Surface treated steel sheet and method for production thereof
AssigneeKawasaki Steel Corporation
InventorsKyoko Hamahara, Hisatada Nakakoji, Kazuo Mochizuki
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Abstract
The coated steel sheet includes a zinc phosphate coating containing Mg on a surface of a galvanized steel sheet, and an orthophosphoric acid ester-containing coating on a surface of the zinc phosphate coating. The coated steel sheet has no coating fall-off even during a chemical conversion treatment step of an automobile producing line and has excellent perforative corrosion resistance either with no-painting or after electrodeposition painting, chemical conversion treatability and press formability.
Claims6
A coated steel sheet having a zinc phosphate coating containing Mg on a surface of a galvanized steel sheet, and a coating consisting essentially of an orthophosphoric acid ester on a surface of the zinc phosphate coating.
Dependencies are inferred from the claim text.