Posco

Posco Co., Ltd

Heung-Yun Kim

Il-Ryoung Sohn

Young-Ha Kim

Dae-Chul Bae

Hyeon-Seok Hwang

Myung-Soo Kim

Kwang-Geun Chin

Do-Kyeong Han

Hyeon-seok Hwang

Provided is a galvanized steel sheet having excellent plating adhesion, having a plated layer with improved friction characteristics by means of a predetermined level of Fe elution, and having excellent corrosion resistance; and a manufacturing method therefor.

Galvanized steel sheet having excellent plating adhesion and corrosion resistance

Provided is a plated steel to be used for automobiles, electric home appliances, building materials and the like and, more specifically, to a zinc alloy-plated steel having excellent corrosion resistance and surface smoothness, and a method for manufacturing the same.

Zinc alloy-plated steel having excellent corrosion resistance and surface smoothness

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 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

Provided is a method of manufacturing an HPF part comprising: preparing a steel sheet comprising C: 0.18% to 0.25%, Si: 0.1% to 1.0%, Mn: 0.9% to 1.5%, P: 0.03% or less, S: 0.01% or less, Al: 0.01% to 0.05%, Cr: 0.05% to 0.5%, Ti: 0.01% to 0.05%, B: 0.001% to 0.005%, N: 0.009% or less, and a balance of Fe and impurities; heating the steel sheet at 550&#xb0; C. to 850&#xb0; C. followed by maintaining at 640&#xb0; C. to 680&#xb0; C., and immersing the steel sheet in a hot dip aluminum plating bath, and a balance of Al and impurities; cooling the plated steel sheet at 15&#xb0; C./s or faster; heating the cooled hot dip aluminum plated steel sheet at 880&#xb0; C. to 930&#xb0; C. followed by maintaining for a certain time; and hot forming the alloyed hot dip aluminum plated steel sheet and quenching at a range of 300&#xb0; C. or lower at the same time.

Method of manufacturing hot press formed parts having excellent powdering resistance

Provided is a hot press formed article having good anti-delamination and having a hot dip aluminized layer formed on the surface of a base steel sheet. The base steel sheet comprises 0.18-0.25 wt % of C, 0.1-0.5 wt % of Si, 0.9-1.5 wt % of Mn, 0.03 wt % or less of P, 0.01 wt % or less of S, 0.01-0.05 wt % of Al, 0.05-0.5 wt % of Cr, 0.01-0.05 wt % of Ti, 0.001-0.005 wt % of B, 0.009 wt % or less of N and the balance of Fe and other impurities. The aluminized layer comprises a single soft diffusion layer comprising &#x3b1;-Fe with solid-solubilized Al, and the hardness of the diffusion layer is 300-600 (Hv).

Hot press formed article having good anti-delamination, and preparation method for same

An HPF molding member having a melted aluminum plating layer formed on the surface of a base steel sheet and excellent delamination resistance. The base steel sheet comprises: 0.18-0.25% by weight of C; 0.1-1.0% by weight of Si; 0.9-1.5% by weight of Mn; 0.03% by weight or less of P; 0.01% by weight or less of S; 0.01-0.05% by weight of Al; 0.05-0.5% by weight of Cr; 0.01-0.05% by weight of Ti; 0.001-0.005% by weight of B; 0.009% by weight or less of N; and the balance Fe and other impurities. The plating layer consists of a soft diffusion layer and a hard alloy layer, the hard alloy layer having a tau layer irregularly and non-continuously dispersed and distributed on the inside thereof at 10% or more of the entire area fraction. The difference in hardness between the alloy layer and the diffusion layer is 400 (Hv) or less.

Hot press formed article having excellent delamination resistance and method for manufacturing the same

Provided is a hot press-formed (HPF) member with excellent powdering resistance at the time of press forming. The HPF member includes a hot-dip coating layer containing Al on a surface of a base steel sheet. The base steel sheet includes, based on wt %, 0.18-0.25% of C, 0.1-1.0% of Si, 0.9-1.5% of Mn, 0.03% or less of P, 0.01% or less of S, 0.01-0.05% of Al, 0.05-0.5% of Cr, 0.01-0.05% of Ti, 0.001-0.005% of B, 0.009% or less of N, the balance Fe, and the other impurities. The hot-dip coating layer comprises a soft diffusion layer and a hard alloy layer. The alloy layer has a Tau phase in the range of 10-30%, in terms of area percent.

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Gwangyang-si, South Korea

Heung-Yun Kim