| 摘要 |
<p>PURPOSE:To obtain a continuous distribution of compressive residual stress having a high peak value in the surface layer of a steel member by subjecting the carburized and hardened surface of the steel member to first shot peening with large shorts and second shot peening with small shots. CONSTITUTION:The surface of a steel member is carburized or carbonitrided and hardened. The surface is then subjected to first shot peening with large shots of <=1mm diameter and second shot peening with small shots whose diameter is 1/3.5-1/2 of the diameter of the large shots. The distribution of compressive residual stress produced by the two-stage shot peening is gentle and continuous, so the fatigue strength of the carburized or carbonitrided and hardened steel member can be improved.</p> |
