Hot rolling method for wide and thin size high-strength cold-rolled base plate for automobile

Abstract

The invention discloses a hot rolling method for a wide and thin size high-strength cold-rolled base plate for an automobile. After continuous casting billets are assembled in a heating furnace in a hot state, the Cu accumulation amount of iron oxide scales and steel substrates is reduced by adopting high-temperature preheating and high-temperature rapid heating technologies; after rough rolling, the thickness of an intermediate billet is reduced, a heat holding cover is used for reducing temperature drop and temperature differences of all parts, so that the finish rolling entry temperature of the intermediate billet is increased; and loads of all racks for finish rolling are reduced, and the stability of finish rolling is improved. In the process from finish rolling to steel belt coiling, a controlled rolling and controlled cooling technology is adopted, so that the cold-rolled base plate has excellent uniformity between the shape and the structure property. According to the method, the cold-rolled base plate with the thickness of 1.5-2.5 mm and the width of 1650-2000 mm can be obtained; the convexity degree of a steel belt is controlled to be in a range between 45-15 mu m and 45+15 mu m; the straightness is controlled to be 30I; the thickness accuracy is in a range between -30 mu m and +30 mu m; the structure property of different edges of the head, the middle, the tail of the steel belt is uniform; and the yield and the production efficiency of the wide and thin size high-strength cold-rolled base plate can be increased and improved, so that the cold-rolled base plate meeting the requirements of the actual product quality and the performance is provided for steel plates with the grade of 450-590 MPa for automobile covering parts.

Description

technical field [0001] The invention belongs to the technical field of steel rolling, and in particular relates to a hot rolling method for a wide and thin high-strength cold-rolled substrate for automobiles. Background technique [0002] In recent years, modern automobile manufacturing technology has developed in the direction of lightweight, energy saving, environmental protection and high safety. According to statistics, every 10% reduction in vehicle weight can reduce fuel consumption by 6% to 10%, and energy consumption is closely related to exhaust emissions. Therefore, lightweight vehicles have great practical significance for energy conservation and environmental protection. The rapid development and application of advanced high-strength steels with good formability and higher strength, such as dual-phase steels (DP), transformation-induced plasticity steels (TRIP) and quench-partition steels (QP), have contributed to making modern automobiles To achieve the unity o...

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Problems solved by technology

[0005] The purpose of the present invention is to provide a hot-rolling method for wide and thin high-strength cold-rolled substrates for automobiles, so as to solve the problem of poor finish rolling stability in traditional hot-rolled production, large temperature differences between the strip width direction and the middle and tail of the strip head, and difficulty in controlling the shape of the strip. Improve the yield and production efficiency of wide and thin high-strength cold-rolled substrates, and ensure that the cold-rolled substrates can obtain a strength level that meets the physical quality and performance requirements through subsequent cold rolling and continuous annealing 450MPa ~ 590MPa wide and thin gauge steel strips for automotive panels

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