ABSTRACT The aluminum oxide is a common component in mold powder,and is a kind of amphoteric oxide, which shows the characteristics of acid oxide under high alkalinity condition and shows the characteristics of alkaline oxide under low alkalinity condition.In general,adding the Al,O,to the traditional CaO-SiO,-based mold flux will increase the viscosity and melting point of the mold flux.which will reduce the mold flux's ability to adsorb inclusions.In addition.as the content of AlO;in the slag increases,the solidification temperature of the slag can be reduced,thereby improving the lubricating ability of the mold flux.At present,the research on the crystallization performance of AlO on mold flux mainly focuses on low-reactivity or non-reactive mold fluxes for high-aluminum steel and high-titanium steel.Relevant studies have shown that Al2O:in low-reactivity or non- reactive mold flux can increase the crystallization incubation time of the mold flux reduce the critical cooling rate of the flux,and inhibit the crystallization process of the flux.In the range of low alkalinity or higher alkalinity (R=1.2~1.5)mold powder or new Cao-Al2O:based low-reactivity mold powder,the addition of AlO;will increase the viscosity of the slag increase the melting point and decrease the solidifmperature (or Increase)and decrease in crystallization performance.In recent vears.ultra-high alkalinity mold powder (R=165-185)has been successfully applied in peritectic steel continuous casting mold powder.effectively coordinating the contradiction between mold powder heat transfer and lubrication function.Howeyer.there is no relevant report on the influence of Al on the performance of mold flux under ultra-high alkalinity conditions.In this paper,ultra-high alkalinity mold flux (comprehensive alkalinity R=1 75 is taken as the research object,and the influence of AlO on the flow characteristics.melting characteristics and solidification characteristics of mold flux is analyzed.The research results show that as Al2O:increases,the viscosity and melting temperature increase. and the transition temperature decreases.As the content of AlO in the slag increases.the viscosity and melting temperature increase.and the transition temperature deefeases Among them.with an average increase of 1% AlO:the melting temperature of the mold flux will increase by about 5C.and the turning temperature will decrease by about 12C.In addition,as the AlOcontent in the slag increases by 1%the starting crystallization temperature drops by about 1C on average The average crystallization rate decreases with the increase of AlO in the slag.and AlO has a significant effect on the crystallization rate.And with the increase of the content of Al,O:in the slag,the proportion of crystals in the crystalline phase of the mold slag gradually decreases,but the type of crystals remains unchanged a eommon eomponent in meld powder,is a kind of amphoterie oxide, which shows the charaeteristies of peid exide under high alkalinity condition and shows the characteristies of alkaline oxide under low alkalinity condition.In this paper,the influence of Al,on the fowing eharaeteristies, fiention eharaeteristies of ultra-high basieity mold fluxes was analyzed.The results showed that with the mereese of AlO,,the viseosity and melting temperature inereased,and the transition temperature deeredsed In addition,the study also found that the initial erystallization temperature deereased by 34 C on average when the ALO,content inereased by 1 wt%.The average erystallization rate deereased with the addition e he mold fluxes,and AlO,had a signifieant effeet on the erystallization rate.The results showed that t proportion of erystals in the fraeture deereased with the inerease of Al2O.,but the erystal phase remained the KEY WORDS Al2O3 mold fluxes ultra-high basicity crystallization property 两性氧化物AO3是治金熔渣中常见的一种组元，对熔渣物化性能具有重要影响。在传 统CaO-SO2基连铸保护渣中，Al2O3含量相对较低，主要来源于生产原料，一般不作为性 能调节的组分。但是，在铝镇静钢连铸过程中，如果钢水洁净度较差，致使大量似乎不去 会适O;上浮到保护渣中，将引起保护渣性能的变化，并进一步妨碍保护渣传热和润滑 功能的正常发挥。在低碱度或较高碱度R=1.2~1.5)保护渣或新型CO-AlO,基低反应性保护 渣范围内，加入AO会使渣的黏度增加、熔点升高、凝固温度降低（或增加）和结晶性能ABSTRACT The aluminum oxide is a common component in mold powder, and is a kind of amphoteric oxide, which shows the characteristics of acid oxide under high alkalinity condition and shows the characteristics of alkaline oxide under low alkalinity condition. In general, adding the Al2O3 to the traditional CaO-SiO2-based mold flux will increase the viscosity and melting point of the mold flux, which will reduce the mold flux’s ability to adsorb inclusions. In addition, as the content of Al2O3 in the slag increases, the solidification temperature of the slag can be reduced, thereby improving the lubricating ability of the mold flux. At present, the research on the crystallization performance of Al2O3 on mold flux mainly focuses on low-reactivity or non-reactive mold fluxes for high-aluminum steel and high-titanium steel. Relevant studies have shown that Al2O3 in low-reactivity or non￾reactive mold flux can increase the crystallization incubation time of the mold flux, reduce the critical cooling rate of the flux, and inhibit the crystallization process of the flux. In the range of low alkalinity or higher alkalinity (R=1.2~1.5) mold powder or new CaO-Al2O3 based low-reactivity mold powder, the addition of Al2O3 will increase the viscosity of the slag, increase the melting point, and decrease the solidification temperature (or Increase) and decrease in crystallization performance. In recent years, ultra-high alkalinity mold powder (R=1.65~1.85) has been successfully applied in peritectic steel continuous casting mold powder, effectively coordinating the contradiction between mold powder heat transfer and lubrication function. However, there is no relevant report on the influence of Al2O3 on the performance of mold flux under ultra-high alkalinity conditions. In this paper, ultra-high alkalinity mold flux (comprehensive alkalinity R=1.75) is taken as the research object, and the influence of Al2O3 on the flow characteristics, melting characteristics and solidification characteristics of mold flux is analyzed. The research results show that as Al2O3 increases, the viscosity and melting temperature increase, and the transition temperature decreases. As the content of Al2O3 in the slag increases, the viscosity and melting temperature increase, and the transition temperature decreases. Among them, with an average increase of 1% Al2O3, the melting temperature of the mold flux will increase by about 5 , and the turning temperature will ℃ decrease by about 12 . In addition, as the ℃ Al2O3 content in the slag increases by 1%, the starting crystallization temperature drops by about 11°C on average. The average crystallization rate decreases with the increase of Al2O3 in the slag, and Al2O3 has a significant effect on the crystallization rate. And with the increase of the content of Al2O3 in the slag, the proportion of crystals in the crystalline phase of the mold slag gradually decreases, but the type of crystals remains unchanged.Al2O3, a common component in mold powder, is a kind of amphoteric oxide, which shows the characteristics of acid oxide under high alkalinity condition and shows the characteristics of alkaline oxide under low alkalinity condition. In this paper, the influence of Al2O3 on the flowing characteristics, melting characteristics and solidification characteristics of ultra-high basicity mold fluxes was analyzed. The results showed that with the increase of Al2O3, the viscosity and melting temperature increased, and the transition temperature decreased. In addition, the study also found that the initial crystallization temperature decreased by 34 ℃ on average when the Al2O3 content increased by 1 wt%. The average crystallization rate decreased with the addition of Al2O3 in the mold fluxes, and Al2O3 had a significant effect on the crystallization rate. The results showed that the proportion of crystals in the fracture decreased with the increase of Al 2O3, but the crystal phase remained the cuspidine. KEY WORDS Al2O3；mold fluxes；ultra-high basicity；crystallization property 两性氧化物 Al2O3是冶金熔渣中常见的一种组元，对熔渣物化性能具有重要影响。在传 统 CaO-SiO2基连铸保护渣中，Al2O3含量相对较低，主要来源于生产原料，一般不作为性 能调节的组分。但是，在铝镇静钢连铸过程中，如果钢水洁净度较差，致使 大量(似乎不太 合适)Al2O3上浮到保护渣中，将引起保护渣性能的变化，并进一步妨碍保护渣传热和润滑 功能的正常发挥。在低碱度或较高碱度(R=1.2~1.5)保护渣或新型 CaO-Al2O3基低反应性保护 渣范围内，加入 Al2O3会使渣的黏度增加、熔点升高、凝固温度降低（或增加）和结晶性能 录用稿件，非最终出版稿