钢包工作衬用耐火材料的研究现状及最新进展

综述了近年来钢包工作衬用耐火材料的研究现状及最新进展, 尤其对传统钢包工作衬用耐火材料的应用背景及存在问题进行了分析和汇总.在此基础上, 进一步提出了适用于超低氧钢(或洁净钢)冶炼用耐火材料的研发方向, 即通过耐火原料组分选择和结构匹配设计, 实现对耐火材料性能的精确控制.新型钢包工作衬用耐火材料需兼顾优异热机械性能的同时, 还应具备钢水净化的功能.      

钢包耐火材料对钢中氧含量及钢水温降的影响

利用氧势指数分析了钢包耐火材料组成、配比以及加热温度对耐火材料分解和向钢中传氧的影响,并利用热传导理论计算了钢包包衬耐火材料的绝热性能对钢水温降的影响.结果表明:随着耐火材料材质由碱性向中性和酸性的顺序变化及温度的升高,耐火材料的氧势指数增大,由耐火材料向钢中的传氧能力增加;通过使用绝热性能良好的耐火材料,可以显著降低...     

冶炼过程钢包温度场和钢水温降的研究

采用有限差分法,建立了钢包的传热物理模型和耐火材料层的温度分布模型,研究炼钢过程中钢包包衬温度场分布和钢水温降的影响.结果表明热态空包每多停留1 min,后续钢水温降增加约0.26℃;空包停留1 h后进行1 h的离线烘烤,后续出钢阶段钢水降温约12℃;永久层导热系数越小,永久层的温度梯度会越大,隔热效果会越好,工作层宜...     

柳钢钢包用耐火材料应用进展

正钢包是炼钢工序中极其重要的冶金设备,其作用不仅是传统意义上承接钢水的盛钢桶,更是炉外精炼工艺的核心载体。钢包包衬耐材的选择不仅关系到钢包的寿命和成本,更直接影响钢水的产量和洁净度。本文主要分析介绍柳钢近20年来钢包包衬用耐火材料的应用情况。     

蓄热式钢包烘烤器的开发与应用

简述了蓄热式燃烧技术的工作原理、性能特点及在济钢150t钢水罐烘烤器上的应用。测定了不同类型的烘烤器烘烤钢水罐衬层时,钢水罐外壳的升温曲线及介质预热达到的温度。通过效果检测,确定了蓄热式燃烧技术在烘烤钢水罐耐火材料时,缩短烘烤时间也可达到需要的衬层温度;同时能使炼钢厂降低能耗、改善工作环境。     

连铸中间包水口堵塞问题浅析

研究了浸入式水口堵塞的形成机理。堵塞沉积主要是由于氧化物颗粒附着到浸入式水口耐火材料的内表面，继而烧结在一起所致。小沉积颗粒的烧结形成不规则的网状物。耐火材料和钢水问反应层的形成，尤其是当耐火材料中含二氧化硅可还原组分，则加速沉积。另外，采取改善水口材质、改善和维护水口形状、提高钢水清洁度、对钢水夹杂物进行变性处理等措施，可有效防止水口堵塞。     

石灰质中包覆层材料的应用

近年来,用户对钢的纯净度要求越来越高,能够有效吸收钢中夹杂的石灰质耐火材料,也因此越来越受到重视。石灰质中包覆层材料就是一个重要的应用实例。所谓“石灰质中包覆层”,就是采用喷涂法、浇注法或贴板法,在中包内衬的表面上覆盖一层石灰质材料。在连铸过程中,这层石灰能与钢水中的A1_2O_3、SiO_2、S等夹杂发生反应,使其脱离钢水,从而达到净化钢水的目的。日本钢铁界从八十年代初期起,就开始着手研究实施这项石灰覆层技术。已有若干厂家申报了这方面的专利,并在有关杂志上     

钢水温度和碳对镁铝尖晶石质耐火材料侵蚀的影响

根据热力学分析和热态实验研究了钢水温度及其碳质量分数对镁铝尖晶石质耐火材料侵蚀的影响,并探讨了耐火材料的侵蚀机理。研究表明,提高温度将加剧钢水对耐火材料的侵蚀,随钢水中碳质量分数的增加,耐火材料的侵蚀指数先增加后减小。侵蚀机理包括：一是钢水中碳与耐火材料组分氧化镁反应化学侵蚀耐火材料;二是钢水向耐火材料内部的渗入以及低熔点物相在耐火材料颗粒界面的析出,降低了耐火材料颗粒间的结合力,加剧了钢水冲刷对耐火材料的损毁程度。     

钢水温度和碳对镁铝尖晶石质耐火材料侵蚀的影响

根据热力学分析和热态实验研究了钢水温度及其碳质量分数对镁铝尖晶石质耐火材料侵蚀的影响,并探讨了耐火材料的侵蚀机理。研究表明,提高温度将加剧钢水对耐火材料的侵蚀,随钢水中碳质量分数的增加,耐火材料的侵蚀指数先增加后减小。侵蚀机理包括：一是钢水中碳与耐火材料组分氧化镁反应化学侵蚀耐火材料;二是钢水向耐火材料内部的渗入以及低熔点物相在耐火材料颗粒界面的析出,降低了耐火材料颗粒间的结合力,加剧了钢水冲刷对耐火材料的损毁程度。     

耐火材料对钢水洁净度的影响

文中就耐火材料对钢水洁净度的影响进行了综述，表明了耐火材料在冶炼过程中的双重重要性，除传统观念外，耐火材料还可起到净化钢水的作用。     

提高精炼钢包使用寿命及降低钢包耐材成本的途径

钢包既盛装钢水，又作为精炼设备，因此，精炼工艺的改进对钢包内衬耐火材料的使用有着较大的影响。同时通过选用优质适价且适应于钢包精炼工艺的耐火材料，优化钢包内衬修砌工艺，加强钢包修砌运行管理，建立科学合理的耐材判废标准，可有效提高钢包内衬使用寿命，降低成本消耗，从而保证生产顺行。     

550 m~3高炉鹅颈管热态修复施工

对某铁厂2#高炉鹅颈管内衬修复进行了总结。通过采用鹅颈管内支模板,使用灌浆料热态下快速恢复耐材内衬的方式,恢复了鹅颈管原有耐材内衬,降低了管壳的表面温度,确保了高炉的安全运行,为其他高炉鹅颈管耐材内衬破损后热态下快速修复提供可借鉴的经验。     

Interaction between molten steel and different kinds of MgO based tundish linings

Abstract

Interactions between the molten steel and the refractory linings are of fundamental importance for the steelmaking industry. During the casting process, the steel cleanliness can be made worse because of the reoxidation of the molten steel in contact with the atmosphere and/or other sources of oxygen (refractories, top slag, etc.). In the industrial trial periods, four tundish refractory linings (preformed boards, two kinds of gunning materials and dry vibrating material, all MgO based refractories) were used in order to evaluate the interactions between the refractories and the molten steel. Owing to the small dimension of the tundish (5 ton) used in the continuous casting at Villares Metals SA, after casting, the chilled steel was cut in order to show, in a single section, the stopper, submerged entry nozzle, MgO ramming and the working refractory lining. Cross-sections of samples from the steel/refractory interface were investigated by electron probe microanalysis (EPMA). Four major aspects were observed at the steel/refractory interface: steel infiltration into the tundish refractory lining, mainly in the gunning materials; a steel oxidised layer formed at the steel/refractory lining interface; formation of a spinel layer between steel and tundish working refractory lining; and many particles were found in the steel phase, near to the steel/refractory interface, being a potential source of non-metallic inclusions.     

钢包内衬用耐火材料对钢中非金属夹杂物的影响

 炉外精炼是炼钢流程中控制钢中非金属夹杂物的重要转折点,作为整个精炼过程中与钢液实时接触的钢包内衬用耐火材料,因为高温物理化学反应易向钢中引入夹杂物,导致精炼效果达不到预期。通过对典型现役钢包内衬用耐火材料与不同脱氧钢之间的界面反应归纳发现,钢包内衬用耐火材料会对钢中夹杂物的形貌、成分和理化性能产生影响,既可向钢中引入夹杂物,也能够吸附去除夹杂物。提出未来钢包内衬用耐火材料应被赋予更多净化钢液等功能指标的发展方向。     

Transient flow and heat transfer in a steelmaking ladle during the holding period

Transient, turbulent flow and heat transfer in a ladle during the holding period are numerically investigated. The ladle refractories including the working lining, safety lining, insulation layer, and steel shell have been simultaneously taken into account. No assumptions are made for the heat transfer between the liquid steel and the inside ladle walls. Both the initial ladle heating and the heat loss from the slag surface are changed to examine their effect on thermal stratification in molten steel. A simplified model for the heat loss from the molten steel to the refractory is proposed. Correlations for the history of mean steel temperature, thermal stratification, and heat loss rate are obtained, which can be easily applied for industrial operations. Predictions are compared with experimental data in an industrial ladle and a pilot plant ladle, and those from previous studies.     

宝钢连铸中间包热状态测试与分析

连铸中间负愉钢水温度是炼钢生产过程的重要工艺参数之一,影响该参数的因素很多,通过对宝钢炼钢部60t中间包的包衬热状态进行测试,分析了包衬蓄热状况对中间包钢水温度的影响。     

Hydrogen Potential Sources in Refractory Materials during Steel Casting

It is well known that the presence of dissolved hydrogen in cast steel can cause defects that appear in hot rolling and forging of steel parts with heavy sections, and also contributes to the formation of internal cracks and blowholes during the solidification of the liquid steel. These problems are especially important in the continuous casting process. So, hydrogen levels must be kept at a minimum in this process. The aim of this work is to investigate possible sources of hydrogen, focusing on the materials that are in contact with the liquid steel during casting. The tundish refractory lining, shrouding tube, tundish covering agents, and casting powders were analysed. The results showed that not only the control of humidity content in those materials is critical, but the phase transformations that the materials suffer during the casting process are important as well.     

Thermal and thermomechanical evaluations of channel induction furnace applying strong insulation containing lightweight aggregates

Monolithic materials with a strong thermal insulating effect are required by the foundry industry for further energy savings, meanwhile possible premature wear of refractory linings caused by over-insulation should be avoided. A monolithic insulating material containing lightweight aggregates possessed strong thermal insulation and was proposed to replace the traditional insulating material made of chamotte currently used in a channel induction furnace. To evaluate the new lining concept, creep of the working lining was considered in the finite element modelling and followed the classical von Mises creep model, which was defined with the Norton–Bailey strain hardening creep equation. The results showed that the lightweight design of the insulating lining reduces the heat loss from the steel shell and material consumption. Moreover, the thermomechanical loads in the refractory linings and steel shell remain within a reasonable range when compared with the currently in-use refractory lining concept.     

Inclusion and Bubble in Steel—— A Review

The type, morphology and sources of inclusion in steels, including indigenous and exogenous inclusions, were discussed and reviewed. Indigenous inclusions are deoxidation products or inclusions precipitated during cooling and solidification of steel. Exogenous inclusions arise primarily from the incidental chemical （reoxidation） and mechanical interaction of liquid steel with its surroundings （slag entrainment and erosion of lining refractory）. Types and causes for the nozzle clogging were also summarized. Reasons for bubble formation and bubble size distribution in steels were discussed thereafter. Finally, morphology and causes of inclusion-related defects in continuously cast steel products were reviewed, such as flange cracking in cans, slag spots and line defects on strips.