精炼渣-钢包挂渣-耐火材料多重作用下帘线钢夹杂物演变机理研究

我国帘线钢质量不能满足精细切割钢丝（直径≤80μm，强度≥3800MPa）的严苛要求，高端帘线钢仍不能自给，其核心问题是大尺寸、硬脆夹杂物尚不能稳定控制，对实际生产中夹杂物的过程行为缺乏深入研究。为此，本项目结合工业实际，研究精炼渣、钢包挂渣和耐火材料等多因素共同作用下帘线钢内生和外来夹杂物的形成和影响机制。通过考察脱氧及精炼过程的夹杂物生成与演变规律，阐明转炉钢液硬脆夹杂物的遗传性影响；通过系统研究精炼渣、钢包挂渣、耐火材料与帘线钢液的相互作用，揭示钢包挂渣对帘线钢夹杂物的影响规律，明确不同挂渣行为对耐火材料侵损的作用机制，并探明“挂渣+耐火材料”剥落颗粒在钢液中的演变规律。全面揭示钢中CaO-SiO2-Al2O3系夹杂物的生成机理，阐明外来大尺寸、硬脆夹杂物的形成和管控机制，从而合理匹配精炼渣系和耐火材料纯度，制定耐火材料使用制度。研究成果可为高端帘线钢工业生产提供理论指导。

The steel quality of domestic steel plants can not meet the strict requirement of ultra-fine saw wire (diameter≤80μm, strength≥3800MPa), and the high-end steel grades are imported from abroad. Big and hard inclusions are the crucial problem of saw wire steel grades in domestic steel plants, and there is still lack of research on the process behaviors of the inclusions during steelmaking practice of these steel grades. Based on industrial practice, the present study aims at the effect mechanism of the combination of refining slag, ladle glaze and refractory on the inclusions (endogenous and extraneous) in tire cord steel and saw wire steel. The formation and evolution of inclusions during deoxidation and refining processes will be investigated, and the hereditary influence of the inclusions in BOF crude steel on the formation of hard inclusions will be revealed. The interaction among refining slag, ladle glaze, refractory and liquid steel will be studied systematically. The effect of ladle glaze on the inclusions in steel will be clarified, and the corrosion behavior of refractory in different glaze cases will be understood. Also, the evolution of the spalled particles of “glaze + refractory” in liquid steel will be elucidated. On this basis, the formation mechanism of CaO-SiO2-Al2O3 system inclusions can be comprehensively described, and some directions will be pointed out to control big and hard extraneous inclusions. The matching between slag composition and refractory purity, and the rules for refractory use can be further obtained as well. The study results can give a theoretic guidance for the production of high-end tire cord steel and saw wire steel in industry.