A temperature-controlled rolling process for medium and large size rolled pieces

Abstract

The invention provides a temperature-controlled rolling line for large -and medium-sized rolled workpieces. The temperature-controlled rolling line comprises an upper rolling mill / heating furnace, a middle water cooling device, a middle conveying roller way and a lower rolling mill in sequential arrangement. At least one temperature control rack is arranged on each of two sides of the middle conveying roller way, and a rolled workpiece conveying mechanism is arranged between each temperature control rack and the middle conveying roller way. The invention further provides a temperature-controlled rolling process of the temperature-controlled rolling line for the large-sized and medium-sized rolled workpieces. By means of a water cooling mode, an air cooling mode, a water cooling and air cooling combined mode and an air overcooling mode, online temperature of the large-sized and medium-sized rolled workpieces can be controlled effectively to acquire constant-temperature rolled workpieces uniform in section texture. Various temperature control routes of the large-sized and medium-sized rolled workpieces made of different steels can be realized, continuous temperature-controlled rolling of the large-sized and medium-sized rolled workpieces can be realized without influences on production efficiency, and products excellent in mechanical performance can be acquired finally.

Description

technical field [0001] The invention relates to the technical field of metallurgy, in particular to a temperature-controlled rolling process for medium and large-sized rolled pieces. Background technique [0002] With the rapid development of industries such as machinery, automobiles, and military industries, the market demand for high-value-added large-scale bar products such as high-carbon steel, gear steel, alloy spring steel, and bearing steel is increasing. At the same time, the quality of large-scale bar products The requirements are increasing day by day. Because such products contain high content of C elements and alloy elements such as Cr, Ni, Mn, V, etc., in order to ensure product quality, high temperature heating is required when heating, and long-term heat preservation is required to fully dissolve C and alloy elements. Diffusion to eliminate or mitigate segregation. [0003] In order to ensure the good performance of the product, the rolled pieces of differen...

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Problems solved by technology

[0005] For medium and large-sized rolled pieces, because of their large cross-section, it is difficult to dissipate the heat of the core quickly through the surface, and it is difficult for medium-sized and large-sized rolled pieces that have been heated at high temperature to obtain a higher cross-section temperature in a short time or a short distance only by water cooling or other methods. Uniform low-temperature rolling, difficult to achieve online temperature-controlled rolling

[0006] In order to meet the temperature-controlled rolling requirements of medium and large-sized rolled pieces, some production lines have to keep the high-temperature rolled pieces on the input roller table in front of the rolling mill for a long time, and then roll them after the cross-sectional temperature of the rolled pieces drops to the required temperature. will greatly reduce the efficiency of the production line

[0007] In order to solve the problem of temperature control in medium and large sizes, some production lines plan to greatly increase the length of the conveying roller table after water cooling of high-temperature rolled pieces, so as to increase the recovery time of water cooling and achieve the purpose of uniform temperature of the section after cooling. If the control is not good, it may cause uneven cross-sectional structure of the rolled piece, which is likely to cause quality problems, and this will greatly lengthen the rolling line, which will also greatly increase the investment

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