Analysis On The Influence Of Roll Wear On Shape Control Of Backup Rolls During Full Service Period

Strip shape is an important index to measure the quality of strip.As the most direct and active factor in strip shape control,roll has been widely concerned.Roll wear directly affects the flatness control and final quality in the rolling process.At present,the research on this part mainly focuses on the influence of work roll wear on flatness control,and there is little research on the wear of backup roll.However,the wear form of backup roll also has a direct impact on the flatness control process after the previous field data analysis.Therefore,it is necessary to systematically analyze the corresponding relationship between the wear form of the backup roller and the shape control process,so as to provide the necessary theoretical basis and improvement basis for field production.In this paper,the backup rolls of the downstream stands of a 2250 mm hot strip mill line are taken as the research object.The data analysis,theoretical analysis,finite element model simulation and field data verification are combined to conduct in-depth research on the roll shape characteristics of typical backup roll wear,the shape control ability of the downstream stands,the comprehensive influence of different support roll wear characteristic curves on the shape control ability,and the evaluation method of the roll shape of backup roll wear.The main work and achievements are reflected in the following aspects:(1)Through the tracking measurement of the support roll wear form and shape control parameters of the downstream stand of a 2250 mm hot rolling production line,it is obtained that the support roll wear of the downstream stand will have a certain impact on the shape control process.Four typical wear forms were extracted by data fitting analysis of the typical backup roller wear roll curve,which provides an analysis basis for the subsequent study of the influence of different wear characteristics on the shape control performance.(2)Combined with the production process,mill parameters and actual production data of a2250 mm hot rolling production line,the finite element model of the roll system of the downstream frame is established by using ANSYS finite element software.The shape control characteristics of different control methods are analyzed by using the established model,and the simulation results are compared with the field production data,which verifies that the established model has good calculation accuracy.(3)Using the established finite element model,the strip crown and shape control ability of the four typical wear forms of the backup roller are analyzed.The analysis process is divided into single feature analysis and composite feature analysis.The change trend of strip crown and shape control ability caused by different wear forms of the backup roller is determined,and the analysis results are quantified.(4)Aiming at the situation that the traditional evaluation method of roll wear can only be simply and qualitatively classified according to the wear roll shape characteristics after roll wear,based on the influence of four typical wear characteristics on the shape control performance obtained in the above analysis,a quantitative analysis method and evaluation standard for the wear roll shape of the backup roller are proposed,and the roll shape of the four groups of backup rollers are evaluated and quantitatively calculated.This part has certain practical significance for the field analysis of the influence of backup roller wear on strip crown and shape control and the optimization strategy.