lot Size, lb kg118 30 and under 1500 680 or fraction thereofOver 118 30 to 134 45,incl45
43、00 2040 or fractionthereofOver 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 112 in. in body diameter and smaller,with body length three times the diameter or longer, and thatare
44、 produced by upsetting or forging (hot or cold) shall besubjected to full size testing in accordance with 6.1.3. Thistesting shall be in addition to tensile testing as specified in6.1.1. Wedge tensile testing shall be limited to product withsocket head cap screw, hexagon, square, hex flange, or twel
45、vepoint flange heads. The lot size shall be shown in 6.1.2.2.Failure shall occur in the body or threaded section with nofailure, or indications of failure, such as cracks, at the junctionof the head and shank. Wedge tensile testing is not required forflat countersunk head or socket button products.6
46、.1.3 Full Size Bolting Components, Wedge TensileTestingWhen applicable, see 6.1.2.3. Headed componentsshall be wedge tested full size. The minimum full size loadapplied (lbf or kN) for individual sizes shall be as follows:W 5 Ts3At(1)where:W = minimum wedge tensile load without fracture,Ts= tensile
47、strength specified in ksi or MPa in Tables 2 and3, andAt= stress area of the thread section, square inches or squaremillimetres, as shown in the Cone Proof Load Tables inSpecification A962/A962M.6.2 Impact Properties:6.2.1 Requirements:6.2.1.1 Impact tests are required for the grades shown inTable 3
48、. Class 1, 1A, and 2 austenitic steels for temperaturesabove 325 F 200 C; Class 1 and 1Aaustenitic Grades B8,B8A, B8P, B8PA, B8C, B8CA, B8LN, and B8LNA above425 F 255 C; and ferritic or austenitic bolting12 in. (12.5mm) and smaller, are exempt from impact testing, unlessSupplementary Requirement S1
49、is specified in the purchaseorder (see 1.4). All other material furnished under this speci-fication shall be tested. Material of Grades L7, L7A, L7B, L7C,L7M, L43, L70, L71, L72, and L73 shall show a minimumimpact energy absorption of 20 ft lbf 27 J and of Grade L1a minimum impact energy absorption of 40 ft lbf 54 J at thespecified test temperature. The temperatu
