Posco Co., Ltd

Posco

Posco Holdings Inc.

Seong-Woo Kim

Jin-Keun Oh

Yeol-Rae Cho

Sang-Heon Kim

A-Ra Cho

Hyo-Sik Chun

Jin-Ho Cha

Si-Myoung Heo

Jeong-Won Seo

Il-Ryoung Sohn

Jeom-Soo Shin

Hyeon-Jeong Shin

Sang-Bin Han

Min-Seo Koo

Seong-Beom Bae

Won-Mo Bak

An aspect of the present invention relates to a cold-rolled steel plate for hot forming, which is excellent in corrosion-resistance and spot-weldability, contains, by weight %, C: 0.1-0.4%, Si: 0.5-2.0%, Mn: 0.01-4.0%, Al: 0.001-0.4%, P: 0.001-0.05%, S: 0.0001-0.02%, Cr: 0.5% to less than 3.0%, N: 0.001-0.02%, and a balance of Fe and inevitable impurities, satisfying formula (1) below, and includes an Si amorphous oxidation layer continuously or discontinuously formed at a thickness of 1 nm-100 nm on the surface thereof. Formula (1): 1.4≤ 0.4*Cr+Si≤3.2 (wherein element symbols denote measurements of respective element contents by weight %).

Cold-rolled steel plate for hot forming, having excellent corrosion-resistance and spot-weldability, hot-formed member, and method for manufacturing same

One aspect of the present invention relates to a plated steel sheet for hot press forming, having an excellent impact property.

Plated steel sheet for hot press forming having excellent impact property, hot press formed part, and manufacturing method thereof

An embodiment of the present invention provides steel for hot forming, a hot-formed member, and methods for manufacturing same, the steel comprising, by wt %, 0.06-0.1% of C, 0.05-0.6% of Si, 0.6-2% of Mn, 0.05% or less of P, 0.02% or less of S, 0.01-0.1% of Al, 0.01-0.8% of Cr, 0.01-0.5% of Mo, 0.02% or less of N, and the remainder of Fe and inevitable impurities, wherein an alloy factor represented by relational expression 1 below is 7 or more, and the number of carbides having a circular equivalent diameter of 0.5 μm or greater is 10/mmor less.Alloy factor=I(Mn)×I(Si)×I(Cr)×I(Mo)  [Relational expression 1]

Steel for hot forming, hot-formed member, and manufacturing methods therefor

A wear resistant steel material has high hardness and excellent cut crack resistance, that can be applied to a thick steel material of which the thickness is 60 mm or more, that is not cracked even after being cut using gas, and a method of manufacturing the wear resistant steel material.

Steel sheet plated with Al—Fe for hot press forming having excellent corrosion resistance and spot weldability, and manufacturing method thereof

Provided are a plated steel sheet for hot press forming including: a base steel sheet containing, by wt %, 0.14 to 0.5% of C, 0.001 to 1% of Si, 0.3 to 4% of Mn, 0.001 to 0.015% of P, 0.0001 to 0.02% of S, 0.001 to 0.1% of Al, 0.001 to 1% of Cr, 0.001 to 0.02% of N, 0.1% or less of Ti, 0.01% or less of B, 0.005 to 0.1% of Sb, and a balance of Fe and unavoidable impurities; an aluminum or aluminum alloy plating layer provided on at least one surface of the base steel sheet; and a Sb-rich layer provided between the base steel sheet and the plating layer, wherein the plated steel sheet for hot press forming satisfies the following Relational Expressions 1-1 and 1-2, a hot press formed member manufactured using the same, and methods for manufacturing the plated steel sheet for hot press forming and the hot press formed member. [Relational Expression 1-1] [Relational Expression 1-2] [In Relational Expressions 1-1 and 1-2, Sbrepresents an average content of Sb in the plating layer, and a unit thereof is wt %, Sbrepresents a maximum value of a content of Sb in the Sb-rich layer, and a unit thereof is wt %, and Δt represents a linear distance from a boundary between the plating layer and the Sb-rich layer to a point where Sbis measured, and a unit thereof is μm.]

Plated steel sheets for hot press forming having excellent hydrogen brittleness resistance and impact resistance, hot press formed parts, and manufacturing methods thereof

An aluminum-iron-plated steel sheet including a base steel sheet and an aluminum-based plating layer on a surface of the base steel sheet. The aluminum-based plating layer includes an alloyed layer on the surface of the base steel sheet and an aluminum layer on the alloyed layer. The alloyed layer may be formed of one or more of FeAl, FeAl(Si), FeAl, and FeAl. A thickness of the alloyed layer may be 90% or more of a thickness of the aluminum-based plating layer. A surface fraction of Ti may be 2% or less and a surface fraction of Zn may be 1% or less, as observed on the surface of the aluminum-based plating layer.

Aluminum-iron-plated steel sheet, having excellent mold wear resistance, for hot press forming, and manufacturing method thereof

The present disclosure relates to an aluminum-based plated steel that is provided for vehicles by hot forming, an aluminum-based alloy plated steel manufactured using the same, and method of manufacturing thereof.

Manufacturing method of aluminum-based alloy plated steel

The present invention provides an aluminum-based plated steel plate used in hot-press forming, the steel plate comprising: a base steel plate; and a plating layer formed on the base steel plate, wherein the plating layer comprises: an alloying layer formed on the surface of the base steel plate and including one or more of Fe 3Al, FeAl(Si), Fe 2Al 5, and FeAl 3; and an aluminum layer formed on the alloying layer and having a thickness less than 10% of the thickness of the plating layer, and the plating layer has a thickness of 5-20 μm and an oxygen content of 10 weight % or less, as measured by GDS, at a depth of 0.1 μm from the surface of the plating layer.

Aluminum-based plated steel plate for hot press having excellent resistance against hydrogen delayed fracture and spot weldability, and method for manufacturing same

Provided are plated steel sheets for hot press forming, hot press formed parts, and manufacturing methods thereof, the plated steel sheets comprising: a base steel sheet comprising, in weight %, C: 0.07 to 0.5%, Si: 0.05 to 1%, Mn: 0.5 to 5%, P: 0.001 to 0.015%, S: 0.0001 to 0.02%, Al: 0.01 to 0.1%, Cr: 0.01 to 1%, N: 0.001 to 0.02%, Ti: 0.1% or less, B: 0.01% or less, Sn: 0.01 to 0.1%, and a balance of Fe and inevitable impurities; an aluminum or aluminum alloy plating layer disposed on at least one surface of the base steel sheet; and an Sn-enriched layer provided between the base steel sheet and the plating layer, wherein the Sn-enriched layer satisfies a specific relationship.

An aspect of the present invention relates to a cold-rolled steel plate for hot forming, which is excellent in corrosion-resistance and spot-weldability, contains, by weight %, C: 0.1-0.4%, Si: 0.5-2.0%, Mn: 0.01-4.0%, Al: 0.001-0.4%, P: 0.001-0.05%, S: 0.0001-0.02%, Cr: 0.5% to less than 3.0%, N: 0.001-0.02%, and a balance of Fe and inevitable impurities, satisfying formula (1) below, and includes an Si amorphous oxidation layer continuously or discontinuously formed at a thickness of 1 nm-100 nm on the surface thereof. Formula (1): 1.4≤0.4*Cr+Si≤3.2 (wherein element symbols denote measurements of respective element contents by weight %).

The present disclosure provides a hot-press formed part comprising a plated steel sheet and an aluminum alloy plated layer formed on the plated steel sheet, wherein the aluminum alloy plated layer comprises: an alloying layer (I) formed on the plated steel sheet and containing, by weight %, 5-30% of Al; an alloying layer (II) formed on the alloying layer (I) and containing, by weight %, 30 to 60% of Al; an alloying layer (III) formed on the alloying layer (II) and containing, by weight %, 20-50% of Al and 5-20% of Si; and an alloying layer (IV) formed continuously or discontinuously on at least a part of the surface of the alloying layer (III), and containing 30-60% of Al, wherein the rate of the alloying layer (III) exposed on the outermost surface of the aluminum alloy plated layer is 10% or more.

Hot press-formed part, and manufacturing method thereof

The present invention pertains to a hot press forming member having excellent resistance to hydrogen embrittlement, and a method for manufacturing same. An aspect of the present invention provides a hot press forming member having excellent resistance to hydrogen embrittlement, the hot press forming member comprising a base steel plate and an alloy-plated layer formed on the surface of the base steel plate, wherein the alloy-plated layer contains pores such that pores having a size of 5 μm or less constitute 3-30% of the surface area of the alloy-plated layer as viewed in a cross-section taken in the thickness direction of the member.

Hot press forming member having excellent resistance to hydrogen embrittlement, and method for manufacturing same

Provided is an Al—Fe-alloy plated steel sheet for hot forming, having excellent TWB welding characteristics since excellent hardness uniformity of a TWB weld zone after hot forming is obtained by suitably controlling a batch annealing condition, after plating Al, such that an Al—Fe-alloy layer is formed; a hot forming member; and manufacturing methods therefor.

Growing community of inventors

Gwangyang-si, South Korea

Seong-Woo Kim