Modified Charpy hammer simulation of Steckel mill rolling of Nb microalloyed steels

Abstract

Laboratory simulation of reversible hot rolling with a modified Charpy hammer has been undertaken on two niobium microalloyed steels and one plain carbon reference steel (0·11%C). Steckel mill hot-rolling schedules have been reproduced. Austenitic grain-size changes, softening behaviour, strain hardening, and carbonitride precipitation have been followed throughout the deformation schedules and during the delay between passes. Simulation of post-deformation treatments was also made via controlled cooling after the last deformation. The authors report the influence of rolling and coiling temperatures, and of C and Nb concentrations on austenite behaviour and ferrite microstructure and mechanical properties.