ZINC AND ZINC-ALLOY HOT-DIP-COATED STEEL SHEET HAVING DECREASED BARE SPOTS AND EXCELLENT COATING ADHESION AND A METHOD FOR MANUFACTURING THE SAME

摘要

A zinc and zinc-alloy hot-dip-coated steel sheet and an alloyed zinc and zinc-alloy hot-dip-coated steel sheet, and a method for manufacturing these steel sheets, which steel sheets are used for automobiles. A zinc and zinc- alloy hot-dip-coated steel sheet which has oxides of readily oxidizable elements just under a coated layer and which shows a decreased number of bare spots and excellent coating adhesion. According to the method, the temperature for coiling during hot rolling is set to not less than 600.degree.C and the cooling is conducted at a slow- cooling rate so that the oxides remain after the following steps.