Effect of Elastic-Plastic Constitutive Relationship on Superficial Rockwell Hardness
Akihiko HIRANO, Masao SAKANE and Naomi HAMADA
Abstract:This paper studies the relationship between Superficial Rockwell hardness and elastic-plastic material constants by finite element (FE) analysis. Finite element analyses for Superficial Rockwell hardness were carried out to study the effects of elastic-plastic material constants and friction on the hardness. The hardness increased with increasing yield stress and strain hardening coefficient but it decreased with increasing strain hardening exponent. A new equation was proposed for predicting the hardness from yield stress and strain hardening coefficient and exponent. The equation predicted the FE and experimental results within a small scatter. The critical thickness of specimen was discussed based on the extent of plastic deformation and the experimental results. The friction between indenter tip and specimen upper face had almost no influence on the hardness. Key Words:Superficial rockwell hardness, Finite element analysis, Yield stress, Strain hardening coefficient, Strain hardening exponent