STEEL STRIP COATED WITH METAL

摘要

PROBLEM TO BE SOLVED: To provide a steel strip coated with an Al-Zn-Si-Mg alloy that suppresses formation of Mg2Si particles having a rough surface to cause a mottled appearance in hot-dip Al-Zn-Si-MG plating.SOLUTION: In a hot-dip plating method, a molten bath contains Sr of less than 3,000 ppm and a coating film of plating contains Sr of 250 ppm or more and a cooling rate is less than 80°C/sec. An alloy coating is formed on a strip by changing the thickness of the coating in a section of an optional diameter of 5 mm of the coating of 40% or less so that 10 wt.% or less of MgSi particles are present on the surface of the coating in MgSi particles distribution during the coating.SELECTED DRAWING: None