Method for producing high-strength Q690D steel plate with thickness of 4 mm on wide and thick plate mill

Abstract

The invention relates to a method for producing a high-strength Q690D steel plate with thickness of 4 mm on a wide and thick plate mill. A technological path is as follows: material selecting-cogging heating-descaling-cogging rolling-cooling-cogged ingot finishing (including inspecting and breaking)-hybrid welding (composite blanks)-inspecting-warehousing; and reheating of the composite blanks-descaling-rolling (finished product rolling)-cooling-finishing (including cutting the steel plate into an upper part and a lower part)-heat treatment-cooling-appearance inspecting-sampling- physical and chemical inspecting-judging-warehousing. Reasonable Q690D chemical component blanks are selected, thicknesses and lengths of rolled pieces are selected scientifically, the blanks are welded in a hybrid manner, and then are heated, rolled, subjected to heat treatment and finishing, checked and inspected, the delivery state of production is Q+T / Q, and the thickness of a finished product is 4.0 mm; and the performance, size and surface quality of the product can completely meet the standard requirement of the GB / T16270 product. The product can stop a gap that domestic and foreign wide and thick plate mills cannot roll thin steel plate products.

Description

technical field [0001] The invention belongs to the technical field of steel plate rolling, and in particular relates to a method for producing thin-gauge high-strength Q690D on a wide-thick plate rolling mill. Background technique [0002] Under the background of the "cost reduction" economy, construction machinery is developing towards large-scale and lightweight; the domestic iron and steel industry and construction machinery industry are facing the challenges and opportunities of "adjusting structure and changing mode". Steel plates have broad application prospects. [0003] At present, for wide and heavy plate rolling enterprises at home and abroad, the rolling thickness limit specification of the rolling mill is 6mm. However, in actual production, the production capacity of wide and heavy plate rolling mills at home and abroad is almost impossible to directly produce steel plates with extreme thickness specifications, especially medium plates with thickness specificat...

AI Technical Summary

Problems solved by technology

However, in actual production, the production capacity of wide and thick plate rolling mills at home and abroad is almost impossible to directly produce steel plates with extreme thickness specifications, especially medium plates with a thickness specification of 5mm or less.

In the production of such thickness products, the rolling torque is large, the plate shape is difficult to control, the temperature of the rolled piece is cooled quickly, the operation (equipment) accidents are frequent, the product quality is not guaranteed, the yield is low, the cost is high, it is difficult to achieve mass production, and the product lacks competitiveness.