| 摘要 |
PURPOSE:To stably produce a grain-oriented silicon steel sheet minimal in iron loss by reducing C content to a specific value in the course between the conclusion of hot rolling and the initiation of final cold rolling at the time of producing a grain- oriented silicon steel sheet with a specific composition. CONSTITUTION:A hot rolled plate of a silicon steel having a composition consisting of 2.5-4.0% Si, 0.03-0.10% C, 0.015-0.040% acid-soluble Al, 0.0040-0.0100% N, 0.01-0.04% S, 0.02-0.2% Mn, further <=0.4% Sn and/or Cu, and the balance Fe with inevitable impurities is annealed. Subsequently, this hot rolled plate is successively subjected to two-time or more cold rollings including forced final cold rolling at >80-95% rolling reduction, to process annealing performed between the cold rolling stages, to decarburizing annealing after final cold rolling, and to final finish annealing, by which the thin grain-oriented silicon steel sheet of 0.10-0.23mm sheet thickness having high magnetic flux density is produced. At this time, in the course between the conclusion of hot rolling and the initiation of final cold rolling, decarburizing is carried out so that C content is reduced to 0.0070-0.0300%. By this method, the grain-oriented silicon steel sheet used for iron core for transformer, etc., and excellent in iron loss characteristics can be obtained. |
