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.