Research On The Tilt Acting Process Of Rolls For Four-high Mill

High rolling technology has always been the research emphasis in the field of rolling,Gauge and shape are crucial indexes in the process of thinner plate and strip rolled, When thefluctuation of strip’s thickness is uneven，higher request is demanded for gauge control system ofmill. Taking the hydraulic AGC system of mill as the object of study with the traditional rollingstrategies, the tilting feature of rollers shown in the process of rolling is deeply analyzed in thispaper，the main contents are as follows:1. The concepts of mill’s bouncing phenomenon and spring equation are extractedaccording to the law of the slab’s plastic deformation firstly, then the graphical method used inanalyzing gauge control, elastic-plastic curve under the mode of artificial-zero, is obtained bybouncing equations and plastic-deformation equations. Additionally, the specified algorithm offeed-forward and feedback control is setup.2. The unilateral mill APC model is established in the composition and running mechanismof APC system after considering the factors including the non-linear and asymmetric of servo-valve, simplification of loading system, the method-selecting of flow compensation and rollingforce model. Then the overall mill AGC system model is determined on the basis of thealgorithm of feed-forward and feedback control.3. The work about time domain analysis of APC system and accuracy testing of AGCsystem is done, which taking the data of mill and rolling craft in production site as the simulationparameters.4. Based on the method of the analysis of unilateral mill APC load model, the drive side andthe operating side of mill is researched in this paper. The dual four degrees of freedom of loadingmodel is established, and then the tilt model of mill roll system is determined combined with therotation equation of roll system tilted. With the determined model, the conditions that stepfluctuations along the width direction of strip in driving side and operating side are analyzedfirstly. Afterward the influences of mill longitudinal-stiffness and slab plastic-coefficient on theroll tilt are analyzed qualitatively.