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, Bhilai Steel Plant, India for achieving high strength and toughness in C-Mn and microalloyed steels while keeping the mechanical properties and the flatness constant. A mathematical model has been developed to predict the temperature distribution in the plate during accelerated cooling, taking into account the heat generation of the phase transformation. Effects of chemistry and mill parameters on ferrite grain refinement are explained in terms of nucleation and growth rate.