Method for controlling finishing elongation rate of strip steel by utilizing second flow

Abstract

The invention provides a method for controlling a finishing elongation rate of strip steel by utilizing second flow, comprising the following steps of: respectively measuring an actual speed value and an actual tension value by using an encoder and a tension meter for measuring the speeds of an inlet and an outlet of a finishing machine; additionally arranging a second flow closed loop control system module in a programmable controller of the finishing machine, i.e., a PLC (Programmable Logic Controller); additionally arranging a second flow function option button in a human-computer interface; adopting a speed control mode for a main motor as well as a front tension roller and a back tension roller of the finishing machine; introducing an outlet tension deviation matching coefficient to a rolling force controller; and carrying out gain processing on a system function according to an input time interval. By using the method, the set value of the rolling force as well as parameters such as speed, tension and the like before and after finishing are not needed to be changed according to the material of the strip steel, the speed and the tension before and after the finishing are in astable state, the elongation rate is controlled more precisely, the steel plate pattern and the elongation rate index before and after the specification changes are effectively improved, a favorable surface quality of a product is obtained, and the yield of the strip steel is increased.

Description

technical field [0001] The invention belongs to the field of steel rolling technology, and in particular relates to a method for controlling elongation by second flow in a cold-rolled continuous annealing furnace skin pass machine. Background technique [0002] The so-called second flow law means that the amount of metal that flows into and out of the skin-passing machine per unit time, that is, the amount of strip steel, is the same. The elongation control in the second flow mode is set by the pre-control strip drive. Therefore, the speed of the outflow of the strip is faster than the inflow of the strip, which accurately shows the reduction (elongation) of the roll gap. The skin pass stand operating point is defined by elongation, rolling force and strip tension. Once the elongation is determined, the rolling force and tension interact with other additional parameters such as hardness, width and thickness depending on the strip material. [0003] The ideal rolling state...

AI Technical Summary

Problems solved by technology

However, the specific application in production practice often affects the rolling stability due to large fluctuations in the entrance tension of the stand, and it is difficult to achieve a good practical application effect