SILICON STEEL SHEET HAVING ELECTRICALLY INSULATED FILM EXCELLENT IN OILLESS PUNCHING PROPERTY

摘要

PURPOSE: To produce a silicon steel sheet having an electrically insulated film excellent in electrical insulating properties, adhesion, punching properties and corrosion resistance. ;CONSTITUTION: This is a silicon steel sheet having an electrically insulated film on the surface. The surface of a silicon steel sheet is coated with a treating soln. contg. a soln. with primary organic resin as solid content, an aq. soln. of chromate contg. at least on kind of bivalent metals and an organic reducing agent, and baking is executed. It is coated with a soln. with secondary organic resin as solid content in the process of cooling the silicon steel sheet. After the coating, it is furthermore cooled to concentrate the resin on the surface of the insulated film, by which the silicon steel sheet having an electrically insulated film excellent in oilless punching properties can be obtd.;COPYRIGHT: (C)1995,JPO