Effect of Temper Rolling Reduction Ratio on Microhardness and Microstructure of DC04 Grade Sheet Material

Abstract

With temper rolling, which is the final stage of the cold rolling manufacturing process, to the surface of sheet metal materials is transferred roughness with specially roughened rolls. In this study, microhardness and microstructural evolution occurring in the section along the thickness of DC04 grade sheet materials temper rolled with various reduction ratios were investigated. As a result, it was concluded that the microhardness distribution taken from the section along the thickness increases with the increase of reduction ratio and the microhardness distribution from the surface to the center in the section decreases. In the temper rolling process with a reduction ratio of 250 µm and 500 µm an increase of approximately 5% and 15% has occurred, respectively compared to before the temper rolling process. It was also concluded that with the increase in reduction ratio, the grains in the section along the thickness elongated and thinned on the surface and this change in the center compared to the regions close to the surface was less.