高速连铸结晶器保护渣技术

讨论了与高速连铸密切相关的保护渣技术。论述了高速连铸保护渣必须保证的理化性能；总结了高拉速结晶器用保护渣的研究现状。     

E2钢连铸结晶器保护渣理化性能的研究

本文详细研究了W-7、W-9、W-18三个连铸保护渣的熔化温度、粘度及吸收Al_2O_3夹杂物能力等理化性能,并用W-7、W-9作为E_2钢连铸结晶器保护渣。在重铜三厂立式连铸机上进行工业性试验,获得了表面质量良好的E_2钢连铸坯。     

连铸保护渣性能选择及对铸坯质量的影响

保护渣的制定实质上就是通过改变其化学组成及矿物组成,使之具有-定的熔点、熔速、粘度、结品温度等特性,以满足不同钢种所需的传热、润滑、夹杂吸收、绝热等要求,从而生产出质量合格的铸坯.重点从制定熔点、熔速、粘度、结晶温度等渣性入手,讨论对铸坯表面缺陷的防治问题.     

关于连铸保护渣润滑性能的研究

在实验室中,通过模拟熔渣在结晶器与铸坯之间的状态,建立了应用测力传感器测试保护渣润滑性能的实验装置。 应用测试装置对现场使用的四种板坯连铸保护渣的润滑性能进行了测定。并根据测定的结果,研究了粘度、结晶温度对熔渣摩擦力的影响,探讨了保护渣在结晶器内的润滑行为。 结果表明,测试装置能够在实验室内简单、可靠地测定熔渣摩擦力;测试结果能够比较全面地反映保护渣的润滑能力。     

连铸保护渣的性能

连铸保护渣对于产品的表面质量具有显著影响。关键过程之一是保护渣渗入结晶器与铸坯之间的间隙，在了解表面缺陷形成原因这方面十分重要的是纵裂的发生与结晶器／铸坯间热流量二者之间的关系。     

连铸结晶器振动参数与保护渣物化性能的关系

提出了连铸过程稳定化的基本条件，建立了结晶器振动参数和保护渣物化性能之间的基本关系式。     

国内外超低碳钢连铸结晶器保护渣的设计与应用

简述了连铸超低碳钢时铸坯增碳的机理 ,介绍了国内外在设计和研制超低碳钢用连铸保护渣时为防止铸坯增碳而采取的各种技术措施及实际应用效果。对攀钢开发超低碳钢用连铸保护渣提出了建议。     

BGX—7Ⅱ连铸保护渣的研制

根据包钢圆坯连铸机的浇铸条件,研制出一种圆坯结晶器保护渣。工业试验结果表明;研制的渣能够替代进口产品,满足圆坯Φ２３０－３５０ｍｍ断面连铸生产工艺要求。     

Analysis of basic network structure of continuous casting mould powder in electromagnetic field

ABSTRACT

In the continuous casting process, the mould powder plays the role of insulator and heat insulator in the crystallizer, prevents molten steel from oxidizing, absorbs non-metallic inclusions, and controls lubrication and heat transfer between the casting billet and the mould. It is an important functional material that promotes the quality of a billet and ensures that the continuous casting process proceeds smoothly. Here in we analyse the changes in the microstructure of the protective flux from the aspect of the infrastructure of the flux slag. Additionally, using the classical molecular dynamics simulation method, the structure of the CaO–SiO₂–Al₂O₃–MgO slag system was simulated in the presence of magnetic fields of various strengths. The magnetic field was found to have the following effects on the slag structure. The participation of the basic elements Si, Al, O, etc. in bond formation is independent of magnetic field strength. The magnetic field causes changes in the peaks, coordination numbers, and peak widths of the radial distribution functions of bonds such as Si–O, Al–O, and Mg–O. The greater the magnetic field strength, the more disordered the ionic clusters are, and the greater is the decrease in slag viscosity. Although the effect of the magnetic field influences the structure of the slag, there is not much change in the way the molecules and atoms are stacked in the slag.     

板坯连铸结晶器内钢液流动的数值模拟

利用Fluent软件对1650mm×220mm板坯结晶器建立了三维稳态数学模型,对三种方案条件下结晶器内钢液流动进行模拟.结果表明,结晶器的宽度对结晶器表面速度分布影响显著,随着结晶器宽度的增加,结晶器表面的速度分布越来越不均匀.表面的最大速度受到多种参数的影响,包括浸入式水口入口钢液的速度、水口出口角度和水口浸入深度等,其中入口钢液的速度影响最为显著.最优方案为：铸坯宽度1100mm,底部结构为山形和出口角度向下30°的水口,水口浸入深度120mm,流量为11.6m³·h^-1,入口速度为0.8384m·s^-1.     

Study on mechanism of mould powder entrapment in funnel type mould of flexible thin slab casting machine

Abstract

A physical model was established to study the mechanism of mould powder entrapment in the funnel type mould of a flexible thin slab casting machine, and the effects of operational parameters on the powder entrapment were investigated. The results show that there are three mechanisms of mould powder entrapment, vis-à-vis entrapment caused by shear stress, entrapment caused by vortex and entrapment caused by shear stress and vortex. Three different modes of the entrapment caused by the shear stress, between the mould powder and the molten steel flow produced by the flow from the upper ports of a four-port submerged entry nozzle, were observed. The entrapment caused by vortex occurs at the lowest position of the metal/slag interface. The entrapment caused by shear stress and vortex is a new mechanism, in which the powder is firstly drawn downward by shear stress and then pulls the powder layers above under the common action of shear stress and vortex.     

专家系统在连铸生产中的应用

介绍专家系统的特点及其结构,总结了专家系统在结晶器液面控制、结晶器漏钢预报以及铸坯质量预报方面的应用,提出了今后的研究方向．     

低碳钢板坯连铸保护渣的研究与应用

通过对武汉钢铁股份有限公司炼钢总厂四分厂低碳钢卷表面缺陷产生原因进行分析,认为结晶器卷渣是主要影响因素。在研究结晶器卷渣机理的基础上,通过调整保护渣成分、提高保护渣的黏度以及生产对比试验,开发出适合该厂连铸生产的高黏度保护渣,并提出了操作要点。应用结果表明,该保护渣对于控制成品质量、提高生产稳定性均具有明显效果。     

Design of mould fluxes for continuous casting of special steels

The melting behaviour of mould powder during continuous casting is an important consideration with respect to caster performance, production rate and steel quality. Two important factors, powder composition and carbon addition, are critical to control the properties and melting behaviour of the mould flux. In this study, the effect of different carbonaceous materials on the melting characteristics of mould powders was evaluated. Correlations were established between the structural factors and chemical reactivity of carbon and melting behaviour of mould flux. In addition, two examples are given of the effect of flux composition on casting performance for specific steels. A flux with reasonable basicity and additives was designed for the casting of heat-resistant steel (Incoloy 800) to reduce surface cracks. Another flux was designed for the casting of non-magnetic steel containing high aluminium by partially replacing SiO₂ with Al₂O₃ to limit aluminium oxidation by SiO₂.     

保护渣对连铸二冷水中氟含量的影响

调查了使用不同氟含量保护渣时连铸二冷水中F^-质量浓度的变化,并在实验室研究了保护渣组分及保护渣在水中的浸泡时间对水浸液中F^-质量浓度的影响．研究结果表明,A厂使用低氟保护渣,二冷水中F^-质量浓度增幅为1．2～24．3mg·L^-1水样呈中性;B厂使用高氟保护渣,二冷水中F^-质量浓度增幅为57．9mg·L^-1,水样呈酸性．保护渣中氟含量越高,保护渣在水中的浸泡时间越长,渣中氟向水中的转移量就越多．控制保护渣中氟不超过2％,有利于减弱保护渣氟的浸出对二冷水的危害．在研究的组成范围内,碱度CaO／SiO₂和Li₂O对渣中氟的浸出无明显影响．增加保护渣中B₂O3含量,有利于降低保护渣中氟在二冷水中的浸出．     

CSP连铸结晶器液位控制系统

介绍珠钢连铸采用Co60为放射源的结晶器液位控制系统配置、控制方式和控制算法．     

结晶器振动双机互备份控制系统

介绍连铸生产中结晶器振动控制系统的组成原理，提出双机互备份并行工作方案，以确保连铸核心装置部分的连续性与稳定性。实际运行表明，该系统工作稳定，有效地提高了连铸生产的可靠性。