基于改进混洗蛙跳算法的冷连轧轧制规程优化

 轧制规程优化是使轧制过程达到最佳状态的重要保证。综合考虑影响冷连轧轧制过程的多种因素,以等功率裕度和克服划痕为目标函数,建立了轧制规程多目标优化模型,并采用自适应混沌变异蛙跳算法对轧制规程进行优化设计。该算法是在基本蛙跳算法中,加入自适应混沌变异操作,具有较好的寻优精度和收敛速度。对某钢厂1370mm冷连轧机轧制规程进行优化的结果表明,优化后的规程较好地实现了各机架等功率负荷分配,降低了划痕出现的概率和程度,大大地提高了产品质量,增加了经济效益。     

基于罚函数法的冷连轧轧制规程优化设计

 合理的轧制规程是使轧制过程达到最佳状态的重要保证。规程设定中采用具有自学习功能的BP神经网络取代传统轧制力数学模型,选用Levenberg Marquardt算法对轧制力进行预报。采用等相对负荷目标函数,考虑到现场和设备所受限制,确定约束条件。利用罚函数法将有约束的最优问题转换成无约束的最优问题,对某厂冷连轧现场规程进行了优化设计,并对优化前后的轧制规程进行了分析和比较,优化效果令人满意,满足实际生产要求。     

初轧机优化轧制规程软件系统

介绍了初轧机优化轧制规程软件系统的组成及功能,优化轧制规程的方法及部分计算用数学模型。该软件系统首次应用于攀钢1150初轧机轧制规程的优化及初轧机的孔型设计并获得成功。该软件为轧钢工作者研究初轧机轧制过程,制定轧制规程等提供了工具,并为轧制过程科学化,自动化打下了良好的基础。     

改进粒子群算法对1420mm五机架冷连轧机轧制规程的优化

某厂1 420mm五机架冷连轧机自试生产以来,出现板形质量不稳定的现象。分析认为,这种现象与现有轧制规程的设定有关。现有的轧制规程是一种经验值,对带钢板形质量未作深入的考虑。为此,对现有轧制规程进行了研究,运用Matlab建立了一种设定给定产品轧制规程的新方法,并基于最优板形质量的目标函数,采用改进的粒子群优化算法,制定出兼顾板形和设备负荷能力的优化的轧制规程。投入实际生产后的实测数据对比表明,优化后的轧制规程生产带钢平直度小于6I的分布由66%上升到88%,带钢板形明显改善。     

重轨开坯孔型系统优化及有限元模拟分析

对重轨BD区开坯轧辊孔型进行重新配置,对箱型孔参数及轧制规程进行优化设计,并利用Deform 3D软件对优化后的箱型孔轧制过程进行有限元模拟,验证了新的箱型孔参数及轧制规程的可行性。通过对重轨开坯孔型系统的优化,将BD区轧辊轧制量提高至6000t以上,将BD区总轧制道次减少至8道次,提高了轧制节奏,降低了辊耗成本。     

中厚楔形板轧制的过程控制模型

提出了两阶段楔形板轧制的观点,并建立了楔形轧制的过程控制模型;运用负荷函数法结合循环迭代法进行了楔形轧制道次数及中间厚度的优化确定;在不改变楔形轧制优化的道次数的前提下,进行了楔形轧制阶段各道次的压下量优化重分配,优化了轧制规程.模拟仿真表明,该过程控制模型能够根据各种坯料规格及目标尺寸规格,很好地优化制定楔形轧制过程控制规程,可以为楔形板的实际生产提供一定的参考依据.     

热轧宽带钢自由规程轧制中负荷分配优化研究

板形控制为实施自由规程轧制的主要难点。兼顾板形控制的热轧负荷分配优化现已有诸多研究,但其目标函数设计存在着假设条件多、实用性差的缺点。在综合考虑自由规程轧制特殊工艺和板形设定计算众多影响因素的基础上,建立了兼顾自由规程轧制的热轧负荷分配优化模型,并采用模拟退火遗传算法对模型进行了优化计算。在济南钢铁集团公司1 700 mm热连轧机的应用表明,优化后的负荷分配使得自由规程轧制中的板形质量得到提高。     

基于动态规划法的中厚板轧制规程优化设计

介绍了用动态规划法优化设计中厚板轧制规程,优化后的轧制规程减少了轧制道次,缩短了轧制周期,并使粗轧机与精轧机的轧制节奏能较好的匹配,提高了小时产量,降低了轧制能耗.     

基于EXCEL规划求解器的轧制规程优化设计

介绍了如何利用EXCEL规划求解器在多约束和多目标函数条件下对轧制规程进行优化,对优化设计的流程进行了图解分析;研究了优化计算中涉及的主要数学模型,通过实例说明了该优化规程的良好效果。计算过程表明,利用EXCEL规划求解器可以快速进行计算,使轧制规程得到优化,起到节能降耗、充分发挥轧机能力的作用。     

冷轧窄带钢节能压下规程的优化设计

介绍了动态规划法优化压下规程建立的数学模型，得出了冷轧窄带钢轧制能耗最小的压下规程，并对现场采用的压下规程进行了分析和比较。     

H型钢热轧轧制力的数值模拟

应力热力耦合大变形有限元方法,模拟了H型钢的热轧变形过程,给出了轧制力的大小及其分布方式,数值模拟结果表明：H远见 腹板与 外表面单位轧制力的最大值一般均出现在出品截面附近,目前比后大得多。此外,模拟计算值与实测值比较接近,从而证明了本模拟计算方法的正确性。     

OptiLam:Design of Optimised Rolling Schedules

Nowadays it is known that the thermomechanical schedules applied during hot rolling of flat products provide the steel with improved mechanical properties.In this work an optimisation tool,OptiLam (OptiLam v.1),based on a predictive software and capable of generating optimised rolling schedules to obtain the desired mechanical properties in the final product is described.OptiLam includes some well-known metallurgical models which predict microstructural evolution during hot rolling and the transformation austenite/ferrite during the cooling.Furthermore,an optimisation algorithm,which is based on the gradient method,has been added,in order to design thermomechanical sequences when a specific final grain size is desired.OptiLam has been used to optimise rolling parameters,such as strain and temperature.Here,some of the results of the software validation performed by means of hot torsion tests are presented,showing also the functionality of the tool.Finally,the application of classical optimisation models,based on the gradient method,to hot rolling operations,is also discussed.     

Optimization of Pass Schedule in Hot Strip Rolling

 Rolling schedule not only determines the rolling process to be going smoothly, but also affects the shape accuracy and structure properties of finished strip. In order to gain good strip crown and flatness, the calculation formulas of the most suitable rolling force and bending force are deduced. By taking relatively equal load of rolling power and good shape as objective functions, the optimization mathematical models of finish rolling schedule are established. By contrast, the rolling schedules after optimization can improve the rolling mill working status and ensure the strip crown and flatness to be good. At the same time, the setting value of bending force is improved and this leaves more space for on-line shape control.     

热轧薄带轧制稳定性影响因素分析

结合热轧薄带生产的技术特点,对其轧制稳定性影响因素进行了分析,提出了应对措施:采取合理安排轧制计划、提高加热温度、减少除鳞道次、严格控制辊形、提高轧机各支承辊和工作辊装配精度等,可以提高热轧薄带轧制的稳定性。     

基于遗传算法的PP及冷连轧轧制规程多目标优化

 针对多目标优化算法中综合目标函数权值难以确定的问题,通过对偏好的数学量化,采用数值分析的方法,构造了6种不同的偏好函数,建立了物理规划（physical programming）数学模型,然后以遗传算法为寻优工具,实现一种更加灵活更加适合于工程技术人员的交互式多目标优化算法。结合某冷轧厂实际的轧制规程优化过程,选取等功率裕量、轧制总能耗及各机架打滑因子为目标函数,运用基于遗传算法的PP进行优化计算。结果表明,优化后的轧制规程很好地实现了各机架等功率负荷分配,降低了打滑出现的概率,大大提高了板材表面质量和成品成材率。     

宝钢大扬程初轧机无槽轧制技术的开发

从初轧工艺、轧制规程等多方面研究宝钢大扬程初轧机实现无槽轧制的可行性.以ANSYS为模拟平台,对大方钢无槽轧制过程进行了三维有限元全尺寸模拟分析,得到了坯料在各阶段的等效应力分布、轧件形状变化及断面尺寸,为轧制生产提供了理论基础.通过研究,开发了新的轧制规程,设计出合理的初轧工艺,顺利地实现了在初轧机上应用无槽轧制技术生产大方钢.     

The Development of Ring Rolling Technology

A thorough survey of work on ring rolling published in the English and German languages by 2004 is presented. The process is briefly introduced and a set of ideals are stated, as the target for all developments in the area. The main challenges which inhibit attainment of these ideals are given, and the process is compared with alternatives. The main body of the review is organised in four parts: the evolution of the design of ring rolling equipment is described, including detailed discussion of the design and manufacture of preforms; the methods used to investigate the process are reviewed, separated into experimental and theoretical categories; the insights gained from these investigations are organised according to the challenges identified at the outset; developments in the control and operation of the process are described. Having given a set of ideal targets for the process, the state of current knowledge about ring rolling is assessed in order to predict likely developments: process modelling capability is nearly able to predict rolling behaviour for a complete cycle with sufficient accuracy to allow effective use of models for design of rolling schedules and preforms; analysis of material behaviour is relatively mature for steel rings, but has scope for significant extension for titanium and aluminium alloys and composites; design choices that seek to extend the flexibility of the process have had some exploration, but could be extended. Finally, the seminal contribution of Professor Kopp is briefly described.     

Effect of Quench and Interpass Time on Dynamic and Static Softening during Hot Rolling

The categories of interpass time encountered in hot rolling are characterized. These are shown to fall into three broad categories: short (in rod rolling); intermediate (in strip processing); and long (in plate schedules). The effects of interpass time on recrystallization and carbonitride precipitation are described, and particularly on the interaction between these two mechanisms. The interactions, in turn, determine the final microstructure produced as well as the mechanical properties.     

An Analytical Model for Dependence of Force and Forward Slip on Speed in Cold Rolling

An explicit analytical method for determining approximations for roll force and forward slip for strip rolling is introduced. It reproduces all main predictions of classical strip theory, but is completely free of any numerical algorithms. Nevertheless, for extreme cases of cold rolling, like foil or skin pass rolling, more sophisticated algorithms are still needed. For the friction coefficient in the roll gap and its increase from the entry to the neutral point also explicit relations are proposed. In the framework of this analysis, they are sufficiently precise for cold rolling with one‐phase lubricants and stochastic surfaces. Only a single parameter of adaptation is needed, the microscopic friction coefficient μ_micro. The quality of the total model is illustrated by means of the dependence of roll force and forward slip on railing speed. For this purpose measured process data (four different pass‐schedules, seven to ten coils each) for cold rolling of copper with rolling oil is analyzed.