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.
出处
《钢铁研究学报》
CAS
CSCD
北大核心
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)
关键词
高周疲劳
中碳非调质钢
胀断连杆
微观组织
high-cycle fatigue property
medium-carbon microalloyed steel
connecting rod of fracture splitting
microstructure