Influence of thermomechanical processing and accelerated cooling on microstructures and mechanical properties of plain carbon and microalloyed steels

A thermomechanical control process consisting of slab reheating, controlled rolling, and accelerated cooling has been adopted at the plate mill, Bhila i Steel Plant, India for achieving high strength and toughness in C-Mn and microalloyed steels while keeping the mechanical proper ties and the flatne ss constant. A mathematical model has been developed to predict the tempera ture distribution in the plate during accelerated cooling, taking into acco unt the heat generation of the phase transformation. Effects of chemistry a nd mill parameters on ferrite grain refinement are explained in terms of nu cleation and growth rate.