Method for straightening buckled pipeline steel plate with thickness less than 20mm at normal temperature

Abstract

The invention discloses a method for straightening a buckled pipeline steel plate with the thickness less than 20mm at normal temperature. During halt of a rolling machine, straightening workers are organized to straighten the buckled pipeline steel plate with the thickness less than 20mm repeatedly straightened by multiple straightening process on a hot straightening machine under small pressure, so that the buckled steel plate subjected to cold straightening can reach the national standard that the unevenness is within 2011mm, thus the overall yield of pipeline steel is greatly improved, and the cost pressure caused by repeated production can be relieved. The invention has the beneficial effects that, compared with a large enterprise adopting a normalizing furnace to straightening the buckled pipeline steel, the normal-temperature cold straightening does not consume fuel or need corresponding manpower or material resource support, thus the production cost can be greatly reduced; the cold straightening means that straightening is directly carried out at room temperature without heating before straightening; and the cold straightening is carried out at the normal temperature.

Description

technical field [0001] The invention relates to steel products, and relates to using a conventional thermal straightening machine to bend a pipeline steel plate with a thickness of less than 20 mm, in particular to a method for straightening and saving a curved pipeline steel plate with a thickness of less than 20 mm at room temperature. Background technique [0002] Pipeline steel, as a high-end product in the plate category, has its own production difficulties. Wuyang Steel Plant, the leader in medium and heavy plate factories, once failed to solve the plate shape problem of pipeline steel, which led to the failure to perform the contract on time and the corporate image. affected. Due to the high performance indicators required by pipeline steel, especially the strength indicators, this puts forward higher requirements for controlled rolling and controlled cooling. Since the pipeline steel needs to meet high mechanical performance standards, and at the same time, cost pre...

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Problems solved by technology

[0003] And the shape control problems brought about by such a process design follow:

[0004] 1. The increase in the reduction rate of finishing rolling will inevitably lead to poor shape of the steel plate. In addition, the thickness of the pipeline steel is generally thin, so the phenomenon of wave bending, warping or knocking of the head after rolling is inevitable, which increases the control of the shape in disguise. difficulty

[0005] 2. The higher the cooling rate, the lower the reddening temperature of the steel plate, and the lower the heat straightening temperature; at the same time, the unevenness of cooling caused by the increase of the cooling rate of the steel plate also aggravates the flatness of the steel plate after rapid cooling. Type deterioration

This further increases the difficulty of straightening

[0006] 3. Limited by the temperature and pressure in the hot straightening process and the straightening pressure of the subsequent steel plate, the number of hot straightening passes for each steel plate is limited, and it is impossible to save every steel plate with all our strength

Most steel mills save curved pipeline steel through normalizing furnaces. The cost pressure brought about by this has to be carefully considered under the circumstances that the steel market is generally sluggish and production costs remain high.

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