Posco

Posco Co., Ltd

Seong-Ung Koh

Yoen-Jung Park

Moo-Jong Bae

Jae-Hyun Park

Hyo-Shin Kim

Hong-Ju Lee

Ju-Seung Lee

Hwan-Gyo Jung

The steel plate material property testing device determining a material property of a surface of the steel plate by generating the eddy current in the steel plate includes: an eddy current tester disposed so as to face the steel plate; and a frame to which the eddy current tester is fixed, in which the eddy current tester includes: a coil disposed so as to form an alternating-current (AC) magnetic field in only one direction; an AC power supply unit connected to the coil; a sensor unit connected to the coil; and a material property determination unit connected to the sensor unit and determining the material property of the steel plate based on a measured signal obtained through the sensor unit.

Steel plate surface material property testing device and steel plate surface material property testing method

The present invention relates to a thick steel suitable for use as a line pipe, a sour-resistant material, or the like and, more specifically, to a high-strength steel having excellent resistance to sulfide stress cracking, and a method for manufacturing same.

High-strength steel having excellent resistance to sulfide stress cracking, and method for manufacturing same

Steel sheets and methods for manufacturing same useful for a line pipe or the like can have excellent hydrogen induced cracking resistance, and longitudinal strength uniformity. The Sttel sheets can include certain amounts of carbon (C), silicon (Si), manganese (Mn), phosphorus (P), sulfur (S), aluminum (Al), nitrogen (N), niobium (Nb), titanium (Ti), calcium (Ca), one or more selected from a group consisting of nickel (Ni), chromium (Cr), molybdenum (Mo), vanadium (V), and a balance of iron (Fe) and other inevitable impurities. A microstructure of the steel sheet can be comprised of ferrite or a composite structure of ferrite and acicular ferrite, and upper bainite is included in an area of 5% or less in a center portion of the thickness of the steel sheet.

Steel sheet having excellent hydrogen induced cracking resistance and longitudinal strength uniformity, and manufacturing method therefor

Provided are: a SOUR-resistant heavy-wall steel plate having excellent low-temperature toughness and post-heat treatment characteristics; and a method for manufacturing the same. The SOUR-resistant heavy-wall steel plate of the present invention comprises: in terms of weight %, 0.02-0.06% of C; 0.5% or less of Si (excluding 0%); 0.8-2.0% of Mn; 0.03% or less of P; 0.003% or less of S; 0.06% or less of Al; 0.01% or less of N; 0.005-0.1% of Nb; 0.005-0.05% of Ti; 0.0005-0.005% of Ca; one or more selected from 0.05-0.5% of Ni, 0.05-0.5% of Cr, 0.02-0.4% of Mo, and 0.005-0.1% of V; and the remainder Fe and unavoidable impurities, wherein the heavy-wall steel plate satisfies relational expressions 1-3, and has a percent ductile fracture of 85% or more in the drop weight tear test (DWTT) at &#x2212;20&#xb0; C.

Sour-resistant heavy-wall steel plate having excellent low-temperature toughness and post-heat treatment characteristics and method for manufacturing same

The present invention relates to a thick steel plate having excellent low-temperature toughness and hydrogen-induced cracking resistance, and a method for manufacturing the same.

Thick steel plate having excellent low-temperature toughness and hydrogen-induced cracking resistance, and method for manufacturing same

Provided is a steel sheet for an oil sand slurry pipe having excellent abrasion resistance, corrosion resistance, and low-temperature toughness including 0.2 wt % to 0.35 wt % of carbon (C), 0.1 wt % to 0.5 wt % of silicon (Si), 0.5 wt % to 1.8 wt % of manganese (Mn), 0.1 wt % to 0.6 wt % of nickel (Ni), 0.005 wt % to 0.05 wt % of niobium (Nb), 0.005 wt % to 0.02 wt % of titanium (Ti), 0.03 wt % or less of phosphorous (P), 0.03 wt % or less of sulfur (S), 0.05 wt % or less (excluding 0 wt %) of aluminum (Al), 0.01 wt % or less (excluding 0 wt %) of nitrogen (N), and iron (Fe) as well as other unavoidable impurities as a remainder.

Steel sheet for an oil sand slurry pipe having excellent abrasion resistance, corrosion resistance, and low-temperature toughness and method for manufacturing same

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Pohang-si, South Korea

Seong-Ung Koh