表層超硬化M50NiL鋼接觸疲勞失效機理

表層超硬化M50NiL鋼接觸疲勞失效機理Failure Mechanism of Contact Fatigue of Surface Super-hardened M50NiL Steel

應用表面輪廓儀、維氏硬度計、殘余應力X射線測定儀、光學顯微鏡、掃描電子顯微鏡（SEM）、滾動接觸疲勞試驗機等，對比研究表層超硬化M50NiL鋼和M50鋼制圓棒試樣的硬度梯度、殘余應力梯度以及組織結(jié)構(gòu)，實測各自滾動接觸疲勞壽命，并對比分析失效過程，探討表層超硬化M50NiL鋼的疲勞失效機理。結(jié)果表明：表層超硬化M50NiL鋼失效機理回歸赫茲理論，為典型的接觸疲勞失效特征，接觸疲勞壽命大幅提高；高的表面硬度和表面殘余壓應力，良好的組織結(jié)構(gòu)，能夠完全抑制表面起始裂紋的形成，是失效機理回歸赫茲理論的主要原因。

Hardness gradient, residual stress gradient and the organization structure of surface super-hardened M50NiL steel roller and M50 steel roller were studied, the rolling contact fatigue life was measured, and the failure process was analyzed and compared by using surface profiler, Vickers hardness tester, X ray residual stress determinator, optical microscope, scanning electron microscope (SEM), rolling contact fatigue test machine and other equipment. The fatigue failure mechanism of surface super-hardened M50NiL steel was revealed. The results show that the fatigue failure mechanism of surface super-hardened M50Nil steel returns to the Hertz theory and shows typical contact fatigue characteristics. The high surface hardness, residual compressive stress and a good organization structure can completely inhibit the initiation of surface cracks; therefore, the failure mechanism is returned to the Hertz theory.

全文下載：https://pan.baidu.com/s/1hss3emg