ASTM_A_991_-_A_991M_-_17.pdf

Designation:A991/A991M17Standard Test Method forConducting Temperature Uniformity Surveys of FurnacesUsed to Heat Treat Steel Products1This standard is issued under the fixed designation A991/A991M;the number immediately following the designation indicates the yearof original adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.A superscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope*1.1 This test method covers the procedures used to conducta temperature uniformity survey on a furnace used to heat treatsteel products.This method is used to determine the capabilityof the furnace to meet the permissible temperature variationspecified in the applicable product specification,or as agreed toby the purchaser and supplier of heat treat services.Surveydocumentation requirements,and the procedure used to subse-quently establish the furnace working zone,are defined in thistest method.1.2 This test method covers heat treat furnaces in any of thefollowing categories:1.2.1 Continuous or semi-continuous conveyance furnaces,1.2.2 Batch furnaces,and1.2.3 Salt or liquid baths and fluidized beds.1.3 This test method only applies when specified in theproduct specification or the purchase order.1.4 Controlling a heat treatment of steel products usingthermocouples attached to the extremities of each load is analternative to performing a furnace survey.1.5 By mutual agreement between the purchaser and thesupplier of heat treat services,more stringent and/or additionalrequirements may be specified.The acceptance of any suchadditional requirements shall be dependent on negotiationswith the supplier and must be included in the order as agreedupon by the purchaser and supplier.1.6 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard.The values stated ineach system may not be exact equivalents;therefore,eachsystem shall be used independently of the other.Combiningvalues from the two systems may result in non-conformancewith the standard.1.7 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.1.8 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:2E207 Test Method for Thermal EMF Test of Single Thermo-element Materials by Comparison with a Reference Ther-moelement of Similar EMF-Temperature PropertiesE220 Test Method for Calibration of Thermocouples ByComparison TechniquesE230 Specification and Temperature-Electromotive Force(EMF)Tables for Standardized ThermocouplesE608/E608M Specification for Mineral-Insulated,Metal-Sheathed Base Metal Thermocouples2.2 SAE Standard:3AMS 2750 Pyrometry3.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 batch furnace,nheating device in which materialmay be stationary or oscillating during the processing cycle.3.1.2 continuous conveyance furnace,nheating devicethrough which material is moved intentionally at a constantrate during the processing cycle.3.1.3 extremities,nas referring to furnace working zone;outer boundaries in all three dimensions(length,width,andheight)of the material being processed.1This test method is under the jurisdiction of ASTM Committee A01 on Steel,Stainless Steel and Related Alloys and is the direct responsibility of SubcommitteeA01.13 on Mechanical and Chemical Testing and Processing Methods of SteelProducts and Processes.Current edition approved April 15,2017.Published April 2017.Originallyapproved in 1998.Last previous edition approved in 2015 as A991/A991M 10(2015).DOI:10.1520/A0991_A0991M-17.2For 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.3Available from Society of Automotive Engineers(SAE),400 CommonwealthDr.,Warrendale,PA 15096-0001,http:/www.sae.org.*A Summary of Changes section appears at the end of this standardCopyright 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 3.1.4 operating range,nexpected range of temperatureover which a