【作者】 胡开艳；

【导师】 顾华志；

【作者基本信息】 武汉科技大学 ， 材料学， 2011， 硕士

【摘要】 帘线钢冶炼对钢水洁净度要求高,精炼条件苛刻,渣线镁碳砖易氧化以及钢包使用过程中的局部损毁严重,导致钢包内衬寿命低。因此,对耐火材料采取适当防护和维护措施,提高钢包内衬的使用寿命,具有重要的意义。本文采用无铝材质制备镁碳砖抗氧化涂层,探讨了涂层组分配比对涂层表面形貌、抗氧化性能的影响,同时对涂层断面显微结构和内部碳元素强度变化进行分析;并对修补内衬用碱性喷射料基质部分浆体的流变特性进行研究,探讨其影响机理,为改善帘线钢冶炼用喷射耐火材料的施工性能提供理论依据。研究结果表明:（1）SiC加入量在9wt%时,涂层在镁碳砖基体表面的铺展性较好,相比无涂层试样,其氧化失重率明显减小;当SiC、熔融石英和碳酸锂的加入量分别控制在9%、30%和4.94%左右时涂层铺展平滑,与基体结合良好,试样的氧化失重率最低;各涂层试样从涂层面到试样内部碳元素强度指数逐渐升高。碳酸锂加入量为4.94%的试样C元素氧化损失最小,涂层抗氧化能力最强。（2）基质的流变类型均符合宾汉姆流体模型。本体系的临界加水量、SiO₂微粉和MgO微粉加入量分别取38%、10%和14%为宜;基质浆体添加分散剂均能显著的提高其流变性能;硼酸和氢氧化钙作为促凝剂对基质浆体的促凝效果最为显著;助凝剂磷酸二氢铝等加入量大于0.2%可明显提高浆体的表观粘度;EDTA·4H、EDTA·2H·2Na和EDTA·4Na对基质浆体都具有较好的螯合效果,其中EDTA·4H螯合能力最好。更多还原

【Abstract】 Cord steel is of high requirements on cleanliness of molten steel, and its refining conditions are harsh. Magnesia carbon brick of slag line is oxidized easily , and the ladle lining damage partially in the course of using, which cause a decrease of the survice life for ladle lining. Therefore, taking appropriate protective and maintenance measures to improve the survice life of ladle lining has great significance. This article used less aluminum materials to prepare anti-oxidation coating for magnesium carbon brick, discussed the effect of compositions on the surface morphology of coatings and the oxidation resistance, while the coating section microstructure and internal carbon element strength changes were analyzed. And the rheological characteristics of matrix composition of alkaline Jetting refractories for repairing were researched. Their influence mechanism were discussed, which can provide theoretical basis for improving the construction performance of spray refractories for cord steel smelting. The results showed that:（1） When the SiC content was 9wt%, the sample with coating spread well on magnesia carbon brick, and showed lower oxidative mass loss than samples without coating. The sample with 9wt% SiC, 30wt% fused silica and 4.94% Li₂CO₃ had the lowest oxidative mass loss, spread smoothly, and had good bonding with the magnesia carbon brick. From the coating surface to the inner of the coated sample, the intensity index of carbon element increased gradually. The carbon element of sample with 4.94% Li₂CO₃ had the minimum oxidation loss, and the oxidation resistance of the coating was the best.（2） The rheological type of the matrix slurry is Bingham model. The appropriate addition of water, SiO₂ power and magnesium powder is about 38%, 10% and 14%. Adding dispersants can improve the fluidity of the matrix slurry significantly. Compared with other accelerants, boric acid and Ca（OH）2 played the most significant role. Coagulant acid aluminum dihydrogen phosphate and so on can improve the viscosity of slurry significantly when additing more than 0.2%. EDTA·4H、EDTA·2H·2Na and EDTA·4Na had good chelation effect on the slurry, and the chelating capacity of EDTA·2H·2Na and EDTA·4Na are far lower than EDTA·4H.更多还原