MANUFACTURE OF STEEL SHEET PLATED WITH MOLTEN ZINC-ALUMINUM ALLOY EXCELLENT IN RESISTANCE TO PEELING-OFF OF PLATING BY LAPSE OF TIME

摘要

PURPOSE:To manufacture a plated steel sheet excellent in corrosion resistance and resistance to plating peeling-off by lapse of time, by hot-dipping a low- carbon steel sheet by Sendzimir process by the use of a plating bath prepared by incorporating specific percentage of Al, Sb, Si and Mg to Zn and limiting the total quantity of inevitable impurities. CONSTITUTION:Mg (0.01-1%) is added to the plating bath which contains, by weight, 0.15-10% Al, 0.1-1.0% Sb and 0.01-2% Si and has the balance consisting of Zn and in which the total quantity of inevitable impurities such as Pb, Sn, Cd, etc., is limited to 0.02%. The low-carbon steel sheet is subjected to hot dipping by the use of the above plating bath by means of continuous hot dipping line by Sendzimir process. In this way, the plated steel sheet in which the peeling-off of Zn-Al plating caused by embrittlement with the lapse of time is inhibited and superior corrosion resistance is provided can be obtained.