ABSTRACT

Industrial experiments and thermodynamic calculations were carried out to investigate the evolution mechanism of Ca-containing inclusions in 20Mn23AlV steel with the Al content up to 2 wt-%. After Al deoxidation in AOD, the main inclusions were spherical shape Ca–Al–Si–Mn–O inclusions. Spherical Ca–Al_rich–Si–Mn–O and spherical Ca–Al–Mn–O became the main inclusions after the first Al alloying. After Ca treatment in LF, the typical inclusions were aggregate CaS–CaO inclusions. In tundish, the types of inclusions were CaS and CaS_rich–CaO, and the size and quantity of inclusions were substantially decreased. Thermodynamic analysis indicated that with the Al content increase to about 2 wt-%, the inclusions containing high Al₂O₃ content formed, which were extremely easy to be removed in the steelmaking process. Moreover, after the second Al alloying, the decrease of oxygen content promoted the formation of CaS inclusions, and CaS or CaS–CaO inclusions were formed Lastly, the evolution mechanism of inclusions was summarized in detail.

摘要

通过工业实验和热力学计算，研究了Al含量高达2 wt-%的20Mn23AlV钢中含Ca夹杂物的演化机理。AOD中Al脱氧后，主要夹杂物为球形Ca-Al-Si-Mn-O夹杂物。_{第一次Al合金化后，球形富}Ca-Al- Si-Mn-O和球形Ca-Al-Mn-O成为主要夹杂物。在 LF 中 Ca 处理后，典型的夹杂物是聚集体 CaS-CaO 夹杂物。中间包夹杂物类型为CaS和_富CaS -CaO，夹杂物的大小和数量均明显减少。热力学分析表明，随着 Al 含量增加到约 2 wt-%，夹杂物含有高 Al ₂ O ₃在炼钢过程中极易去除。此外，二次Al合金化后，氧含量的降低促进了CaS夹杂物的形成，形成了CaS或CaS-CaO夹杂物。最后详细总结了夹杂物的演化机理。