Recent development of technology of grain oriented silicon steel

Grain oriented silicon steels are mainly produced by three different methods: ARMCO method, Nippon steel method and Kawasaki method. These three methods are analyzed based on the theory of secondary recrystallization developed by the present authors. It is concluded that the utilization of aluminum nitride as an inhibitor and the high reduction at the cold rolling before primary recrystallization annealing is the best method in controlling the sharpness of the Goss secondary recrystallization orientation. These three methods are categorized as an inherent inhibitor method as they have common features in the inhibitor preparation process. Two methods of AlN preparation before the onset of secondary recrystallization, which are referred as an acquired inhibitor method, are shown, namely, equilibrium nitriding method and non-equilibrium nitriding method. Finally the possibility of new products by the non-equilibrium nitriding process is demonstrated.