Influence of hot plastic deformation and cooling rate on martensite and bainite start temperatures in 22MnB5 steel

► Reduction of cooling rate, can cause to increase or decrease Ms and Mf. ► 40% hot plastic deformation hindered the martensitic transformation. ► Hot plastic deformation, caused to decrease Mf and Ms, while Bs increased. ► The critical cooling rate increased 40 °C/s due to apply 40% hot deformation.