Abstract: The flux agents in common mould powder normally are fluoride and sodium oxide, both all produce environmental pollution. Therefore the physical properties such as melting point, viscosity, crystallizing properties and surface ten- sional force of mould powder containing flux agent B₂Os were studied. The test results showed that for the mould powder with CaO/SiO₂= 0.88 and ingredient being 37.91%CaO-43.09%SiO₂-5%A₂O₃-5%MgO-2%Li₂O-7%B₂O₃,the melting point was 909℃, the flexible melting temperature was 1160 ℃, viscosity value at 1300 ℃ was 0.4 Pa's and surface tensional force was 0.32 N/m which could meet the service requirements of concasting mould powder for normal steel grades and some special steel grades.

Key words: Concasting,Mould Powder Containing B?O?, Free Fluoride, Physical Properties

摘要： 常规保护渣中配入的助熔剂一般是氟化物和Na₂O,但二者都对环境产生严重污染。为此试验 研究了含助熔剂 B2O3 保护渣及其熔点、粘度、结晶性能和表面张力等物理性能。试验表明，当保护渣碱度 (CaO/SiO₂)等于0.88,成分(%)为37.91CaO-43.09SiO2-5Al₂O₃-5MgO-2Li₂O-7B₂O₃ 时的熔点909℃,熔化性温度 1160℃,1300℃粘度值0.40 Pa ·s,1300 ℃表面张力值0.32N/m,能满足常规钢种和部分特殊钢种对连铸保 护渣的使用要求。

关键词: 连铸, 含硼保护渣, 无氟, 物理性能