| 摘要 |
PROBLEM TO BE SOLVED: To provide a conversion treated steel sheet in which, even when defects such as cracks are generated on a chemical conversion coating by working such as press forming, the defects are self-restored, and which maintains excellent corrosion resistance internally and externally. SOLUTION: A steel sheet in which an Al-Si alloy plated layer containing 5 to 13% Si is formed on the surface, and projecting parts essentially consisting of metallic Si are dispersed over the surface by concentrating Si into the surface layer is used as a base material. A chemical conversion coating containing a combined compound of Ti and Mn is deposited on the surface of the base material. As the combined compound of Ti and Mn, one or more kinds selected from oxides, hydroxides, phosphates, fluorides and organic acid salts can be cited. The chemical conversion coating may further contain phosphates, combined phosphates, lubricants or the like.
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