盛钢桶用铝尖晶石－炭砖的生产和使用

盛钢桶用铝尖晶石－炭砖的生产和使用贵阳耐火材料厂许文前，龙吉安，贺韵秋１前言宝钢采用国内最大的３００ｔ连、模铸通用钢包。随着连铸投产、护外精炼技术的应用、钢水温度提高及钢水在钢包内停留时间的延长，使高铝质衬砖出现明显的挂渣、鼓包、变形、向砖缝内渗钢、...     

长子□滑动水□成型工艺的改进

目前,尽管钢铁企业已经普遍采用了连铸工艺,但是,对于一些优质钢材,尤其是优质铸钢件,仍然采用模铸方式浇钢.由于模铸工艺的特殊性,浇钢过程要采取控流浇铸的方式,尤其在浇铸后期的补浇阶段,滑板频繁拉动,而且为半流浇注.在半流浇注过程中,由于滑板浇铸孔错位,钢水不是垂直下落,而是倾斜一定的角度,其冲刷点正好集中在滑板与下水口的接缝位置,使该处容易出现漏钢、跑钢事故.为保障模铸方式浇钢过程的安全性,将下滑板子口长度由20 mm增加至40 mm,使接缝处避开钢水冲刷点.     

抑制钢水渗透的钢包衬砖及钢包寿命的延长

为抑制钢水渗透钢包工作衬，开发出一种新的钢包砖系列。这一系列砖是树脂结合的高铝质砖并添加有碳和镁，在十多个车间里试用，从未发生过钢水渗透，从而延长了钢包的寿命。     

向Al2O3—C质滑板砖中添加Mg—B系原料的效果

1.前言 滑动水口用滑板砖,当承受钢中氧含量高的钢种时,同承受一般钢时相比损毁显著增大。其原因可以认为是由于在滑板砖与钢水接触的部位,钢中的氧和FeO使砖中的碳原料和形成碳结合的碳发生氧化,引起组织脆化,伴随钢水接触部位的强度下降,导致耐磨性降低,以及生成低熔化合物,导致耐侵蚀性降     

盛钢桶用不烧镁铝尖晶石炭砖的研制及使用

盛钢桶用不烧镁铝尖晶石炭砖的研制及使用随着炼钢技术的发展，盛钢桶除了作为盛钢容器外，还兼有二次精炼等功能。由于出钢温度的升高，钢水滞留时间延长，钢液沸腾与气体搅拌作用，使用条件越来越苛酷，使传统的粘土衬砖、高铝材砖、铝镁砖等内衬寿命大幅度下降。为了寻...     

出钢口的衬砖组成与形状对其耐用性与出钢时间的影响

出钢口是熔融钢水从BOF炉(转炉)流向钢包的通道,它所用的耐火材料至关重要。不仅影响钢水冶炼的生产效率,而且影响钢水的质量。韩国在过去的10年中,出钢口衬砖从分段型(短衬砖)转变为整体型(一个长衬砖),延长了转炉的使用寿命。本文通过以下两种途径来提高出钢口衬砖的使用寿命:一种途径通过优化材料的化学组成改善材料的耐磨性,并控制材料的初始抗热剥落性来延长出钢口衬砖的使用寿命;另一种途径通过改善出钢口入口处形状缩短初始出钢时间来提高转炉的生产效率。此外,期望通过改善出钢口衬砖组成与形状来控制辅料进料时间。研究发现:出钢口衬砖用Mg O-C质耐火材料通过改变鳞片石墨的种类及其含量来改善其使用寿命,另外,通过水模型试验改善出钢口入口处形状缩短了出钢时间。     

改变熔块池炉流出口砖材质及结构解决流出口堵塞问题

采用自制锆英石流出口砖代替高铝质流出口砖，并改进流出口结构，可提高流出口砖的抗侵蚀性能，避免流出口堵塞，延长熔块池炉的大修周期。不便保证熔块质量，而且降低了熔块成本。     

中间包内衬结构的开发

用多铸槽连铸机连续浇钢是强化冶金生产的手段之一。此种方法不仅可以从减少切边损耗来增加钢产量,而且还能通过钢在中间包内进一步精炼来提高钢的质量。 连铸机的中间包是连铸的主要设备之一,因此,对中间包内衬结构和耐火材料质量提出很高要求;耐火衬砖在浇钢过程中必须具有最佳的热阻和耐磨性;从工作衬砖方面讲,中间包内型结构必须保证钢水流动制度,以便为连铸机启动和钢水搅拌创造有利条件,钢水搅拌目的是中和钢水温度和化学组成。     

用后钢包透气砖显微结构分析

对60 t LF VD精炼钢包用刚玉-尖晶石透气砖和45 t LF精炼钢包用铬刚玉-尖晶石透气砖用后残砖进行了显微结构分析。结果表明:LF精炼工艺用透气砖狭缝及裂纹有明显的渣侵蚀和渗透,LF VD精炼工艺用透气砖狭缝和裂纹有钢液渗透。在周期性操作过程中,狭缝口部的扩大和热震造成的裂纹会使钢液或渣液的渗透侵蚀作用加剧并导致剥落现象的发生。透气砖狭缝堵塞直接影响吹通率和使用寿命,所以,要优化狭缝尺寸,提高材料的抗热震性。     

镁钙耐火材料对钢水的净化作用

研究了不同CaO含量的镁钙耐火材料与AR0 16钢水之间的作用。利用岩相、真空直读光谱分析仪、扫描电镜能谱等手段对镁钙耐火材料与钢水作用前后钢水和耐火材料的成分变化以及耐火材料的显微结构变化进行了研究。研究结果表明 :镁钙耐火材料在 16 0 0℃下与AR0 16钢发生作用后生成了新相 ;CaO含量大于 30 %的镁钙耐火材料与钢水作用 6 0min时脱S效果最佳 ;在本实验条件下 ,作用 30min可使钢中Al降到较低 ;增加镁钙耐火材料中的CaO含量可进一步降低钢中S和Al。     

不锈钢冶炼用铁水包Al2O3-SiC-C内衬砖的性能与侵蚀机理

铁水包内衬材料长期服役于间隔周期较长的高、低温交替环境,极易发生剥落与侵蚀损毁。为了探索影响铁水包内衬材料使用寿命的主要因素,对市面上四种铁水包Al₂O₃-SiC-C内衬砖的化学成分、物相组成、物理性能和微观结构进行了分析,并以高炉渣为侵蚀介质,重点研究了不锈钢冶炼用铁水包Al₂O₃-SiC-C内衬砖的侵蚀机理。结果表明:铁水包Al₂O₃-SiC-C内衬砖中Al₂O₃含量越高,高温下制品的液相量越低,越有利于提高耐火砖的高温力学性能;随着含碳量的增加,铁水包Al₂O₃-SiC-C内衬砖的抗渣性得到明显改善,但抗氧化性及高温抗折强度呈下降趋势;高炉渣中CaO、MgO向耐火砖中渗透,与耐火砖中的Al₂O₃、SiO₂发生反应形成高熔点的镁铝尖晶石及低熔点的钙长石等,生成的低熔相会加剧耐火砖的侵蚀。     

Multifunctional Refractory-lined Vessel: Ladle Aggregate

A ladle primarily is a container used to transport molten steel from the steelmaking unit to the casting facility.The essential requirements are heat resistant,insulative and strong enough to hold molten steel up to 300 t,with a structure of multilayered refractory lining in a steel shell vessel.When a ladle is assembled with three-phase graphite electrodes,a ladle furnace forms,starting steel refining process with/without the vacuum tank degasser and RH circulating degasser,in order to meet the growing demand on high purity and higher quality steel.The working lining is under aggressive conditions that comprise the chemical reaction with molten steel,the severe corrosion of liquid slag,the disaggregation through oxidation,and the strong stress due to the impacting of the melts and gases and the effects of thermomechanical behaviors.Magnesiacarbon brick is one of the major materials,being indispensable for the slagline of a ladle furnace.Alumina-magnesiacarbon brick has played an important role to substantially increase the service life in the metal zone,from the early lining materials of high alumina and doloma bricks.The permanent lining must assume sufficient responsibility to allow finishing the process of the engaged charge in case of a failure in the working lining.The insulation layer must be as thin as possible in order to maximize the ladle’s capacity,and reduce the shell temperature for saving energy.In this issue,several integrant refractories are reviewed or investigated in order to compile a lining overview,and to contribute a prolonged service life under aggressive working conditions of the ladle furnace.     

Interaction of slip‐ and flame‐spray coated carbon‐bonded alumina filters with steel melts

Ceramic foam filters play an essential role in the quest for cleanliness of cast steel parts as they facilitate turbulence reduction during mold filling as well as removal of nonmetallic inclusions. A coating on these filters is able to increase their strength and filtration efficiency by improving the adhesion of inclusions to the filter strands. In this study, Al₂O₃‐C filters were coated with an alumina slip via slip and flame spraying. The phase composition and the microstructure of the coatings were investigated before and after immersion into molten steel contained in a metal casting simulator. After contact with molten steel, Al₂O₃‐C reference filter shows intense decarburization which often influence the quality of cast steel parts due to formation of gas bubbles. Slip‐sprayed alumina coatings on such a filter promote the deposition of inclusions due to formation of a vitreous alumina layer but will also cause gas bubble formation as they exhibit a high porosity. Flame‐spray coatings have low porosity and hence, prevent formation of gas bubbles. Furthermore, they showed the highest reactivity toward the steel melt and hence, are recommended for filtration of cast products with a high demand on cleanliness.     

高温模压炭砖的研制

介绍了炼铁高炉用高温模压炭砖的研制概况。重点介绍了"抗铁水"炭砖研制情况,选用电煅煤和高温电煅煤为骨料,煤沥青作黏结剂在特制设备中快速压型烧结试制出高温模压炭砖。对原材料优化给出了炭砖的耐压强度、铁水溶蚀指数、透气度依赖于高温电煅煤含量的三个回归方程。还给出了3种炭砖的抗热震因子的结果。同时就远洋公司生产的高温模压炭砖质量指标与国内外优质炭砖进行了对比分析。     

Slag Resistance of Refractories for Direct Reduction of Laterite Nickel Ores in Rotary Kilns

Aiming at prolonging the service life of refractories for direct reduction of laterite nickel ores in rotary kilns, the slag resistance of ten materials(corundum bricks, chrome corundum bricks, silicon nitride bonded silicon carbide bricks, high alumina silicon carbide bricks, high alumina bricks, magnesia chrome bricks, magnesium aluminate spinel bricks, spinel chrome corundum bricks, chrome corundum castables and magnesia alumina chrome composite spinel bricks) was evaluated by rotary slag tests, which simulate the service conditions in rotary kilns. The corroded residual bricks were analyzed by SEM and EDS. The results show that the magnesia alumina chrome composite spinel brick possesses the advantages of magnesium aluminate spinel bricks and chrome corundum bricks; MgO-rich spinel can absorb the penetrated ferric oxide, and forms a dense zeylanite layer, which prevents the penetration of the molten laterite nickel ores; therefore, it is an ideal lining of rotary kilns for direct reduction of laterite nickel ores.     

两种不同铁水熔蚀炭砖微观结构分析

为提高高炉炭砖的抗铁水熔蚀性,对两种不同铁水熔蚀性炭砖进行了岩相和电子显微镜分析.炭砖的微观结果分析表明,无烟煤基质的炭砖抗铁水熔蚀性优于在原料中添加石墨的炭砖;往基质中加入Al_2O_3可大为改善炭砖的扰铁水熔蚀性;工艺上使Al_2O_3均匀分布是提高炭砖抗铁水熔蚀性的重要措施.     

锰渣与再生砖骨料制备免烧砖的性能及应用

锰渣与再生砖骨料均属于大宗固废,提升大宗固废利用率具有重要的环境效益和经济效益。本文利用锰渣、再生砖骨料等制备了免烧砖,探究了锰渣掺量对免烧砖各项性能的影响,且对其微观结构及有害物质浸出行为进行了分析。结果表明:制备的免烧砖外观质量优良,色泽均一,尺寸标准;结合强度要求和抗冻性要求,锰渣掺量不超过10%(质量分数)时,可制备出强度、耐水性和耐久性优异的MU20免烧砖,锰渣掺量不超过15%时,可制备出性能优异的MU15免烧砖;掺适量锰渣的免烧砖中形成了较多的钙矾石相,有利于强度发展。锰渣和再生砖骨料制备的免烧砖可以应用于人行道等市政工程,应用效果良好。研究结果可为锰渣低碳资源化利用以及生态砖制品的生产和应用提供技术支持。     

Innovative Lining of Unburnt Al_2O_3-MgO Brick for 300t Steel Ladle in Baosteel

The manufacture of clean steel needs high performance carbon-free bricks for ladle lining.Based on long term application experiences of the prefab Al₂O₃-MgO blocks,unburnt Al₂O₃-MgO brick has been developed by pressing a mix of alumina,spinel and magnesia as major raw materials and Al₂O₃-MgO gel powder as binder.In addition to low open porosity and high strength,the unburnt Al₂O₃-MgO brick shows superior corrosion resistance and thermal shock resistance to the prefab block.Field trials in a 300t steel ladle have indicated the residual lining of unburnt Al₂O₃-MgO bricks showed smooth surface without large spalling and seldom steel infiltration,consequently longer service life than the prefab blocks.The reliable,unburnt Al₂O₃-MgO bricks have more advantages of high efficiency,energy-saving and eco-friendly production.It will be one of the best options for ladle lining in the manufacture of high-purity steel.     

Plasma-sprayed graded ceramic coatings on refractory materials for improved chemical resistance

Plasma-sprayed ceramic coatings were manufactured on sintered alumina–mullite refractory bricks to improve their chemical resistance to molten glass. Mullite and alumina powders were employed. Graded layered coatings were designed and produced, to reduce the thermal expansion mismatch with the substrate: in all cases, the upper layer consisted in pure alumina (very resistant to chemical attack); alumina–mullite intermediate layers were added to match the low thermal expansion of the porous substrates. Plasma-sprayed coatings definitely improved both the abrasion resistance and the chemical resistance to long-time (8 h at 1400 °C) contact with molten glass, since the coating preserved its original microstructure. However, in thermal shock tests, some transverse cracks appeared; thus, thermal cycling tests in presence of molten glass indicated that, after a few cycles, the glass can penetrate down to these cracks. The tested samples were studied by means of scanning electron microscopy (SEM) with energy dispersive spectrometry (EDS) and X-ray diffraction (XRD).     

Progress in Research and Development of Refractory Oxide-Nonoxide Composites

Some of the progress made in our laboratories in collaboration with industry in research and development work on high performance oxide-nonoxide composites for metallurgical applications has been reviewed. (1) SiAlON bonded corundum composites for blast furnace usage have been produced by reduction-nitridation sintering at high temperature, using bauxite instead of alumina in the matrix. (2) Low carbon Al2O3-SiAlON slide plate materials successfully used in high quality steel continuous casting have been developed in which most or all of the graphite in Al2O3-C brick is replaced by bauxite-based β-SiAlON. (3) Al/Si metal bonded Al2O3-C material characterized by low carbon content, low firing temperature and in-situ formation of carbides and nitrides at high temperature during service are found to possess very high hot strength and very good thermal shock resistance and have also been successfully used as slide plates in ladles and tundishes for high quality steel casting.