Method for producing steel board with thickness of 5-8mm by utilization of heavy and medium plate mill

Abstract

A method for producing a steel board with the thickness of 5-8mm by the utilization of a heavy and medium plate mill comprises the steps that a casting blank with the thickness of 120-250mm is heated for the first time, rolled for the first time and split according to user requirements; the casting blank is heated and rolled for the second time, wherein the thickness is controlled to be 25-40mm; the casting blank is rolled in a fine mode; the steel board is meshed under the condition of 30-40 turns per minute and is rolled under the condition of 60-80 turns per minute, steel casting is carried out under the condition of 30-40 turns per minute, air blowing and cooling are carried out in the rolling process, and the steel board is straightened to be used. The method effectively overcomes the defects of edge waves, middle waves, deflection, steel overlapping and waste rolling occurring when the steel board with the thickness standard of 5-8mm is produced by the heavy and medium plate mill. The differences of the strength indexes of the head, the middle and the tail of the produced steel board are within the range of 5-20MPa; the degree of convexity of the steel board is low, the intra-plate difference is small, namely the degree of convexity of the steel board is smaller than or equal to 0.1mm, the intra-plate difference is smaller than or equal to 0.2mm, the intra-plate temperature uniformity is good, the unevenness degree of the steel board is small than three per thousand, no buckling phenomenon exists, the shape of the steel board is good, cost is low and the production process is simple.

Description

technical field [0001] The invention relates to a rolling method of a steel plate, in particular to a method for producing a steel plate with a thickness of 5-8mm by using a plate rolling mill. Background technique [0002] For medium and thick steel plate rolling mills, 5~8mm steel plates are extremely thin steel plates. Although the steel plate rolling specifications designed by the medium and heavy plate rolling mill are generally 6~200mm thick and 900~4100mm wide. However, in the actual production process, when the medium and heavy plate rolling mill rolls the steel plate below 8mm, there will be many problems such as edge wave, middle wave, deviation, stacked steel and rolling waste, which will lead to poor shape of the steel plate, low process hit rate and poor performance. Large fluctuations and poor uniformity. In addition, limited by the size of the billet, the 5~8mm steel plate can only be rolled by double-length rolling, resulting in a large temperature differen...

AI Technical Summary

Problems solved by technology

Its shortcomings: the temperature drop increases, which is not conducive to the control of the shape and temperature of the steel plate; at the same time, due to the large size of the billet, it can only be rolled at double lengths. The width of the steel plate is too wide, the length is too long, and the temperature drops quickly, making the Poor temperature uniformity and large temperature difference will easily lead to steel plate warping and uneven performance

[0005] The Chinese patent application number is 20121089870.9, which discloses a 2800mm double-stand medium-thick plate rolling mill limit specification steel rolling process. The same process disclosed in this document still adopts the one-fire process, and the thickness of the selected blank is relatively large. , there are many rolling passes, and the temperature drop increases, which is not conducive to the shape and temperature control of the plate. At the same time, due to the large size of the billet and double-size rolling, the width of the steel plate is too wide, the length is too long, the temperature drop is fast, and the temperature of the same plate is uniform Poor performance, large temperature difference, easy to cause steel plate warping and uneven performance

Due to the high finish rolling temperature, if the laminar flow cooling system is not used, the grains of the steel plate will be relatively coarse, which is not good for low temperature toughness

Also because it still uses a large-sized billet, it needs double-scale rolling, and there are also problems such as rapid temperature drop, poor temperature uniformity on the same plate, and large temperature difference, which may easily lead to steel plate buckling and uneven performance.