MANUFACTURE OF GRAIN-ORIENTED ELECTRICAL STEEL SHEET HAVING VERY SMALL IRON LOSS AND CONTROLLED MAGNETIC DOMAIN

摘要

PURPOSE:To obtain a grain-oriented electrical steel sheet having very small iron loss by subdividing the magnetic domain of a grain-oriented electrical silicon steel sheet having specified properties subjected to secondary recrystallization annealing. CONSTITUTION:The hot rolled steel sheet having a prescribed composition contg. 2.5-4.5% Si is subjected to secondary recrystallization annealing to form a grain-oriented electrical steel sheet having =19250G magnetic flux density B10 and 0.05-0.20mm. thickness. Microstrains are produced in the electrical steel sheet by a mechanical means such as the pressing of small spherical bodies against the surface of the steel sheet, an optical means such as the irradiation of CO2 or YAG laser light on the surface, or a thermal means such as the irradiation of heat rays on the surface to subdivide the magnetic domain. It is preferable that the microstrains are produced at about 2-15mm. intervals and less than several mum depth. Thus, a grain-oriented electrical steel sheet having very small iron loss and controlled magnetic domains is obtd.