中文摘要：

采用化学纯试剂配制保护渣,运用工艺矿物学方法分析测试了不同Na2O配加量的试验粘度和对应的渣膜矿相结构。结果表明：等温条件下,保护渣粘度随Na2O含量的增多呈现降低的趋势;Na2O含量相同时,保护渣温度升高,熔渣粘度逐渐减小。不同Na2O含量的保护渣所对应渣膜的矿物种类基本相同,主要为枪晶石、硅灰石和黄长石,且随Na2O增加,渣膜结晶率不断增大,黄长石含量增多,晶体逐渐发育;枪晶石和硅灰石的结晶受到抑制,含量不断减少,晶形逐渐变小。建议浇注中碳钢、包晶钢等裂纹敏感性钢种时,适当提高Na2O在保护渣中的比例,以协调渣膜的润滑和传热,减少铸坯质量缺陷的发生。

英文摘要：

The influences of Na2O content on viscosity and mineralogical structure of flux film were studied systematically using the heat flux simulation and viscosity tester, polarizing microscope and X-ray diffraction. The results show that, under the isothermal condition, the viscosity of mold flux decreases with the increase of Na2O content. With the specified amount of Na2O, the viscosity of mold flux decreases in response to the rise of temperature. The crystalline minerals of flux films with different Na2O are the same kind, mainly are cuspidine, wollastonite and melilite. The corresponding crystallization ratio of flux film increases with more Na2O added, and melilite content continuesly increases while cuspidine and wollastonite decrease significantly. Therefore, in order to control the heat transfer and lubrication, it is suggested that the proportion of Na2O in mold flux should be appropriately increased in producing crack sensitive steels.