PRODUCTION OF THIN GRAIN-ORIENTED SILICON SHEET WITH HIGH MAGNETIC FLUX DENSITY EXCELLENT IN MAGNETIC PROPERTY OF PRODUCT BY SINGLE-STAGE COLD ROLLING METHOD

摘要

PURPOSE:To stably produce the grain-oriented silicon sheet by a single-stage cold rolling method by specifying the contents of N and acidsoluble Al in a silicon steel slab, the thickness of a hot rolled plate, the content of N in the form of AlN in the hot rolled plate, and the average hardness in the plate-thickness direction, respectively. CONSTITUTION:At the time of producing a thin grain-oriented silicon sheet from a silicon steel slab having a composition consisting of, by weight, 0.060-0.120% C, 2.9-4.5% Si, 0.050-0.090% Mn, 0.020-0.060% S and/or Se, 0.02-0.25% Sn, 0.0050-0.0100% N, {(27/4)XN%+0.0035} to {(27/4)XN%+0.0100}% of acid soluble Al, and the balance Fe with inevitable impurities, hot rolling is carried out by regulating the thickness of hot rolled plate so that draft in cold rolling becomes 85-92% and also controlling the content of N in the form of AlN in the hot rolled plate to 0.0005-0.002%. Further, the average hardness of the hot rolled plate in the thickness direction of the cross section of the steel plate after annealing and cooling is controlled to Hv(1kg)200 to 230. By this method, the thin grain-oriented silicon sheet with high magnetic flux density excellent in magnetic properties of product can be stably produced by a single-stage cold rolling method.