Research and application on threefold regulation of crown distribution in rolling direction of hot-rolled strip
WANG Xiaogong1, LI Hongbin1, KONG Chao2, TIAN Yaqiang1, LU Jianlong2, CHEN Liansheng1
1. Key Laboratory of the Ministry of Education for Modern Metallurgy Technology, North China University of Science and Technology, Tangshan 063210, Hebei, China; 2. Plate and Strip Business Department, Chengde Vanadium and Titanium New Material Co., Ltd., Chengde 067102, Hebei, China
Abstract:Due to the temperature difference between the two ends of the strips and the longer rolling time of the thin strips, a significant attenuation of thin strips in rolling direction occurred on the 1 780 mm hot-rolling production line of Chengde Vanadium and Titanium New Material Co., Ltd., affecting the quality of strips. In response to this phenomenon, an analysis was conducted on the site, including the original roller shape of CVC, the lateral displacement setting of work rolls, and the bending force setting of each stand. It was found that the existing process parameters had reached the limit of plate crown control without changing the existing cooling equipment and rolling rhythm. Based on that, the threefold regulation combining original roller shape optimization of CVC, axial shifting control of work roll and dynamic adjustment of bending force is put forward, which provides theoretical guidance and basis for improving the crown attenuation of strips. Based on the three-dimensional metal deformation model and the elastic deformation model of the roll system, a crown control model suitable for the hot-rolled thin strips was constructed in light of the on-site working conditions and process characteristics. Four roller shape optimization schemes were proposed with the goals of F1, F1-F2, F1-F3, and F1-F4, respectively, which then were combined with the lateral displacement of work rolls and the dynamic adjustment of bending force. The effects on longitudinal distribution of crown and the rules of it were analyzed. The results show that with a target crown of (45±15)μm, the crown distribution of strip steel in rolling direction can be 34-45, 37-45, 40-47 and 41.2-49.4 μm respectively using the optimization schemes above. The corresponding attenuations are 11, 8, 7, and 8.2 μm respectively. The bending forces of F1 to F4 are increased by 500, 550, 740, and 680 kN respectively. In addition, the crown attenuation can be reduced from 8 μm to 10 μm after this method is applied to the production line of 1.5 mm×1 250 mm strips.
王小巩, 李红斌, 孔超, 田亚强, 鲁剑龙, 陈连生. 热轧带钢板凸度纵向分布三重调控研究与应用[J]. 钢铁, 2023, 58(10): 92-101.
WANG Xiaogong, LI Hongbin, KONG Chao, TIAN Yaqiang, LU Jianlong, CHEN Liansheng. Research and application on threefold regulation of crown distribution in rolling direction of hot-rolled strip[J]. Iron and Steel, 2023, 58(10): 92-101.
[1] 王国栋. 板形控制和板形理论[M].北京:冶金工业出版社, 1986. (WANG G D. Shape Control and Theory[M]. Beijing: Metallurgical Industry Press, 1986.) [2] 张金飞, 么洪勇, 李子正, 等. 七机架热连轧机组板形综合控制技术[J]. 钢铁, 2023, 58(3): 97. (ZHANG J F, YAO H Y, LI Z Z, et al. Integrated flatness control technology for seven-stand tandem hot strip mill[J]. Iron and Steel, 2023, 58(3): 97.) [3] 靳皓越, 孙杰, 魏臻, 等. 基于有限元法的拉伸弯曲矫直过程板形控制分析[J].钢铁,2022,57(6):100. (JIN H Y, SUN J, WEI Z, et al. Analysis of plate shape control in tensile bending and strightening process based on finite element method[J]. Iron and Steel, 2022, 57(6): 100.) [4] 邓继飞. 基于数据驱动的热连轧板凸度预测与故障分类[D]. 沈阳:东北大学, 2019. (DENG J F. Data-Driven Strip Crown Prediction and Fault Classification for Hot Rolled Strips[D]. Shenyang:Northeastern University, 2019.) [5] 宋君, 任廷志, 王奎越, 等. 基于CF-PSO-SVM的冷连轧非稳态工作辊弯辊模型优化[J]. 钢铁, 2021, 56(11): 78. (SONG J, REN T Z, WANG K Y, et al. Optimization of work roll bending model in unsteady process of tandem cold rolling based on CF-PSO-SVM[J]. Iron and Steel, 2021, 56(11): 78.) [6] 曾尚武, 李激光. 热轧板凸度控制实践分析[J]. 轧钢, 2011, 28(6): 8. (ZENG S W, LI J G. Analysis about crown of hot rolled plate[J]. Steel Rolling, 2011, 28(6):8.) [7] 李兴田,李帅,刘鹏宇,等. 热轧CVC工作辊周期轴向横移技术的开发与应用[J]. 轧钢, 2023, 40(2): 129. (LI X T, LI S, LIU P Y, et al. Development and application of CVC work roll cyclical axial shifting technology in hot rolling[J]. Steel Rolling, 2023, 40(2): 129.) [8] 贾俊彪, 严彪, 吴成军. 支撑辊倒角对热轧钢板板形的影响[J]. 上海金属, 2022, 44(1): 105. (JIA J B, YAN B, WU C J. Effect of backup roll chamfer on flatness of hot-rolled plate[J]. Shanghai Metals, 2022, 44(1): 105.) [9] 董强, 刘慧慧, 张建水. 横向温度分布对无取向电工钢热轧板形的影响[J]. 中国冶金, 2019, 29(8): 19. (DONG Q, LIU H H, ZHANG J S. Effects of transverse temperature distribution on strip shape of non-orientation electrical steel in hot rolling process[J]. China Metallurgy, 2019, 29(8): 19.) [10] 渠福泉, 李旭, 张宇峰, 等. 冷轧工作辊热凸度及其对板形影响[J]. 中国冶金, 2022, 32(4): 84. (QU F Q, LI X, ZHANG Y F, et al. Thermal crown of cold rolling work roll and its effect on strip shape[J]. China Metallurgy, 2022, 32(4): 84.) [11] 张彩霞. 四辊CVC热连轧机板形板凸度控制能力研究[D]. 秦皇岛:燕山大学, 2010. (ZHANG C X. Shape and Profile Control Study of Four-High CVC Hot Strip Mill[D]. Qinhuangdao: Yanshan University, 2010.) [12] 李伯群, 范璇, 李伟红, 等. 板形设定模型参数优化与控制技术应用[J]. 钢铁, 2019, 54(2): 41. (LI B Q, FAN X, LI W H, et al. Parameter optimization of shape setting model and application of control technology[J]. Iron and Steel, 2019, 54(2): 41.) [13] 张建雷, 岳重祥, 陈卫, 等. 板形辊位置补偿模型的研究及应用[J]. 上海金属, 2022, 44(2): 104. (ZHANG J L, YUE C X, CHEN W, et al. Research and application of position compensation model for flatness measuring roll[J]. Shanghai Metals, 2022, 44(2): 104.) [14] 赵铁勇, 肖宏, 王健, 等. 板宽和轧辊凸度对热轧板带凸度控制的影响[J]. 钢铁, 2011, 46(3): 51. (ZHAO T Y, XIAO H, WANG J, et al. Influence of strip width and roll crown on hot rolled strip crown[J]. Iron and Steel, 2011, 46(3): 51.) [15] 王涛, 肖宏, 王健, 等. 工作辊直径对热轧带钢凸度的影响分析及优化[J]. 塑性工程学报, 2012, 19(3): 25. (WANG T, XIAO H, WANG J, et al. The analysis and optimization for the effect of work roll diameter on the hot rolled strip crown[J]. Journal of Plasticity Engineering, 2012, 19(3):25.) [16] 何安瑞. 热轧宽带钢板形控制技术的现状及未来发展[J]. 轧钢, 2022, 39(3): 1. (HE A R. Present situation and future development of profile and flatness control technology of hot rolled wide strip[J]. Steel Rolling, 2022, 39(3): 1) [17] 王雪松, 张跃飞, 田士平, 等. PC轧机板形板凸度控制策略[J]. 钢铁, 2012, 47(11): 45. (WANG X S, ZHANG Y F, TIAN S P, et al. Shape and crown strategy for PC mill[J]. Iron and Steel, 2012, 47(11): 45.) [18] 李韦良. 新型十二辊板带轧机变形分析及板凸度控制研究[D]. 秦皇岛:燕山大学, 2013. (LI W L. Deformation Analysis and Crown Controlling Study of the New Type of Twelve High Rolling Strip Mill[D]. Qinhuangdao: Yanshan University, 2013.) [19] 徐星星, 魏立群, 付斌, 等. 1 400 mm十二辊轧机轧制薄带的板凸度控制[J]. 塑性工程学报, 2020, 27(3): 115. (XU X X, WEI L Q, FU B, et al. Plate crown control of 1 400 mm 12-high mill rolling thin strip[J]. Journal of Plasticity Engineering, 2020, 27(3): 115.) [20] 彭良贵, 周一林, 陈亚飞, 等. HC冷轧机凸度工作辊使用制度[J]. 中国冶金, 2023, 33(3): 144. (PENG L G, ZHOU Y L, CHEN Y F, et al. Using system for crown work roll of HC cold rolling mill[J]. China Metallurgy, 2023, 33(3):144.) [21] 白振华, 王楠, 崔熙颖, 等. 冷连轧升降速过程板形控制工艺润滑制度优化[J]. 钢铁, 2021, 56(12): 96. (BAI Z H, WANG N, CUI X Y, et al. Optimization of lubrication system for flatness control process in cold tandem rolling[J]. Iron and Steel, 2021, 56(12): 96.) [22] 王四海, 翟德家, 刘立辉, 等. 1 250 mm热连轧工作辊磨损控制策略[J]. 钢铁, 2020, 55(9): 57. (WANG S H, ZHAI D J, LIU L H, et al. Wear control strategy of work roll in 1 250 mm hot continuous rolling[J]. Iron and Steel, 2020, 55(9): 57.) [23] DENG J, SUN J, PENG W, et al. Application of neural networks for predicting hot-rolled strip crown[J]. Applied Soft Computing, 2019, 78: 119. [24] SIKDAR S, KUMARI S. Neural network model of the profile of hot-rolled strip[J]. International Journal of Advanced Manufacturing Technology, 2009, 42(5/6): 450. [25] 姬亚锋, 宋乐宝, 原浩, 等. 基于KPLS与SVM的热连轧板凸度预测[J]. 中国冶金, 2021, 31(1): 20. (JI Y F, SONG L B, YUAN H, et al. Strip crown prediction of hot-rolled strip based on KPLS integrate SVM[J]. China Metallurgy, 2021, 31(1): 20.) [26] 丁肇印, 丁成砚, 孙杰, 等. 基于类别特征梯度提升的冷轧带钢板形预测模型[J]. 轧钢, 2022, 39(6): 99. (DING Z Y, DING C Y, SUN J, et al. Prediction model of cold rolled strip flatness based on CatBoost[J]. Steel Rolling, 2022, 39(6): 99.) [27] 田玉新, 陆建生, 赵欣. 因瓦合金带材的平整工艺[J]. 上海金属, 2019, 41(6): 97. (TIAN Y X, LU J S, ZHAO X. Temper rolling process of Invar alloy strip[J]. Shanghai Metals, 2019, 41(6): 97.) [28] 蒲实, 孔超, 王小巩, 等. 热轧薄规格带钢板凸度纵向分布特征的研究[J]. 热加工工艺, 2023. DOI: 10.14158/j.cnki.1001-3814.20220686. (PU S, KONG C, WANG X G, et al. Study on LONGITUDI-NAL distribution characteristics of crown of hot rolled thin gauge strip[J]. Hot Working Technology, 2023. DOI: 10.14158/j.cnki.1001-3814.20220686.) [29] 辛建卿, 余伟, 唐荻. 用原始辊型法改善热带板形的工艺研究[J]. 轧钢, 2007, 24(5): 10. (XIN J Q, YU W, TANG D. Improvement of hot rolled strip shape by initial crown method[J]. Steel Rolling, 2007, 24(5): 10.) [30] 连家创, 刘宏民. 板厚板形控制[M]. 北京:兵器工业出版社, 1996. (LIAN J C, LIU H M. Plate Thickness and Shape Control[M]. Beijing: Weapon Industry Press, 1996.) [31] LIU H M, LIAN J C. Transverse distributions of front and back tension stresses in cold strip rolling[J]. Journal of Materials Science and Technology, 1992, 8(6): 427.