LZ50钢液中微量稀土脱氧及夹杂物生成机理研究

Study on Deoxidization Thermodynamics of Trace Rare Earth Element and Formation Mechanism of Inclusions in LZ50 Molten Steel

用真空感应炉在MgO坩埚中熔化2.5 kg的LZ50车轴钢,添加稀土(RE)元素后进行二次精炼,制备了微RE合金化后的试样。结合钢化学成分分析、SEM和EDS检测结果,计算并讨论了微量RE元素对LZ50钢中O、S等元素的影响。结果表明,微量RE(质量分数0.0026%)能降低低氧、低硫在LZ50钢中的O含量,对S含量却无明显影响;RE的脱氧产物为CeAlO3,且能把钢中带棱角的Al2O3-SiO2夹杂物变为圆球状SiO2-Al2O3-RE2O3复合夹杂物。

The steels with trace rare earth（RE） element were prepared by the secondary refining after adding rare earth to 2.5 kg of LZ50 axle steel melted in magnesia crucible of vacuum induction furnace.The effects of rare earth elements on the oxygen and sulfur element of LZ50 axle steel were computed and discussed from the chemical compositions of steel,SEM and EDS.The results show that trace RE（0.0026%ωt）,the content of oxygen was decreased,but the content of sulfur had no significant change;the deoxidization products were CeAlO3,and angular Al2O3-SiO2 inclusions were spheroidized and refined to SiO2-Al2O3-RE2O3 complex inclusions.