Setting method of rolling schedule for reversible four- high mill of narrow strip

The small four- high rolling mill of narrow strip has such structural features of small absolute value of working roll diameter, which causes problems like non- negligible horizontal displacement of the work rolls, larger thermal crown of the work roll, and more complicated shape control of the plate. The shape was more dependent on rolling schedule. The equipment and process characteristics of reversible four- high mill of narrow strip were fully considered. The influence model of rolling schedule of small four- high rolling mill on shape was established. The influence of specific path rolling schedule parameter on the shape was quantitatively analyzed. The targets were that the rolling pass was minimum and the relative load was the most uniform. Meanwhile, the influences of such factors as shape control, rolling stability and prevention of surface defects were also considered. A set of comprehensive optimization method for rolling schedule was put forward, which was suitable for small four high mill and taking account of shape control. Relevant technology was applied to the production practice of 450 small four high rolling mill in a company. Good results were achieved after the application in the field. The shape closure rate of the unit decreases by 45. 5%.     

Schedule pass planning with dialogic computer program for reversing hot strip rolls

Algorithms and calculations of a dialogic computer program for the planning of the schedule pass of reversing hot strip rolls. The input data and output tables of the computer program. Fields of application and developing possibilities.     

热轧宽度模型改造

为了改善国内某热轧厂宽度控制稳定性和精度,在对原有模型和质量问题分析基础上,针对粗轧宽度模型实施了模型架构、模型算法、模型参数、自学习方式、短行程控制以及宽展预测模型的改造和优化。对钢种层别进行细分,自适应参数考虑了不同轧制生产模式的影响,带钢的头尾短行程控制曲线采用了可变多点方式,增加了立辊孔型模型以及立辊磨损模型,在宽展计算时考虑孔型的影响磨损量的贡献,提高了宽度模型预报精度。实际应用结果表明,经过优化改良的宽度模型有效提高了宽度控制稳定性和产品精度。     

宝钢2050热轧卷取薄带钢尾部“飘”起分析及改进

从宝山钢铁股份有限公司2050热轧卷取G辊道速度控制原理出发,指出原速度控制方法不足,分析了薄带钢尾部在G辊道“飘”起从而导致在卷取夹送辊前出现拱钢、断尾现象及尾部松卷等问题的原因,设计了G辊道新的带钢尾部滞后速度控制方法,通过对G辊道速度模型的优化,使带钢能够平稳地通过G辊道,避免了带钢尾部“飘”起的发生。     

末道次轧制力锁定法在中厚板规程计算中的应用

  在中厚板轧机无液压弯辊条件下,为防止传统轧制规程计算方法造成的板形问题,提出了一种末道次轧制力锁定的轧制规程计算方法。该方法将操作工提前给定的末道次轧制力作为轧制规程计算的约束条件之一,通过控制道次规程末道次的轧制力达到控制板形的目的。实际应用结果表明,该方法使操作工能够根据经验对板形进行有效控制,明显减少中浪、边浪等板形问题,具有良好的使用价值。     

过程控制级模拟轧钢系统的研制及在热轧试车中的应用

宝钢集团上海第一钢铁有限公司(后面简称一钢)新建的不锈钢工程1780热轧项目中,为了能在较短周期内完成所有的应用软件开发与测试任务,特别研制了模拟轧钢功能。本论文主要阐述利用计算机的集成思想,结合热轧工艺,来开发模拟轧钢功能,以及利用模拟轧钢进行现场各种情况的模拟测试。     

Finite element modelling of strip curvature during hot rolling

Abstract

Finite element techniques have been used to decouple some of the major causes of strip curvature in the roughing stages of a hot strip mill. A plane strain elastic-plastic model is used to predict the direction and severity of strip curvature caused by asymmetrical factors at each pass of the rougher. Asymmetrical factors considered include work roll speed mismatch, temperature differentials across the thickness of the workpiece, pass height, and frictional differences between upper and lower work rolls. A full factorial experiment was then designed and performed, using finite element predictions, to identify which asymmetrical factors are most influential to strip curvature, and to determine the interactions, if any, between factors. The results show that three of the asymmetrical factors are significant to strip curvature, but their influence depends on the rolling pass. This study will allow the rolling operator to identify which asymmetrical factor may be causing strip curvature and, thus, provide a suitable course of action.     

基于板厚板形综合目标函数的冷连轧机轧制参数智能优化新方法

板厚、板形精工是衡量板带质量的二个主要指标，本文以板厚板形为目标函数，首次采用智能化的优化方法－－免疫遗传算法（IGA）对冷连轧机轧制参数进行优化。应用实例证明其性能优于传统优化方法，可获得满意的综合效果，这为新产品的试制和原有产品轧制规程的优化提供了依据。     

平整机升速过程带钢与张力辊打滑分析

某厂平整机在升速过程中频繁出现带钢打滑问题,严重影响带钢表面质量。通过分析生产过程数据,提出一种判断升速过程带钢与张力辊发生打滑的时间的方法。进一步建立了平整机张力辊与带钢之间运动的数学模型,并分析了升速过程中影响带钢打滑的主要因素。研究发现,较小的张力辊摩擦因数、较大的平整机速度和升速加速度以及较大的张力辊组张力差都会增加带钢与张力辊间的打滑风险,并提出了解决带钢发生打滑的措施,优化后升速过程中的打滑发生率由3.33%降低至0.17%,为平整机稳定生产起到积极作用。     

基于多目标满意优化的热轧非对称工作辊设计

热轧非对称工作辊可兼顾板形控制和自由规程轧制,其关键参数通常采用经验设计法,缺乏相应的依据.本文提出了热轧非对称工作辊关键参数的理论设计方法.由于设计过程中无法精确给定已知条件,因此把多目标满意优化引入到非对称工作辊的参数设计中,建立了综合满意度目标函数,并用模拟退火遗传算法进行满意度最优值求解.采用满意解代替最优解,使得辊形参数的优化设计结果更具科学性.在某热连轧生产线上的实际应用表明,优化设计的辊形在板形控制和自由规程轧制方面均取得了理想的效果.      

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.     

冷轧带材板形辊传动方案设计

 板形在线测控是提高冷轧带材板形质量的关键措施。不同轧机的板形检测辊结构和尺寸差别较大，传动方案有被动与主动两种。不合理的传动方案可能导致带材与检测辊之间发生打滑，划伤带材。为解决上述问题，首先阐述了主、被动方案的整体选择依据。然后提出了打滑安全系数的概念，分析了引起打滑的主要因素，并将打滑安全系数作为新增板形仪传动方案的选择依据。针对被动方案，提出了提高打滑安全系数的具体措施，针对主动方案，建立了具体的电机选型理论。最后通过两套工业应用的板形检测辊，分别对主、被动方案进行了验证。     

热轧带钢平整线自动分卷控制系统

介绍热轧厂平整分卷自动机组中带钢自动分卷控制系统的基本组成及工作原理 ,对钢卷的分卷计算和终端估算进行了分析与讨论。该系统采用二级工业监控网络系统 ,可实现生产过程的实时检测与控制。实际运行表明 ,系统工作稳定、控制性能良好 ,满足生产工艺要求     

Detection and evaluation mechanism of cold rolling strip edge shape

The edge shape problem of strip has great influence on the shape control precision, so it is extremely necessary to establish the high-precision strip edge shape model. Based on the theoretical analysis and the practical engineering, a new high-precision shape detection model, which consists of wide channels in the middle of detection roll and narrow channels on both sides, is established to analyse the problem of strip edge shape. Instance data showed that the strip lateral thickness difference was directly related with the shape state of strip, and the strip edge coverage rate and the strip deviation amount had important influences on the shape detection precision, the pattern recognition accuracy and the shape control effect, so the strip edge shape model has become one of the key factors to improve industrial application effect of the shape closed-loop control system in the present situation.     

1580热连轧机减少轧件温降措施的研究

宝钢1580热连轧机采取了保温罩、较厚的粗轧出口中间坯、先进的粗轧道次负荷分配方式等措施，以减少轧制过程温降。其温度计算数学模型计算精度较高。本文介绍了该轧机的温度数学模型，分析轧制过程中的轧件温降，较详细地介绍其减少轧件温降的措施。     

热轧板形的负荷分配变化控制方法

通过合理变化精轧各架的压下负荷分配,可在实现带钢良好凸度控制的同时,兼顾到平直度的控制。该方法考虑到带钢板形取决于下游机架轧制时金属的流动,同时平直度可通过末机架的轧制状态得以控制,其实质是通过改变精轧各架的压下负荷分配来补偿轧辊热凸度变化。文中列出3种压下模式,在保证比例凸度近乎常数的前提下,通过比较这几种模式下得到的计算凸度值和实际凸度值,来说明该方法可补偿轧辊热凸度变化对带钢板形的影响,具有实际的应用价值。     

冷轧带钢来料断面对张应力与出口断面的影响

为了降低冷轧带钢的横向同板差,通常需要采用紧边轧制工艺,带钢边部处于大拉伸应力状态,很容易引起边裂或断带。提出一种冷轧带钢来料横断面形状的简单描述方法,以热轧来料横断面参数作为输入参数,采用板形模拟软件分析了来料断面形状的两个关键参数对带钢出口张应力与出口断面形状的影响规律。模拟结果表明,减小热轧来料边部15和40mm处凸度值C_(15)和C_(40),改善热轧带钢边部减薄,不仅有利于减小冷轧带钢横向同板差,而且可以改善带钢边部残余拉应力,从而减小冷轧带钢边部张应力,有利于避免第一道次带钢发生边裂与断带事故。     

Relation between the variation in thickness of sintered strip materials and the rolling force

Conclusions On the basis of theoretical considerations, it was established that strip thickness variation in the rolling of sintered materials affects the rolling force. An expression has been derived describing the relationship between the permissible rolling force variation and the tolerance limit for a given type of product. The fact that these two quantities are interrelated shows the need for control of the rolling force in the deformation of sintered materials. The densification rolling of comparatively wide and thin strip with narrow thickness tolerances should be performed in four-high mills with regulation of roll pass geometry and roll stand stress or in cluster mills.Translated from Poroshkovaya Metallurgiya, No. 8 (140), pp. 1–5, August, 1974.     

卷取带钢速度测量系统的开发

卷取温度（CT）精度是冷却过程控制的核心,而卷取带钢速度是作为热轧带钢CT控制的重要参数。结合某热轧厂CT控制系统的改造,提出了一种卷取带钢速度测量系统。该系统能精确测量卷取带钢的速度,为提高带钢尾部CT的控制精度提供有力保证。     

Mathematical modelling for rolling force and microstructure evolution and microstructure controlling with heavy reduction in tandem hot strip rolling

A new mathematical model to predict rolling force and microstructure evolution in hot strip rolling has been proposed. This model is constructed by Orowan's theory, FDM analysis for temperature and incremental theory for the evolution of microstructure. It enables us to predict rolling force accurately, since the flow stress is directly calculated by dislocation density. As the time for computation is quite short, the proposed model can be used to ensure the deviation of grains in the product coils. The proposed model has been used to characterise large reduction tandem hot rolling. There is good relationship between ferrite grain size of the hot strip and dislocation density. Then one can plan the best schedule to roll ultra fine grain strip considering strain, strain rate and rolling temperature. Also, the proposed model is general so that one can predict microstructure in any rolling process to product new steel with correcting material data.