1、Designation: A400 69 (Reapproved 2012)Standard 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,
2、 the year of last revision. 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 Department of Defense.1. Scope1.1 This practice covers the
3、 selection of steel bars accordingto 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 mecha
4、nical property requirements 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 Table
5、s 1-4 by liquid quenchingfrom a suitable austenitizing temperature, and tempering at800F (427C) or higher. A hardness indicated by tests made ata location shown in Fig. 1, A, B, or C, is taken as evidence thata composition is capable of meeting other equivalent mechani-cal properties shown in the ta
6、bles. Normal good shop practicesare assumed, with control of austenitizing and temperingtemperatures, and mild agitation of the part in the quenchingbath.1.2.2 Class R should be capable of developing the me-chanical properties shown in Tables 5 and 6 as hot rolled, bycold drawing, or by cold drawing
7、 with additional thermaltreatment. The locations for obtaining tension tests are de-scribed 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 satisfac
8、tory through the use of special processing tech-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.2. Referenced Documents2.1 AST
9、M Standards:2A108 Specification for Steel Bar, Carbon and Alloy, Cold-FinishedA304 Specification for Carbon andAlloy Steel Bars Subjectto End-Quench Hardenability RequirementsA311/A311M Specification for Cold-Drawn, Stress-Relieved Carbon Steel Bars Subject to Mechanical Prop-erty RequirementsA322 S
10、pecification for Steel Bars, Alloy, 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
11、 are as described in4.1.1 for material identified 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
12、 set forth in 4.1.3 formaterial identified 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
13、 composition or composi-tions from Tables 1-6 that fulfills these requirements and ismost suitable for processing.4. Classification4.1 Steel bar compositions under this practice are classifiedaccording to mechanical property requirements and the criticalsection size of the part to be produced, as fo
14、llows:4.1.1 Classes P-1 through P-7 comprise bars for parts tooperate under severe service conditions requiring high yieldstrength (90 000 psi (621 MPa) and over), good ductility, and1This practice is under the jurisdiction of ASTM Committee A01 on Steel,Stainless Steel and Related Alloys and is the
15、 direct responsibility of SubcommitteeA01.15 on Bars.Current edition approved March 1, 2012. Published April 2012. Originallyapproved in 1956. Last previous edition approved in 2006 as A400 69 (2006).DOI: 10.1520/A0400-69R12.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcon
16、tact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.relatively high notch
17、 toughness. The applicable section sizes,identified as Classes P-1 through P-7, are shown in Table 7.The steel compositions suitable for Classes P-1 through P-7and for various desired mechanical properties are listed inTables 1 and 2.4.1.2 Classes Q-1 through Q-7 comprise bars for partsoperating und
18、er moderate service conditions requiring moder-ate to high yield strength (75 000 to 185 000 psi (517 to 1276MPa), corresponding tensile-strength levels, and good ductil-ity. The applicable section sizes, identified as Classes Q-1through Q-7, are shown in Table 7. The steel compositionssuitable for
19、Classes Q-1 through Q-7 and various desiredmechanical properties are listed in Tables 3 and 4.4.1.3 Classes R-1 through R-6 comprise bars for partsrequiring a lower yield strength (30 000 to 120 000 psi (207to 827 MPa), with fair to good ductility. The applicablesection sizes, identified as Classes
20、R-1 through R-6, are shownin Table 7. The steel compositions capable of developing thevarious desired mechanical properties are listed in Tables 5 and6.TABLE 1 Steels for Moderately Quenched PartsClasses P-1 Through P-7(Applicable to oil-quenching or equivalent rate of heat-removal.)NOTE 1Steels lis
21、ted as approved for a certain section or strength may be used for lighter sections and lower strengths.NOTE 2Steel composition numbers correspond to SAE, AISI, or ASTM designations. Those in italics are no longer considered standard grades dueto decreased usage.NOTE 3An H-steel with the same grade d
22、esignation as a standard SAE-AISI steel is capable of meeting the same section and strength requirementsas the standard steel (see Specification A304), and is the preferred method of specification.NOTE 4Steels having a maximum carbon content of 0.40 % or over, or a hardness of HB 293 or over after h
23、eat-treating, are not recommended forapplications involving welding.Desired MinimumHardnessEquivalentTensileStrength, psiAEquivalentYieldStrength, psiAMinimumBAs-QuenchedHardnessClassP-1 P-2 P-3 P-4 P-5 P-6 P-7Diameter of Round (or Distance Between Faces of Squareor Hexagonal) Sections, in.CTo12 , i
24、ncl Over12 to 1,inclOver 1 to112 , inclOver 112to 2, inclOver 2 to212 , inclOver 212to 3, inclOver 3to 312 ,inclThickness of Flat Sections, in.CHB HRC HB HRCTo 0.3, incl Over 0.3 to0.6, inclOver 0.6to 1,inclOver 1to 1.3,inclOver 1.3to 1.6,inclOver 1.6to 2.0,inclOver 2.0to 2.3,incl229 to 293,incl20 t
25、o 33,incl110 000 to145 000,incl90 000 to125 000,incl388 42 13304130 50B3051328630Over 293to 341,inclOver 33to 38,inclOver 145 000to 170 000,inclOver 125 000to 150 000,incl409 44 1335 94B30 3140 4137 4142 9840 43373135 41354042 46405135 86408740Over 341to 388,inclOver 38to 42,inclOver 170 000to 190 0
26、00,inclOver 150 000to 170 000,incl455 48 1340 4137 4140 4145 4147 43403140 6145 TS4140 9840 43374047 8642 86B454135 8645 94B405140 87428637TS14B5050B40Over 388 to429, inclOver 42to 45,inclOver 190 000to 205 000,inclOver170 000to 185 000,incl496 51 1345 8645 5147 4142 8660 4147 4150 E43404063 8740 51
27、55 4145 9840 4161 4161 98504068 8742 5160 4337 4340 TS41504140 9260 6150 8650 86B454640 9261 9262 86555145 TS4140 50B605150 50B46 94B40 51B608640 50B44 81B458642 50B50A1 psi = 0.006895 MPa.BMinimum as-quenched hardness for obtaining desired hardness after tempering at 800F (427C) or higher.C1 in. =
28、25.4 mm.A400 69 (2012)25. Applicable Procurement Specifications5.1 For procurement of steel, it is recommended that thefollowing ASTM specifications of latest issue be used: Speci-ficationA108, SpecificationA304, SpecificationA311/A311M,Specification A322, Specification A633/A633M, and Specifi-catio
29、n A675/A675M.6. Location at Which Desired Properties Are Obtained6.1 Classes P-1 Through P-7 and Q-1 Through Q-7Themechanical properties shown in Tables 1-4 are based onobtaining hardness test specimens from the locations shown inFig. 1, A, B, and C. For bars, the location should be at leasttwice th
30、e diameter or minimum distance between faces from anend; and for flat sections, at least twice the thickness from anedge.6.2 Classes R-1 Through R-6The mechanical propertiesshown in Tables 5 and 6 are based on obtaining tension testspecimens from the following locations:6.2.1 Center of bars or plate
31、s under 112 in. (38.1 mm) indiameter or in distance between parallel surfaces, and6.2.2 Mid-radius or a quarter of the distance betweenparallel faces from the surface for larger sections.7. Hardness Criteria for Quenched and Tempered Parts7.1 Classes Q-1 Through Q-7To obtain the propertiesstated in
32、4.1.2 at the locations shown in Fig. 1, A, B, and C, amicrostructure containing a minimum of 50 % martensite isnecessary.8. Keywords8.1 steel barsTABLE 2 Steels for Drastically Quenched PartsClasses P-1 Through P-7(Applicable to water-quenching or equivalent rate of heat-removal See Note 5)NOTE 1Ste
33、els listed as approved for heavier sections or higher strengths may be used in the same conditions for lighter sections and lower strengths.NOTE 2Steel composition numbers correspond to ASE, AISI, or ASTM designations. Those in italics are no longer considered standard grades dueto decreased usage.N
34、OTE 3An H-steel with the same grade designation as a standard SAE-AISI steel is capable of meeting the same section and strength requirementsas the standard steel (see Specification A304), and is the preferred method of specification.NOTE 4Steels having a maximum carbon content of 0.40 % or over, or
35、 a hardness of HB 293 or over after heat-treating, are not recommended forapplications involving welding.NOTE 5Parts made of steel with a carbon content of 0.33 % or higher, where the section is under 1 1/2 in. (38.1 mm) should not be quenched inwater without careful exploration for quench-cracking.
36、Desired MinimumHardnessEquivalentTensileStrength, psiAEquivalentYieldStrength, psiAMinimumBAs-QuenchedHardnessClassP-1 P-2 P-3 P-4 P-5 P-6 P-7Diameter of Round (or Distance Between Faces of Squareor Hexagonal) Sections, in.CTo12 , incl Over12to 1,inclOver 1 to112 , inclOver112 to2, inclOver 2to 212
37、,inclOver 212to 3, inclOver 3to 312 ,inclThickness of Flat Sections, in.CHB HRC HB HRC To 0.3, incl Over 0.3to 0.6,inclOver 0.6to 1.0,inclOver1.0to 1.3,inclOver 1.3to 1.6,inclOver 1.6to 2.0,inclOver 2.0to 2.3,incl229 to 293,incl20 to 33,incl110 000 to145 000,incl90 000 to125 000,incl388 42 8625 4130
38、 94B308627 5130863050B30Over 293to 341,inclOver 33to 38,inclOver 145 000to 170 000,inclOver 125 000to 150 000,incl409 44 4032 1330 1335 1340D3140 41374037 5132 5135 3135D4135 43374130 94B30 5140 4640 98405130 50B40 8637D8630 8640TS14B35 8740508B30A1 psi = 0.006895 MPa.BMinimum as-quenched hardness f
39、or obtaining desired hardness after tempering at 800F (427C) or higher.C1 in. = 25.4 mm.DThese steels have insufficient hardenability for Class P-4, because of difference in test locations, but are satisfactory for other smaller sizes.A400 69 (2012)3TABLE 3 Steels for Moderately Quenched PartsClasse
40、s Q-1 Through Q-7(Applicable to oil-quenching or equivalent rate of heat-removal.)NOTE 1Steels listed as approved for heavier sections or higher strengths may be used in the same conditions for lighter sections and lower strengths.NOTE 2Steel composition numbers correspond to ASE, AISI, or ASTM desi
41、gnations. Those in italics are no longer considered standard grades dueto decreased usage.NOTE 3An H-steel with the same grade designation as a standard SAE-AISI steel is capable of meeting the same section and strength requirementsas the standard steel (see Specification A304), and is the preferred
42、 method of specification.NOTE 4Steels having a maximum carbon content of 0.40 % or over, or a hardness of HB 293 or over after heat-treating, are not recommended forapplications involving welding.Desired MinimumHardnessEquivalentTensileStrength,psiAEquivalentYieldStrength,psiAMinimumBAs-QuenchedHard
43、nessClassQ-1 Q-2 Q-3 Q-4 Q-5 Q-6 Q-7Diameter of Round (or Distance Between Faces of Squareor Hexagonal) Sections, in.CTo12, inclOver12to 1,inclOver 1to 112,inclOver112to 2,inclOver 2to 212,inclOver 212to 3,inclOver 3to 312,inclThickness of Flat Sections, in.CHB HRC HB HRC To 0.3, inclOver 0.3 to 0.6
44、,inclOver 0.6to 1.0,inclOver 1.0to 1.3,inclOver 1.3to 1.6,inclOver 1.6to 2.0,inclOver 2.0to 2.3,incl187 to 293, 91 (Rb) 95 000 to 75 000 to 388 42 1330 8630 8637 3140 4140 4142incl to 33, 145 000, 125 000, 4130 50B30 8740 TS4140incl incl incl 5132 94B40Over 293 Over 33 Over Over 409 44 1335 3140 874
45、0 4137 TS4140 81B45 4142 4145 4147to 341, to 38, 145 000 125 000 4042 50B30 4135 4140 4337incl incl to to 5135 4640 8642 9840170 000, 150 000, 94B30 8640 8645 86B45incl incl 8742Over 341 Over 38 Over Over 455 48 1340 8637 1345 8742 4142 94B40 51B60 4145 4147 4150to 388, to 42, 170 000 150 000 3135 T
46、S14B50 4137 TS4140 5147 8655 4337 4340incl incl to to 3140 50B40 4140 50B50 5155 9840 86B45 TS4150190 000, 170 000, 4047 5150 6150incl incl 4135 86425140 8645Over 388 Over 42 Over Over 496 51 1345 8645 4142 4145 9840 4147 4150 E4340to 429, to 45, 190 000 170 000 4047 8740 5147 4337 4340 TS4150 9850i
47、ncl incl to to 4063 8742 5155 5160 8660205 000, 185 000, 4068 9260 6150 8650 86B45incl incl 4140 TS4140 9261 86554640 50B46 94B40 92625145 50B44 50B605150 50B50 51B608640 81B458642A1 psi = 0.006895 MPa.BMinimum as-quenched hardness for obtaining desired hardness after tempering at 800F (427C) or hig
48、her.C1 in. = 25.4 mm.A400 69 (2012)4TABLE 4 Steels for Drastically Quenched PartsClasses Q-1 Through Q-7(Applicable to water-quenching or equivalent rate of heat-removalSee Note 5)NOTE 1Steels listed as approved for heavier sections or higher strengths may be used in the same conditions for lighter
49、sections and lower strengths.NOTE 2Steel composition numbers correspond to SAE, AISI, or ASTM designations. Those in italics are no longer considered standard grades dueto decreased usage.NOTE 3An H-steel with the same grade designation as a standard SAE-AISI steel is capable of meeting the same section and strength requirementsas the standard steel (see Specification A304), and is the preferred method of specification.NOTE 4Steels having a maximum carbon content of 0.40 % or over, or a hardness of HB 293 or over after h
