Method for medium plate of controlled rolling at two stages in non-recrystallization region

Abstract

The invention discloses a method for a medium plate of controlled rolling at two stages in a non-recrystallization region. The method is to perform two-stage rolling in a temperature range of the non-recrystallization region so as to improve the initial rolling temperature of rolling in the non-recrystallization region, and reduce the soaking time of an intermediate billet at high-temperature stage. The method comprises the following steps: the intermediate billet is immediately subject to first high pressure water descaling operation, when the intermediate billet is cooled to the temperature of the non-recrystallization temperature region, and then is subject to the first-stage rolling in the non-recrystallization region; the intermediate billet is subject to swing holding on the front or rear roller bed of a rolling mill; and the intermediate billet is subject to second high pressure water descaling operation after the billet is held to the set temperature, and then is subject to second-stage rolling in the non-recrystallization region to obtain the medium plate in accordance with the requirement. The method has few rolling passes and large total deformation of rolling in the non-recrystallization region, improves the output per hour, can stabilize the low-temperature impact performance of the steel plate, and improves the performance qualification rate.

Description

technical field [0001] The invention relates to a medium plate rolling method, in particular to a two-stage controlled rolling medium plate method in a non-recrystallized zone. Background technique [0002] In the current nationwide medium and heavy plate factories, for medium and heavy plates with high performance requirements, two-stage controlled rolling in the recrystallization zone and non-recrystallization zone, and controlled cooling after rolling are used for production. The main process is as follows: [0003] 1. The steel billet that has been fully austenitized and alloyed is heated, descaled with high-pressure water, and the as-cast structure of the billet is refined into recrystallized tissue. At the same time, the thickness of the billet is compressed to 2-4 times the thickness of the finished product. [0004] 2. The intermediate billet is cooled on the roller table and waited for temperature (by air cooling, water cooling or steam mist cooling) to the non-re...

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Problems solved by technology

[0008] 1. The intermediate billet stays warm on the roller table for a long time, corresponding to the long time of contact with oxygen in the air, and the secondary oxide scale produced is thick. It is difficult to remove the secondary oxide scale with high-pressure water before rolling in the non-recrystallized area. Correspondingly high metal consumption

[0009] 2. Due to the low rolling temperature in the non-recrystallized area and the corresponding large deformation resistance, within the limited capacity of the rolling mill, it is necessary to control the pass reduction and increase the rolling pass

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