Estimation of Lankford Coefficients of Austenitic and Ferritic Stainless Steels using Mean Grain Orientations from Micro-texture Measurements

Abstract

A new method to calculate the plastic anisotropy r-values of austenitic and ferritic stainless steels has been developed. The mean orientation of individual grains is obtained from SEM-EBSD data and r-values for individual grains are calculated by weighting all slip systems according to their Schmid factors. Calculated and measured r-values are in good agreement for austenitic stainless steels. However, in ferritic stainless steels, which are highly anisotropic, good agreement requires the introduction of a Schmid factor threshold below which slip systems are inactive. The present method can be used to estimate local differences in r-values in ferritic stainless steels showing the local variations in texture responsible for ridging.