Manufacturing method of high magnetic flux density oriented electrical steel sheet by slab low temperature heating

摘要

PURPOSE: A method is provided to stably produce an oriented electric strip having high magnetic flux density by setting a proper hot rolled sheet annealing condition according to the heating temperature of a slab. CONSTITUTION: A slab is composed of 2.0 to 4.0wt% of Si, 0.010 to 0.040wt% of sol-Al, 0.006 to 0.010wt% of N, less than 0.060 of C, 0.3 to 1.0wt% of Cu, less than 0.32wt% of Mn, 0.02 to 0.1wt% of Ni, 0.02 to 0.1wt% of Cr, less than 0.006wt% of S and the remain of Fe and incidental impurities. The slab is reheated in a temperature of 1100 to 1320C and hot rolled. The rolled slab is annealed and cold rolled in 0.20 to 0.35mm of thickness. The slab is decarbonized and nitrified at the same time in a temperature of 800 to 950C under the mixed gas with hydrogen and nitrogen. Then MgO is coated on the slab and the slab is finally annealed in a high temperature to be an oriented electric strip having high magnetic flux density.