The Development of a mathematical model for handling severe plastic flow in hot torsion

Abstract

A series of investigations with Nb microalloyed specimens were made so as to determine rheological parameters in hot torsion tests. The aim was to produce a mathematical model capable of substantially reduce the serrated and unwanted effects of torque and twist obtained from high temperature tests, thus producing less interference so as to improve the interpretation of the real behavior of the deformed material. The modeling was particularly difficult for severe strains at elevated strain rates. The equivalent Von Mises stress-strain was calculated by the Fields and Backofen equations and the heterogeneous deviations evaluated. The proposed model has provided smoother curves that presented very low deviations from experimental data.