NONORIENTED SILICON STEEL SHEET EXCELLENT IN IRON LOSS AFTER STRESS RELIEF ANNEALING AND ITS PRODUCTION

摘要

PURPOSE: To accelerate the growth of crystal grains at the time of short-time stress relief annealing at low temp. and to obtain superior iron loss characteristics by adding Al and trace amount of REM to a low Si silicon steel. ;CONSTITUTION: A silicon steel, having a composition consisting of, by weight ratio, ≤0.01% C, ≤1.0% Si, 0.1 to 1.5% Mn, 0.2×1.5% Al, 2 to 80ppm REM, and the balance Fe with inevitable impurities, is used. This steel is cast, and the resulting slab is subjected, directly or after cooling, to reheating and then to hot rolling. The resulting rolled plate is subjected, in the as-rolled state or after hot rolled plate annealing or self-annealing, to cold rolling once or two or more times and then to finish annealing. Further, it is preferable to control the amounts of Ti and Zr inevitably mixing into the composition, to 15ppm and ≤80ppm, respectively. By this method, the nonoriented silicon steel sheet, having iron loss (W_15/50)4.0W/kg after stress relief annealing at 725°C for 1hr, can be obtained.;COPYRIGHT: (C)1996,JPO