Hot rolled steel sheet for hot galvanized iron having high surface quality and high strength and method for producing the same

摘要

The present invention relates to a hot-rolled steel sheet for a high-strength galvanized steel sheet excellent in surface quality and a method for producing the steel sheet, which comprises 0.08 to 0.2% of C, 0.03 to 0.15% of Si, 1.4 to 2% of Mn, Si: 0.001 to 0.03%; Al: 0.002 to 0.05%; balance Fe and other unavoidable impurities; the weight ratio of Mn / Si is 20 to 30; the weight ratio of C / Si is 1 to 5; / P is 3 to 10, The microstructure is composed of 10 to 40% of bainite, 20 to 30% of pearlite and 40 to 60% of ferrite in an area fraction, And a ternary eutectic compound of FeO, Fe ₂ SiO ₄ , and Fe ₃ (PO) ₄ is formed within 50 μm from the surface, and a method for producing the same.