Product Code:SAE AS1260
Title:Equivalent Sections of Certain Shapes to Round Bars
Issuing Committee:Ams E Carbon And Low Alloy Steels Committee
Scope: Primarily to provide the aerospace industry with approximate standards for comparing various shaped sections to round bars, in determining the response to hardening characteristics when heat treating low-alloy and marensitic corrosion-resistant steels.
【英文标准名称】:StandardTestMethodforDeterminationofSlowCrackGrowthParametersofAdvancedCeramicsbyConstantStress-RateFlexuralTestingatElevatedTemperatures
【原文标准名称】:高温下用恒定应力速度挠曲试验测定高级陶瓷的慢裂增长系数的标准试验方法
【标准号】:ASTMC1465-2008
【标准状态】:现行
【国别】:美国
【发布日期】:2008
【实施或试行日期】:
【发布单位】:美国材料与试验协会(US-ASTM)
【起草单位】:C28.01
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:
【英文主题词】:advancedceramics;constantstress-ratetesting;elevatedtemperatures;flexuralstrength;flexuraltesting;four-pointflexure;slowcrackgrowth;slowcrackgrowthparameters;Advancedceramics;Constantstress-rateflexuraltesting;Cracking--crackgro
【摘要】:Formanystructuralceramiccomponentsinservice,theiruseisoftenlimitedbylifetimesthatarecontrolledbyaprocessofslowcrackgrowth.Thistestmethodprovidestheempiricalparametersforappraisingtherelativeslowcrackgrowthsusceptibilityofceramicmaterialsunderspecifiedenvironmentsatelevatedtemperatures.ThistestmethodissimilartoTestMethodC1368withtheexceptionthatprovisionsfortestingatelevatedtemperaturesaregiven.Furthermore,thistestmethodmayestablishtheinfluencesofprocessingvariablesandcompositiononslowcrackgrowthaswellasonstrengthbehaviorofnewlydevelopedorexistingmaterials,thusallowingtailoringandoptimizingmaterialprocessingforfurthermodification.Insummary,thistestmethodmaybeusedformaterialdevelopment,qualitycontrol,characterization,andlimiteddesigndatagenerationpurposes.Note38212;Datageneratedbythistestmethoddonotnecessarilycorrespondtocrackvelocitiesthatmaybeencounteredinserviceconditions.Theuseofdatageneratedbythistestmethodfordesignpurposesmayentailconsiderableextrapolationandlossofaccuracy.Inthistestmethod,theflexuralstresscomputationisbasedonsimplebeamtheory,withtheassumptionsthatthematerialisisotropicandhomogeneous,themoduliofelasticityintensionandcompressionareidentical,andthematerialislinearlyelastic.Theaveragegrainsizeshouldbenogreaterthanonefiftieth(1/50)ofthebeamthickness.Inthistestmethod,thetestspecimensizesandtestfixtureswerechoseninaccordancewithTestMethodC1211,whichprovidesabalancebetweenpracticalconfigurationsandresultingerrors,asdiscussedinRefs(7,8).Onlythefour-pointtestconfigurationisusedinthistestmethod.Inthistestmethod,theslowcrackgrowthparameters(nandD)aredeterminedbasedonthemathematicalrelationshipbetweenflexuralstrengthandappliedstressrate,logx03C3;f=[1/(n+1)]logx02D9;x03C3;+logD,togetherwiththemeasuredexperimentaldata.Thebasicunderlyingassumptiononthederivationofthisrelationshipisthatslowcrackgrowthisgovernedbyanempiricalpower-lawcrackvelocity,v=A[KI/KIC]n(seeAppendixX1).Note48212;Therearevariousotherformsofcrackvelocitylawswhichareusuallymorecomplexorlessconvenientmathematically,orboth,butmaybephysicallymorerealistic(9).Themathematicalanalysisinthistestmethoddoesnotcoversuchalternativecrackvelocityformulations.Inthistestmethod,themathematicalrelationshipbetweenflexuralstrengthandstressratewasderivedbasedontheassumptionthattheslowcrackgrowthparameterisatleastnx2265;5(3,10).Therefore,ifamaterialexhibitsaveryhighsusceptibilitytoslowcrackgrowth,thatis,nx003C;5,specialcareshouldbetakenwheninterpretingtheresults.Themathematicalanalysisoftestresultsaccordingtothemethodin4.4assumesthatthematerialdisplaysnorisingR-curvebehavior,thatis,noincreasingfractureresistance(orcrack-extensionresistance)withincreasingcracklength.Itshouldbe......
基本信息
| 标准名称： | 冷镦六角头螺栓模具 切边冲头 |
| 中标分类： |
机械 >>
工艺装备 >>
模具 |
| 替代情况： | JB 4209.3-1986 |
| 发布部门： | 中华人民共和国机械工业部 |
| 发布日期： | 1996-09-03 |
| 实施日期： | 1997-07-01 |
| 首发日期： | 1900-01-01 |
| 作废日期： | 1900-01-01 |
| 提出单位： | 全国模具标准化技术委员会 |
| 归口单位： | 机械工业部北京机电研究所 |
| 起草单位： | 沈阳标准件研究所 |
| 起草人： | 李坚 |
| 出版社： | 机械工业出版社 |
| 出版日期： | 1997-07-01 |
| 页数： | 4页 |
| 批文号： | 机械科[1996]685号 |
适用范围
本标准规定了冷镦GB 5780~5786六角头螺栓M3~M20切边冲头的结构型式与尺寸、技术要求和标记。 本标准适用于多工位自动冷镦机和自动切边机的模具
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所属分类： 机械 工艺装备 模具