Flow stress modeling of a new HSLA steel by Zerilli-Armstrong model

Abstract

The selection of an appropriate constitutive model is vital for the design of thermo-mechanical treatment as it describes the flow patterns and governs the metallurgical transformations. In this research, the constitutive behavior of a newly developed high-strength steel has been studied employing a physical-based Zerilli-Armstrong model. For this purpose, the experimentally generated stress–strain data from isothermal compression tests performed over a wide range of temperatures (1073–1323 K) and strain rates (0.01–10 s−1) have been considered. The constitutive relationships of flow stress as functions of temperature, strain rate, and true strain have been developed for both original and modified Zerilli-Armstrong models. The comparison between the measured and predicted flow stresses demonstrates better predictability of the modified model with a higher correlation coefficient (R = 0.982) and a much lower average absolute relative error (AARE = 7.31%) since the values of R and AARE for the original model are 0.845 and 23.96%, respectively. The better accuracy of the modified Zerilli-Armstrong model is attributed to the fact that it additionally considers the coupled effects of temperature and strain, unlike the original Zerilli-Armstrong model.