Method for obtaining constant elongation in states of acceleration and deceleration

Abstract

The invention provides a method for obtaining constant elongation in states of acceleration and deceleration. The method comprises the following steps of respectively acquiring the speed of strip steel of an entrance and the speed of strip steel of an exit; setting a length-variable calculating period; calculating an actual value of the elongation; comparing the actual value of the elongation to a setting value of the elongation to obtain an elongation difference value; using a product of the elongation difference value and an elongation adaptive adjustment factor as an inputting value of a PI (proportional integral) controller; outputting additional controlled quantity of a rolling force control ring and additional controlled quantity of a tension control ring; and superposing the additional controlled quantity of the rolling force control ring, the additional controlled quantity of the tension control ring and a rolling force adaptive adjustment factor to obtain final rolling force adjustment amount. Elongation length calculating periods are set at different speed sections, so that the problem of slipping of strip steel in processes of acceleration and deceleration can be solved. By correlation operation of three-times extraction of a square root of actual speed, elongation fluctuation adjustment in the processes of acceleration and deceleration is accelerated in a feedforward control manner; and adaptive factors are set according to dynamic correction of errors of an actual rolling force and an elongation expected rolling force and relation of thickness, width and elongation, and the control precision and the stability of the elongation in the processes of acceleration and deceleration are improved.

Description

technical field [0001] The invention relates to the field of production of cold-rolled strip tempering mills, in particular to a method for obtaining constant elongation under acceleration and deceleration states. Background technique [0002] In the annealing process, due to the recrystallization of the strip steel, strain aging occurs, and a yield platform will appear in the subsequent processing. This kind of strip steel after annealing is almost completely in a soft state, which is not suitable for processing; and as long as it is slightly stamped Processing, the surface of the strip will produce tensile strain and irregular slip lines. Therefore, the cold-rolled strip after annealing should be mildly smoothed to eliminate the yield platform, increase the tensile strength, make it have good mechanical properties of the strip, improve the shape of the strip, and adjust the surface roughness of the strip to obtain a conforming required steel coils. [0003] Elongation is...

AI Technical Summary

Problems solved by technology

However, in the state of acceleration and deceleration, the speed, tension, rolling force, elongation, and leveling liquid adhesion of the skin pass unit are all in an unstable state, so the fluctuation of the elongation rate is too large, which makes the performance of the strip steel in the acceleration and deceleration section not meet the requirements. Process requirements

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