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, ...

AI Technical Summary

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 grade quenched and tempered steel plate with a thickness of 120-180mm, and the carbon content of the invention is 0.08%-0.10% , carbon equivalent Ceq<0.52%, unable to meet the mechanical performance requirements of rack steel with a thickness of 178-210mm

[0008] The patent "A Low Compression Ratio 690MPa Extra-Thick Steel Plate and Its Production Method" with the publication number CN106319380A proposes a low compression ratio 690MPa steel plate and its production method. The invention has a low alloy content and the maximum thickness of the finished product is 115mm. Also cannot be applied in the production of extra-thick specification rack steel

[0009] The patent No. CN102965592B "A Production Method of Low Compression Ratio Thick Specification Ultra-High Strength Steel Plate for Ocean Engineering" proposes a production method of low compression ratio steel plate, which is only suitable for continuous casting slabs with a thickness of 220mm and a thickness of 80mm. Steel plate, the limitation is too large and cannot be promoted to the production of thicker steel plate

Images