METHOD OF PRODUCING METAL-COATED STEEL STRIP

摘要

A method of forming a coating of an Al-Zn-Si-Mg alloy on a steel strip to form an Al-Zn-Mg-Si coated steel strip is disclosed. The method includes the steps of dipping steel strip into a bath of molten Al-Zn-Si-Mg alloy and forming a coating of the alloy on exposed surfaces of the steel strip and cooling the coated strip with cooling water. The cooling step includes controlling the p H of cooling water to be in a range of pH 5-9. Particular embodiments focus on Al-Zn-Si-Mg alloys that contain the following elements in % by weight: Zn: 2 to 19, Si: 0.01 to 2, Mg: 1 to 10, and Balance Al and unavoidable impurities.