ASTM_E_2050_-_12a.pdf

Designation:E205012aStandard Test Method forDetermination of Total Carbon in Mold Powders byCombustion1This standard is issued under the fixed designation E2050;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.1.Scope1.1 This test method covers the determination of totalcarbon in mold powders in the concentration range from 1%to25%.NOTE1As used in this test method,“percentage”or“%”refers to amass fraction of the form(wt/wt%)(g/100g).1.2 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.3 This test method has been evaluated in accordance withPractice E1601 and Guide E1763.Unless otherwise noted inthe precision and bias section,the lower limit in the scope ofeach method specifies the lowest analyte content that may beanalyzed with acceptable error(defined as a nominal 5%riskof obtaining a 50%or larger relative difference in results onthe same test sample in two laboratories).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:2E29 Practice for Using Significant Digits in Test Data toDetermine Conformance with SpecificationsE50 Practices for Apparatus,Reagents,and Safety Consid-erations for Chemical Analysis of Metals,Ores,andRelated MaterialsE135 Terminology Relating to Analytical Chemistry forMetals,Ores,and Related MaterialsE882 Guide for Accountability and Quality Control in theChemical Analysis LaboratoryE1019 Test Methods for Determination of Carbon,Sulfur,Nitrogen,and Oxygen in Steel,Iron,Nickel,and CobaltAlloys by Various Combustion and Fusion TechniquesE1601 Practice for Conducting an Interlaboratory Study toEvaluate the Performance of an Analytical MethodE1763 Guide for Interpretation and Use of Results fromInterlaboratory Testing of Chemical Analysis Methods3.Terminology3.1 DefinitionsFor definitions of terms used in this testmethod,refer to Terminology E135.3.2 Definitions of Terms Specific to This Standard:3.2.1 mold powder,n in the continuous-casting of steel,ametallurgical flux used to provide lubrication of the mold,enhance heat transfer at the strand-mold interface,and providethermal insulation of the liquid metal surface to preventunwanted solidification.3.2.1.1 DiscussionKey chemical components of thesepowders are fluorides,the oxides of silicon and calcium,andcarbon.4.Summary of Test Method4.1 Carbon in the test sample is converted in a furnace to amixture of carbon dioxide and carbon monoxide by combus-tion in a stream of oxygen.Full conversion of carbon monox-ide to carbon dioxide occurs by the passage of sample gasesthrough a catalytic heater assembly.The amount of carbondioxide is measured by infrared absorption.Any interferencefrom halogens in the sample is eliminated by placement of ahalogen trap between the furnace and the analyzer.5.Significance and Use5.1 This test method for the determination of total carbon inmold powders is primarily intended to test such materials forcompliance with compositional specifications.It is assumedthat all who use this test method will be trained analystscapable of performing common laboratory procedures skill-fully and safely.It is expected that the work will be performedin a properly equipped laboratory and that proper waste1This test method is under the jurisdiction of ASTM Committee E01 onAnalytical Chemistry for Metals,Ores,and Related Materials and is the directresponsibility of Subcommittee E01.02 on Ores,Concentrates,and Related Metal-lurgical Materials.Current edition approved June 1,2012.Published July 2012.Originally approvedin 1999.Last previous edition approved in 2012 as E205012.DOI:10.1520/E2050-12A.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 disposal procedures will be followed.Appropriate qualitycontrol practices must be followed such as those described inGuide E882.6.Rounding Calculated Values6.1 Calculated values shall be rounded in accordance withPractice E29.7.Interferences7.1 Halogens,normally present in mold powders as fluoride,will interfere with this test method.A halogen trap,asdescribed in 8.4,must be installed in the measure line betweenthe furnace and analyzer to prevent this interference.8.Apparatus8.1 Combustion-Infrared Absorption Carbon Analyzer,equi