Effects of deformation in the two phase region γ+α on steel properties and process technology for hot strip production

摘要

As a result of the development of new strategies in hot strip rolling, the deformation of steel in the two phase γ+α region and the effect of such a deformation on the final microstructure and properties has become of great importance. Aim of the presented work was to acquire information on the flow stress behaviour and the softening behaviour during deformation in the temperature range of γ+α-two-phase-region with various fractions of ferrite and austenite. These investigations were carried out mainly on an ELC-steel and a C-Mn-steel. To this aim, the transformation behaviour with and without deformation was analysed using dilatometry and the flow stress behaviour was investigated by uniaxial compression tests. The static softening kinetics were determined by double stroke technique. The experimental results have been used for the development and adaptation of mathematical models to describe the material behaviour in the two phase region. Finally, laboratory rolling experiments were performed to verify the impacts of rolling in the two phase region on the properties of hot strip.