A PROCESS FOR PRODUCING ACQUIRED ALUMINUM NITRIDE INHIBITOR PRECIPITATION IN COLD ROLLED GRAIN ORIENTED STEEL

摘要

The current investigation provides an improved process for producing an acquired inhibitor, Aluminum Nitride (AlN) precipitation, to produce abnormal grain growth of Goss nuclei formed in the hot band of Fe-3.2Si electrical steel sheets during hot rolling process. The scope of present invention limits to nitriding annealing process to develop AlN precipitated that are critical for inducing selective abnormal growth of grains having Goss orientation. The hot-rolling method to prepare hot-strip for Fe-3.2Si CRGO was similar to the co-pending patent by the authors. This method involves two-stage nitriding process of cold rolled sheet after primary recrystallisation in the temperature ranges of 850-950 C to precipitate AlN which is expected to act as grain growth inhibitor, except Goss grains. The cold rolled and primary recrystallised annealed sheet can be used as stock material for production of cold rolled grain oriented steel by secondary recrystallisation.