高硅含钛奥氏体不锈钢“结晶器结鱼”分析及改进

Analysis and improve of the floater in mould of high silicon titanium stabilized austenitic stainless steel

通过对“结晶器结鱼”物和中间包夹杂物检测,系统分析了高硅含钛奥氏体不锈钢“结晶器结鱼”现象发生的根本原因。结果表明:“结晶器结鱼”物和中间包中夹杂物类型主要为纯的TiN和以镁铝尖晶石为核心的TiN。TiN夹杂物是导致“结晶器结鱼”产生的根本原因。结合热力学计算和试验结果,TiN夹杂物在1455℃的液相线温度下就会析出。通过控制钢水w(N)<0.01%,中间包钢水温度大于1500℃,可以避免“结晶器结鱼”的发生。

The floater in mould were analyzed by sampling the floater of mould and the molten steel in tundish during high silicon titanium stabilized austenitic stainless steel casting process.The results show that the inclusions in the floater of mould and tundish are both mainly pure TiN and TiN with MgO·Al_(2)O_(3)as core.TiN inclusions are the cause of floater in mould.By combining both the experimental results and thermodynamic calculation,TiN inclusions would be formed at liquidus temperature of 1455℃.As the mass fraction of nitrogen is less than 0.01%in molten steel and the temperature in tundish is higher than 1500℃,the floater cannot been found in mould.