Low-rolling-compression-ratio rack steel plate and manufacturing method thereof

Abstract

The invention discloses a low-rolling-compression-ratio rack steel plate and a manufacturing method thereof. Steel comprises the rack steel plate with the compression ratio. The low-rolling-compression-ratio rack steel plate is characterized by comprising the chemical components of, by mass, 0.12% -0.15% of C, 0.1% -0.3% of Si, 1.0% -1.3% of Mn, 0-0.02% of P, 0-0.01% of S, 0.01% -0.03% of Als, 2.5% -3.0% of Ni, 0.5% -0.8% of Cr, 0.5% -0.8% of Mo, 0.2% -0.5% of Cu, 0.02% -0.04% of Nb, 0.03% -0.06% of V, 0.005% -0.03% of Ti, 0.001% -0.0015% of B, and the balance iron and inevitable impurities. After electroslag remelting and forging, the first-stage rolling starting temperature is 1150-1250 DEG C, the second-stage rolling starting temperature is 950-1000 DEG C, the finish rolling temperatureis 850-900 DEG C, and the rolling compression ratio is smaller than or equal to 2; and then high-temperature quenching, sub-temperature quenching and tempering treatment are adopted, and the Charpy impact energy single value of the core part of the finished steel plate at the temperature of-40 DEG C is larger than or equal to 90J.

Description

technical field [0001] The invention belongs to the field of iron and steel material preparation, in particular to a component design and a manufacturing method of a rack steel plate with a low rolling compression ratio. Background technique [0002] The 21st century is the century of the ocean. With the development of science and technology and the improvement of people's living standards, all countries in the world are focusing their attention on the huge resources contained in the ocean. In recent years, the continuous and rapid development of the offshore engineering equipment industry has also promoted a large demand for steel for offshore engineering platforms and product upgrading. The market urgently needs ultra-high-strength and extra-thick marine engineering steel plates with good comprehensive properties. [0003] The service environment of offshore engineering platforms is harsh. In addition to conventional stresses, various factors such as strong winds, surges, ...

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Problems solved by technology

[0005] Patent No. CN103031498B "Manufacturing method of low-compression bit-thick ultra-high-strength strain-aged steel plate for marine engineering" proposes a method for manufacturing ultra-thick ultra-high-strength marine steel plate with low compression ratio. The alloy composition and processing proposed by the invention The method cannot produce rack steel with a thickness greater than 178mm

[0006] The patent "A Low Compression Ratio 690MPa Extra-Thick Steel Plate and Its Manufacturing Method" with the publication number CN110791713A proposes a 690MPa-grade steel plate with a thickness of 120-160mm and its manufacturing method. The lower alloy composition cannot guarantee the impact toughness of the steel plate core, and the upgrade and optimization of the casting billet preparation process should also be considered for rack steel plates with greater thickness, which is not mentioned in the patent

[0007] Patent No. CN109266967A "An ultra-low compression ratio ultra-thick quenched and tempered hydropower steel plate and its production method" proposes a 690MPa gr

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