The effect of sintering behaviour and phase transformations on strength and thermal conductivity of disposable tundish linings with varying compositions

The durability of insulating tundish linings depends on the sintering characteristics of the mix formulation and its ability to restrict corrosion. The present work studied the effect of mix variations on the performance of tundish working lining material. This was evaluated in terms of bond formation, strength and thermal conductivity of the lining material. In the present study, a siliceous olivine-periclase and a low silica magnesia based compositions were investigated. The samples evaluated were heat treated at 250–1450 °C for 2 h. Microstructure of the heat treated samples was analysed by QEM SCAN and SEM. A solid-state sintering by formation of high refractory phases like forsterite and magnesio-wustatite at the interface of the grains is believed to have enhanced the high temperature strength of olivine based recipe. In contrast, liquid phase sintering was predominant in periclase based formulation, imparting a lower strength at high temperature. The sintering behaviour of the mixes was also found to have a profound effect on thermal conductivity of the two materials.