Baoshan Iron & Steel Co., Ltd.

Xiufang Wang

Yan Yu

Yuan Fang

Jianchun Wu

Bo Qin

Wei He

Feng Zhang

A method for manufacturing thin strip continuously cast 700 Mpa grade high strength weather-resistant steel, the method comprising the following steps: 1) casting a 1-5 mm thick cast strip in a double roller continuous casting machine, the cast strip comprising the following chemical compositions by weight percent: C 0.03-0.1%, Si&#x2264;0.4%, Mn 0.75-2.0%, P 0.07-0.22%, S&#x2264;0.01%, N&#x2264;0.012%, and Cu 0.25-0.8%, further comprising more than one of Nb, V, Ti and Mo: Nb 0.01-0.1%, V 0.01-0.1%, Ti 0.01-0.1%, and Mo 0.1-0.5%, and the balance being Fe and unavoidable impurities; 2) cooling the cast strip at a rate greater than 20&#xb0; C./s; 3) hot rolling the cast strip under a temperature of 1050-1250&#xb0; C. at a reduction rate of 20-50% and a deformation rate greater than 20 s&#x2212;1; then conducting austenite online recrystallization, the thickness of the hot rolled strip being 0.5-3.0 mm; 4) cooling at a rate of 10-80&#xb0; C./s; and 5) rolling up under a temperature of 500-650&#xb0; C. The obtained steel strip microstructure mainly consists of uniformly distributed bainites and needle-shaped ferrites.

Method for manufacturing thin strip continuously cast 700MPa-grade high strength weather-resistant steel

A manufacturing method for strip casting 550 MPa-grade high strength atmospheric corrosion-resistant steel strip, comprising the following steps: 1) smelting, where the chemical composition of a molten steel is that: C is between 0.03-0.08%, Si&#x2266;0.4%, Mn is between 0.6-1.5%, P is between 0.07-0.22%, S&#x2266;0.01%, N&#x2266;0.012%, Cu is between 0.25-0.8%, Cr is between 0.3-0.8%, and Ni is between 0.12-0.4%, additionally, also comprised is at least one micro-alloying element among Nb, V, Ti, and Mo, where Nb is between 0.01-0.08%, V is between 0.01-0.08%, Ti is between 0.01-0.08%, and Mo is between 0.1-0.4%, and where the remainder is Fe and unavoidable impurities; 2) strip casting, where a 1-5 mm-thick cast strip is casted directly; 3) cooling the strip, where the cooling rate is greater than 20&#xb0; C./s; 4) online hot rolling the cast strip, where the hot rolling temperature is between 1050-1250&#xb0; C., where the reduction rate is between 20-50%, and where the deformation rate is &#x3e;20 s; austenite online recrystallizing after hot rolling, where the thickness of the hot rolled strip is between 0.5-3.0 mm; and, 5) cooling and winding, where the cooling rate is between 10-80&#xb0; C./s, and where the winding temperature is between 570-720&#xb0; C. The microscopic structure of a steel strip acquired is primarily constituted by fine polygonal ferrite and pearlite.

Manufacturing method for strip casting 550 MPa-grade high strength atmospheric corrosion-resistant steel strip

A manufacturing method for strip casting 700 MPa-grade high strength atmospheric corrosion-resistant steel, comprising the following steps: 1) smelting, where the chemical composition of a molten steel in terms of weight percentage is that C is between 0.03-0.1%, Si&#x2266;0.4%, Mn is between 0.75-2.0%, P is between 0.07-0.22%, S&#x2266;0.01%, N&#x2266;0.012%, Cu is between 0.25-0.8%, Cr is between 0.3-0.8%, and Ni is between 0.12-0.4%, additionally, also comprised is at least one micro-alloying element among Nb, V, Ti, and Mo, where Nb is between 0.01-0.1%, V is between 0.01-0.1%, Ti is between 0.01-0.1%, and Mo is between 0.1-0.5%, and where the remainder is Fe and unavoidable impurities; 2) strip casting, where a 1-5 mm-thick cast strip is casted directly; 3) cooling the cast strip, where the cooling rate is greater than 20&#xb0; C./s; 4) online hot rolling the cast strip, where the hot rolling temperature is between 1050-1250&#xb0; C., where the reduction rate is between 20-50%, and where the deformation rate is &#x3e;20s; austenite online recrystallizing after hot rolling, where the thickness of the hot rolled strip is between 0.5-3.0 mm; and, 5) cooling and winding, where the cooling rate is between 10-80&#xb0; C./s, and where the winding temperature is between 520-670&#xb0; C. The microscopic structure of a steel strip acquired is primarily constituted by evenly distributed bainite and acicular ferrite.

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Shanghai, China

Xiufang Wang