1994 Volume 80 Issue 2 Pages 131-136
It is well known that residual compressive stress is an important factor to fatigue strength of carburized parts for automotive industry etc. A systematic study of effect of hard shot peening conditions using high pressure water jet on the surface residual stress distributions in carburized and nitrized SCM-420 steel with surface retained austenite of 4, 12 and 24 pet has been conducted. As a result, high peak value, 1125 MPa and high integrated mean value of stress distribution of compressive residual stress from surface to 300μ m depth were obtained by hard or high energy shot peening with water jet. These increment were caused by elasto-plastic peening effect of matrix and transformation of retained austenite, especially most effective to the specimen with 4 pct surface retained austenite.
Effect of 2 step peening on compressive residual stress at most surface was not conspicuous in this study.
