Effects of Hardened Depth and Relative Radius of Curvature on Surface Durability of a Nitrided SACM645 Steel Roller

Abstract

In this report, the effects of hardened depth and relative radius of curvature on surface durability of a nitrided aluminium chromium molybdenum steel roller are experimentally elucidated. The experimental results are discussed in terms of the amplitude of ratio of shear stress to Vickers hardness. The surface failure mode in this experiment was spalling due to a crack having its point of origin beneath the surface. The depth of the spalling crack agreed well with the depth of the maximum amplitude of the ratio of the orthogonal shear stress to Vickers hardness. The surface durability of the nitrided roller tended to increase as the hardened depth increases and the relative radius of curvature decreased.