关键词: 高钛无氟保护渣, 熔融性能, 结晶性能, 硼砂加入量

Abstract: Titanium-containing fluorine-free mold fluxes show great advantages in environmental protection and melting performance optimization.However,excessively high titanium content tends to generate high-melting-point substances,which deteriorates the crystallization properties of mold fluxes,and adding borax can remedy the defects of such mold fluxes.High-titanium fluorine-free mold fluxes were prepared using high-titanium blast furnace slag,limestone,quartz sand,soda ash and witherite as raw materials.The influence of flux borax additions (4%,6%,8%,10%,and 12%,by mass) on the performance of the high-titanium fluorine-free mold fluxes was studied,such as the melting temperature,viscosity,crystallization temperature,critical crystallization cooling rate and crystallization incubation time.The results show that with the increase of the borax addition,all the melting temperature indexes of the high-titanium fluorine-free mold fluxes decrease nonlinearly;the viscosity decreases to a low level and then tends to be stable;both the maximum crystallization cooling rate and initial crystallization temperature first increase and then decrease.When the borax addition is 8%,the melting and crystallization properties of the high-titanium fluorine-free mold fluxes are synergistically improved.

Key words: high-titanium fluorine-free mold fluxes, melting properties, crystallization properties, borax addition