六辊UCM可逆冷轧机带钢断面形状精细控制技术

针对六辊UCM可逆冷轧机的断面形状控制问题,首先通过模拟计算揭示冷轧带钢的变形机理,分析中间辊窜辊、工作辊弯辊、中间辊弯辊3种调控手段对带钢断面形状与平直度的控制效果,指出3种调控手段的局限性;然后分析了工作辊辊型对带钢断面形状与平直度的控制效果,得到辊型设计的基本原则;进而提出一套适用于UCM可逆冷轧机的"辊型精细优化+目标平直度调整"的断面形状控制技术方案,最终提高了冷轧边缘降控制效果。将上述技术方案应用于3套1 420 mm UCM可逆冷轧机,硅钢横向同板差显著减小,为同类轧机断面形状控制提供了有益参考。     

板带轧机辊缝影响因素与板形的关系

通过板带轧机辊缝形状诸因素对带钢断面形状影响的分析,阐述了轧制力、弯辊力以及HC、CVC和PC轧机可控辊形等工艺与带钢板凸度、平直度的关系,为保证良好板形、制定合理的工艺制度提供了依据.     

板形

1什么是板型?答：对冷轧带钢来说，“板形”(shape)这个术语的概念是相当含糊的，既可以指带钢横断面的厚度差(即带钢中间与边部之间的厚度差)，也可以指平直度(即带钢几何形状畸变的程度)。但一般来说“板形”这个概念通常指平直度，平直度通常是指不平直的程度，亦即对一平坦平面的偏离程度，平直度也就是这种偏离程度的计量。“板形”就其实质而言，是指带钢内部残余应力的分布程度。     

四辊式冷轧机辊型设计的探讨与实践

一、辊型设计的目的若带钢在轧制后弹性变形忽略不计,则带钢在宽度方向上的断面是由轧制时轧辊辊缝形状和轧件原始断面形状所决定。也就是说在轧制时辊缝形状必须与带钢横断面形状相吻合或者是基本吻合,这样才会使带钢横断面上厚度公差较小,而且板型较平直。因此正确的辊型设计不仅可以提高产品质量,还能大大减少轧辊消耗,提高产品的产量。二、轧辊的凸度(曲线) 配置方法     

国外带钢轧机板形控制技术的新进展(下)

三、带钢热轧机的板形检测和 控制系统 1.具有喷水式平直度检测器的控制系统 日本水岛厂带钢热连轧机的板形控制系统包括凸度控制和平直度控制,如图15所示。在轧制带钢时,沿宽度方向的厚度分布(带钢凸度)同平直度有密切关系。轧制过程产生的极其微小的凸度变化就足以改变平直度。相反地,平直度的变化却极少引起带钢凸度的变化。在实际轧制过程中,要求带     

热轧带钢断面形状的评价及其控制

 为简便客观地评价带钢断面形状,特别提出了一种适合于供冷轧原料的带钢断面评价新方法,并基于金属塑性变形和辊系弹性变形等模型耦合建立起描述带钢断面形状的仿真系统,定量分析了初始辊形、轧辊磨损和热变形等因素对带钢断面形状的影响和断面形状评价方法的可行性。数学模型的可靠性得到了模拟计算和生产试验验证,从而为热轧带钢断面形状控制提供了重要的技术支持。研究结果表明,采用合理的初始辊形可以一定程度上弥补轧辊磨损和热变形对带钢断面的不良影响,大大优化了带钢断面形状。     

CSP生产线带钢平直度检测和控制

介绍了涟钢CSP热连轧机组基本情况和带钢平直度检测和控制原理,实测了大量平直度控制数据,在此基础上对涟钢CSP机组的平直度控制水平进行了分析,得出了该机组平直度控制水平很高的结论。     

热轧平直度仪重启失败故障分析

梅钢热轧板厂使用平直度仪设备对带钢的平直度指标进行测量,实现了带钢平直度的自动控制,介绍了梅钢热轧板厂平直度仪设备,结合图纸对平直度仪的重启失败故障进行了分析,并针对故障原因制定了相应的对策。     

热轧带钢平直度的连续在线测量

本文介绍一种连续在线测量热轧带钢平直度的精密、可靠的系统。方法是测量沿带钢宽度方向上三点或多点的相对长度,以确定末架轧机出口的带钢平直度。这个系统为控制台的操作工提供平直度的直观指示,使操作工能够对轧制过程进行校正,并能立即检查这种校正对轧制带钢平直度的作用。 系统的主要设计目标是: (1)无论带钢松弛还是处于卷取机的张力下,都能确定带钢全长的平直度; (2)不管带钢相对于辊道和测量仪器的位置     

热连轧带钢断面形状的修正模型及其应用

 为实现热轧带钢断面凸度和局部高点的准确预报,基于模型、传递和遗传等多因素考虑,从轧机承载辊缝对带钢断面形状的传递效应角度出发,建立起热轧带钢断面形状修正模型,定量分析了带钢厚度和压下率等条件对修正系数的影响。数学模型的有效性得到了生产试验验证,不仅提高了带钢断面形状仿真系统的计算精度,而且为热轧带钢断面形状的准确预报与控制提供了重要的技术支持,并将其应用到鞍钢1 580 mm七机架热连轧机的生产实践中,取得了良好的使用效果。     

Improved Pattern Clustering Algorithm for Recognizing Transversal Distribution of Steel Strip Thickness

Transversal distribution of the steel strip thickness in the entry section of the cold rolling mill seriously affects to the flatness and transversal thickness precision of the final products. Pattern clustering method is introduced into the steel rolling field and used in the patterns recognition of transversal distribution of the steel strip thickness. The well-known k-means clustering algorithm has the advantage of being easily completed, but still has some drawbacks. An improved k-means clustering algorithm is presented, and the main improvements include: (1) the initial clustering points are preselected according to the density queue of data objects; and (2) Mahatanobis distance is applied instead of Euclidean distance in the actual application. Compared to the patterns obtained from the common k-means algorithm, the patterns identified by the improved algorithm show that the improved clustering algorithm is well suitable for the patterns' recognition of transversal distribution of steel strip thickness and it will be useful in on-line quality control system.     

Improved Pattern Clustering Algorithm and its Application in Recognition of Transversal Thickness Distribution of Steel Strip

 Transversal thickness distribution of steel strip in the entry section of cold rolling mill has distinct affections to the flatness and transversal thickness control precision of final products. Pattern clustering method is introduced to steel rolling area and is first time to be used in the patterns recognition of transversal thickness distribution of steel strip. K-means clustering algorithm as the best-known one has the advantage of being easy to implement, it has drawbacks. In this paper, an improved k-means clustering algorithm is presented, main improvement points include the amount of clusters is indirectly determined by experience, the initial clustering points are preselected according to the density queue of data objects and Mahalanobis distance is applied instead of Euclidean distance. Compared to the clustered patterns obtained from the common k-means algorithm, the patterns identified from the improved algorithm is more reasonable. The results of application in one coil further show the improved clustering algorithm is well suitable for the patterns’ recognition of transversal thickness distribution of steel strip. It will do great help in the online quality control system.     

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.     

四辊轧机板形测,控系统的设计

介绍东北大学轧制技术及连轧自动化国家重点实验室三机架四辊冷连轧机板形检测与控制系统的设计，并对板形的测，控原理进行了阐述，通过板形测，控系统的使用，使被轧带杜板形质量有了较大的程度的提高。     

高精度薄带材冷连轧过程智能优化控制

带钢冷连轧控制是系统性极强、技术难度极大、精度要求极高的综合性技术，是保证冷轧带钢产品质量和生产效率的主要手段。东北大学自主开发了冷连轧全套自动化系统，涵盖了轧机主令控制、自动厚度控制、自动板形控制、物流跟踪、模型设定等功能，并研发了高精度数学模型、轧制规程多目标优化算法、加减速过程带钢厚度与张力补偿及轧制工艺优化等先进控制技术。所开发的系统已推广应用到多条冷连轧生产线中，现场应用表明,系统运行稳定，实现了0. 17mm极薄规格带钢高速稳定轧制，厚度偏差小于±2. 5μm，板形标准差小于7I。最后对轧制过程的智能化发展进行了展望。     

宽带钢热连轧机板形设定的解耦与应用

板形与板厚是带钢几何尺寸精度的两个重要质量指标,板形与板厚控制之间存在耦合关系,使得分别控制的热连轧机板形和板厚均达不到目标值,在建立耦合关系模型的基础上,完成了板形设定和自适应穿带控制的解耦设计,实现板形板厚的综合控制。板形解耦模型已经成功地在大型工业轧机上投入运行,取得了明显的效果。     

1 700 mm冷轧带钢轧机板形控制能力研究

带钢的板形包括凸度、边部减薄和平坦度3个要素.采用轧制过程的跟踪纪录、板形控制过程的数据分析和轧件取样测量的综合评价方法分析了1 700 mm冷连轧机的板形控制能力,并结合现场实际提出了提高板形质量的对策.     

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.     

空气轴承式板形辊的校正及其算法研究

本文介绍了空气轴承式板形辊的结构和原理，阐述了板形辊的校正过程和校正算法。实际应用结果表明，采用本算法校正后的板形测量值能够比较准确地反映实际板形。     

Great reduction pratice of SUS304 in cold-rolling

SUS304 stainless steel is typical of austenitic stainless steel,which organization is metastable austenite,easily appears work hardening in cold rolling.According to the common process,the max reduction of cold rolling in one stage is below 80%,we try to rasie the max reduction to 90%in one stage (wecalled that "great reduction" ) from the view of cuting cost.Due to the work hardening,great reduction brings lots of problem(the difficulty of flatness control,strip break..etc)。This article analyzed the great reduction from properity of SUS304 steel,mill types,flatness control,rolling technics etc,supplied the corresponding solutions,and formed a sophisticated great reduction theory. This article focuses on the unusual thermal crown of raw materials(ie,abnormal distribution of horizontal thickness) and the rolling force fluctuations in "great reduction" rolling.First,the "distortion" phenomenon which caused by unusual thermal crown of raw materials is explained,wedge-shaped strip In coiling, because of a big difference in thickness on both sides,leads to different compressive stress on both sides of flatness roll,so that the flatness measurement is distorted;Second,the "strip shifting" phenomenon caused by wedge shape of strip is explained,we analysis the stress on both sides of the strip,concluded that the wedge-shaped strip on the coiler will shift to the thick side of the deviation,the amount of strip shifting is related to the wedge level;Because of the characteristics of SUS304,the strip is difficult to be rolled in the last few passes.so the strip breaking is easily occurred,we found the reasonable parameters(rolling speed, cooling oil,tension,etc) to solute that problem;The deviation of rolling force will cause the shape of the roll gap,thus affecting the shape control,especially in the head and tail part of the strip,It is important to minimize the deviation of rolling force;The "great reduction" process provide the favorable flatness(< 8I-unit) and thickness deviation which less than±3 um,with no significant difference between common process.In mechanical properties,the elongation of the great reduction strip is less than common products by 2%-3%,but that can be adjusted through the annealing process improvement.At present,we have been using this technology for mass production,achieving good economic benefits.