Deformation behavior of a Nb-Ti-V microalloyed steel to achieve the HSLA X80 grade by simulation with a torsion test and pilot hot rolling mill

摘要

In the present study, the main objective is to improve the mechanical properties of a high steel HSLA grade such as X80 for welded pipes. A study was conducted to optimise the thermomechanical treatment and to attain the mechanical properties of the X80 grade of HSLA steels. From the same chemical composition of the hot rolled X60 grade Nb-Ti-V microalloyed strip steel, we want to enlarge the production to the superior X80 grade type. Dilatometry tests, hot torsion and hot rolling using a pilot mill allowed the simulation of operating process sequences. The results of the rolling schedules performed in a pilot mill allowed us to analyse the effect of the deformation parameters (temperature conditions and reduction) on the evolution of the final structure and the mechanical properties of the Nb-Ti-V microalloyed steel.