Relationship between Vickers hardness and inelastic material constants

Abstract

This paper describes the relationship between Vickers hardness and the elastic-plastic material constants by using finite element analyses. The hardness increased with increasing yield stress and strain hardening coefficient, but it decreased with increasing strain hardening exponent. A new equation for predicting Vickers hardness was proposed as a function of yield stress, and of strain hardening coefficient and exponent. The hardness predicted by the equation agreed well with the finite element and experimental results. The fatigue limit and threshold of stress intensity factor were discussed in relation to the elastic-plastic material constants based on the proposed equation. The critical thickness of specimen for hardness testing was also discussed in connection with JIS and ISO standards. © 2007 The Society of Materials Science, Japan.