渗碳齿轮钢的组织和疲劳性能.pdf

2009’高品质特殊钢技术与市场论坛 渗碳齿轮钢的组织和疲劳性能 and ofCaseCarburizedSteels Microstructure FatigueProperties 王毛球，马莉，张国强，董瀚 MaoqiuWang，LiMa，Guoqiang．Zhang，HanDong (钢铁研究总院先进钢铁材料技术国家工程研究中心，北京100081) ResearchCenterofAdvancedSteel IronandSteelResearch (National Institute， Engineering Technology，Central No．76 XueYuanNanLu，Beijing100081，China) 摘要：本文利用旋转弯曲试验方法，研究两种渗碳钢的疲劳性能。结果表明，由于细小的Nb(Cm析出相在奥氏体晶界起钉 现，疲劳裂纹主要起源于氧化物夹杂物，然后沿原奥氏体晶界扩展，因此细化渗碳层晶粒有利于提高疲劳性能。 on ABSTRACT-Fatigueoftwocase steelshavebeen meansof tests properties hardening investigatedby rotatingbendingfatigue smoothbar after thatthe hada limitofll70 than carburization．Resultsshow 0．04％Nbsteel fatigue MPa．18％higher specimens tlIat oftheNb．freesteel．Itisalsoshownthatthe0．04％Nbsteelhadfiner austenitesizesinthecarburizedcase弱aresult prior grain ofthe effectoffine onaustenite electron pinning Nb(C，N)particlesgraincoarseningduringcarburization．Scanningmicrographic observationsthefracture ofthe show crack fromoxide and on surfacefatigue thatfatigue initiated inclusions specimens usually austenite thatthefiner austenitesizeinthecarburizedcaseofthe propagatedalongprior grainboundaries，indicatingprior grain 0．04％Nbsteelcancontributetoits higherfatigueproperties． 关键字：渗碳钢，旋转弯曲疲劳，品粒度，微合金化 KEYWoRDS：case hardeningsteel；r