PRODUCTION OF TIN-FREE STEEL SHEET EXCELLENT IN SURFACE APPEARANCE AND RETORTING RESISTANCE PROPERTY

摘要

PROBLEM TO BE SOLVED: To provide the production method of the tin-free steel sheet excellent in surface brightness and in retorting resistance property. ;SOLUTION: In the production method of an electrolytic chromate-treated steel sheet, at the time of producing the electrolytic chromate treated-steel sheet consisting of a lower layer of metal chromium and an upper layer of chromium hydrated oxide by cathodic-energizing to the steel sheet in the chromium plating bath, a weak cathodic electrolytic treatment is applied to the steel sheet at between anodic electrode pair and next anodic electrode pair, and the metal chromium is formed by cathodic-energizing to the steel sheet in the chromium plating bath, then the chromium hydrated oxide is formed by cathodic-energizing to the steel sheet on which the metal chromium is formed in an electrolytic chromic acid treating bath.;COPYRIGHT: (C)1999,JPO