Two-Step Cutting for Improving Surface Integrity and Rolling Contact Fatigue Performance of Hard Machined Surfaces

Abstract

For finish hard machining, it is challenging to obtain excellent surface integrity without losing production efficiency. A large material removal rate improves production efficiency, but generates unfavorable surface integrity properties. In this study, an innovative approach, consisting of a major cut step followed by a finish cut step, is proposed to tackle the challenge. It shows that the surface integrity of hard machined surface is significantly improved by the finish cut in terms of microhardness and residual stress distributions. Moreover, rolling contact experiments reveal that the fatigue performance of machined surfaces produced by the two-step approach is superior to that produced by only one major cut by up to a factor of two.

Keywords:

• Fatigue life
• Finish cut
• Hard machining
• Surface integrity
• Two-step