NON-CHROMATE SURFACE TREATING AGENT FOR PCM, PCM SURFACE TREATMENT METHOD AND TREATED PCM STEEL SHEET

摘要

PROBLEM TO BE SOLVED: To provide a non-chromate surface treating agent for PCM which is capable of imparting excellent workability and corrosion resistance to a PCM steel sheet and has excellent storage stability, a metallic surface treatment method of the PCM steel sheet using the same and a method for manufacturing the PCM steel sheet. SOLUTION: This non-chromate surface treating agent for PCM contains (a) silane coupling agent and/or its hydrolysis condensate at 0.01 to 100 g/l, (b) water dispersible silica (solid content) at 0.05 to 100 g/l and (c) a zirconium compound as zirconium ions at 0.01 to 50 g/l and/or a titanium compound as titanium ions at 0.01 to 50 g/l in one liter of the metallic surface treating agent.