Direct thermal treatment process technology after rolling steel plate

Abstract

The invention belongs to the technical field of metallurgy, in particular to a direct thermal treatment process technology after rolling a steel plate. The invention provides the direct thermal treatment process technology after rolling the steel plate, which can overcome the deficiencies of the prior art. The process technology comprises the steps of heating the steel plate on an outlet roller way of a rolling machine for quenching mainly, using a steel plate electromagnetic induction heating device arranged on the outlet roller way between a medium and heavy plate finish rolling machine and a post-rolling controlled cooling device which is a direct quenching and accelerated cooling device for heating and soaking the steel plate passing through the steel plate electromagnetic induction heating device according to the process requirements, and improving the flatness and the plate shape of the steel plate through a straightening roller matched with the electromagnetic induction heating device. The steel plate electromagnetic induction heating device with the straightening roller is arranged on the roller way between the medium and heavy plate finish rolling machine and the cooling device. The process technology can realize the one-line quenching thermal treatment process of the steel plates with various specifications. The process technology is applicable to new construction and transformation projects of medium and heavy plate plants. The process way and the devices have important popularization value.

Description

technical field [0001] The invention belongs to the technical field of metallurgy, and in particular relates to a direct heat treatment technology after steel plate rolling. Background technique [0002] At present, after the medium and heavy plate is rolled by the rolling mill, the accelerated cooling device (ACC) can be used to cool the steel plate according to the need, so as to control the internal grain size and internal structure of the metal, so as to improve the performance of the steel plate. Partially accelerated cooling technology is also equipped with a strong cooling section with a higher cooling rate to achieve high-speed cooling of the steel plate. It is expected to achieve the purpose of direct quenching (DQ), replace the offline quenching heat treatment production line, and save a lot of energy consumption for secondary heating of heat treatment. [0003] The existing accelerated cooling (ACC) and direct quenching (DQ) of medium and heavy plate mainly adopt ...

AI Technical Summary

Problems solved by technology

There are three main reasons. First, the quenching treatment requires a higher temperature for the steel plate to start cooling, and the required range is 950-880°C. The purpose is to make the steel plate grain structure have sufficient undercooling during the cooling phase transformation process to ensure hardening and the formation of quenching structure; the current direct quenching technology is to quench the steel plate at the final rolling temperature after rolling. The final rolling temperature of the thinner steel plate is generally lower than 880°C. If the temperature is lower than 800°C, the product cannot meet the specified performance; secondly, the temperature difference between the head and the tail of the steel plate after rolling affects the performance of the steel plate after cooling. In order to reduce the temperature difference between the head and the tail, the length of the rolled piece is usually shortened.

Third, the shape defects of the steel plate without thermal straightening after rolling will directly affect the cooling uniformity of the steel plate, and the steel plate after quenching can no longer be eliminated by straightening, which will affect the product quality

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