低碳鋼晶粒細化后的力學性能研究.pdf

1、東北大學碩士學位論文低碳鋼晶粒細化后的力學性能研究姓名：趙志華申請學位級別：碩士專業(yè)：材料加工工程指導教師：杜林秀李長生20040201東北走學碩士學位論文AbstractAbstractTheworksofthisthesiswerecarriedoutintegratingwiththe863projectofTheAdvancedIndustrialManufactureTechnologyof500MPaCarbonSteelT

2、hemechanicalpropertiesof400MPaand500MPaultra—finegrainedsteelwereinvestigatedthroughsingleaxletensiletest，seriallowtemperaturesimpacttestunderlowtemperatureandcoldbendingtest，combiningwiththeanalysisofthemicrostructuresa

3、ndthefractureappearancetherelationshipbetweenthemicrostructureandthepropertieswerealsoinvestigatedthroughhotrollingexperimentinthelaboratory，thestrengtheningandtougheningmechanismofthecompoundstrengtheningsuchasfinegrain

4、strengthening，phasetransformationstrengthening，precipitationstrengtheningectIntheultrafinegrainsteelwerecarriedoutwithcorrespondingTMCPconditionsThemainachievementsofthispresentWOrkwereasfollows：1Throughsingleaxletensile

5、test，thestrengthandplasticityoftheindustrialultrafinedgrainsteelsandhotrollingexperimentsteelswereinvestigated，andthestrengtheningandtougheningmechanismwasalsoinvestigatedcombiningwiththemicrostructureThesizeoftheferrite

6、grainoftheultrafinegrainsteelwas35Bm，themicrostructurewasferriteandpearlitewithsomebainiteWiththefine—grainstrength，solutionstrengthandthetransformationstrength，theyieldstrengthof400MPaultrafinedgrainsteelscouldreach430M

7、Pa，thepercentageelongationafterfracturecouldreach30％，whiletheyieldstrengthof500MPaultrafinedgrainsteelscouldreach530MPa，thepercentageelongationafterfracturecouldreach26％2Thevaluesofplasticstrainratio，，thevaluesofstrainha

8、rdeningexponentnoftheindustrialultrafinedgrainsteelsandhotrollingexperimentsteelsweremeasuredandtheformationsabilitywasanalysedbycombiningwiththecoldbendingtestTheexistofthebainitecouldhighlyraisethestrengthfotheultrafin