Posco

Young-Ha Kim

Heung-Yun Kim

Myung-Soo Kim

Jong-Sang Kim

Hyeon-Seok Hwang

Seok Jong Seo

Hyo Jung Kwak

Yon-Kyun Song

Kwang-Geun Chin

Tae-Jin Song

Kwang-Tai Min

Joong-Chul Park

Won-Tae Cho

Chang-Sik Choi

Tai-Ho Kim

Ju-Youn Lee

Hyeon-seok Hwang

Provided are an austenite-based molten aluminum-plated steel sheet comprising: a steel plate which contains, by weight %, 0.3 to 0.9% of C, 12 to 25% of Mn, 0.5 to 2.5% of Si, 0.3 to 3.0% of Al, 0.01 to 0.5% of Ti, 0.05 to 0.5% of V, 0.01-0.5% of Mo, 0.01-0.2% of Sn, 0.001-0.1% of Co, and 0.001-0.1% of W, the remainder being Fe and unavoidable impurities; and a molten aluminum-based plated layer formed on a surface of the steel plate, and a method for producing the same.

Austenite-based molten aluminum-plated steel sheet having excellent properties of plating and weldability

Provided are a high manganese hot dip aluminum-plated steel sheet and a method for manufacturing the same, the steel sheet including: a base steel comprising, by wt %, 0.3-0.9% of C, 10-25% of Mn, 0.01-0.5% of Ti, 0.01-0.2% of Sn, 0.01-0.1% of Sb, and the balance of Fe and inevitable impurities; a hot dip aluminum-based steel plated layer formed on the base steel sheet and comprising 0.1 wt % or more of a sum of one or more types among Li, Na, and K, and the balance of Al and inevitable impurities; and an Al&#x2014;Fe&#x2014;Si&#x2014;Mn based alloy layer formed between the base steel sheet and the aluminum-based plated layer, and having a dual structure with different average Fe amounts.

High manganese hot dip aluminum-plated steel sheet having excellent sacrificial corrosion resistance and platability and manufacturing method therefor

Provided is a method of manufacturing a hot-dip galvanized steel sheet. According to an aspect of the present invention, the method may include preparing a base steel sheet, forming a iron (Fe)-plated layer on the prepared base steel sheet, oxidation heating the steel sheet having the Fe-plated layer formed thereon at a temperature ranging from 600&#xb0; C. to 800&#xb0; C., maintaining the heated steel sheet at a temperature ranging from 750&#xb0; C. to 900&#xb0; C. for 5 seconds or more in a reducing atmosphere with a dew point of between &#x2212;30&#xb0; C. to 5&#xb0; C. including 20 ppm or less of oxygen, 1 vol % to 20 vol % of H, and Nas well as unavoidable gases as a remainder, cooling the maintained steel sheet, and plating the cooled steel sheet by dipping in a hot-dip galvanizing bath.

High-strength hot-dip galvanized steel sheet having excellent plating surface quality and adhesion, and method of manufacturing the same

Provided is a high-manganese hot-dip aluminum-coated steel sheet comprising: a base steel sheet containing, by weight, 5% to 35% of Mn, 0.3 to 6% of Al, 0.1 to 1.2% of Si, the balanced amount of Fe, and inevitable impurities; a hot-dip aluminum-coated layer, formed on a surface of the base steel sheet, containing, by weight, 3 to 12% of Si and the balanced amount of Al, and inevitable impurities; and an alloy layer, 0.1 to 10 &#x3bc;m in thickness with a Fe&#x2014;Al&#x2014;Si&#x2014;Mn-based alloy phase on an interface between the base steel sheet and the hot-dip aluminum-coated layer, containing, by weight, 40 to 70% of Al, 2 to 13% of Si, 3 to 9% of Mn, the balance amount of Fe, and inevitable impurities.

High-manganese hot-dip aluminum-coated steel sheet having excellent coating adhesion

Provided is an aluminum-based alloy plate steel sheet, which comprises a base steel sheet, an interfacial alloy layer, and an aluminum-based plated layer comprising a Mg&#x2014;Si-based alloy phase, and in which b/a is 1-5 when the area fraction of the Mg&#x2014;Si-based alloy phase contained in the aluminum-based plated layer is a and the area fraction of the Mg&#x2014;Si-based alloy phase contained in the region of the lower 20% in the thickness direction of the aluminum-based plated layer is b.

Aluminum-based alloy plated steel sheet having excellent processing part corrosion resistance

The present invention relates to a hot-rolled steel sheet for a high strength galvanized steel sheet, having excellent surface quality, and a method for producing the same, the hotrolled steel sheet comprising, by weight %: C: 0.08 to 0.2%, Si: 0.03 to 0.15%, Mn: 1.4 to 2%, P: 0.001 to 0.05%, S: 0.001 to 0.03%, Al: 0.002 to 0.05%, and the remainder being Fe and unavoidable impurities. The weight ratio of Mn/Si is 20 to 30, the weight ratio of C/Si is 1 to 5, and the weight ratio of Si/P is 3 to 10. The hot-rolled steel sheet has a microstructure consisting of, in area fraction, 10 to 40% of bainite, 20 to 30% of pearlite and 40 to 60% of ferrite, and includes a ternary eutectic compound of FeO, FeSiOand Fe(PO)formed within 50 &#x3bc;m from the surface.

Hot-rolled steel sheet for high strength galvanized steel sheet, having excellent surface quality, and method for producing same

The present invention relates to a hot-rolled steel sheet for a high strength galvanized steel sheet, having excellent surface quality, and a method for producing the same, the hot-rolled steel sheet comprising, by weight %: C: 0.05 to 0.15%, Si: 0.03 to 0.10%, Mn: 0.7 to 1.39%, P: 0.001 to 0.05%, S: 0.001 to 0.03%, Al: 0.002 to 0.035%, and the remainder being Fe and unavoidable impurities. The weight ratio of Mn/Si is 15 to 25, the weight ratio of C/Si is 1 to 5, and the weight ratio of Si/P is 3 to 10. The hot-rolled steel sheet has a microstructure consisting of, in area fraction, 10 to 40% of bainite, 20 to 30% of pearlite and 40 to 60% of ferrite, and includes a ternary eutectic compound of FeO, FeSiOand Fe(PO)formed within 50 &#x3bc;m from the surface.

Provided is a metal coated steel sheet having a coating layer including a metal having a level of Gibbs free energy equal to that of Fe or above and an oxide thereof. Accordingly, the quality of a plated steel sheet may be improved by preventing the generation of bare spots through inhibition of the formation of Mn oxide, Si oxide, or Al oxide on the surface thereof, and simultaneously, the complexity of a manufacturing facility or an increase in manufacturing costs may be minimized. Economic benefits are thus realized.

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Gwangyang-si, South Korea

Young-Ha Kim