Advanced hot rolling strategies for IF and TRIP steels

Abstract

Steel producers are forced to reduce the production cost on the one hand and increase the performances of the products on the other hand, to maintain or even increase their market share. A likely method to save on production costs is to cut down the rather long production chain for conventional cold rolled strip, and to substitute certain cold rolled steel grades by hot rolled steel. Certainly this can rarely be achieved for exposed parts, requiring a perfect surface finish, whereas for unexposed parts, e.g. structural components, with lower surface requirements, the use of hot strips might be a cost saving alternative. The aim of this thesis is to contribute to the understanding of the microstructure and texture development of deep-drawing steels during ferritic rolling, subsequent cold rolling and annealing on the one hand and to appraise the possible improvement of the mechanical and deep-drawing properties on the other hand. On the basis of these results guidelines for the industrial production of ferritic rolled hot strip are proposed. Furthermore, a new hot rolling strategy for the production of hot rolled low alloy TRIP steel is proposed and the development of the microstructure and the mechanical properties to be obtained are investigated in a set plain strain compression test using a hot deformation simulator.