【摘要】 研究了JIS-SUJ2轴承钢的超高周疲劳行为及高压气相热充氢对疲劳性能的影响。结果表明,高压气相热充氢后疲劳性能明显降低,裂纹源周围"GBF"区的颗粒状特征变浅甚至消失。断口上裂纹源处缺陷尺寸及分布对疲劳寿命没有影响,疲劳寿命随着"GBF"与夹杂物尺寸比的增加而增加。充氢前后裂纹源边缘的应力强度因子范围均近似正比于裂纹尺寸的1/3次方,"GBF"裂纹扩展的门槛值正比于"GBF"尺寸的1/6次方。高压气相热充氢明显提高了氢致附加应力强度因子,估算的"GBF"裂纹尺寸的极限值与实验值能够较好地吻合。更多还原

【Abstract】 The very high cycle fatigue(VHCF)behavior of JIS-SUJ2bearing steel and the effects of high pressure thermal hydrogen charging(HPTHC)on fatigue properties were investigated.The results demonstrate that the fatigue properties of this bearing steel is obviously reduced after being precharged by HPTHC.The granular feature of"GBF"area for pre-charged specimens becomes light,sometimes even vanished.The distributions and size of the defects at the crack origins have no apparent effect on fatigue life.The fatigue life increases with increasing the relative size of"GBF"to inclusion.The stress intensity factor range at the periphery of crack origin before and after being precharged is approximately proportional to 1/3power of the crack origin size,the crack growth threshold for"GBF"crack is proportional to 1/6power of the"GBF"size.The additional stress intensity factor created by hydrogen multiplies up after being pre-charged by HPTHC,the calculated critical values of"GBF"are well in agreement with the experimental values.更多还原