PROCESS FOR PRODUCING MIRROR-FINISHED DIRECTIONAL ELECTRIC SHEET

摘要

A process for producing a mirror-finished directional electric sheet having a high magnetic flux density by conducting the smoothening (mirror finishing) of a steel sheet boundary, which is necessary for achieving ultralow core loss, in a finish annealing furnace, which process comprises the steps of conducting decarburizing annealing, removing the oxide layer present on the surface of a steel sheet by pickling, and coating the resultant surface with an annealing/separating agent comprising a substance which does not react or difficulty reacts with SiO2 to conduct finish annealing. The core loss can be reduced by subdividing magnetic domains and applying tension coating. The finish annealing step can dispense with hydration time, so that it can be completed in a shorter time.