資源描述：
《Use of EBSD technique to examine microstructure and cracking in a bainitic steel 》由會(huì)員上傳分享，免費(fèi)在線閱讀，更多相關(guān)內(nèi)容在學(xué)術(shù)論文-天天文庫(kù)。
1、ScriptaMaterialia,Vol.39,No.3,pp.295±300,1998ElsevierScienceLtdPergamonCopyright?1998ActaMetallurgicaInc.PrintedintheUSA.Allrightsreserved.1359-6462/98$19.001.00PIIS1359-6462(98)00170-5USEOFEBSDTECHNIQUETOEXAMINEMICROSTRUCTUREANDCRACKINGINABAINITICSTEEL32
2、E.Bouyne,H.M.Flower*,T.C.Lindley*andA.Pineau*DepartmentofMaterials,ImperialCollege,LondonSW72BP,UK2CentredesMate?riauxDEcoledesMinesdeParis,BP87,91003Evry(France)(ReceivedFebruary16,1998)IntroductionDynamiccrackpropagationandcrackarrestisanimportantissuei
3、nthefieldofstructuralintegrity.Focusisusuallyplacedontheinitiationstep(KIc)toavoidcatastrophicfailuresofstructures.Nevertheless,itisoftenrequiredinsafetyanalysistoconsiderthatacrackmightinitiate(forexampleinlocalbrittlezones)andleadtothepropagationathighs
4、peedofacleavagecrack.Itisimportanttoknowwhetherornotthematerialwillbeabletoarrestthatcrackbeforeitgoesthroughtheentirestructure.Toanswerthatquestionitisessentialtounderstandcleavagemicromechanismsduringcrackpropagationinordertoassesstheenergydissipatedahe
5、adofthecracktip.Inapreviousstudy[1]thesemicro-mechanismswereinvestigatedinalowalloysteelwithabainiticmicrostructure.Itwasshownthatacrackpropagatingathighvelocity(a?'500m/s)isformedbyanetworkofmicrocracksinterconnectedtoeachothersurroundingislandsofunbroke
6、nligamentsleftbehindthecrackfront.Theseligamentswhichneedtobedeformedplasticallybeforefinalfracturelargelycontributetothedissipatedenergyduringcrackpropagationandatcrackarrest.TheseobservationsaresimilartothoseofHoaglandetal.[2]madeonothersteels.Togofurth
7、er,itisnowimportanttounderstandthelinkbetweenthematerialmicrostructureandthisnetworkofcleavagemicro-cracks,specificallytoidentifytherelevantmicrostructuralfeaturesleadingtoasinglemicro-crack(unitcrackpath)andthecrystallographicnatureofcleavagefracture.The
8、preliminaryresultspresentedinthispaperwereobtainedusingtheElectronBack-ScatterDiffractiontechnique(EBSD).Thismethodenablescrystallographicinformationstobeobtainedfromsmallsurfaceregionsofbulksamples(;1mmdiameterand3
