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

摘要： 含钛无氟保护渣在绿色环保和优化熔融性能方面展现出了极大的优势,但钛含量较高时易产生高熔点物质导致保护渣结晶性能恶化,添加硼砂可以改善此类保护渣的缺陷。以高钛高炉渣、石灰石、石英砂、纯碱、毒重石为原料制备高钛无氟型保护渣,研究了助熔剂硼砂加入量(质量分数分别为4%、6%、8%、10%和12%)对高钛无氟型保护渣的熔化温度、黏度、结晶温度、结晶临界冷却速度和结晶孕育时间等性能指标的影响规律。结果表明:随硼砂加入量的增加,高钛无氟型保护渣的熔化温度指标均呈非线性下降,黏度下降至较低水平后趋于稳定,结晶最大冷却速度和结晶初始温度都表现为先升高后降低的趋势;当硼砂加入量为8%(w)时,可协同提高高钛无氟型保护渣的熔融和结晶性能。

关键词: 高钛无氟保护渣, 熔融性能, 结晶性能, 硼砂加入量