提高含镧、铈钢水可浇性的热力学分析

Thermodynamic Analysis of Improving Castability of Molten Steel Containing Lanthanum and Cerium

稀土元素的合金化工艺、中间包水口结瘤问题仍是阻碍稀土元素在钢中应用的重要问题。针对含镧和铈稀土钢的连铸水口结瘤情况进行了统计和热力学分析。结果表明,非铝脱氧钢的水口结瘤物主要是稀土硫氧化物(RE_(2)O_(2)S)及氧化物(RE_(2)O_(3)),铝脱氧钢的水口结瘤物为稀土铝酸类化合物(REAlO_(3))、稀土硫氧化物(RE_(2)O_(2)S)及少量氧化物(RE_(2)O_(3))。对产生这些结瘤物的生成热力学进行分析,并对水口堵塞的过程进行了探析,提出控制RES_(x)夹杂物、RES_(x)包裹体、Al_(2)O_(3)生成是解决堵塞的可行途径。对RES_(x)夹杂物生成途径进行分析,提出了夹杂物调控方案,同时给出提高含镧和铈稀土钢可浇性的技术措施。

The alloying process of rare earth elements and nozzle clogging in tundish are still important problems hindering the application of rare earth elements in steel. Statistics and thermodynamic analysis are carried out on the clogging of continuous casting nozzles of rare earth steels containing lanthanum and cerium. The results show that the nozzle blockages of non-aluminum deoxidized steel are mainly rare earth oxysulfide(RE_(2)O_(2)S) and oxides(RE_(2)O_(3)), and the nozzle blockages of aluminum deoxidized steel are rare earth aluminates(REAlO_(3)) and rare earth oxysulfide(RE_(2)O_(2)S) and a small amount of oxides(RE_(2)O_(3)). The thermodynamics of the formation of these blockages were analyzed, and the process of the clogging of the nozzle was analyzed. It was proposed that controlling the formation of RES_(x) inclusions, RES_(x) inclusions and Al_(2)O_(3) was a fea-sible way to solve the clogging. The formation of RES_(x) inclusions was analyzed, and the control scheme of inclusions was proposed. At the same time, the technical measures to improve the castability of rare earth steel containing lanthanum and cerium were given.