1、Designation:A40017Standard Practice forSteel Bars,Selection Guide,Composition,and MechanicalProperties1This standard is issued under the fixed designation A400;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision
2、.A number in parentheses indicates the year of last reapproval.Asuperscript 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 practice covers the selection of steel bars a
3、ccordingto section and to the mechanical properties desired in the partto be produced.This is not a specification for the procurementof steel.Applicable procurement specifications are listed inSection 5.1.2 Several steel compositions intended for various sectionsand mechanical property requirements
4、are presented in Tables1-6.The criteria for placing a steel composition in one of thethree general class designations,Classes P,Q,and R(describedin Section 4)are as follows:1.2.1 Classes P and Q should be capable of developing themechanical properties shown in Tables 1-4 by liquid quenchingfrom a su
5、itable austenitizing temperature,and tempering at800 F(427 C)or higher.A hardness indicated by tests madeat a location shown in Fig.1,A,B,or C,is taken as evidencethat a composition is capable of meeting other equivalentmechanical properties shown in the tables.Normal good shoppractices are assumed,
6、with control of austenitizing and tem-pering temperatures,and mild agitation of the part in thequenching bath.1.2.2 Class R should be capable of developing the mechani-cal properties shown in Tables 5 and 6 as hot rolled,by colddrawing,or by cold drawing with additional thermal treatment.The locatio
7、ns for obtaining tension tests are described in 6.2.1.3 It is not implied that the compositions listed in the tablesare the only ones satisfactory for a certain class and mechanicalproperty requirement.Steels with lower alloy contents areoften satisfactory through the use of special processing tech-
8、niques.1.4 The values stated in inch-pound units are to be regardedas standard.The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.5 This international standard was developed in accor-dance with international
9、ly 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 TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2A108 Specificatio
10、n for Steel Bar,Carbon and Alloy,Cold-FinishedA304 Specification for Carbon and Alloy Steel Bars Subjectto End-Quench Hardenability RequirementsA311/A311M SpecificationforCold-Drawn,Stress-Relieved Carbon Steel Bars Subject to Mechanical Prop-erty RequirementsA322 Specification for Steel Bars,Alloy,
11、Standard GradesA633/A633M Specification for Normalized High-StrengthLow-Alloy Structural Steel PlatesA675/A675M Specification for Steel Bars,Carbon,Hot-Wrought,Special Quality,Mechanical Properties3.Significance and Use3.1 If the desired mechanical properties are as described in4.1.1 for material id
12、entified as Classes P-1 through P-7,or in4.1.2 for material identified as Classes Q-1 through Q-7,thestrength level desired can be based on hardness or theequivalent tensile or yield strength as shown in Tables 1-4.Ifthe desired mechanical properties are as set forth in 4.1.3 formaterial identified
13、as Classes R-1 through R-6,the strengthlevel is based on yield strength as shown in Tables 5 and 6.3.2 The user,after determining the mechanical propertyrequirements of the critical section(that carrying the greateststress)of the part,should select the composition or composi-tions from Tables 1-6 th
14、at fulfills these requirements and ismost suitable for processing.1This practice is under the jurisdiction of ASTM Committee A01 on Steel,Stainless Steel and Related Alloys and is the direct responsibility of SubcommitteeA01.15 on Bars.Current edition approved Nov.1,2017.Published December 2017.Orig
15、inallyapproved in 1956.Last previous edition approved in 2012 as A400 69(2012).DOI:10.1520/A0400-17.2For 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 to the standards Documen
16、t 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 internationally 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
