Method for controlling convexity of single-rack double-coiler aluminum hot mill

Abstract

The invention relates to a method for controlling convexity of a single-rack double-coiler aluminum hot mill. A convexity control strategy of the single-rack double-coiler aluminum hot mill is made according to the characteristics of the mill and field rolling experience; a convexity presetting model, a thermal expansion calculation model and convexity feed-forward and feedback control systems, which are suitable for a single rack, are established; excellent full-automatic control on convexity and flatness of an aluminium sheet strip in the rolling process of the mill is implemented; a corresponding convexity control strategy is made according to the alloy characteristics of the strip; roll bending force set values and head convexity guarantee values in a cooling spray mode in two rolling stages of rough rolling and finish rolling are given by the convexity presetting model and the thermal expansion model; feed-forward compensation on a roll bending force is carried out in the finishing pass so as to reduce influence of fluctuation of a rolling force on convexity; in the last third pass or the final pass in which convexity measurement is carried out, closed-loop control on the roll bending force is carried out according to the alloy characteristic condition so as to ensure full-length convexity and the sheet shape; and after rolling is finished, self-learning of the roll bending force and a cooling spray model is carried out so as to improve accuracy of the presetting model.

Description

technical field [0001] The invention relates to a crown control method in aluminum hot rolling production, in particular to a crown and plate shape control method within the full strip length range of a single stand double coil aluminum hot rolling mill. Background technique [0002] The single-stand double-coil aluminum hot rolling mill has become the first choice for many aluminum processing enterprises to produce hot-rolled products. Different from the iron and steel field, due to the small scale of aluminum strip production, its process level and equipment automation level are obviously low. At present, the hot rolling mills used by most enterprises generally have unstable product quality and backward control methods. Crown is a very important quality index of hot-rolled products. With the continuous improvement of customer requirements, more and more aluminum strip manufacturers have begun to pay attention to the control of the crown of hot-rolled products. [0003] Co...

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Problems solved by technology

Relying on manual experience to control the shape has the following disadvantages: first, it cannot control the convexity while controlling the flatness; secondly, it lacks a reasonable shape control strategy, and the shape adjustment device cannot exert its maximum effect, and often There is a phenomenon that the shape adjustment device has reached the limit value and cannot control the shape well; the shape quality of the third product will fluctuate with the experience of the operator, which is not conducive to obtaining stable product quality

[0004] Aiming at the lack of artificial experience method to control the shape of the strip, foreign related enterprises have developed a complete set of crown control system on the hot continuous rolling of aluminum strips, but the control method and strategy are not suitable for single-stand hot rolling mills, mainly because: firstly, hot rolling The continuous rolling mill has the ability to adjust the roll bending of multiple stands, and adjust the distribution of the bending force of each stand according to the crown measured on the exit side, while the adjustment of the bending force of the single-stand hot rolling mill can only be completed in the rolling pass. Higher requirements are put forward for the setting and calculation of the bending force; secondly, the hot continuous rolling mill can only measure the strip crown at the exit of the last stand, and for the single-stand hot rolling mill, the measurement of two tracks Therefore, the measured crown information can be used to correct the target crown value of the subsequent pass, thereby improving the setting accuracy; thirdly, it is different from each rack of the hot strip mill being responsible for one pressing pass , the single-stand hot rolling mill is responsible for all the rolling passes, which will lead to more frequent changes in the thermal expansion of the work rolls. Real-time forecasting of the thermal crown of the work rolls is necessary to improve the accuracy of the crown setting

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