Abstract: Provided is a plated, ultra-low carbon steel sheet which has excellent strength, formability, and surface properties to allow for the weight lightness of automobiles and a manufacturing method therefor and, more specifically, to a galvanized steel sheet and a manufacturing method therefor, wherein the galvanized steel sheet has high strength and high formability and as such, can be suitably used as a material for an automobile outer body.

Abstract: Provided is a plated steel sheet having excellent surface quality, as well as having excellent formability while also having high strength characteristics; and a method for manufacturing same. The plated steel sheet includes: base iron; and a plating layer provided on at least one surface of the base iron. The base iron includes by weight: 0.002 to 0.01% of carbon (C), 0.1% or less of silicon (Si), 0.4 to 1.0% of manganese (Mn), 0.04 to 0.1% of phosphorus (P), 0.01% or less of sulfur (S), 0.005% or less of nitrogen (N), 0.1% or less of aluminum (S·Al), 0.005 to 0.03% of titanium (Ti), 0.01 to 0.05% of niobium (Nb), 0.06 to 0.1% of copper (Cu), 0.0015% or less of boron (B), a content of molybdenum (Mo). The base iron includes ferrite as a matrix structure.

Abstract: Provided is a galvannealed steel sheet having excellent powdering resistance, and a manufacturing method therefor. The galvannealed steel sheet includes: base iron; and an alloying hot-dip galvanized layer provided on the surface thereof. The base iron includes, by weight %; 0.003 to 0.009% of carbon (C); 0.05% or less of silicon (Si); 0.4 to 1.0% of manganese (Mn); 0.04 to 0.09% of phosphorus (P); 0.01% or less of sulfur (S); 0.005% or less of nitrogen (N); 0.1% or less of aluminum (S.Al); 0.05 to 0.08% of molybdenum (Mo); 0.005 to 0.03% of titanium (Ti); 0.02 to 0.045% of niobium (Nb); 0.06 to 0.1% of copper (Cu); 0.0015% or less of boron (B), and a balance of Fe and inevitable impurities. An average thickness of a gamma (?) phase present at an interface between the base iron and the alloying hot-dip galvanized layer is 0.20 ?m or less.

Abstract: Provided are a high-strength hot-dip galvanized steel sheet with excellent formability and a process for producing same. The steel sheet comprises, in mass %: 0.005 to 0.009% of C; 0.05% or less of Si; 0.3 to 0.8% of Mn; 0.06 to 0.09% of P; 0.01% or less of S; 0.005% or less of N; 0.1% or less of Al; 0.05 to 0.08% of Mo; 0.01 to 0.03% of Ti; 0.03 to 0.045% of Nb; 0.06 to 0.1% of Cu; 0.0015% or less of B; and a balance of Fe and inevitable impurities, and 95% or more of ferrite in terms of area fraction. The ferrite has an average grain size of 15 pm or less, with ultrafine grains of 6 pm or less occupying 5 to 10% in a 1 mm×1 mm, and the steel sheet has a surface nanohardness value of 1 to 1.5 GPa.

Abstract: Provided is a plated steel sheet and a method for manufacturing the same, and more particularly, to a zinc-based plated steel sheet having high strength and high formability that may be suitably applied as a material for an automotive outer panel and a method for manufacturing the same.

Abstract: Provided are a high-strength galvanized steel sheet having excellent distinctness of image after painting and a manufacturing method therefor. The steel sheet includes: by mass %, 0.003 to 0.005% of C, 0.05% or less of Si, 0.4 to 1.0% of Mn, 0.04 to 0.06% of P, 0.01% or less of S, 0.005% or less of N, 0.1% or less of S. Al, 0.05 to 0.08% of Mo, 0.005 to 0.03% of Ti, 0.02 to 0.035% of Nb, 0.06 to 0.1% of Cu, 0.0015% or less of B, and a balance of Fe and inevitable impurities. The alloy microstructure has ferrite in an amount of 95% by area fraction or greater, and the ferrite has a grain average size of 15 ?m or less, with the ultra-fine grain 5 ?m or less having an occupancy ratio to 7 to 10% within 1 mm×1 mm area.