Comparison of simulated and experimental strain ratio R for different grain shapes in sheet metal

Abstract

Predicting mechanical properties by means of a simple indicator is of great importance to sheet metal forming. An important parameter characterising the formability of a rolled sheet is the plastic strain ratio R which is strongly determined by the texture. The angular variation of R value in the rolling plane has been calculated from the orientation distribution function using the Bunge method. The following grain interaction models have been tested: two Taylor full constraint models ({hkl}〈111〉 and {110}〈111〉 plus {112}〈111〉), three relaxed constraints models (RC4 , RC3 , RC2 ), and the Sachs–Kochendörfer model. The shapes of the grains were investigated by means of the secant method which allowed the spatial parameters of the two- dimensional structure image to be measured. The comparison of simulated and experimental data has proved that in the case of aluminium killed steels, the relaxed constraints model RC4 is the best predictor of the plastic strain ratio. Good results were also obtained using the Sachs-Kochendörfer model.