Work Roll Shifting Strategy of Uneven “Cat Ear” Wear Control for Profile and Flatness of Electrical Steel in Schedule‐Free Rolling

Abstract

There are severe uneven “cat ear” wear contours of work rolls, the key factors to affect high‐quality profile and flatness control of electrical steel strips, in the schedule‐free rolling process with a large number of the same width strip rolling campaigns of hot rolling mills. The work roll wear prediction model, thermal roll contour model, and a 3D finite‐element model of roll stacks and strip are established using MATLAB and ABAQUS software. The effects of the work roll wear contour on the loaded roll gap profile within the entire rolling campaign are analyzed. A variable stroke and step (VSS) shifting strategy is developed based on the exponentially damped sinusoids function, which can get the smooth work roll wear contours. The main parameters including attenuation coefficient of stroke, the coil number and the attenuation coefficient of the first shifting cycle, and the initial phase avoiding repetition of the shifting position, are obtained by genetic optimization. The industrial application of the VSS shifting strategy gives remarkable results. The “cat ear” height value of local work roll wear contours is decreased by 67.3% and the high‐precision rate of crown from 25 to 40 μm of the electrical steel is increased by 22.5%.

Effects of Transversal Temperature Distribution and Phase State on Strip Profile During Hot Rolling Process

“…Li et al [6] put forward a reverse continuously variable crown backup roll contour, and roll wear can be improved with this contour. Shang et al, [7,8] Cao et al, [9] Dong et al, [10] and Yamaguchi et al [11] developed work roll shifting strategies, thereby keeping work roll contour be effective in adjusting strip profile. In addition, high-wear resistance materials are adopted to produce work roll.…”

Influences of thermal crown and wear crown of work roll on strip shape in tandem cold rolling using a novel 3D multi-pass FE model

“…Yan et al 18 analysed the effect of TWW on the crown of the LRGP in hot strip rolling using the influence function method, and discovered that when the wear crown is up to 0.2 mm, the control ability of the WR continuously variable crown (CVC) shifting on the LRGP will become ineffective. Cao et al 19 simulated and analysed the influence of the WR wear on the LRGP in different rolling stages in hot strip rolling, and found that the crown of the LRGP increases with the WR wear. Likewise, Pathak et al 20 found that the strip crown increases with roll wear in hot strip rolling via experimental data.…”

Research on High‐Precision Transverse Thickness Difference Control Strategy Based on Data Mining in 6‐High Tandem Cold Rolling Mills

“…Abdulrahman et al [ 11 ] studied the influences of rolling process parameters such as the work roll cross angle and work roll shifting on the strip shape and profile of the thin strip. Cao et al [ 16 ] proposed a variable stroke and step (VSS) shifting strategy to reduce uneven “cat ear” wear contours of work rolls, and the industrial application of the VSS shifting strategy gives remarkable results.…”