Overproof control method of thickness of head and tail of wide and thick plate mill

Abstract

The invention relates to an overproof control method of the thickness of a head and a tail of a wide and thick plate mill. The overproof control method is achieved by adding an overproof control module which assists the thickness of the head in a wide and thick plate mill L1 thickness automatic control system. The method specifically comprises the steps that a head roll gap compensation factor coefficient modification submodule and a head roll gap direct modification submodule are additionally arranged in the plate mill L1 thickness automatic control system, modification is carried out on a head roll gap in the process of rolling a wide and thick plate, and the control accuracy of the thickness of the head and the tail of the wide and thick plate is greatly improved. By the adoption of the control method, the overproof total length of the thickness of the head and the tail is shortened, the total length is shortened from 1m to below 0.4m, and yield is increased by 1%.

Description

technical field [0001] The invention relates to the control technology of a hot-rolling production line for wide and thick plates, in particular to a method for controlling the head-to-tail thickness tolerance of a wide and thick plate rolling mill, and belongs to the technical field of rolling. Background technique [0002] As one of the most important products in the iron and steel industry, wide and thick plates play a very important role in the development of the national economy. They are generally used in shipbuilding, building components, machine manufacturing, transportation, military industry, and large-diameter welded pipes, containers, boilers, etc. . With the rapid development of modern industry and science and technology, on the one hand, the requirements for the thickness and dimensional accuracy of wide and thick plates are getting higher and higher; on the other hand, the entire steel industry is currently facing severe challenges such as fierce market compet...

AI Technical Summary

Problems solved by technology

On the one hand, the problem of over-tolerance of the head and tail thickness of wide and thick plates affects the thickness and dimensional accuracy of the entire plate, and on the other hand, if it is seriously out of tolerance, it will lead to product degradation or increase the loss of head and tail, which directly affects the economic benefits of the enterprise

[0005] (1) There is a large temperature difference between the head and tail of the steel plate and the middle area, and the rolling force deviation at the head and tail is relatively large, resulting in thickness deviation at the head and tail. In addition, the wide and thick plate rolling mill is a multi-pass reciprocating rolling process, and the accumulation of multi-pass effect exacerbates head-to-tail thickness deviation

[0006] (2) When the steel plate bites in, there will be a large impact, causing fluctuations in the rolling force, elastic retraction of the oil column in the hydraulic cylinder, and gaps in the rolling mill archway and other equipment, etc., which can cause fluctuations in the roll gap of the rolling mill

[0007] (3) The AGC system only works for a period of time after the rolling mill bites the steel, so it cannot automatically control the thickness within a certain length of the head

[0009] It can be seen that there are many factors affecting the thickness tolerance of the head and tail of wide and thick plates, but there are not many controllable factors in the actual production process, especially for large wide rolling mills with a width of about 5000mm, it is very difficult to accurately control the thickness of the head and tail. difficulty

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