Very high cycle fatigue for GCr15 steel with smooth and hole-defect specimens  

作　　者：Zhengqiang Lei Aiguo Zhao Jijia Xie Chengqi Sun Youshi Hong 

机构地区：[1]State Key Laboratory of Nonlinear Mechanics,Institute of Mechanics,Chinese Academy of Sciences,Beijing 100190,China

出　　处：《Theoretical & Applied Mechanics Letters》2012年第3期7-10,共4页力学快报（英文版）

基　　金：supported by the National Natural Science Foundation of China(11021262 and 11172304);the National Basic Research Program of China (2012CB937500)

摘　　要：Very high cycle fatigue（VHCF） properties of a low temperature tempering bearing steel GCr15 with smooth and hole-defect specimens are studied by employing a rotary bending test machine with frequency of 52.5 Hz.Both smooth and hole-defect specimens break in VHCF regime with some difference in fatigue crack initiation.For smooth specimens,a fine granular area（FGA） is observed near the grain boundary in the fracture surface of the specimens broken after 10~7 cycles. But no FGA is observed in the hole-defect specimens broken in VHCF regime,and the VHCF crack does not initiate from the small hole at the surface as it does at low or high cycle fatigue regime. Internal stress is employed to explain the VHCF behavior of these two types of specimens.At last,an advanced dislocation model based on Tanaka and Mura model is proposed to illustrate the internal stress process and to predict fatigue crack initiation life with FGA observed in the fracture region.Very high cycle fatigue（VHCF） properties of a low temperature tempering bearing steel GCr15 with smooth and hole-defect specimens are studied by employing a rotary bending test machine with frequency of 52.5 Hz.Both smooth and hole-defect specimens break in VHCF regime with some difference in fatigue crack initiation.For smooth specimens,a fine granular area（FGA） is observed near the grain boundary in the fracture surface of the specimens broken after 10~7 cycles. But no FGA is observed in the hole-defect specimens broken in VHCF regime,and the VHCF crack does not initiate from the small hole at the surface as it does at low or high cycle fatigue regime. Internal stress is employed to explain the VHCF behavior of these two types of specimens.At last,an advanced dislocation model based on Tanaka and Mura model is proposed to illustrate the internal stress process and to predict fatigue crack initiation life with FGA observed in the fracture region.

关 键 词：Very high cycle fatigue GCR15 FGA hole-defect experimental research 

分 类 号：TG142.15[一般工业技术—材料科学与工程] TB43[金属学及工艺—金属材料]