Effect of residual stress on fatigue strength of induction hardened specimens of a medium carbon steel

Abstract

The effect of residual stress on fatigue strength of a medium carbon steel was investigated. Specimens were induction hardened and subsequently reheated in three conditions to give them various distributions of residual stress. Fatigue limit was improved by reheating in a condition compared with as induction hardened. Residual stress after the heat-treatments was compressive around the surface of the specimens, and varied to tensile stress in the inner unhardened region. A method to estimate fatigue limit from the total stress which is the sum of the residual stress and applied stress was proposed.