HIGH STRENGTH HOT-ROLLED STEEL SHEET HAVING EXCELLENT CONTINUOUSLY PRODUCING PROPERTY HIGH STRENGTH GAVANIZED STEEL SHEET HAVING EXCELLENT SURFACE PROPERTY AND PLATING ADHESION AND METHOD FOR MANUFACTURING THEREOF

摘要

The present invention relates to a high strength hot rolled steel sheet with excellent continuous productivity, a high strength galvanized steel sheet with excellent surface quality and plating adhesion, and a manufacturing method thereof. According to the present invention, the hot rolled steel sheet comprises: 0.14 to 0.3 weight percent of C; 1 to 2.0 weight percent of Si; 2.6 to 5 weight percent of Mn; 0.001 to 2 weight percent of soluble Al; (48 / 14) x [N] to 0.1 weight percent of Ti; 0.04 weight percent or less of P (excluding 0 weight percent); 0.015 weight percent or less of S (excluding 0 weight percent); 0.02 weight percent or less of N (excluding 0 weight percent); 0.08 to 0.2 weight percent of a sum of one or more of Sb, Bi, Sn, and Zn; and the remainder being Fe and unavoidable impurities, wherein internal oxide including one or more elements among Si, Mn, Al, and Fe exists on a surface layer part of the hot rolled steel plate, and the maximum depth of the internal oxide is 1 μm or less (excluding 0 μm).