GALVANIZED STEEL SHEET AND METHOD FOR PRODUCING THE SAME
First Claim
1. A galvanized steel sheet comprising a steel sheet and a galvanized coating layer formed on the steel sheet,wherein the coating layer includes an oxide layer in a surface layer, the oxide layer having an average thickness of 20 nm or more, andthe oxide layer comprises Zn, O, H, S, C, and unavoidable Impurities, and contains 50 mg/m2 or more of Zn, 5 mg/m2 or more of S, and 0.2 mg/m2 or more of C.
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Accused Products
Abstract
Provided is a method for producing a galvanized steel sheet that includes an oxide layer forming step of bringing a galvanized steel sheet into contact with an acidic solution containing sulfate ions, then holding the galvanized steel sheet in contact for 1 to 60 seconds, and then washing the galvanized steel sheet with water; and a neutralization treatment step of holding a surface of an oxide layer, which has been formed in the oxide layer forming step, in contact with an alkaline aqueous solution for 0.5 seconds or longer, and then performing washing with water and drying. The alkaline aqueous solution contains 0.1 g/L or more of carbonate ions.
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Citations
18 Claims
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1. A galvanized steel sheet comprising a steel sheet and a galvanized coating layer formed on the steel sheet,
wherein the coating layer includes an oxide layer in a surface layer, the oxide layer having an average thickness of 20 nm or more, and the oxide layer comprises Zn, O, H, S, C, and unavoidable Impurities, and contains 50 mg/m2 or more of Zn, 5 mg/m2 or more of S, and 0.2 mg/m2 or more of C.
Specification