钇基稀土钢中间包水口结瘤机理研究

Research on the nozzle clogging mechanism of yttrium-based rare earth steel

针对某钢厂生产E36稀土处理钢时水口结瘤的问题,分析了水口结瘤物结构和成分变化.检测结果表明水口结瘤物主要由稀土铝酸盐、稀土硅酸盐及金属相组成,通过分析稀土在钢液中发生的反应,其生成物熔点基本在1 800℃以上,夹杂物颗粒逐渐析出.因此,结瘤机理可以表述为,稀土与钢液中SiO_2、Al_2O_3等进行反应,并且在流经水口时,与水口耐材发生反应,夹杂物颗粒沉积在水口壁上,经高温烧结后,聚集增大;附着在水口壁上的夹杂物在粘附力的作用下能够克服钢液流动带来的阻力,可以通过提高钢液温度,减少钢液中Al_2O_3含量,来降低稀土处理钢的水口结瘤.

As to the problem that nozzle clogging was produced in the production of E36 rare earth treated steel in a steel plant, the structure and compositional change of clogging materials were analyzed. The results showed that the clogging was mainly composed of rare earth aluminates, rare earth silicate and metal phase. By analyzing the reaction of rare earth in molten steel, the melting point of the product is basically over 1800 degrees, and the inclusions gradually precipitate. Therefore the mechanism of clogging can be explained as follows: Rare-earth reacts with SiO2 and Al2O3 in molten steel and reacts with refractories when flows through SEN. The particles of inclusions were deposited on the wall of the nozzle and were increasingly aggregated after high temperature sintering. The inclusions attached to the wall of the nozzle can overcome the resistance brought by the molten steel flow under the action of adhesive force. The clogging of the molten steel outlet would be reduced by increasing the temperature and reducing the Al2O3 content in the molten steel.