Determination and prediction of the inherited ferrite texture in a HSLA steel produced by compact strip production

Abstract

The ferrite and residual austenite textures were measured in a microalloyed (high strength low alloy, HSLA) steel produced by compact strip production, a process for the production of hot strips from a continuously cast slab using direct charging. The conditions of the thermomechanical rolling influence the texture and microstructure of austenite and thus modify the mechanical behaviour of the final products, obtained after a γ to α phase transformation. The ferrite and residual austenite phases show strong texture gradients in the thickness of the sheet. Simulations of the thermomechanical rolling using the Taylor model allowed us to relate qualitatively the main trends of the surface and mid-thickness textures of the austenite to the process. By modelling the phase transformation, the surface and mid-thickness inherited ferritic textures have been computed, without variant selection, from the residual austenite texture. These simulated textures are compared with the experimental ones and the texture inheritances are discussed.