ASTM-E112-2010-Standard-Test-Methods-for-Determining-Average-Grain-Size

Copyright ASTM International.100 Barr Harbor Drive.West Conshohocken.Pennsyl vania 19428.USADistributed under ASTM Iicense agreement by Shanghai Institute of Standardization (SIS)Tel:86-21-64370807Designation:E112-10NTERNATIONALStandard Test Methods forDetermining Average Grain Size1This standard is issued under the fixed designation E112;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.This standard has been approved for use by agencies of the Department of Defense.INTRODUCTIONThese test methods of determination of average grain size in metallic materials are primarilymeasuring procedures and,because of their purely geometric basis,are independent of the metal oralloy concerned.In fact,the basic procedures may also be used for the estimation of average grain,crystal,or cell size in nonmetallic materials.The comparison method may be used if the structure ofthe material approaches the appearance of one of the standard comparison charts.The intercept andplanimetric methods are always applicable for determining average grain size.However,thecomparison charts cannot be used for measurement of individual grains.1.Scope1.4 These test methods describe techniques performed1.1 These test methods cover the measurement of averagemanually using either a standard series of graded chart imagesgrain size and include the comparison procedure,the planimet-for the comparison method or simple templates for the manualric (or Jeffries)procedure,and the intercept procedures.Thesecounting methods.Utilization of semi-automatic digitizingtest methods may also be applied to nonmetallic materials withtablets or automatic image analyzers to measure grain size isstructures having appearances similar to those of the metallicdescribed in Test Methods E1382.structures shown in the comparison charts.These test methods1.5 These test methods deal only with the recommended testapply chiefly to single phase grain structures but they can bemethods and nothing in them should be construed as definingapplied to determine the average size of a particular type ofor establishing limits of acceptability or fitness of purpose ofgrain structure in a multiphase or multiconstituent specimen.the materials tested.1.2 These test methods are used to determine the average1.6 The measured values are stated in SI units,which aregrain size of specimens with a unimodal distribution of grainregarded as standard.Equivalent inch-pound values,whenareas,diameters,or intercept lengths.These distributions arelisted,are in parentheses and may be approximate.approximately log normal.These test methods do not cover1.7 This standard does not purport to address all of themethods to characterize the nature of these distributions.safety concems,if any,associated with its use.