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

• Published in: Steel research international 2022-06, Vol.93 (6), p.n/a
• Main Authors: Wang, Yan-Wen, Cao, Jian-Guo, Song, Chun-Ning, Wang, Lei-Lei, Sun, Lin, Xie, Da, Lu, Yu-Long
• Format: Article
• Language: English
• Subjects: cold rolling; Cold rolling mills; Cold strip mills; Cold tandem mills; Data mining; Electrical steels; Hydraulics; Metal strips; Prediction models; Production methods; Roll bending; shape control; Strip steel; Thickness; Work rolls
• ISSN: 1611-3683; 1869-344X
• DOI: 10.1002/srin.202100514

To meet the “dead flat” transverse thickness profile requirement of electrical steel strip in 5‐stand 6‐high universal crown mill (UCM) tandem cold rolling mills, a random forest predictive model for electrical steel strip profile is established to reduce the dimension of the data and make predictions for the strip transverse thickness difference (TTD), based on the collected and processed real‐time data of the steel strip transverse thickness profile and multi‐methods of the industrial production mills. The control strategy of multi‐methods including positive and negative hydraulic work roll bending system (WRB), positive hydraulic intermediate roll bending system (IRB), and hydraulic intermediate roll shifting system (IRS) of different stands in 5‐stand 6‐high mills is proposed by comprehensively considering association rules mining which shows the optimal combination of ranges of key control parameters and analysis of 5‐stand 6‐high mills with the developed edge drop control work rolls for non‐shifting of work rolls (EDW‐N) with divided width groups technology on stand No. 1 and No. 2. The strategy is continuously and stably applied to 1420 mm 5‐stand 6‐high UCM tandem cold rolling mills and shows remarkable results. The rate of TTD less than or equal to 7 μm increases from 38.58% to 67.74%. To achieve high‐precision control of cold tandem rolling, a random forest model is built, and a multi‐methods strategy is proposed and tested after integrating association rule mining and the analysis of 5‐stand 6‐high universal crown mill (UCM) tandem cold rolling mills. The test shows excellent results. The method can reduce strip transverse thickness difference significantly.