The Elastic Strain Ratio, the Lüders Strain Ratio and theEvolution of r ‐Value During Tensile Deformation

Abstract

The elastic counterpart of the plastic strain ratio is derived from ultrasonic data measured on twenty commercial deep drawing steels. It is shown that the observed variations in plastic r are related to the evolution of texture, and are not affected either by the elastic range of deformation or by the propagation of Lüders bands. Further quantitative analysis suggests that the elastic strain ratio, determined non‐destructively, can be used to predict plastic r ‐values by means of an empirical relationship.