Effects of deformation parameters on the final microstructure and mechanical properties in warm rolling of a low-carbon steel

Abstract

The effects of warm rolling parameters on the final microstructure and mechanical properties of a low-carbon steel were investigated. In doing so, the steel strips were pre-heated at various temperatures and rolled at different reductions and rolling speeds. Then, microstructural studies were performed and, also, the mechanical properties of the rolled samples were measured by tensile and hardness testing. An optimum rolling program was determined with the aids of experimental results and a mathematical model based on the finite element method (FEM) developed for the warm rolling conditions. The results show that, at high temperatures and low rolling speeds, the roll forces are reduced; however, the possibility of strain inhomogeneity and non-uniformity in the grain size distribution are increased. On the other hand, at very low temperatures, the roll force increases sharply. For the case of the employed steel, a temperature between 550–700°C and a rolling speed of 55–70 (rpm) are found to be the suitable rolling conditions for producing warm-rolled steels with uniform and fine-grain structures.