Steel ladle exchange models during steelmaking and continuous casting process

The models and influencing factors of steel ladles exchange during the steelmaking and continuous casting process of H steel plant were investigated.Based on analysis of the operation process and turnover time of steel ladles, relationship models for the turnover number, turnover rate, continuous casting number, number of ladles with additional turnover, and number of ladles without additional turnover were built.The turnover rules of steel ladles for one basic oxygen furnace (BOF) matching one continuous caster (CC) and two BOFs matching two CCs modes were simulated by using a Gantt chart.The models of steel ladle exchange were proposed for casting of a single CC and overlapping casting of two CCs.By analyzing the influencing factors, the following conclusions were drawn.The exchange ladle should not have the task of transporting liquid steel in the CC that stops casting earli-er.The end time of the empty ladle in the CC that stops casting earlier should be earlier than the start time of the full ladle in the CC that stops casting later.After evaluating the factors influencing the start casting time, turnover cycle, casting time, continuous casting number, and overlapping time, a prioritization scheme of steel ladle exchange was proposed based on the steel grade.First, the turn-over cycle and single heat casting time were determined; based on these, a reasonable ladle turnover number was calculated.Second, the turnover number and continuous casting number were optimized for maximizing the number of ladles without additional turnover.Lastly, to reduce the casting number during the overlapping time to be lower than the turnover number, the overlapping time was shortened.     

炼钢—连铸区段生产调度与计算机仿真

炼钢-连铸区段的生产调度包括炉次计划、浇次计划的生成和时间、设备的分配,以及针对各种扰动的动态调整.根据钢种和规格的限制,提出了最优炉次计划模型,并采用禁忌搜索算法进行求解;根据炉次计划和连铸机连浇限制,生成浇次计划;根据炉机匹配和等待时间最小原则,生成静态调度甘特图,并对仿真过程中出现的出钢延迟提出了动态调度的策略和算法.仿真结果表明,基于模型的动态调度策略能够有效地解决出钢延迟问题.     

论连铸设备在连铸生产中的地位和作用

本文对连铸设备对提高连铸生产效率、质量和效益的作用，连铸设备组成与连铸设备管理中几个主要问题，连铸装备水平的优化与提高，连铸工艺与设备的结合，抓好连铸设备人员培训等问题进行了论述。     

考虑铸轧协调的炼钢-连铸-热轧一体化生产计划

炼钢-连铸-热轧生产计划编制是一个多目标、多约束的复杂组合优化问题。从有利于多工序生产组织的角度,提出了一种可分工序独立编制工序计划,并且按铸轧衔接关系进行系统协调的一体化生产计划编制方法。即首先以铸坯作为热轧与炼钢-连铸不同工序生产阶段统一的生产计划对象,并将炼钢、连铸与热轧的生产目标和约束进行归类抽象,使得炼钢炉次计划、连铸浇次计划和热轧单元计划的制定模型具有内在的逻辑相关性;以缩小铸轧时间差作为铸轧界面衔接关系的协调控制目标,来优化连铸与热轧之间的生产衔接,进而获得一体化生产计划。采用某钢厂的生产订单数据和生产计划目标、约束条件,通过模型仿真计算与生产实绩数据的对比检验了该一体化生产计划编制方法的有效性。     

安钢板坯连铸机高效生产实践

安钢第一炼轧厂一机一流板坯连铸机自投产以来,通过依靠技术进步,强化以连铸为中心组织生产,实现单流板坯连铸机产量达130余万t的国内先进水平,最高浇次连拉451炉、产量5.3万t的记录,几年来取得的成绩令人瞩目.本文主要介绍了该台连铸机取得各项经济指标的生产实践和下步的打算.     

炼钢-连铸区段多工序运行协同控制

针对炼钢厂车间平面布置不合理、生产订单多样化导致多工序运行协同性不佳的问题,阐述了炼钢厂多工序运行协同控制的技术架构,通过开展物质流运行规律的解析,生产调度规则库、基于炉-机对应原则的生产调度模型、多工序运行仿真模型的构建,以及多工序协同运行水平量化评价方法的研发,形成了一种具有较高普适性的多工序运行协同控制技术.该技...     

谈我国连铸设备制造的发展

本文简要介绍了我国现有的连铸设备，并着重叙述了国内连铸设备制造情况，以及对今后连铸设备制造的设想。     

连铸准沸腾钢生产技术的发展

介绍了连铸准沸腾钢生产技术的发展现状,提出了我国钢厂连铸生产中采用准沸腾钢生产技术的有关建议     

特殊钢厂炼钢-连铸调度模型

针对特殊钢厂的炼钢-连铸调度问题,建立了多目标调度模型.在模型求解过程中,对静态调度策略和动态调度策略进行了探讨.在静态调度部分,结合炼钢厂运行原则,并根据炼钢炉和连铸机作业周期的不同对应关系,对生产模式进行了分类,给出了相应的求解方法.在动态调度部分,给出了基于规则的动态调度策略以及具体的时间调整方法.最后,根据某转炉特殊钢厂的实际生产状况,在三台连铸机同时生产的情形下,对三个浇次的调度计划进行了仿真计算.通过与实际生产数据的比较,表明所采用方法的有效性.     

全连铸生产钢包工艺的优化

论文介绍了炼钢厂钢包工艺的改进情况及对连铸生产顺行和提高透气砖使用次数带来的益处.     

炼钢连铸动态调度子系统及其应用研究

炼钢连铸生产调度是钢铁企业MES的重要组成部分。在生产调度的过程中存在许多突变和不确定性因素，怎样及时有效进行动态调度，是炼钢连铸调度成败的关键。本文提出了人机协调、多种方法组合、四维一体综合集成的动态调度方案，并在开发炼钢连铸调度系统中得到了具体的应用。     

圆坯连铸生产45Mn2钢的工艺实践

针对方圆铸机生产45Mn2管坯钢易发生水口堵塞及铸坯质量较难控制的难点,采用了炉后渣洗、LF使用高碱度渣精炼、钙处理等技术措施试制45Mn2管坯钢。试验结果表明,半钢炼钢条件下“转炉→LF→φ1200mm圆坯连铸”生产工艺流程可行,连铸圆坯无表面缺陷及内部缺陷,低倍各项缺陷评级均小于1．0级,轧制后成材率为90．2％,钢材力学性能满足用户要求。     

应用改进遗传算法求解炼钢连铸生产调度问题

炼钢连铸制造流程是一个复杂的多阶段、多产品生产过程,其生产调度问题可建模为车间调度问题.提出一个改进遗传算法求解炼钢连铸生产调度问题.改进包括三个方面:基于排序的适应度分配、基于排序的工件过滤交叉算子和基于指数关系的变异率曲线.经24个benchmark的比较测试表明,改进遗传算法比传统遗传算法的寻优能力更强.通过16个生产计划和6个处理工序的炼钢连铸生产调度实例计算结果表明,改进遗传算法是有效的.     

基于混合遗传算法的两流薄板坯连铸连轧流程生产调度系统

首先建立了两流薄板坯连铸连轧流程生产调度规则库.然后根据该生产流程的特点,提出了遗传算法新的编码、交叉、变异操作及改良的概念,并在遗传算法的初始种群建立和改良过程中引入调度规则.在此基础上,利用调度规则和遗传算法相结合的混合遗传算法建立了两流薄板坯连铸连轧流程生产调度系统.该调度系统可以较好地解决两流薄板坯连铸连轧流程的动态调度问题,进一步优化生产组织.     

Experimental study of oscillation mark depth in continuous casting of steel

Abstract

Mould oscillation is needed to reduce friction and thus prevent sticking and breakout of the liquid metal during casting. However, this oscillation is known to cause surface defects in the solidified steel slabs, so called oscillation marks. In this paper, the depth and the depth variation of these oscillation marks were studied using a two-level full factorial experiment (2) with four additional centre point runs. Four factors were studied: stroke length of the mould, oscillation frequency, motion pattern (strip factor) and casting speed. The stroke length affected the depth of the marks the most, where larger strokes created deeper marks. The interaction between the oscillation frequency and the strip factor of the mould also affected the oscillation mark depth. The oscillation mark depth variation was also increased by increased stroke lengths and at higher oscillation frequencies. The largest effect on the oscillation depth variation was found for the interaction between the stroke length and the oscillation frequency.     

板坯连铸机动态轻压下过程控制系统通信接口研究与开发

分析了梅山2#连铸机动态轻压下控制网络构成,基于WinPcap调用和交换机端口镜像功能实现了原过程控制系统TCP/IP报文获取。在分析原系统报文的基础上,通过单体扇型段通信报文测试与分析,得出二级系统与一级系统通信协议,开发了新过程控制系统通信接口,最终实现了新系统与原控制体系通信的无缝对接。     

宝钢连铸板坯动态轻压下模型的研究与开发思想(上)

以宝钢2#连铸机轻压下改造项目为背景,介绍了连铸动态轻压下模型内部计算方法及技术关键,通过仿真研究分析了模型参数误差对模型精度的影响,得出结论:散热系数和固相线误差是造成模型误差的主要因素,为寻找模型修正方法奠定了基础。简要介绍了宝钢轻压下模型的软件体系。宝钢2#连铸机轻压下改造完成后,次月实现月达产,分析结果表明,产品质量显著提高。     

Experimental study of surface defects in continuous casting using developed laser scanning system

Abstract

Various methods of detecting surface defects are being used in automated industrial manufacturing environments. This work presents the design and development of a laser charged couple device (CCD) displacement scanning system. The surface defect detection method using a laser CCD displacement sensor is derived from an idea in which surface defects such as cracks, inclusions and holes of three‐dimensional morphology characteristics are compared to normal surface especially in continuous casting slabs. Some novel research methods have been applied to develop the surface defect detection system used: first, getting a one‐dimensional distance matrix along transverse direction and a two‐dimensional matrix combining with a certain moving speed through the laser CCD displacement sensor; second, obtaining the slab surface profile and mapping to a greyscale image and finally, obtaining the surface defect regions by an image processing and searching algorithm and quantitatively detecting slab surface defect shape and depth. The research results in the lab trials have shown that the methodology proposed is effective to detect two‐dimensional defect size and reconstruct a three‐dimensional surface defect shape. At the same time, it is also able to accurately locate and identify surface defects and realise automatic surface defect non‐destructive detection online, and provides a theoretical base and technology idea for further studying surface defects online inspection for hot continuous casting slab.     

Development and application of model for predicting molten metal temperature in continuous casting process

An unsteady mathematical thermal model was developed for predicting the time,molten-steel weight,induction heating power,and temperature changes of the steel from the end of ladle refining to the end of the continuous-casting process of a tundish. The calculations revealed that for a specific strip-casting process,the ladle tonnage should be controlled to about 90 t. If the ladle capacity reaches 130 t,the provision of a 1 500-kW tundish induction heating device is recommended. By comparing the measured and predicted molten-steel temperature values in the Ningbosteel-Baosteel strip casting industrialization demo project( NBS) of a tundish,it was determined that the prediction accuracy of the model could meet the forecasting accuracy requirements for the molten-steel temperature in the tundish during mass production. Simultaneously,the heat flux density on each surface of the tundish was found at about 50 min,which is entirely consistent with the values reported in the related literature,and the tundish had not reached a heat balance during the casting test period. This model can also be applied to calculate the suitable size of a tundish for a specific continuous-casting process,thereby providing a theoretical basis for the design of the continuous-casting tundish.