Method for controlling shape of X80 pipeline steel hot rolling middle plate

Abstract

The invention relates to a method for controlling a plate shape of an X80 pipeline steel hot-rolled medium plate, which comprises a heating process, a roll crown matching process, a reduction schedule selecting process, a cooling control process and a straightening process. In the heating process, secondary heating temperature and soaking zone temperature are controlled; in the roll crown matching process, a working roll has a sinusoidal structure; the diameter of an upper roll is larger than that of a lower roll; period of a grinding roller and the crown of the working roll are determined by rolling capacity and plate width; in the reduction schedule selecting process, rolling pass and reduction ratio of each pass are distributed according to the thickness of a plate material during the process of precision rolling; in the cooling control process, water volume and pressure forming four cooling zones of a cooling bed, sheltering range of a controlled cooling edge part, proportion of upper surface cooling water and lower surface cooling water of a steel plate, distance from the steel plate surface are adjusted; and in the straightening process, positions of a guide-in roll and a delivery roll are reduced by positive and negative bowed roll straightening process. The method can greatly reduce the buckling rate of a high steel grade steel plate, improve the plate shape, improve production efficiency, and prolong service life of equipment.

Description

technical field [0001] The invention relates to a method for controlling the shape of a hot-rolled pipeline steel plate in the technical field of pipeline steel rolling, in particular to a method for controlling the shape of a hot-rolled X80 pipeline steel plate. Background technique [0002] At present, energy materials such as oil and natural gas are mainly transported through pipelines. Due to the long transmission distance, the transmission pressure must be increased to increase the transmission flow rate, and the geographical environment through which the transmission pipeline passes is complex, so the pipeline steel constituting the transmission pipeline must have great strength and toughness. From the 1950s to the beginning of this century, the pressure involved in the transmission pipeline has gradually increased from 6.3MPa to more than 20MPa, and with the continuous increase in the transmission pressure of the gas pipeline, the transmission steel pipe has also rapi...

AI Technical Summary

Problems solved by technology

However, with the application of the above-mentioned technology, in the production process of pipeline steel, the phenomenon of buckling and deformation of the steel plate after rolling and cooling often occurs, which in turn causes: 1. The flatness of the steel plate exceeds the standard and cannot be delivered; 2. Seriously affects The production rhythm and efficiency will increase the production cost; 3. The curved steel plate will cause great damage to the output roller table, cooling bed, conveyor chain, cutting blade, pinch roller, sprayer and typewriter during the conveying process. , which seriously affects the service life of the equipment

In particular, it should be pointed out that the curvature of the plate shape also indicates that the internal residual stress distribution is uneven, which will directly affect the performance of the steel plate