Method for producing thin-gauge high-strength structural steel plate by steckel mill

Abstract

The invention discloses a method for producing a thin-specification high-strength structural steel plate by a steekle mill. Belongs to the metallurgy field. The method comprises the following specific steps: 1, steelmaking; a continuous casting blank is obtained; 2, heating: heating at high temperature in a heating furnace; 3, rolling by a steekle mill to obtain a rolled steel plate; and 4, cooling: finally obtaining the thin-gauge high-strength structural steel plate. The component design that the carbon content is 0.16-0.18% is adopted, microalloy elements of Nb, V and Ti are properly added, the advantage that a steekle mill can conduct heat preservation on a steel plate coil in a furnace in the rolling process of the thin steel plate with the thickness of 6-10 mm is utilized, the temperature reduction speed of the steel plate in the rolling process is reduced, the thin high-strength structural steel plate with the tensile strength of 570 MPa is obtained, and the steel plate is excellent in-5 DEG C impact performance, good in heat preservation performance and good in heat preservation performance. And the plate shape quality is good, the flatness does not exceed 6 mm / m, an additional heat treatment procedure of normalizing or quenching and tempering is not needed, the process is simple, and the cost is low.

Description

technical field [0001] The invention relates to the field of metallurgy, and relates to a production method of a steel plate, more specifically, to a production method of a thin-gauge high-strength structural steel plate produced by a steckel mill. Background technique [0002] SM570 is the steel plate grade with the highest strength level in the JIS 3106 rolled steel standard for welded structures. It is mainly used in key structural parts such as bridges, buildings, and wind power. There are strict requirements on welding performance and so on. Generally, medium and heavy plate rolling mills roll thin specifications due to the high temperature drop rate in the process, and the rolling in low temperature area leads to poor performance of the steel plate. Usually, the steel plate is required to be produced by additional normalizing or quenching + tempering process. . [0003] With the rapid development of the world economy and the accelerated upgrading of the manufacturing ...

AI Technical Summary

Problems solved by technology

After checking the relevant patent applications for thin-gauge high-strength structural steel plate products, generally in order to ensure the strength, shape, stress and performance of thin-gauge high-strength structural steel plate, Cr, Ni, Mo and other precious alloy elements are generally added. Production by normalizing or quenching + tempering process leads to a decline in product competitiveness, resulting in less application in the design of existing large-scale engineering projects

[0004] Application No. 201811450050.4, "Production method of thin-gauge, easy-to-weld low-temperature structural steel plates", this invention is for thin-gauge steel plates with yield strengths of 420, 460, and 500 MPa. The composition design of the invention is to add Cr, Ni, Mo and other precious alloying elements. The disadvantages are: Alloy cost is high; after rolling, the steel plate needs additional normalizing + tempering heat treatment process, many production processes, long process and high cost

[0005] In addition, for the existing thin-gauge high-strength structural steel plates, especially high-strength steel plates with a thin gauge of 6-10 mm and a tensile strength of 570 MPa, the temperature drop rate of thin-gauge steel plates is large during the rolling process of general medium and heavy plate rolling mills, and the last 3 ~5 passes are often rolled in a low-temperature region below 800°C, resulting in problems such as unqualified steel plate strength, poor shape quality, and uneven internal stress. The production of medium and heavy plate rolling mills is very difficult, and generally requires composition design Precious alloy elements such as Cr and Mo are added, and the rolled steel plate is additionally produced by normalizing or quenching+tempering process to solve the matching problems of performance and shape of thin-gauge high-strength structural steel plate and meet user performance

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