Process for controlling shape of hot-rolled flat-rolled high-grade pipeline steel plate by using single-rack steckel mill

Abstract

The invention discloses a process for controlling the shape of a hot-rolled flat-rolled high-grade pipeline steel plate by using a single-rack steckel mill. The process realizes the shape control of a hot-rolled flat-rolled high-grade pipeline steel plate by using a single-rack steckel mill by the following steps of: optimizing the two-stage rolling temperature and the thickness of a blank to be heated, reasonably optimizing and using reduction per pass, particularly the reduction of the last three passes in a finish rolling stage, adjusting the roll bending force, controlling convexity of a working roll, accelerating a final rolling on line, performing an edge shielding process additionally according to plate width, and optimizing the laminar cooling water ratio and the inlet / outlet roll gap setting, straightening speed and the like of a straightener. Through the invention, the maximum length of the blank that can be flat-rolled is 13m. When a long blank with thickness of 150 mm is rolled into a high-strength steel plate with thickness of less than or equal to 32 mm, the shape of the steel plate is comprehensively controlled while the performance uniformity of the final product is improved.

Description

technical field [0001] The invention belongs to the field of steel rolling, and in particular relates to a shape control process for hot-rolled flat-rolled high-grade pipeline steel plates in a single-stand furnace coil rolling mill. Background technique [0002] At present, when using a 150mm thick billet to flat-roll high-grade pipeline steel plates, both performance and shape need to be controlled. In order to ensure performance, the redness temperature of high-grade steel pipelines is below 520°C, and the redness temperature of X120 pipeline steel is even lower than 100°C. The lower redness temperature increases the difficulty of plate shape control, not only to ensure that the furnace coil The original rolling shape of the rolling mill, and at the same time ensure the shape of the plate after cooling and the straightening of the straightening machine. At the same time, in mass production of high-grade pipeline steel, the change of roll crown caused by wear and thermal ...

AI Technical Summary

Problems solved by technology

If the billet length is greater than 7.8m, no matter how you increase the heating temperature or rolling speed, etc., because the rolled piece is too long in the finishing rolling stage, the rolling process will become thinner and thinner with the steel plate rolling process, and the steel plate will be thinner and thinner. The temperature drop will become faster and faster, resulting in extremely uneven temperature distribution along the length of the rolled piece, which increases the difficulty of controlling the shape and performance of the rolled piece

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