铸铁热分析试样的宏观组织及影响因素

探讨了铸铁热分析试样内部偶点附近的宏观组织及影响因素,试验结果表明:一般的热分析试样中大都存在严重的宏观缩松,此缩松位置正好位于热电偶结点周围,这会降低热分析仪器对铁水含Si量的测试精度,石英管和加入的T3粉对这种宏观缩松没有影响,但增加样杯的锥度,可以把宏观缩松区上移至石英管以外的区域,使得偶点附近的凝固组织均匀致密。

Macrostructure of Thermal Analysis Samples of Cast Iron and Other Factors' Effect on It

The inner macrostructures adjacent to the thermocouple node in the samples of cast iron thermal analysis were studied. The experiments indicated that the serious macroporosity, which is around the thermocouple node, often exists in the thermal analysis samples so that the accuracy of Si content predicted by thermal analysis device is reduced. The quartz glass tube and Te content added have no effect on the inner macroporosity, but when the taper of the sample cup is increased, the macroporosity area can rise away from the vicinity of the quartz glass tube and the inner macrostructure near the thermocou-ple node will be sound and homogeneous.