冷轧无取向硅钢横向厚差控制

冷轧中中低牌号的无取向硅钢多采用万能凸度轧机(Universal crown mill,UCM)生产,其板形好坏受制于UCM轧机板形调节手段的协调使用.为掌握UCM轧机的板形控制特点,建立基于二维变厚度有限元的辊系弹性变形和基于三维差分的轧件塑性变形的六辊轧机耦合模型,对UCM轧机的板形调控性能进行详尽的分析,包括工作辊和中间辊弯辊、中间辊窜辊的调控功效、辊间接触压力分布等.在此基础上,提出可用指导生产的板形控制策略,指出UCM轧机在横向厚差控制方面的不足.针对工业生产中UCM轧机轧制无取向硅钢横向厚差大的问题,在大量仿真计算的基础上,开发具有高次曲线函数的边部变凸度(Edge variable crown,EVC)的工作辊.采用该工作辊后,各种品种的无取向硅钢的横向厚差不大于10 μm的百分比由24%提高到99%,横向厚差的均值小于6μm,远小于之前的13μm.     

冷轧超高强钢平直度与断面形状前馈控制技术

针对六机架冷连轧机组超高强钢生产过程中因机架数多、控制工艺复杂、各机架控制能力得不到充分发挥而导致成品平直度与断面形状超差的问题,充分结合六机架冷连轧机组的设备与工艺特点,基于超高强钢冷轧过程平直度与断面形状预报模型,分析了超高强钢冷连轧过程平直度与断面形状前馈控制策略,提出了基于来料的各机架出口目标平直度曲线设定方法,开发了适合于六机架冷连轧机组的超高强钢平直度与断面形状前馈控制技术。将该技术应用到某钢厂六机架冷连轧机组,各机架控制能力得到了充分发挥,成品平直度比该技术应用前提高了12.5%,且断面形状分布更加均匀,具有进一步推广应用的价值。     

宽带钢冷连轧机综合耦合模型的建立与分析

宽带钢冷连轧过程中,板形、板厚和张力控制之间存在着很强的耦合关系,相互影响对方的调节功效。为了进一步提高控制精度,进行解耦设计实现解耦控制是十分有效的手段,而其前提和基础就是冷连轧机综合耦合模型的建立和分析。首先,运用轧制理论对轧制过程中板形、板厚和张力控制的各种影响因素进行了系统的分析,然后考虑执行内环的动态特性建立冷连轧机综合耦合模型,以定量地描述轧制过程中辊缝、弯辊力、本架轧辊速度、前架轧辊速度和出口厚度、出口凸度、出入口张力之间的耦合影响关系。最后,基于Matlab/Simulink工具,采用此耦合模型对某冷连轧机末机架的耦合特性进行仿真分析,指出对其进行解耦控制的必要性。     

[成形过程仿真优化与集成计算材料工程]限动芯棒连轧管机轧制过程轧件变形行为及规律仿真

基于ABAQUS有限元软件建立了180 mm限动芯棒连轧管机组钢管连轧过程仿真模型。通过仿真模拟展现了连轧各机架连续轧制过程中轧制区钢管横截面上应力、应变及位移的分布和壁厚形成演变过程,揭示了轧制压力分布和轧辊上总轧制力的变化规律以及轧件温度与轧制区摩擦因数对壁厚与轧制力的影响。使用三次样条插值方法从仿真结果数据中提取钢管壁厚和直径,通过研究对象机组的工业生产实测数据验证了有限元模型的正确性。仿真发现:连轧过程中,金属在纵向上先发生减径变形后发生减壁变形,横向上金属主要从孔顶区流向开口区;前三机架接触压力主要集中在孔顶区,变形量较大,是主变形机架,第四五机架接触压力最大在侧壁区,变形量较小,主要起到精整和归圆作用;随着轧制温度的升高,出口壁厚增大,轧制力减小,随着芯棒与轧件之间摩擦因数的增大,壁厚减小,轧制力减小。仿真研究结果支撑了针对该机组的关键轧机结构参数设计、轧制工艺参数确定以及工程调试中工艺参数优化。     

尼日利亚900mm冷连轧机组调试总结

首先介绍尼日利亚首条冷连轧带钢机组—900 mm五机架六辊冷连轧机组的技术特点;重点阐述调试过程中出现的问题和难点,分析问题的原因并制定解决方案;最后对尼日利亚冷连轧调试工作进行总结。     

基于线性化动态模型的冷连轧最优解耦控制系统

以多机架冷连轧机为背景,研究了冷连轧轧制过程的动态模型,建立了冷连轧过程的增量式线性化动态模型,提出了一种相邻机架间的最优解耦控制方法.仿真结果说明了该方法的有效性.     

冷连轧机工作辊温度场与热凸度模型的研究

经过大量的现场试验与理论研究,结合冷连轧高速轧制过程中的设备与工艺特点,以宝钢1220五机架冷连轧机为研究对象,建立了一套冷连轧高速轧制过程中工作辊温度场与热凸度计算模型,给出了相应的计算框图,编制出了与之配套的温度场与热凸度预报软件,达到了相当高的预报精度,具有进一步推广应用的价值.     

一个轧制单元内实时辊系综合凸度预测及应用

用有限元法在精确计算机械板凸度并在验证其计算结果有效性基础上,通过解析板形刚度理论,解析凸度遗传方程中的遗传系数,建立计算带钢的板凸度方程。利用现场实际生产工艺参数依次计算各架轧机出口带钢凸度并和末机架后凸度仪测量的板凸度值比较,预测热连轧机辊系综合凸度在一个轧制单元内的变化规律。预测结果通过对现场各机架大量的工作辊辊型测量数据经计算后得到验证,在一定工况条件下,预测的辊系综合凸度整体变化趋势和实际辊系凸度变化保持一致。这种预测方法避免了热连轧过程中为精确控制板凸度而计算各单个机架轧辊实时热、磨凸度变化所带来的复杂性,完成了一个轧制单元内实时辊系综合凸度预测值在各单个机架轧机上的凸度分配及应用。应用效果表明,现场带钢板凸度目标值在±10μm内的命中率由91%提高到97%,产品实物质量得到明显改善。所建模型与预测结果对板形理论研究和现场操作实践具有实际参考价值。     

5机架冷连轧系统加工过程自动控制研究

与常见的独立冷轧工艺不同,利用全连续冷连轧工艺进行金属带材的轧制是一个更加复杂的多变量过程,对它的精确控制具有重要意义。本文提出了一种基于状态相关Riccati方程（SDRE）的新型控制方法,用于5机架全连续冷连轧系统的加工过程控制。结果表明,该方法成功实现了对全连续冷连轧加工过程的控制,在过焊缝阶段和外加干扰因素的影响下,轧机工作状态和加工性能均保持稳定。     

机架疲劳寿命分析

利用ANSYS Workbench对1450 mm冷带钢连轧机机架进行疲劳寿命分析,结果表明机架的疲劳寿命满足设计要求。     

板形标准曲线的理论计算方法

联立板形预报模型和板形判别模型,提出板带轧机板形标准曲线的理论计算方法。该理论计算方法的思路和原则是最大限度地消除板凸度并同时兼顾板形良好,最终使板形趋于最好,这种计算方法的目标是实现板形和板凸度的综合最优控制。以1 220 mm五机架带钢冷连轧机和900 mm单机架带钢冷轧机5道次轧制为例,分别对轧制中凸板和中凹板的情况进行计算,计算结果证实了理论分析计算的正确性。这种板形标准曲线的理论计算方法为进一步从理论上定量研究板形标准曲线模型奠定了良好的理论基础。     

Study on the improved accuracy of strip profile using numerical formula model in continuous cold rolling with 6-high mill

The quality requirements for thickness accuracy in cold rolling continue to become more stringent. In cold rolling mill, it is very important that the rolling force calculation considers rolling conditions. The rolled strip thickness was predicted using calculated rolling force. However, the prediction of strip thickness in cold rolling is very difficult; in particular, for 6-high mill with shifted intermediate roll (IMR), the accuracy of thickness is not good. In this study, to improve the accuracy of rolled strip thickness, the roll gap flattening can be given based on Hertz contact theory, with contact between rolls and the smooth cylindrical rolls for the rolling elastic deformation. Also, the distribution of the roll gap flattening may be calculated using the contact force of unit transverse length. The strip profile at the continuous cold rolling is calculated by using the numerical analysis model considering the initial strip profile before cold rolling. Hence, we propose that the numerical model can predict the rolled strip profile more quickly and accurately and be applicable to the field. The results of the proposed numerical model were verified by FE-simulation and cold rolling experiments of 6-high mill with five stands.     

Coupled dynamic modeling of rolls model and metal model for four high mill based on strip crown control

The crown is a key quality index of strip and plate,the rolling mill system is a complex nonlinear system,the strip qualities are directly affected by the dynamic characteristics of the rolling mil.At present,the studies about the dynamic modeling of the rolling mill system mainly focus on the dynamic simulation for the strip thickness control system,the dynamic characteristics of the strip along the width direction and that of the rolls along axial direction are not considered.In order to study the dynamic changes of strip crown in the rolling process,the dynamic simulation model based on strip crown control is established.The work roll and backup roll are considered as elastic continuous bodies and the work roll and backup roll are joined by a Winkler elastic layer.The rolls are considered as double freely supported beams.The change rate of roll gap is taken into consideration in the metal deformation,based on the principle of dynamic conservation of material flow,the two dimensional dynamic model of metal is established.The model of metal deformation provides exciting force for the rolls dynamic model,and the rolls dynamic model and metal deformation model couple together.Then,based on the two models,the dynamic model of rolling mill system based on strip crown control is established.The Newmark-β method is used to solve the problem,and the dynamic changes of these parameters are obtained as follows:(1) The bending of work roll and backup roll changes with time;(2) The strip crown changes with time;(3) The distribution of rolling force changes with time.Take some cold tandem rolling mill as subject investigated,simulation results and the comparisons with experimental results show that the dynamic model built is rational and correct.The proposed research provides effective theory for optimization of device and technological parameters and development of new technology,plays an important role to improve the strip control precision and strip shape quality.     

冷连轧动态变规格及厚度预设定的研究

研究冷连轧机的动态变规格技术,对于维持轧机的正常生产,提高产品产量和质量具有非常重要的意义.以常规的五机架冷连轧机作为研究对象,给出了五机架冷连轧机的动态变规格的计算公式,分析厚度、轧制力、流量、速度、张力的组成及模型,并对模型进行简化,针对动态变规格及其厚度的预设定应用VB编写界面,进行仿真,效果清晰,突出表现了变规格在厚度预设定方面的作用.     

STUDY ON STRIP AND ROLL DEFORMATION COUPLING OF COLD STRIP ROLLING ON 4-H MILL

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Improvement on edge drop in cold rolling of silicon steel

Since silicon steel is used in a laminated form, thickness profile in the width and the rolling directions should be accurately controlled. It is well known that the phenomenon of edge drop is one of very serious problems in cold rolling of silicon steel. In order to determine one of the better methods for reducing edge drop, a computer simulation was carried out in this study under various rolling conditions. It was found that the better way to reduce edge drop was to use a tapered work roll. A table was given for the optimal taper crown depending upon the diameter of work roll and the width of strip. The optimal condition was applied for actual cold rolling of silicon steel. As a result, edge drop was significantly alleviated.     

四辊冷轧机辊系参数优化设计理论及其应用

四辊冷轧机结构设计中关键问题是辊系参数的确定,建立了包括轧机重要,轧制功率,辊间压力分布特性,纵向刚度,横向刚度和辊缝形状改变能力指标的多目标函数优化设计新模型,以上海宝钢（集团）益昌薄板公司1219冷轧机为例,进行了应用研究。     

冷轧带钢边部减薄和平坦度模糊预测控制的研究

针对配备轧辊横移的新型四辊冷连轧机边部减薄控制控制中,轧机模型具有多变量间的强耦合、易变的模型参数、不确定的干扰因素和不稳定的动态特性,设计一种复合的智能控制系统。设计在模糊控制基础上增加一个积分环节的控制器,与轧机预测模型相结合对带钢边部减薄和平坦度进行闭环控制。经过仿真结果表明,该控制系统可实现四辊冷连轧机边部减薄的稳定跟踪控制及边部减薄和平坦度的非线性解耦控制。