深层滚压加工对高碳铬轴承钢超长寿命疲劳行为的影响

深层滚压加工对高碳铬轴承钢超长寿命疲劳行为的研究表明：与深层滚压加工前相同，在高应力幅短寿命区，疲劳裂纹萌生于试样表面；由于表面压缩残余应力的影响，疲劳强度有所提高．在低应力幅长寿命区，疲劳裂纹萌生位置从未经深层滚压加工试样的次表面向深层滚压加工试样内部没有压缩残余应力和硬化层的位置转移；因弯曲应力梯度的影响，疲劳强度有了较大的提高．深层滚压加工可以提高高碳铬轴承钢在超长寿命区的旋转弯曲疲劳强度．

EFFECT OF SURFACE TREATMENT ON ULTRA LONG LIFE FATIGUE BEHAVIOR IN HIGH CARBON-CHROMIUM BEARING STEEL

Influence of deeply rolling process on fatigue behavior of high-carbon chromium bearing steel was investigated in ultra-long life regime. The results are as follows: (1) in the region of short fatigue life and high stress amplitude level, the fatigue cracks initiate at the specimen surface as the same as that before deeply rolling. In this case, fatigue strength is improved little due to the effect of compressive residual stress in the specimen surface layer; (2) in the region of long fatigue life and low stress amplitude level, the fatigue crack initiation sites transfer from subsurface in the specimens before processing to interior in the rolled specimens, where the compressive residual stress and hardened layer vanished. In this case, fatigue strength is improved much more; (3) fatigue strength of the tested bearing steel in ultra long life regime under rotating-bending load can be improved by deeply rolling process.