Quantitative analysis of thermo-mechanical behavior in 414 stainless steel using flow curves and processing maps

The hot deformation behavior of a typical martensitic stainless steel containing 2.1% Ni was investigated by means of the compression test in the strain rate range of 0.001-1 s-1 and temperature range of 950-1150 °C. The flow behavior of the steel was evaluated using the flow stress curves and flow softening map and by microstructural investigation. Taking into account of the strain effect on the hot deformation behavior, the Z and Q maps were plotted as a function of the strain rate and the strain. In order to obtain the optimum hot deformation regime, the m-map was constructed. It was found that, all restoration mechanisms i.e. dynamic recovery and dynamic recrystallization phenomena take place at different hot working conditions. It was also found that, the dominant softening mechanism at different hot deformation domain depends upon Z parameter. According to the flow curves and also Z, Q and m maps, the optimum hot deformation conditions have been obtained as: strain range of 0.25-0.5, the temperature range of 1000-1100 °C and strain rate of 0.01-0.1 s-1.