Baoshan Iron & Steel Co., Ltd.

Boashan Iron & Steel Co., Ltd.

Sixin Zhao

Wei Wang

Jun Zhang

Liandeng Yao

Xiaobo Wang

Yuchuan Miao

Xiaoting Zhao

Hongsheng Jiang

Jiaqiang Gao

Pengjian Wang

The invention discloses a high-strength steel plate, comprising the following chemical elements in mass percentages: C: 0.070-0.115%, Si: 0.20-0.50%, Mn: 1.80-2.30%, Cr: 0-0.35%, Mo: 0.10-0.40%, Nb: 0.03-0.06%, V: 0.03-0.06%, Ti: 0.002-0.04%, Al: 0.01-0.08%, B. 0.0006-0.0020%, N&#x2264;0.0060%, O&#x2264;0.0040% Ca: 0-0.0045%, and the balance of Fe and unavoidable impurities. The invention further discloses a process of manufacturing said high-strength steel plate.

High strength steel plate and manufacturing method thereof

Provided is a low-yield-ratio high-strength-toughness thick steel plate with excellent low-temperature impact toughness, which comprises: 0.05%-0.11% of C, 0.10%-0.40% of Si, 1.60%-2.20% of Mn, S&#x2264;0.003%, 0.20-0.70% of Cr, 0.20%-0.80% of Mo, 0.02%-0.06% of Nb, 3.60%-5.50% of Ni, 0.01%-0.05% of Ti, 0.01%-0.08% of Al,&#x3c;N&#x2264;0.0060%, 0&#x3c;O&#x2264;0.0040%, and 0&#x3c;Ca&#x2264;0.0045%, with the balance being Fe and inevitable impurities; in addition, Ni+Mn&#x2265;5.5 is also satisfied. The manufacturing method for the above-mentioned steel plate comprises smelting, casting, heating, two-stage rolling, quenching, cooling after quenching, and tempering.

Low-yield-ratio high-strength-toughness thick steel plate with excellent low-temperature impact toughness and manufacturing method therefor

The invention discloses an ultra-high obdurability steel plate having a low yield ratio, comprising the chemical elements in mass percentages of: C: 0.18-0.34%, Si: 0.10-0.40%, Mn: 0.50-1.40%, Cr: 0.20-0.70%, Mo: 0.30-0.90%, Nb: 0-0.06%, Ni: 0.50-2.40%, V: 0-0.06%, Ti: 0.002-0.04%, Al: 0.01-0.08%, B: 0.0006-0.0020%, N&#x2264;0.0060%, O&#x2264;0.0040%, Ca: 0-0.0045%, and the balance of Fe and other unavoidable impurities. The invention also discloses a process of manufacturing the steel plate, wherein the heating temperature is 1080-1250&#xb0; C.; the quenching temperature is 860-940&#xb0; C.; and the tempering temperature is 150-350&#xb0; C.

Ultra high obdurability steel plate having low yield ratio and process of manufacturing same

The present invention provides a steel plate having a low welding crack susceptibility and a yield strength of 800 MPa and a manufacturing method for the same. The steel plate having a low welding crack susceptibility comprises the following chemical components (wt. %: percent by weight): C: 0.03-0.08 wt. %, Si: 0.05-0.70 wt. %, Mn: 1.30-2.20 wt. %, Mo: 0.10-0.30 wt. %, Nb: 0.03-0.10 wt. %, V: 0.03-0.45 wt. %, Ti: 0.002-0.040 wt. %, Al: 0.02-0.04 wt. %, B: 0.0010-0.0020 wt. %, the balance being Fe and unavoidable impurities, and the welding crack susceptibility index meets the following formula: Pcm&#x2266;0.20%. The thermo-mechanical controlled rolling and cooling processes is used to obtain an ultrafine bainite batten matrix structure, which increases the intensity, plasticity and toughness of the steel plate. The steel plate with a low welding crack susceptibility of the present invention has a yield strength of greater than 800 MPa, a tensile strength of greater than 900 MPa, a Charpy impact energy Akv (&#x2212;20&#xb0; C.) of no less than 150 J and an excellent welding performance.

Steel plate having a low welding crack susceptibility and a yield strength of 800MPa and manufacture method thereof

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Shanghai, China

Sixin Zhao