188宝金博页面版

Designation: E2050 − 17Standard Test Method forDetermination of Total Carbon in Mold Powders byCombustion 1This standard is issued under the f i xed 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 %.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 specif i es the lowest analyte content that may beanalyzed with acceptable error (def i ned 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.1.5 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards: 2E29 Practice for Using Signif i cant Digits in Test Data toDetermine Conformance with Specif i cationsE50 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 Methods(Withdrawn 2015) 33. Terminology3.1 Def i nitions—For def i nitions of terms used in this testmethod, refer to Terminology E135.3.2 Def i nitions of Terms Specif i c to This Standard:3.2.1 mold powder, n— in the continuous-casting of steel, ametallurgical f l ux 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 solidif i cation.3.2.1.1 Discussion—Key chemical components of thesepowders are f l uorides, 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 (CO 2 ) and carbon monoxide (CO)by combustion in a stream of oxygen. Full conversion of CO toCO 2 occurs by the passage of sample gases through a catalyticheater assembly. The amount of CO 2 is measured by infraredabsorption. Any interference from halogens in the sample iseliminated by placement of a halogen trap between the furnaceand the analyzer.1 This 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 April 1, 2017. Published June 2017. Originallyapproved in 1999. Last previous edition approved in 2012 as E2050–12a. DOI:10.1520/E2050-17.2 For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at service@astm.org. For Annual Book of ASTMStandards volume information, refer to the standard’s Document Summary page onthe ASTM website.3 The last approved version of this historical standard is referenced onwww.astm.org.Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1 Copyright by ASTM Int'l (all rights reserved); Sat Sep 30 22:58:49 EDT 2017Downloaded/printed byUniversity of Edinburgh (University of Edinburgh) pursuant to License Agreement. No further reproductions authorized.