ASTM_A_321_-_90_2001.pdf

Designation:A 321 90(Reapproved 2001)Standard Specification forSteel Bars,Carbon,Quenched and Tempered1This standard is issued under the fixed designation A 321;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon(e)indicates an editorial change since the last revision or reapproval.1.Scope1.1 This specification covers hot-rolled,quenched,and tem-pered carbon steel bars,of the following sections and sizeranges:1.1.1 Rounds,14to 912in.(6.35 to 241.3 mm)incl,indiameter.1.1.2 Squares,14to 512in.(6.35 to 139.7 mm)incl,between parallel surfaces.1.1.3 Hexagons,14in.(6.35 mm)and over betweenparallel surfaces.1.2 The values stated in inch-pound units are to be regardedas the standard.The values given in parentheses are forinformation only.2.Referenced Documents2.1 ASTM Standards:A 29/A29M Specification for Steel Bars,Carbon and Alloy,Hot-Wrought and Cold-Finished,General Requirementsfor2A 370 Test Methods and Definitions for Mechanical Testingof Steel Products33.Ordering Information3.1 Orders for material under this specification shouldinclude the following information:3.1.1 Quantity(weight or number of pieces),3.1.2 Name of material,3.1.3 Stress relief anneal(if required),3.1.4 Finish(specify descaled and oiled if required),3.1.5 Dimensions(cross sectional shape,size,and length),3.1.6 Straightness(if other than standard is required),3.1.7 Leaded steel(if required),3.1.8 Heat analysis or test report(if required),3.1.9 ASTM designation and date of issue,and3.1.10 Additional requirements,if any.NOTE1A typical ordering description is as follows:10 000 lb,hot-rolled bars quenched and tempered,straightened,stress relieved,descaled,1.000 in.diameter by 10 ft long,heat analysis required,ASTMA 321,dated_.4.Manufacture4.1 Melting PracticeThe steel shall be made by one ormore of the following primary processes:open-hearth,basic-oxygen,or electric-furnace.The primary melting may incor-porate separate degassing or refining and may be followed bysecondary melting using electroslag remelting or vacuum arcremelting.Where secondary melting is employed,the heatshall be defined as all of the ingots remelted from a singleprimary heat.4.2 DiscardA sufficient discard shall be made(from eachingot,when ingot cast)to secure freedom from injurious pipingand undue segregation.4.3 Heat Treatment:4.3.1 CoolingImmediately after rolling,the bars shall beallowed to cool to a temperature below the critical range undersuitable conditions to prevent injury by too rapid cooling.4.3.2 Quenching and TemperingThe material shall beuniformly heated to the austenitizing temperature,soaked for asufficient length of time to produce the desired change instructure(a group thus heated being known as a“quenchingcharge”),and quenched in some medium under substantiallyuniform conditions for each quenching charge.The materialshall then be uniformly reheated to the proper temperature fortempering(a group thus reheated being known as a“temperingcharge”),and allowed to cool uniformly.The temperatureselected for tempering shall not be less than 800F(427C).4.3.3 Stress RelievingWhen it is desirable to minimizeinternal stresses introduced by straightening,the purchasermay specify a stress relief anneal as a final operation.5.Chemical Composition5.1 Chemical CompositionThe steel shall conform to therequirements for chemical composition specified in Table 1.5.2 Leaded SteelWhen required,lead may be specified asan added element.A range from 0.15 to 0.35%,inclusive,iscommonly specified.Heat analysis for lead is not determinablesince lead is added to the ladle stream while each ingot ispoured.1This specification 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 Jan.26,1990.Published March 1990.Originallypublished as A 321 49 T.Last previous edition A 321 89.2Annual Book of ASTM Standards,Vol 01.05.3Annual Book of ASTM Standards,Vol 01.03.1Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.6.Grain Size Requirements6.1 The steel shall conform to the fine austenitic grain sizerequirement of Specification A 29/A 29M.7.Mechanical Properties7.1 Tensile PropertiesThe material,after final heat treat-ment and straightening,shall conform to the requirements as totensile properties specified in Table 2.7.2 Test Specimens:7.2.1 Test specimens shall be prepared for testing from thematerial in the quenched and tempered condition.7.2.2 Specimens shall be taken longitudinally and may betested in full thickness or section,or they may be machined tothe dimensions shown in Figs.4 or Figs.6 of Test Methods andDefinitionsA 370.If test specimens are selected conforming tothe dimensions of Fig.6 for sizes 112in.(38.1 mm)and largerin diameter or