ULTRAHIGH STRENGTH HOT GALVANIZING STEEL PLATE WITH EXCELLENT SURFACE QUALITY AND COATING ADHERENCE, AND MANUFACTURING METHOD THEREFOR

摘要

The present invention relates to an ultrahigh strength hot galvanizing steel plate with excellent surface quality and coating adherence and a manufacturing method therefor, the ultrahigh strength hot galvanizing steel plate comprising: 0.1-0.3% by weight carbon (C); 0.1-2.0% by weight silicon (Si); 0.005-1.5% by weight aluminum (Al); 1.5-3.5% by weight manganese (Mn); 0.04% by weight or less phosphorus (P) (excluding 0% by weight); 0.015% by weight or less sulphur (S) (excluding 0% by weight); 0.02% by weight or less nitrogen (N) (excluding 0% by weight); the balance being Fe; and other inevitable impurities, and further comprising 0.01 wt.% to 0.07 wt.% of at least one kind of element selected from the group consisting of bismuth (Bi), tin (Sn) and antimony (Sb).