耐火材料对钢水纯净度影响的试验研究

通过对钢包、中间包衬层内示踪剂在浇铸过程中变化的试验分析，判断衬层耐火材料在钢水中的变化情况，分析每炉钢水对耐火材料的冲刷量及耐火材料对钢水纯净度的影响程度。从而提出减少耐火材料衬层对钢水污染的措施。     

Durability of Brick Lined Steel Ladles from a Mechanical Point of View

The refractory lining in steel ladles is exposed to chemical and mechanical loads during the heats. Mechanical loads develop from the thermal expansion of the refractories which is confined either by the steel construction or by regions of different temperature within the refractory material. The aim of this work was the investigation of factors influencing the mechanical durability of refractory steel ladle linings and the clarification of failure mechanisms. Especially irreversible strains at the hot face of the working lining caused by compressive stresses induce an opening of joints at the hot face. The irreversible strains reduce the compressive stresses in circumferential direction and increase the probability of tensile failure. A further effect of the irreversible strains is a reduced stability of the working lining. Of special interest in this context is a possible controlled expansion of bricks to counterbalance the irreversible compressive strains.     

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.     

武钢CSP加热炉内衬的优化设计

武钢CSP加热炉炉衬较薄,使用全纤维模块砌筑,其隔热性能好,但使用寿命较短。在保证炉衬厚度不增加、隔热效果不降低的前提下,通过传热计算对炉衬材料进行了优化设计。耐火层选用浇注料延长使用寿命,分析了隔热层分别采用纤维毡、纳米隔热板、超级憎水隔热板等不同隔热材料对外表温度与散热量的影响,确定了合理的材料组成,达到了既能延长使用寿命,又能降低成本的目的。     

MgO–C bricks for BOF linings

Abstract

MgO–C brick linings have become standard in basic oxygen furnaces (BOFs) all over the world. Developments in the refractory technology for BOFs over the last few years and their impact on the lifetime and performance of refractory linings are presented. These developments comprise optimised shapes for the lining of BOF and steel fibre reinforced MgO–C bricks. Optimised shapes with double wedges lead to a smooth inner surface of the refractory lining and fewer stresses and refractory consumption. Stainless steel fibre reinforced MgO–C bricks have proven to be the ultimate choice for scrap impacts or other areas with ultra high mechanical loads. They have brought down refractory wear in these particular areas significantly. Moreover, typical lining patterns of different zones in a BOF and the development of the raw material grades (MgO grades and graphite) for refractories as well as the development of lining lifetimes over the last years are discussed.     

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。     

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...     

Monolithic Lining for Steel-Pouring Ladles

The increasing amount of steel being treated outside the furnace and the increase in the quantity of molten metal being transported by rail in ladles are making it necessary to tighten standards on the durability and service life of the ladle linings. Plans developed for a new department at the Chelyabinsk Metallurgical Combine to line steel-pouring ladles will make it possible to replace the traditional brick lining by cast linings composed of refractory concrete. This change will make the lining considerably more durable, decrease accidents, and sharply reduce the amount of manul labor required in the lining operation. This article describes the process and equipment used to make the new monolithic linings.__________Translated from Metallurg, No. 3, pp. 39–40, March, 2005.     

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...     

提高中频炉酸性炉衬寿命的工艺探讨

从筑炉材料的选择、筑炉工艺、炉衬烧结工艺、熔炼与日常维护保养方面对如何提高中频炉酸性炉衬寿命的工艺进行了研究,使炉衬的吨钢成本消耗大幅下降.     

覆盖剂和保温层对钢包钢水温降影响的数值模拟

通过建立数学模拟研究了添加覆盖剂和保温层对钢包静置过程中钢水温降的影响。结果表明:钢包静置过程中,钢水通过其上表面及钢包的包衬向外界传递热量,钢水温度下降。添加保温覆盖剂可使钢水上表面热损失大幅度下降,从而有效减小钢水温降。添加保温层可有效减小钢水通过钢包包衬向外界环境散失的热量,从而有效减小钢水温降。     

喷涂造衬技术在济钢5~#350m~3高炉的应用

济钢第一炼铁厂对 5 #3 5 0 m3高炉进行以部分更换第四至六段冷却壁并辅以喷涂造衬为主项的修理 ,采用 XA-1型耐火喷涂料进行人工喷涂 ,解决了炉壳频繁发红 ,上部砖衬无支撑等问题 ,保证了炉况长期稳定顺行 ,延长了炉体寿命     

基于VB的稳定态多层壁炉衬参数的计算

根据稳定态下多层平壁炉衬传热原理,介绍了炉衬各层间温度及热流密度的计算方法。利用VB编程环境中的可视化编程,建立各种耐火材料的热传导系数数据库,有利于平壁层数及材质种类等参数的选取,输入热面温度及各层平壁厚度,计算出炉衬相应的各种参数。在实际应用中,该程序性能稳定,界面美观。     

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.     

转炉炉壳采用汽雾冷却时的瞬态温度场及应力场研究

大型转炉用镁碳砖炉衬后,炉壳温度急剧增加,已超出炉壳材料的蠕变温度,造成炉壳蠕变变形.采用汽雾冷却技术可对转炉炉壳实施温度控制.利用有限元法模拟了炉壳实施汽雾冷却的瞬态温度场和炉壳瞬态应力场.     

炉衬热应力分析中几类特殊结构的建模方法

耐火材料炉衬决定高温容器件的使用寿命,热机械应力过大是其破坏的主要原因。有限单元法是进行应力分析的重要手段。论述了高温炉衬系统进行热应力分析中,对炉衬结构中所含砖缝和金属锚固件在建立有限元分析模型时的处理方法。     

耐材方案对炼钢过程节能的贡献

在目前欧洲能源价格上涨以及CO2排放税成本高企的背景下,提高能源利用效率和降低CO2排放量已日趋重要。基于上述目标,奥镁公司可提供一系列多样化解决方案,包括使用优质耐材内衬、优化内衬维护以及改进工艺等。用多个实例论证了在炼钢过程中,智能耐材方案对于提高能源利用效率和减少CO2排放所起的作用。在电炉和转炉炉底使用含底吹气系统的一体化耐材产品,能加强熔池搅拌和加快冶金反应,从而改善多项生产参数,包括电耗、处理周期、电弧稳定性以及加快脱碳反应速率。毫无疑问,对于能量和质量转换效率、成本和CO2排放等多方面都有着重要意义。经过计算流体动力学(CFD)优化的电炉和转炉出钢系统,是改善能源效率管理的另一个耐材解决方案实例。利用这些先进的系统,不但缩短了出钢时间,同时节约了能源损耗以及提高了产能。另外,还有一种节约能源的有效方式是优化钢包衬和使用耐材内衬包盖,可减少热损失,降低转炉或电炉的出钢温度,同时降低LF炉中能量输入或化学反应热的需求。近期,奥镁公司新研发出一种中间包工作内衬(即自硬性喷涂料)。由于省去了像普通中间包工作内衬的烘烤过程,从而相应减少了CO2排放。综述了各种耐火材料产品的特点,并重点讲述了它们在节能和CO2减排等方面的应用效果。     

连铸保护渣性能对中板表面夹杂缺陷的影响

针对柳钢中板表面夹杂物缺陷的特点,分析了夹杂物的来源和保护渣性能、形态对夹杂物的影响。柳钢中板表面夹杂缺陷,由钢中溶解铝被二次氧化而产生的Al2O3,在水口中凝结长大,被钢流冲刷进入结晶器,以及水口耐火材料被冲入结晶器内被凝固壳捕捉而产生的。保护渣的绝热性能对夹杂物能否避开凝固壳的捕捉而上浮到渣金界面有重要影响。其绝热性能受其熔化性能及其形态影响。     

钢包钢水温降及其影响因素的模拟

通过有限元方法建立了120 t钢包的传热模型,计算分析了钢包在使用过程中的传热行为,研究了钢包内衬及厚度对钢水温降的影响.结果表明:使用导热系数较低的保温材料,在传统钢包内衬中添加绝热层能显著提高钢包的保温效果,减低钢水温降速率;改变工作衬厚度对钢水温降速率的影响较小.