PRODUCTION OF UNIDIRECTIONAL SILICON STEEL PLATE HAVING VERY HIGH MAGNETIC FLUX DENSITY AND LOW IRON LOSS

摘要

PURPOSE:To provide a unidirectional silicon steel plate having a high magnetic flux density and low iron loss by adding specific amount of Mo to a silicon steel material having a specified composition and applying a specific rate of cooling to the material after intermediate annealing and immediately before the final cold rolling. CONSTITUTION:0.003-0.1% of Mo is contained in a silicon steel material containing less than 0.06% of C, 2.0-4.0% of Si, 0.005-0.20% of Sb, and less than 0.10% of one or more of Se and S. The material is hot rolled, is subjected to a uniforming annealing, then repeated with cold-rolling and intermediate annealing to provide a cold rolled steel plate having the final thickness. The plate is then subjected to the first recrystallization annealing which simultaneously acts as decarburization, followed by the final finishing annealing to develop a secondary recrystallization grains of [110]001 orientation. Among the repeated intermediate annealing, at least one immediately before the final cold rolling uses a cooling rate more than 5 deg.C/s from 900-500 deg.C. The process provides the desired unificational silicon steel plate.