四种列车车轮材料近表层的硬度值分布规律

Subsurface Hardness Distribution Regularity of Four Railway Wheel Materials

在试验数据的基础上利用数值分析方法研究车轮试件近表层的硬化规律,提出以硬化率、硬化层厚度和曲率半径函数面积为指标的集合来描述试件近表层的硬化规律,分析不同车轮材料近表层表现出不同硬化规律的原因。结果表明,车轮试件近表层硬度值随深度的分布规律与某个指数函数的曲线非常接近,故将该函数作为其硬化规律的经验公式;提出的硬化指标集能有效地评价试件近表层硬化程度的强弱和硬化规律;在磨损和硬化作用的共同作用下,车轮材料含碳量的不同使其近表层表现出不同的硬化规律。

he regularity of Vickers hardness varies with the depth from contact surface of railway wheel specimens was investigated by using a numerical analysis method on the basis of a large number of experimental data. Through a series of data mining,the set of the hardening rate,the thickness of hardened layer and the area of the curvature radius function were taken as indexes to describe the regularity of hardening of subsurface layer of specimens,and the reason that different wheel material shows different hardening regularity was analyzed. The results indicate that the distribution regularity of hardness is similar to the curve of an exponential function,so this function can be assumed to be the experience formula of the hardening regularity of the subsurface layer of railway wheel specimens. The index set mentioned above can effective evaluation the degrees of hardening in the near surface area of specimen. The distribution regularity of Vickers hardness in the near surface area of specimens is the result of the combined effect of wear and hardening.