Modeling Deformation Flow Curves and Dynamic Recrystallization of BA-160 Steel During Hot Compression

The hot deformation behavior of a high strength low carbon steel was investigated using hot compression test at the temperature range of 850-1100 A degrees C and under strain rates varying from 0.001 to 1 s(-1). It was found that the flow curves of the steel were typical of dynamic recrystallization at the temperature of 950 A degrees C and above; at tested strain rates lower than 1 s(-1). A very good correlation between the flow stress and Zener-Hollomon parameter was obtained using a hyperbolic sine function. The activation energy of deformation was found to be around 390 kJ mol(-1). The kinetics of dynamic recrystallization of the steel was studied by comparing it with a hypothetical dynamic recovery curve, and the dynamically fraction recrystallized was modeled by the Kolmogorov-Johnson-Mehl-Avrami relation. The Avrami exponent was approximately constant around 1.8, which suggested that the type of nucleation was one of site saturation on grain boundaries and edges.