1、Designation:D230418Standard Test Method forThermal Endurance of Rigid Electrical Insulating Materials1This standard is issued under the fixed designation D2304;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision
2、.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope*1.1 This test method2provides procedures for evaluating thethermal endurance of rigid electrical insulating materials.Dielectric strength,f
3、lexural strength,or water absorption aredetermined at room temperature after aging for increasingperiods of time in air at selected-elevated temperatures.Athermal-endurance graph is plotted using a selected end pointat each aging temperature.A means is described for determin-ing a temperature index
4、by extrapolation of the thermalendurance graph to a selected time.1.2 This test method is most applicable to rigid electricalinsulation such as supports,spacers,voltage barriers,coilforms,terminal boards,circuit boards and enclosures for manytypes of application where retention of the selected prope
5、rtyafter heat aging is important.1.3 When dielectric strength is used as the aging criterion,itis also acceptable to use this test method for some thin sheet(flexible)materials,which become rigid with thermal aging,but is not intended to replace Test Method D1830 for thosematerials which must retain
6、 a degree of flexibility in use.1.4 This test method is not applicable to ceramics,glass,orsimilar inorganic materials.1.5 The values stated in metric units are to be regarded asstandard.Other units(in parentheses)are provided for infor-mation.1.6 This standard does not purport to address all of the
7、safety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.Aspecific warning statement is given in 11.3.4.1.7 This inte
8、rnational 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)Com
9、mittee.2.Referenced Documents2.1 ASTM Standards:3D149 Test Method for Dielectric Breakdown Voltage andDielectric Strength of Solid Electrical Insulating Materialsat Commercial Power FrequenciesD229 Test Methods for Rigid Sheet and Plate MaterialsUsed for Electrical InsulationD570 Test Method for Wat
10、er Absorption of PlasticsD790 Test Methods for Flexural Properties of Unreinforcedand Reinforced Plastics and Electrical Insulating Materi-alsD1830 Test Method for Thermal Endurance of FlexibleSheet Materials Used for Electrical Insulation by theCurved Electrode MethodD5423 Specification for Forced-
11、Convection Laboratory Ov-ens for Evaluation of Electrical Insulation2.2 IEEE:4No.1 General Principles Upon Which Temperature LimitsAre Based in the Rating of Electric EquipmentNo.98 Guide for the Preparation of Test Procedures for theThermal Evaluation of Electrical Insulating MaterialsNo.101 Guide
12、for the Statistical Analysis of Test Data3.Terminology3.1 Definitions:3.1.1 Arrhenius plot,na graph of the logarithm of thermallife as a function of the reciprocal of absolute temperature.3.1.1.1 DiscussionThis is normally depicted as the beststraight line fit,determined by least squares,of end poin
13、tsobtained at aging temperatures.It is important that the slope,1This test method is under the jurisdiction of ASTM Committee D09 onElectrical and Electronic Insulating Materials and is the direct responsibility ofSubcommittee D09.07 on Electrical Insulating Materials.Current edition approved May 1,
14、2018.Published May 2018.Originally issuedas D2304 64 T.Last previous edition approved in 2010 as D2304 10.DOI:10.1520/D2304-18.2This test method is a revision of a procedure written by the Working Group onRigid Electrical Insulating Materials of the Subcommittee on Thermal Evaluation,IEEE Electrical
15、 Insulation Committee,which was presented as CP 59-113 at theIEEE Winter General Meeting Feb.16,1959.See references at end of this testmethod.3For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume
16、information,refer to the standards Document Summary page onthe ASTM website.4Available from the Institute of Electrical and Electronics Engineers,445 HoesLn.,P.O.Box 1331,Piscataway,NJ 08854-1331.*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 i
