A METHOD FOR SHOT PEENING

摘要

The present invention is to provide a method for shot peening for producing a compressive residual stress that exceeds 60% of the yield strength at 0.2% offset without using stress shot peening. Shot media are peened onto a processed steel that has an amount of retained austenite in a range between 5 to 30%, and any change in the amount of retained austenite is controlled to be in a range of 2 to 30% before and after shot peening to produce the compressive residual stress in the processed steel.