CaF_(2)在不同酸碱性CaO-Al_(2)O_(3)基保护渣中的作用研究  

Study on the role of CaF_(2) in CaO-Al_(2)O_(3)-based mold fluxes with different acid-base property

作　　者：施怡 亓捷 刘承军[1,2] 姜茂发 Shi Yi;Qi Jie;Liu Chengjun;Jiang Maofa(Key Laboratory of Ecological Metallurgy of Multimetallic Mineral(Ministry Education),Shenyang 110819,Liaoning,China;School of Metallurgy,Northeastern University,Shenyang 110819,Liaoning,China)

机构地区：[1]多金属共生矿生态化冶金教育部重点实验室,辽宁沈阳110819 [2]东北大学冶金学院,辽宁沈阳110819

出　　处：《钢铁钒钛》2023年第6期139-148,共10页Iron Steel Vanadium Titanium

基　　金：国家自然科学基金(U1908224,51904064)资助;中央高校基本科研业务专项资金(N2125013)资助。

摘　　要：采用新型CaO-Al_(2)O_(3)基结晶器保护渣进行高铝钢浇铸,可有效抑制钢液中Al与渣中组元的界面反应。但是,浇铸过程中仍存在着结晶性能强、传热不均等问题。助熔剂是调整熔渣理化性能的关键因素之一。基于此,系统研究了典型助熔剂CaF_(2)对不同酸碱性CaO-Al_(2)O_(3)基保护渣微观结构、黏度及结晶物相的影响。结果表明,在近中性CaO-Al_(2)O_(3)基保护渣中加入CaF_(2)后,析晶物相由Ca_(12)Al_(14)O_(33)+Ca_(3)Al_(2)O_(6)转变为Ca_(12)Al_(14)O_(32)F_(2)+LiAlO_(2)+CaF_(2),LiAlO_(2)的析出可导致转折点温度上升,升幅约175℃,熔渣高温段黏度基本保持不变。在偏碱性CaO-Al_(2)O_(3)基保护渣中加入CaF_(2)后,析晶物相由Ca_(3)Al_(2)O_(6)+CaO转变为Ca_(12)Al_(14)O_(32)F_(2)+LiAlO_(2)+CaF_(2),单一CaO的过早析出得到有效抑制,转折点温度降低约70℃,高温段黏度明显减小。The new CaO-Al_(2)O_(3) based mold fluxes can effectively inhibit the interfacial reaction between Al and slag components in high-aluminum steel casting.However,there were still some problems in the casting process,such as strong crystallization performance and uneven heat transfer.Fluxing agent was one of the key factors to adjust the physical and chemical properties of slag.Based on this,the effects of typical flux CaF_(2) on the microstructure,viscosity and crystalline phase of CaO-Al_(2)O_(3) based mold fluxes with different acid-base property were studied.The results show that in the near-neutral CaO-Al_(2)O_(3)-based mold flux,the crystallization phase changes from Ca_(12)Al_(14)O_(33)+Ca_(3)Al_(2)O_(6) to Ca_(12)Al_(14)O_(32)F_(2)+LiAlO_(2)+CaF_(2) after adding CaF_(2).The precipitation of LiAlO_(2) can lead to the increase of the breaking temperature by about 175℃,and the viscosity of the high temperature section of the slag remains basically unchanged.In the alkaline CaO-Al_(2)O_(3)-based mold flux,the crystalline phase changed from Ca_(3)Al_(2)O_(6)+CaO to Ca_(12)Al_(14)O_(32)F_(2)+LiAlO_(2)+CaF_(2) after adding CaF_(2),and the premature precipitation of single CaO was effectively inhibited.The breaking temperature is reduced by about 70℃,and the viscosity at high temperature is significantly reduced.

关 键 词：连铸 高铝钢 CaO-Al_(2)O_(3)基保护渣 助熔剂 黏度 结晶物相 熔体结构 

分 类 号：TF777[冶金工程—钢铁冶金]