ASTM_E_1077_-_14.pdf

Designation:E107714Standard Test Methods forEstimating the Depth of Decarburization of SteelSpecimens1This standard is issued under the fixed designation E1077;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()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.INTRODUCTIONThese test methods may be used to estimate the average or greatest depth of decarburization inhardened or non-hardened steel products.The test methods described range from simple screeningtests to more statistically rigorous test methods depending upon the needs of the investigation.1.Scope1.1 These test methods cover procedures for estimating thedepth of decarburization of steels irrespective of thecomposition,matrix microstructure,or section shape.Thefollowing basic procedures may be used:1.1.1 Screening methods.1.1.2 Microscopical methods.1.1.3 Microindentation hardness methods.1.1.4 Chemical analysis methods.1.2 In case of a dispute,the rigorous quantitative or linealanalysis method(see 7.3.5 and 7.3.6)shall be the refereemethod.These methods can be employed with any cross-sectional shape.The chemical analytical methods generallyreveal a greater depth of decarburization than the microscopi-cal methods but are limited to certain simple shapes and byavailability of equipment.These techniques are generallyreserved for research studies.The microindentation hardnessmethod is suitable for accurate measurements of hardenedstructures with relatively homogeneous microstructures.1.3 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.4 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2A941 Terminology Relating to Steel,Stainless Steel,RelatedAlloys,and FerroalloysE3 Guide for Preparation of Metallographic SpecimensE7 Terminology Relating to MetallographyE340 Test Method for Macroetching Metals and AlloysE350 Test Methods for Chemical Analysis of Carbon Steel,Low-Alloy Steel,Silicon Electrical Steel,Ingot Iron,andWrought IronE384 Test Method for Knoop and Vickers Hardness ofMaterialsE407 Practice for Microetching Metals and AlloysE415 Test Method for Analysis of Carbon and Low-AlloySteel by Spark Atomic Emission SpectrometryE1951 Guide for Calibrating Reticles and Light MicroscopeMagnifications3.Terminology3.1 Definitions:3.1.1 For definitions of terms used in these test methods,seeTerminology E7 and Terminology A941.3.2 Definitions of Terms Specific to This Standard:3.2.1 average depth of decarburizationthe mean value offive or more measurements of the total depth of decarburiza-tion.3.2.2 average free-ferrite depththe mean value of five ormore measurements of the depth of complete decarburization.1These test methods are under the jurisdiction of ASTM Committee E04 onMetallography and are the direct responsibility of Subcommittee E04.14 onQuantitative Metallography.Current edition approved Jan.1,2014.Published March 2014.Originallyapproved in 1985.Last previous edition approved in 2005 as E1077 01(2005).DOI:10.1520/E1077-14.2For 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 Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.2.3 complete decarburizationloss of carbon content atthe surface of a steel specimen to a level below the solubilitylimit of carbon in ferrite so that only ferrite is present.3.2.4 free-ferrite depththe perpendicular distance from thesurface of the specimen to that location where the structure isno longer fully ferritic,that is,other transformation productsare observed.NOTE1The term free ferrite has also been used to describe globular,isolated grains of proeutectoid ferrite in the microstructure of medium-carbon hypoeutectoid steels.3.2.5 maximum depth of decarburizationthe largest mea-sured value of the total depth of decarburization.3.2.6 partial decarburizationloss of carbon content at thesurface of a steel specimen to a level less than the bulk carboncontent of the unaffected interior but greater than the roomtemperature solubility limit of carbon in ferrite.3.2.7 total depth of decarburizationthe perpendicular dis-tance from the specimen surface to that location in the interiorwhere the bulk carbon content is reached;that is,the sum of thedepths of complete and partial decarbur