小方坯连铸机结晶器凝固传热的分析

根据安钢德马克小方坯的现场数据，建立了小方坯连铸机结晶器的二维凝固传热模型，采用有限差分法对数学模型求解，得到铸坯在结晶器内的表面温度分布和坯壳的生长规律，同时讨论了拉速、过热度、结晶器冷却水强度对铸坯的表面温度和坯壳生长的影响．     

水平连铸是如何实现拉坯的？

水平连铸是如何实现拉坯的？对弧形连铸机，凝固开始于结晶器的弯月面，结晶器振动，向下拉坯。对水平连铸机，由于中间包与结晶器密封连结，钢水供应与拉坯方向垂直，拉坯方式就不能按弧形连铸机的办法。水平连铸钢水凝固开始与结晶器连接的分离环（ＢＮ），钢水从中间包...     

结晶器厚度方向锥度对铸坯质量的影响

从铸机结晶器参数入手，对比了不同类型铸机所生产铸坯表面纵裂纹的差异。认为结晶器厚度方向锥度小是导致铸坯表面产生纵裂纹的主要原因，锥度越大越有利于降低铸坯表面纵裂纹的发生率。通过研究结晶器的发展过程指出，在结晶器设计过程中，厚度方向的锥度应满足钢种的凝固收缩，尽量减少气隙，改善传热，降低铸坯缺陷。     

水平连铸的拉坯方式与弧形连铸有何不同？

水平连铸的拉坯方式与弧形连铸有何不同？弧形连铸机采取结晶器振荡方式拉坯，结晶器作正弦波振荡，拉坯机等速拉坯，当向下振速大于拉速时，产生“负滑脱”。水平连铸机采取铸坯振荡的方式拉坯，即结晶器固定，拉坯辊作拉－停－推－停的动作。两者的区别是：（１）弧形连...     

连铸板坯在结晶器内凝固行为的研究

在考虑结晶器铜板水槽结构尺寸和分布的基础上，建立了连铸板坯在结晶器内温度场和应力场之间耦合过程的有限元分析模型。通过耦合计算，发现板坯在连铸结晶器中宽窄面方向上的坯壳表面温度、坯壳生长及其受力变形等行为沿拉坯方向上的变化规律，为分析和解决铸坯在结晶器中产生的质量问题、设计或优化有关结晶器工艺和结构参数提供了理论依据。     

连铸结晶器振动过程连铸坯应力分布有限元分析

对连铸结晶器振动过程进行了有限元模拟,获得了结晶器振动过程连铸坯表层应力分布,分析了结晶器锥度、结晶器与连铸坯间摩擦系数、拉速和连铸坯厚度对连铸坯表层应力分布的影响。振动过程结晶器末端附近区域连铸坯表层出现应力集中。随结晶器锥度减小和连铸坯宽度增加,连铸坯表层最大应力增加;拉速和连铸坯与结晶器间摩擦对连铸坯表层最大应力影响很小。研究结果对分析和认识连铸坯表面振痕的产生原因和结晶器磨损具有指导作用。     

喷淋结晶器传热特性的实验研究

喷淋结晶器是一种新型结晶器，它是用特殊的喷嘴将水喷淋到结晶器的铜板表面上进行铸坯冷却的，这种冷却方式具有较高的传热速度，便于调节结晶器的热流密度，可以提高拉坯速度和铸坯质量，喷淋结晶器的传热现象是很复杂的，本文通过建立传热实验台，对喷淋冷却过程进行较细致的实验研究，找出喷水量和换热系数的关系等，为设计喷淋冷却结晶器提供必要的参数。     

钢的连铸过程结晶器与铸坯之间的传热分析

针对连铸过程中的结晶器传热模型，分析总结了结晶器与坯壳之间的热阻构成，并研究了结晶器壁和坯壳界面热流的影响因素，为传热模型的求解和结晶器锥度的优化设计提供了理论依据。     

小方坯连铸机喷淋结晶器的研究

建立小方坯喷淋结晶器凝固传热数学模型，模拟计算了铸坯温度场、坯壳厚度、热流场，坯壳与铜壁间气隙厚度。计算坯壳厚度与实测坯壳厚度基本吻合；与普通水缝式结晶器相比，铸坯温度场均匀，坯壳厚度均匀，冷却强度有所提高。     

连铸矩形坯结晶器的改造与应用

介绍了普通矩形坯结晶器改造为高效卡板式内止口结晶器的主要措施、内止口结晶器的特点及其使用效果。实践证明，改造后结晶器具有拉坯速度高，铸坯质量高，工艺性能好，运行平稳等特点，适于炼钢厂连铸高效改造。     

Improvement of water slot design for beam blank casting mould

Abstract

Two-dimensional thermo–elastic–plastic creep finite element models of two beam blank moulds with different water slot designs, the large hole mould and the small hole mould, are set up and their thermomechanical behaviour is numerically investigated by means of ABAQUS software. The temperature, distortion, stress and inelastic strain range across the hot faces as well as the fatigue life of the two moulds are discussed in detail, based on which it is shown that the distributions of temperature and distortion of the small hole mould are more uniform than those of the large hole mould, and the peak temperature of the former mould is smaller than that of the later mould. However, the fatigue life of the small hole mould is shorter than that of the large hole mould. Both moulds were put into service in an industry and it is demonstrated that the quality of the product cast by the small hole mould is better than that by the large hole mould, and the service life of the small hole mould is longer than that of the large hole mould because the service life of a mould chiefly depends on the wear of its hot face, which is much shorter than the fatigue life. An improved water slot design for the beam blank mould is then proposed and it is numerically demonstrated that this improved mould is superior to the large hole mould and the small hole mould.     

薄板坯连铸结晶器铜板温度及热流密度分布

薄板坯连铸结晶器的传热过程直接影响到铜板的寿命,有必要研究薄板坯连铸结晶器的传热特征。为了研究薄板坯结晶器的热流密度,通过开发的结晶器温度监测软件检测了珠钢结晶器铜板的温度。根据在线实测的铜板温度以及薄板坯连铸机冷却参数,建立了薄板坯结晶器铜板传热模型,计算并验证了结晶器热流密度的分布函数,同时通过二次回归得出了结晶器热流密度与结晶器高度的关系式。结果表明,在宽度方向上铜板温度和热流密度的分布具有相似的规律性,距离弯月面越近,热流密度和温度的波动越大。弯月面处热流密度值大于4．2MW／m^2,是造成结晶器铜板被侵蚀的主要原因。     

正弦振动结晶器摩擦力与负滑脱参数对比分析

结晶器摩擦力是反映结晶器与铸坯间相互作用、评价保护渣润滑性能的重要参数.由于摩擦力的检测与计算比较复杂,一般通过对振动工艺参数的理论分析来估算结晶器与铸坯间的润滑与摩擦.基于液压振动装置的板坯连铸试验平台,对结晶器摩擦力和振动速度进行了检测实验研究.通过对理论与实测计算结果的对比分析,讨论了结晶器摩擦力状态与负滑脱参数的关系及二者随拉速的变化趋势.该研究在制定适宜的振频-拉速匹配关系、定量理解结晶器与铸坯间的瞬态摩擦行为等方面具有一定的指导作用.     

奥氏体不锈钢板坯连铸结晶器锥度的优化

针对奥氏体不锈钢连铸中的质量问题 ,对太钢三炼钢 1260mm× 160mm板坯结晶器的锥度进行了分析。通过不锈钢铸坯在结晶器内收缩的计算和拉坯速度、过热度等工艺参数对铸坯收缩影响的分析 ,得出采用双锥度结晶器比单锥度结晶器更符合铸坯在结晶器内的收缩规律 :液面附近 80～200mm区域采用较大锥度 ,液面下 200～800mm的结晶器下部 ,采用较小锥度 ,并在此基础上设计了曲线锥度结晶器。生产试验表明 ,双锥度设计显著改善了铸坯质量 ,消除了窄面鼓肚和中间凹陷等缺陷     

国内外模具钢生产现状及发展

介绍了国内外模具钢生产与发展的现状，并对目前国内外模具钢的应用状况进行分析比较，提出我国模具钢生产存在的问题以及与国际模具钢水平的差距，探讨了我国模具钢生产发展的思路与策略。     

连铸结晶器摩擦力的研究现状

 结晶器内部发生的热力综合作用是影响并制约连铸生产过程的主要因素，铸坯与结晶器之间的摩擦及润滑行为对铸坯质量及生产效率有着重要的影响。综述了结晶器摩擦力计算的研究现状，简要介绍了国内外就摩擦力在线监测研究方面所取得的研究成果，并对结晶器热力联合在线监控技术进行了展望。     

Thermal behaviour of moulds with different water channels and their influence on quality in continuous casting of beam blanks

Abstract

Two-dimensional finite element heat transfer models have been developed to predict temperature distribution in beam blank moulds with large and small hole water cooling channels. The effects of water channel design and grinding thickness on transverse temperature profile in meniscus region were analysed in detail. The effects of both moulds during plant trials are also compared. The results show that the peak temperature is found in the fillet area of the large hole mould and is 20°C higher than that of the small hole mould. With increasing grinding thickness, peak temperature in both moulds decreases linearly, and when the grinding thickness reaches 9 mm, the peak temperature of the small hole mould exceeds that of the large hole mould. The transverse temperature uniformity of the hole mould is superior to that of the large hole mould. It is also found that longer mould life, better strand surface quality and more homogeneous surface microstructure are obtained when using the small hole mould.     

连铸保护渣与氧化铝的交互作用研究现状

保护渣中Al2O3质量分数变化是渣钢交互作用的结果,包括吸附钢液中Al2O3夹杂和渣金反应产物。氧化铝对保护渣成分与性能稳定性影响突出,进而影响铸坯质量。分析指出,影响保护渣吸附Al2O3夹杂的因素包括接触角、润湿速率和界面张力、熔渣成分和性能等。熔渣与夹杂物的交互作用行为决定了其对上浮夹杂的去除率。高铝钢连铸过程渣金反应尤为突出,保护渣的工作性能将发生明显改变。基于近年关于Al2O3夹杂的吸附溶解试验研究,以及高铝钢浇铸渣金反应及其保护渣性能变化的研究结果,探讨了通过合理设计保护渣成分或更换渣系等措施来实现该类钢种保护渣工作性能的相对稳定性。     

倾动炉智能钢模研究及应用实践

目前国内铜阳极板浇铸主要采用铁模和铜模,且钢模应用较少。钢模具有变形量小、模面耐冲刷性好、脱模剂消耗量少等优点,但是钢模也存在加工成本高、使用寿命短等缺点。倾动炉针对钢模的缺点对钢模材质、钢模结构、冷却水系统、喷涂系统、浇铸系统等进行了创新及智能控制优化。通过以上技术创新,在保证阳极板物理合格率的基础上提高了钢模寿命,降低了硫酸钡单耗,钢模成本竞争能力得到提高。     

Analysis of variability and non-uniformity of mould heat extraction for round billet continuous casting in plant trials

Abstract

Maintaining a stable and uniform heat transfer from steel shell to mould is important to produce high quality casting billet. In the present paper, a large amount of measured data of heat flux and temperature for round billet continuous casting mould from a plant trial has been analysed to shed light on the variability and non-uniformity of mould heat transfer around the perimeter. The results show that the variability and non-uniformity of heat extraction from the steel through the mould is affected slightly by operational parameters, such as pouring temperature, casting speed, meniscus, electromagnetic stirring current, but strongly by the steel carbon content and mould powder type. The installation of the mould in caster machine determines the magnitude of non-uniformity of heat transfer to a great extent. The relative root mean square (rRMS) of mould heat flux, presenting the variability and non-uniformity of mould heat transfer around the perimeter in transverse section, has wider range of variation and higher mean value compared with that of temperature. When the abnormality of heat transfer happens, such as deposit, the non-uniformity of mould heat transfer is also studied.