鉴于接触疲劳试验周期长、工作量大,提出了一种金属材料小滑差率接触疲劳加速试验方法,其主要步骤是: (1)用滑差率连续可调的滚动接触疲劳试验机进行试验。(2)先进行无润滑磨损实验,利用主动轴试样和从动轴试样磨损率的差异,在被测试样(从动轴试样)上预制剪切裂纹。(3)再加润滑剂,进行液体润滑接触疲劳实验。实验结果表明,在被测试样和陪试样材料基本相同的条件下,当循环周次达到约104时,被测试样表面即出现接触疲劳失效,而陪试样(主动轴试样)基本上无点蚀或剥落。激光离散熔凝可大幅提高珠光体钢的接触疲劳寿命,其机理是激光作用使珠光体转变为奥氏体与细小马氏体混合组织,这种组织具有较好的塑性,不利于疲劳裂纹的扩展。

Contact fatigue testing is a hard work, it requires many testing specimens and testing time is longer. For this reason a novel method for low slip-ratio contact fatigue accelerating test is proposed. The main steps of this method including: (1) it is tested on a rolling contact fatigue test machine with slip-ratio continually adjusted; (2) carrying out non-lubricated wear testing to prefabricate shear crack on the tested specimen, i.e. the driven roller, by means of the wear difference between the driving roller and driven roller; (3) carrying out contact fatigue test with lubricant. It is confirmed by a lot of experiments that the tested specimen failure occurs about 104cycles, while the counterpart specimen, i.e. the driving roller, is without any pitting or spalling, if the two specimens are made in the same materials. Laser dispersed melting pearlite steel will greatly enhance the life of contact fatigue by a mixture of retained austenite and fine martensite, which was transformed from pearlite by laser remelting, has good plasticity and unfavorable for fatigue crack propagation.