Microstructure evolution and static recrystallization kinetics in hot-deformed austenite of coarse-grained Mo-free and Mo containing low-carbon CrNiMnB ultrahigh-strength steels

The static recrystallization characteristics and microstructure evolution in hot-deformed austenite were evaluated for a newly developed low-carbon CrNiMnB ultrahigh-strength steel with without molybdenum addition. time 50% (t50%) over wide range of strains hot-deformation temperatures obtained using the stress-relaxation technique on Gleeble thermomechanical simulator. Moreover, effect deformation parameters size distribution average prior grains are investigated. A novel semi-automatic stress relaxation test reading tool graphical user interface was created used successfully current study. results strain´s power apparent activation energy within stated literature C-Mn microalloyed steels. Addition increase strain from − 1.9 to 2.6 206 212 kJ/mol, respectively. retardation addition shown by new regression equation devised calculating t50%. equations show good agreement experimental data can be designing roughing during processing. i.e., temperature, holding have significant grains.