Effect of Condition of Hot-band Annealing on Secondary Recrystallization of Sn Added Grain-oriented Electrical Steel

Abstract

A study was made on the effect of the cooling condition in hot-band annealing on the secondary recrystallization of the grain-oriented electrical steel produced by use of MnS and A1N as inhibitors with additional Sn. The following conclusions were obtained. In the specimen without Sn, perfect secondary recrystallization was observed under the cases of air cooling and quenching in boiling water, and no secondary recrystallization under quenching in water. The failure of secondary recrystallization under quenching in water is attributed to the small amount of the product of {110} pole density and {111} pole density, that is, presumably, the small opportunity of meeting of Goss nuclei with easily consumable grains. In the specimen with Sn, perfect secondary recrystallization was obserbed in the all cases of cooling conditions mentioned above. The following factors are considered to be the reason why the secondary recrystallization occurs more easily in case of Sn addition ; the small size of primary grains, the large amount of the product of {110} pole density and 11111 pole density in the primary texture, the large amount of MnS and A1N, and, the fine and uniform dispersion of precipitates after decarburizing annealing.