PREPARATION OF THIN HIGH MAGNETIC FLUX DENSITY ONE- DIRECTIONAL ELECTROMAGNETIC STEEL PLATE EXCELLENT IN SMALL IRON LOSS

摘要

PURPOSE:To obtain a thin electromagnetic steel plate excellent in small iron loss, by applying tension coating to a silicon steel slab having a specific composition having Sn contained therein at the stage of molten steel to which hot rolling, cold rolling and finish annealing are applied. CONSTITUTION:A silicon steel slab containing 0.02-0.12%, pref,, 0.06-0.12% C, 2.5-4.0% Si, 0.03-0.15% Mn, 0.01-0.05% S, 0.01-0.05% Al, 0.004-0.012% N, 0.03-0.3% Sn added at the stage of molten steel and further pref. containing 0.02-0.3% Cu is subjected to hot-rolling, and the obtained hot-rolled plate is followed by annealing and quenching treatment. The treated slab is subjected to one-step cold rolling under high pressure to reduce the thickness thereof after final cold rolling to 0.15-0.25m/m and, after the cold rolled slap is subjected to decarburization annealing in a wet hydrogen atmosphere and finish annealing in a hydrogen atmosphere, a tension coating liquid is applied to the annealed slab and flattening annealing is applied to the coated slab to obtain a thin high magnetic flux density one-directional electromagnetic steel plate excellent in small iron loss.