ASTM_E_1245_-_03_2008.pdf

Designation:E124503(Reapproved 2008)Standard Practice forDetermining the Inclusion or Second-Phase ConstituentContent of Metals by Automatic Image Analysis1This standard is issued under the fixed designation E1245;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.INTRODUCTIONThis practice may be used to produce stereological measurements that describe the amount,number,size,and spacing of the indigenous inclusions(sulfides and oxides)in steels.The method may also beapplied to assess inclusions in other metals or to assess any discrete second-phase constituent in anymaterial.1.Scope1.1 This practice describes a procedure for obtaining stereo-logical measurements that describe basic characteristics of themorphology of indigenous inclusions in steels and other metalsusing automatic image analysis.The practice can be applied toprovide such data for any discrete second phase.NOTE1Stereological measurement methods are used in this practiceto assess the average characteristics of inclusions or other second-phaseparticles on a longitudinal plane-of-polish.This information,by itself,does not produce a three-dimensional description of these constituents inspace as deformation processes cause rotation and alignment of theseconstituents in a preferred manner.Development of such informationrequires measurements on three orthogonal planes and is beyond the scopeof this practice.1.2 This practice specifically addresses the problem ofproducing stereological data when the features of the constitu-ents to be measured make attainment of statistically reliabledata difficult.1.3 This practice deals only with the recommended testmethods and nothing in it should be construed as defining orestablishing limits of acceptability.1.4 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.5 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:2E3 Guide for Preparation of Metallographic SpecimensE7 Terminology Relating to MetallographyE45 Test Methods for Determining the Inclusion Content ofSteelE768 Guide for Preparing and Evaluating Specimens forAutomatic Inclusion Assessment of Steel3.Terminology3.1 Definitions:3.1.1 For definitions of terms used in this practice,seeTerminology E7.3.2 Symbols:A=the average area of inclusions or particles,m2.AA=the area fraction of the inclusion or constituent.Ai=the area of the detected feature.AT=the measurement area(field area,mm2).HT=the total projected length in the hot-workingdirection of the inclusion or constituent in thefield,m.L=the average length in the hot-working directionof the inclusion or constituent,m.LT=the true length of scan lines,pixel lines,or gridlines(number of lines times the length of thelines divided by the magnification),mm.n=the number of fields measured.NA=the number of inclusions or constituents of agiven type per unit area,mm2.1This practice is under the jurisdiction of ASTM Committee E04 on Metallog-raphy and is the direct responsibility of Subcommittee E04.14 on QuantitativeMetallography.Current edition approved Oct.1,2008.Published January 2009.Originallyapproved in 1988.Last previous edition approved in 2003 as E1245 03.DOI:10.1520/E1245-03R08.2For 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 Ni=the number of inclusions or constituent particlesor the number of feature interceptions,in thefield.NL=the number of interceptions of inclusions orconstituent particles per unit length(mm)of scanlines,pixel lines,or grid lines.PPi=the number of detected picture points.PPT=the total number of picture points in the fieldarea.s=the standard deviation.t=a multiplier related to the number of fieldsexamined and used in conjunction with thestandard deviation of the measurements to deter-mine the 95%CIVV=the volume fraction.X=the mean of a measurement.Xi=an individual measurement.l=the mean free path(m)of the inclusion orconstituent type perpendicular to the hot-working direction.X=the sum of all of a particular measurement overn fields.X2=the sum of all of the squares of a particularmeasurement over n fields.95%CI=the 95%confidence interval.%RA=the relative accuracy,%.4.Summary of Practice4.1 The indigenous inclusions or second-p