The effects of thermo-mechanical and re-austenitization treatments on the microstructures and the mechanical properties were investigated with 12% Cr steel.
The finish-rolling temperature and holding after hot-deformation had no significant influence on the tensile properties. The result of Charpy impact test indicated that an-isotropy decreased with finish rolling temperature and holding time.
The increase of hardness and strength were observed because of the increase of carbon concentration in matrix by dissolution of carbide as the re-austenitization temperature increased. The decrease of impact energy was observed due to dissolution of carbide and grain growth as re-austenitization temperature increased. The re-austenitization treatment in the range of 900∼950℃ result from Charpy impact test indicated that ductility and impact energy increased significantly.