METHOD FOR PRODUCING ORIENTED ELECTRIC STRIP HAVING HIGH MAGNETIC FLUX DENSITY BY HEATING SLAB IN LOW TEMPERATURE

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 1320°C 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 950°C 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.