Research and Application of Dynamic Substitution Control of Actuators in Flatness Control of Cold Rolling Mill

The work roll bending control has a strong ability to eliminate the symmetrical flatness defects of strip. However, if the incoming strip is coming with severe symmetrical flatness defects, it happens that the position limit of work roll bending is prone to be reached or exceeded during the execution of the displacement, resulting in the residual symmetrical flatness defects without further elimination, as well as a limited flatness control process. Abilities of work roll bending and intermediate roll bending / shifting for flatness control have been analyzed based on the actuator efficiencies for the purpose of solving the problem of work roll bending control reaching threshold. Meanwhile, a self‐learning determination model of actuator efficiency factors, which can be utilized to determine the actuator efficiency factors online accurately, was developed from the measurement data extracted from the rolling mill. Models of intermediate roll bending and intermediate roll shifting substitution control in case of work roll bending control over‐limitation have been developed, in accordance with the practical conditions and the degree of work roll bending over‐limitation. Applications show that the substitution control can play an important role in the residual symmetrical flatness deviation control, which should have been removed completely by the work roll bending control.     

宽带钢热连轧机选型配置与板形控制

通过测试并分析机组上游与下游机架对控制性能的不同要求、服役周期内工作辊和支持辊辊形变化及其对板形控制性能的影响,结合1700mm热连轧机进行的现场试验及工程应用实践,提出热轧上游机架应采用凸度控制能力较强的轧机机型,下游机架宜采用长行程窜辊型轧机机型,全机组均可采用强力弯辊和变接触轧制技术提高机组板形控制能力。     

UCM轧机中间辊横移控制模型与应用

为了提高冷轧带钢的板形质量,在1250单机架6辊可逆冷轧机板形控制系统改造中,根据轧制工艺,设定了中间辊初始位置。基于板形调节机构的调控功效,由闭环板形控制系统给出了中间辊在线横移的调节量。为了减少横移对轧辊磨损的影响,通过试验以及数值计算分析了中间辊横移阻力与横移速度以及轧制力之间的关系,对中间辊横移速度进行了设定。经现场应用表明,中间辊横移控制模型具有较高的板形控制精度,对实现冷轧带钢的高精度板形控制具有重要作用。     

SmartCrown中厚板轧机支持辊辊形研究

针对国内某4200mm中厚板轧机首次采用SmartCrown板形控制新技术,采用ANSYS9.0建立了辊系三维有限元模型,通过有限元仿真分析发现在SmartCrown工作辊和常规凸度支持辊的辊型配置下,采用SmartCrown的轴向移位变凸度技术,中厚板轧机的板形控制能力大大增强,但是辊间接触压力的不均匀性和接触压力峰值明显增大。在结合VCR支持辊优势的基础上,提出了4200mm中厚板轧机SmartCrown工作辊相匹配的辊形SVR(SmartCrown-VCR Compounded Roll)。对比分析发现采用SVR支持辊后可以明显减小辊间压力尖峰、均化辊间压力分布和提高轧机对板形调控能力。     

Study on Error Compensation Method of Online Roll Profile Measurement

Flatness and surface quality are important quality indexes of strip steel, and roll wear will directly affect the product's flatness and surface quality. Online roll profile measurement technology can obtain the information of roll profile in real time, guide the optimization of roll change rhythm, and improve the flatness control ability of rolling mill and surface quality of strip product. However, the error caused by roll displacement, clearance, roll thermal crown, and other factors is usually the same order of magnitude as the roll shape or roll wear, or even one order of magnitude higher. So error compensation is the key to ensuring the accuracy of online roll profile measurement. Herein, the position measurement technology of the roll bearing block is considered in the online roll profile measurement, and the measurement error caused by the deviation of the roll axis is separated. The thermal crown model is established to separate the measurement errors caused by the thermal crown. The error compensation model of online roll profile measurement is established, and the simulation calculation is carried out. This error compensation method is of great significance to improve the accuracy of online roll profile measurement and realize the fine management of mill roll in service.     

Control Strategies of Asymmetric Strip Shape in Six-High Cold Rolling Mill

 It is a complicated problem for cold-rolled strip to improve asymmetric strip shape in strip production. A roll system and strip coupled model of six-high cold rolling mill was established with finite element method to estimate the effect of intermediate roll shifting, tilting, symmetric and asymmetric bending technologies on strip profile. To reduce asymmetric defects of strip shape as much as possible, some control strategies were proposed, including tilting and asymmetric bending of intermediate roll and work roll. The combinations of these three control strategies can effectively eliminate asymmetric strip shape defects. Finally, the closed-loop control model of asymmetric flatness at the last stand was given, and the flatness control system with the function of asymmetric strip shape control was also designed for cold tandem mill.     

1420 mm冷连轧机机型改进与板形控制能力扩展

 以宝钢1420 mm镀锡板（兼做薄规格冷轧板）冷连轧机为研究平台,针对目前国内外板带材生产中被广泛选用的CVC冷轧机型及CVC板形控制技术存在的2个特殊应用问题——支持辊表面磨损量轴向分布不均匀度较为明显和对轧件边部板形（含边降）控制能力相对不足,进行了深入研究并分别提出了改进方案,包括一种CVC冷连轧机的支持辊辊形设计方法及技术和专用于DI材等对边降有特殊要求高端产品的边降控制技术,一定程度上改进了此CVC冷连轧机组的机型,并使其板形控制性能显著提高。生产实践表明,改进工作达到了进一步提高产品板形质量,拓展产品品种与产能,以及提高生产效率的目的。     

六辊冷连轧机板形前馈控制方法的研究

 本文针对六辊冷连轧机,研究了采用工作辊弯辊的整体补偿板形前馈控制方法和采用工作辊与中间辊弯辊相结合的最优综合补偿板形前馈控制方法。实际控制效果表明,整体补偿板形前馈控制方法只能抑制由于轧制力波动产生的二次板形,而对四次板形几乎不产生影响;最优综合补偿板形前馈控制方法对轧制力波动造成的二次和四次板形均具有很强的控制能力。     

六辊CVC冷轧机凸度控制能力分析及应用

 基于三维有限元建立了六辊CVC辊系模型,该模型耦合了CVC辊形曲线、辊间轧制力分布以及带钢的弹塑性变形和辊系弹性变形,通过迭代计算辊间轧制力及轧辊与轧件的弹塑性变形。通过实际轧制规程数据对比验证了模型的有效性,其模拟计算结果与实际数据的绝对误差在10 μm内,相对误差小于1%。采用该模型研究了板形控制机构如中间辊弯辊、中间辊窜辊和工作辊弯辊对带钢2次凸度和4次凸度的控制规律,并成功消除了生产现场宽薄带钢的边中复合浪缺陷。     

SmartCrown冷连轧机板形控制新技术改进研究与应用

SmartCrown板形控制新技术在宽带钢冷连轧机首次工业应用中存在SmartCrown工作辊窜辊行程利用不充分、工作辊磨损严重且不均匀等问题.采用ANSYS有限元建立辊系三维有限元模型,分析了辊间压力对磨损辊形的影响.在解析掌握1 700冷连轧机引进的SmartCrown辊形基础上,研究开发出了改进的SmartCrown plus新辊形,经过现场工业试验研究,SmartCrown plus工作辊取得磨削量小,且磨损更均匀化,其辊形自保持性良好的明显效果,现已成功投入1 700大型工业轧机实际应用.     

4100mm宽厚板轧机支承辊辊型曲线优化仿真分析

 辊间接触压力分布是影响宽厚板板形质量和轧辊使用寿命的重要因素,为了获得均匀的辊间压力分布,以4100mm宽厚板四辊轧机为对象,考虑轧件弹塑性变形和辊系弹性变形耦合作用,采用弹塑性热-力耦合非线性有限元方法,数值模拟分析了宽厚板轧制过程的辊间接触压力分布规律,并通过仿真分析,对支承辊辊型及其边部卸载曲线进行了选型和优化改进,获得了以二次曲线为辊凸度和抛物线为辊肩部卸载曲线的辊形,延长了轧辊的使用寿命,改善了宽厚板的板型质量。     

适用于六辊UCM轧机中间辊侧向横移变凸度的新辊形研发

六辊轧机是目前生产冷轧、箔轧带材常见的机型,主要有UCM及CVC两种类型。针对UCM类型的六辊轧机在轧制较窄宽度和一般宽度带材过程中、通过中间辊时轴向横移板形控制能力较弱的问题,提出了一种中间辊单侧轴向横移变凸度的新辊形,简称SVC(Side Variable Crown)辊形,由此建立普通六辊和SVC辊形六辊的有限元三维仿真模型。通过模型,分析了SVC辊形空载辊缝调节能力,分别比较了在轧制窄宽度和一般宽度带材的两种辊形中间辊轴向横移时的板形调控能力,发现SVC辊形可增强六辊轧机中、窄带材的板形调控能力,增加了轧机的板形调控手段,同时改善辊间接触压力尖峰,可减轻辊间压痕,提高轧辊的使用寿命。     

Development and application of roll contour configuration in temper rolling mill for hot rolled thin gauge steel strip

Abstract

In order to improve the flatness of hot rolled thin gauge steel strip, a new type of roll contour configuration was developed for a four-high temper rolling mill based on the finite element method analysis. The roll contour configuration consists of a variable contact back-up roll contour and a positive crown work roll contour. Both can be described as sixth order polynomial functions. The variable contact back-up roll not only reduces the roll stack deflection and contact stress concentration between work and back-up rolls, but also increases the control capability of the bending force of the work roll. Positive crown work roll contour is utilised to compensate roll wear and in turn the length of temper rolling schedule can be prolonged. After this roll contour configuration was applied on the temper rolling mill of Qiangang Company of Shougang Group, the flatness of hot rolled thin gauge strip was improved by 10% and the working efficiency was also increased as the length of temper rolling schedule was increased.     

冷轧平整机板形问题的特点及对策

对某冷轧厂1700mm单机架平整机的板形问题进行了综合研究，发现该轧机在辊形加工、轧辊磨损及弯辊使用等方面存在的问题，并通过有限元模型研究了辊形对板形的作用，分析了平整上弯辊对板厚的影响，指出平整机板形问题的特殊性。针对平整板形的设备工艺特点，提出了新的辊形配置方案并正式投入生产。结果表明，改进后的辊形配置对降低弯辊调整量、改善板形、提高生产过程稳定性效果显著。     

Screwdown load deviation model of 5 m heavy plate mill based on influence of back-up roll axial force

Screwdown load deviation threatens rolling mill safety and product quality. The contact between a 5?m rolling mill screwdown device and the back-up roll (BUR) bearing chock was simplified to a fixed hinge constraint, and the constraint of the keeper plates on the BUR bearing chock was simplified to a sliding hinge constraint. According to the BUR space force and moment equilibrium, a screwdown load deviation model affected by the BUR axial force was used to simulate the effect of the roll crossing degree on the screwdown load deviation. Screwdown load deviations were calculated for three rolling passes. The results are more consistent with the data than outputs calculated by a model that neglects axial force. Assumptions about the relationship between the load deviation and the work roll axial forces agree with the data. The results show that the BUR axial force causes a dynamic deviation of the screwdown load.     

UCM冷连轧机边降控制工作辊辊形优化

国内大量应用的1 700 mm以下的UCM冷连轧机组不具备工作辊窜辊功能,只能依靠工作辊边部辊形设计对硅钢板带进行边降控制。提出了针对UCM冷连轧机的工作辊端部辊形设计方法,在大幅提高边降控制能力的同时,通过边部保护段的设计有效减少断带风险。辊形曲线有利于轧辊磨削,避免轧辊表面质量对带钢表面造成影响。充分利用工作辊与中间辊弯辊的板形调控特性,使用高效实用的弯辊力组合板形控制方法,对轧制过程中产生的二次和四次板形缺陷实施快速精确的控制,在控制硅钢边降的同时很好地抑制板形问题,具有重要的研究价值与推广前景。     

中板轧机板形控制性能的研究

运用变厚度平面有限元方法建立了专门针对2800中板轧机的辊系变形（即凸度预测）仿真模型，并计算出辊形、钢板密度及轧制力等对钢板凸度的影响关系。仿真计算与实测值相一致，从而为中板轧机的板形控制系统的开发等提供必要的理论依据。     

辊径比对带钢轧制平直度影响的有限元模拟分析

采用大变形弹性有限元法,借助MSC.Marc有限元软件,建立了昆明钢铁公司双机架紧凑式可逆炉卷轧机轧制过程的二维模型,对C45(0.43%～0.49%C)钢的2 mm×1200 mm带钢轧制平直度进行模拟。对带钢沿宽度方向上的应力分布进行三维模拟,得出上、下工作辊的辊径比对带钢平直度的影响。结果表明,当辊径比为420/418.5时,带钢的平直度最佳。     

热轧薄规格带钢平整过程板形控制技术

为了提高热轧薄规格带钢平整的板形质量,在平整机上采用了新的辊形配置。在支撑辊上采用变接触式 支撑辊辊形,在工作辊上采用六次方多项式正凸度辊形。变接触支撑辊辊形可以降低轧辊挠曲变形和边部应力的 集中,增大弯辊力的调控功效。采用正凸度工作辊辊形,可以弥补平整机的磨损辊形,延长平整轧制计划单位的长 度。此辊形配置在首钢迁钢热轧平整机上应用,保证了平整改善薄规格带钢板形质量,延长了平整轧制计划的长度。     

冷连轧机变接触支承辊板形控制性能研究与应用

通过现场跟踪测试和生产实践发现武钢1700冷连轧机组 "酸轧联机"改造工程中存在常规凸度辊形配置方案不合理,由此引起了薄规格轧制的工作辊"压肩"现象和轧制过程欠稳定导致成品板形质量欠佳等问题.采用二维变厚度有限元方法建立辊系弹性变形仿真模型,研制了酸轧联机条件下的VCR变接触支承辊,经过工业轧机现场轧制已成功投入1700冷连轧机实际应用.现场应用表明:改善了轧机板形调控性能,提高了带钢板形质量,增强了薄规格品种轧制能力,支承辊辊形自保持性较好.