胀断连杆用中碳非调质钢的高周疲劳性能  

High-Cycle Fatigue Property of Medium-Carbon Microalloyed Steel for Connecting Rod of Fracture Splitting

作　　者：刘智雄[1,2] 惠卫军[1,2] 陈思联[1] 张英建[1] 董瀚[1,2] 刘荣佩[2] 

机构地区：[1]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 [2]昆明理工大学材料科学与工程学院,云南昆明650093

出　　处：《钢铁研究学报》2011年第6期49-53,共5页Journal of Iron and Steel Research

基　　金：国家科技支撑计划项目(2007BAE51B03)

摘　　要：采用旋转弯曲疲劳试验和疲劳裂纹扩展速率试验对比研究了一种新型胀断连杆用中碳非调质钢50SiMn VPS(R9)与传统高碳钢C70S6(R8)的高周疲劳性能。结果表明,R9的疲劳极限和疲劳极限比均明显高于R8。硅和磷元素的铁素体固溶强化作用及钒元素的析出强化和组织细化作用,使得R9的微观组织细小、均匀,珠光体与铁素体的显微硬度比HP/HF降低,从而具有优异的疲劳性能。The high-cycle fatigue properties of newly developed medium-carbon microalloyed steel 50SiMnVPS（R9） and conventional high carbon steel C70S6（R8） for connecting rod of fracture splitting were studied by using rotating-bending fatigue test and fatigue crack growth rate test.The results show that microstructure has a significant effect on the fatigue properties of the microalloyed forging steels.Both the fatigue limit and fatigue limit ratio of steel R9,which has fine and uniform microstructure of ferrite and pearlite,are significantly higher than that of steel R8,which has mainly coarse pearlite and few film-like ferrite along coarse prior austenite grain boundary.Furthermore,the microhardness ratio of ferrite to pearlite of steel R9 is lower than that of steel R8.It is considered that the significant solidification strengthening effect of higher content of Si and P elements and precipitation strengthening and microstructure refining effect of V element are the main reasons for the improved fatigue properties of steel R9.

关 键 词：高周疲劳 中碳非调质钢 胀断连杆 微观组织 

分 类 号：TG115.57[金属学及工艺—物理冶金]