A247 -19 Standard Test Method for Evaluating the Microstructure of Graphite in lron Castings

Designation: A247 -19 Standard Test Method for Evaluating the Microstructure of Graphite in lron Castings1 1. Scope 1.1 This test method covers the classification of graphite incast irons in tenms of type，distribution. and size by visualcomparison to reference photomicrographs. This test mcthod isintended to be applicable for all iron-carbon alloys containinggraphite particles.and may be applied to gray irons. malleableirons.compacted graphite irons.and the ductile (nodular)irons. 1.2 The reference photomicrographs included in this testmethod are in no way to be construed as specifications. In anappropriate specification for a specific material where graphitemicrostructure is an important considcration, this test methodmay be used as a reference to concisely define the graphitemicrostructure required. 1.3 These reference photomicrographs are offered primarilyto permit accurate reporting of microstructures of cast ironsand to facilitate the comparison of reports by different labora-tories or investigators. 1.4 The values stated in Sl units are to be regarded asstandard. No other units of measurement are included in thisstandard. 1.5 This standard does nor purport to address all of thesafety concerns.if ary. associated wirh irs use. It is rherespowsibility of the user of this standard to establish cappro-priate sefety，healhe,and ertvironarteatal practices and deter-imine rhe applicabiliry of regualctory linirations prior to use.l.6 This insernctioal siandard was developed inr cccor-dance wirh insernarionally recognized principles ow stadard-izationestablished in the Decisiow on Principles for rheDevelopmenr of Intermctioncl Standards，Guides cnd Recon-merderios issued by the World Trade Organizatiow TechnicalBarviers to Trade(TBTy Comnniaree.