The wear of refractories of a fused periclase-chromite material in equipment for the batchwise vacuum refining of steel

Conclusions

An investigation revealed an interrelation between the pattern of destruction of the refractory in the lining of BVRS equipment and its conditions of service. The severe spalling of the brick is caused by the formation and growth of open cracks in the intermediate zone of the refractory as a result of the abrupt changes in the mechanical loads and gaseous medium (from slightly oxidizing to reducing) and the additional stresses produced by the crystallization of the silicate melts in the cracks and pores of the refractory during the process of cooling and the consequent considerable shrinkage.

The displacement of the primary high-refractoriness minerals by the low-melting components of the steel and slag melts promote the formation of relatively low-melting phases in the reacted crust (i. e., on the boundary between the refractory and the melt). The rate of the chemical erosion of the refractory depends on the total amount of these phases. This factor did not play a significant part in the overall pattern of the wear of the lining (in the first campaign).