Simulation of strain and residual stress in nitriding process

Abstract

Based on the nitrogen distribution and associated volume dilatation in substrate during nitriding process evaluated in the first report of this series of papers, a method to simulate induced strain and elastic-plastic stress by incremental strain hypothesis is proposed. Bearing in mind that the process is limited in the very thin layer of the substrate, stress and strain condition is carefully discussed to clarify to be plain stress state. Strain incremental theory by use of Prandtl-Reuss constitutive equation with bilinear stress-strain relation is applied. Simulated results on residual stress distribution gives reasonable correspondence with experiments.