无碳化物贝氏体高碳钢滚动接触疲劳失效分析

对无碳化物贝氏体高碳钢开展滚动接触疲劳试验, 利用扫描电镜(SEM)、透射电镜(TEM)、X射线衍射仪(XRD)、三维轮廓仪、显微硬度计和纳米压痕等分析方法, 对比分析低应力和高应力水平下的失效行为, 研究其失效机制. 结果表明, 无碳化物贝氏体高碳钢在1.8 GPa低接触应力下有更优异的滚动接触疲劳性能, 其失效形式为表面剥落; 在2.6 GPa高接触应力水平下, 表面出现严重的塑性变形, 表面粗糙度增加导致最大剪切应力增加, 位置逐渐靠近表面. 在2.6 GPa接触应力下塑性变形层形成梯度结构, 但是在1.8 GPa接触应力下并未发现梯度结构, 在塑性变形层发现大量的孔洞.

Failure analysis of carbide-free bainitic high carbon steel under rolling contact fatigue

Rolling contact fatigue test was carried out on carbide-free bainitic high carbon steel. The failure behavior and mechanism were studied under low and high stress levels by means of scanning electron microscope (SEM), transmission electron microscope (TEM), nano-indentation, microhardness tester and three-dimensional profilometer. The results showed that carbide-free bainitic high carbon steel showed much longer rolling contact fatigue performance under lower contact stress of 1.8 GPa. Specimens failed in the way of surface spalling. Under high contact stress level of 2.6 GPa, severe plastic deformation was observed on the surface. The increased surface roughness led to the rise in the magnitude of the maximum shear stress and the location shifted close to the surface. Gradient microstructure was generated in the plastic deformation layer under 2.6 GPa, but was not observed under 1.8 GPa, where many voids were presented in the plastic deformation layer.