Posco Co., Ltd

Posco

Yoen-Jung Park

Seong-Ung Koh

Hong-Ju Lee

Moo-Jong Bae

Hyo-Shin Kim

Sang-Deok Kang

Yong-Jin Kim

Hong-Yeol Oh

Young-Deok Jung

Jae-Hyun Park

Jang-Yong Yoo

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 according to one preferred aspect of the present invention are austenitic steel material having superb abrasion resistance and toughness, and a method for producing the austenite steel material. The austenitic steel material having superb abrasion resistance and toughness according to one preferred aspect of the present invention comprises, in wt %, 0.6-1.9% carbon (C); 12-22% manganese (Mn); 5% or lower (excluding 0%) chromium (Cr); 5% or lower (excluding 0%) copper (Cu); 0.5% or lower (excluding 0%) aluminum (Al); 1.0% or lower (excluding 0%) silicon (Si); 0.1% or lower (including 0%) phosphorous (P); 0.02% or lower (including 0%) sulfur (S); and the rest in Fe and unavoidable impurities, and has the microstructure comprising, by surface area fraction, 97% or higher (including 100%) austenite and 3% or lower (including 0%) carbide.

Austenitic steel material having excellent abrasion resistance and toughness and manufacturing method the 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

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Pohang-si, South Korea

Yoen-Jung Park