SURFACE-TREATED STEEL SHEET AND ITS PRODUCTION METHOD

• Main Authors: ANDO SATOSHI, FUJITA SAKAE, UMEBAYASHI RIE
• Format: Patent
• Language: English
• Published: 01.11.2007
• Subjects: APPARATUS THEREFOR; APPLYING LIQUIDS OR OTHER FLUENT MATERIALS TO SURFACES, IN GENERAL; CHEMICAL SURFACE TREATMENT; CHEMISTRY; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY IONIMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING MATERIAL WITH METALLIC MATERIAL; COATING METALLIC MATERIAL; DIFFUSION TREATMENT OF METALLIC MATERIAL; ELECTROFORMING; ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; LAYERED PRODUCTS; LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT ORNON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM; METALLURGY; PERFORMING OPERATIONS; PROCESSES FOR APPLYING LIQUIDS OR OTHER FLUENT MATERIALS TOSURFACES, IN GENERAL; PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTIONOF COATINGS; SPRAYING OR ATOMISING IN GENERAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; TRANSPORTING

PROBLEM TO BE SOLVED: To provide a surface-treated steel sheet producible without using chromium, phosphorous and heavy metals, and having excellent bare corrosion resistance and corrosion resistance at defective parts. SOLUTION: In the surface-treated steel sheet, at least one side of a steel sheet is provided with a film composed of a reaction layer comprising Ti and Fe and a coating layer stacked on the reaction layer, the oxygen reduction current after the formation of the film is ≤1/10 of the oxygen reduction current before the formation of the film. COPYRIGHT: (C)2008,JPO&INPIT