Control method of stretch-reducing mill steel tube thickening terminal

Abstract

The invention relates to the cutting loss control technology of the thickened end of the steel pipe head and tail during the tension reduction process of the seamless steel pipe. A method for controlling the thickening end of a tensioning and reducing machine steel pipe is to calculate the control factor table of the thickening end of the steel pipe according to the distribution law of the wall thickness of the pipe end of the tensioning and reducing machine. Adaptive increase or decrease in the number of racks participating in the CEC action, and the adjustment of the additional tension acting on the thickening end of the steel pipe head and tail to shorten the thickening end of the head and tail; the steps to calculate the CEC factor table of the tensioning and reducing machine are: determine the basic adjustment according to the average tension Speed ​​grade and maximum speed regulation grade; calculate the original CEC speed regulation factor according to the change of roll working diameter; construct the original CEC speed regulation factor table; The number of racks participating in the CEC function at the same time, and the original CEC factor table is corrected. The invention can effectively shorten the length of the thickening end of the steel pipe and improve the yield of the steel pipe.

Description

technical field [0001] The invention relates to a Crop End Control (CEC for short) technology of a steel pipe head and tail thickened end cut loss control (CEC) in a tension reduction process of a seamless steel pipe. Background technique [0002] The wall thickness change of the steel pipe in the tension reducer is realized by adjusting the tension of the steel pipe between the racks, and the tension between the racks is generated by the speed difference between the rolls. The thickening phenomenon at the end of the steel pipe is a characteristic phenomenon of tension reduction. The thickening of the pipe end is generally considered to be caused by the fact that when the head and tail of the steel pipe pass through the tension-rising and tension-decreasing racks during the rolling process, the tension it bears is smaller than the stable rolling state between the tension-invariant racks. Therefore, the idea of ​​steel pipe thickening end control (hereinafter referred to as ...

AI Technical Summary

Problems solved by technology

[0004] During the rolling process, the thickened end of the steel pipe head and tail actually grows continuously as the steel pipe advances in the rolling mill. Only a few fixed racks are used to perform CEC on the thickened end. The consequences are: on the one hand, the effect Too many racks will affect the CEC to the normal end of the steel pipe. On the other hand, too few racks will not achieve the effect of shortening the thickened end.

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