Structure and properties of a corundum-carbon refractory material sintered at 1600°C

Abstract

The factors responsible for the failure of blow plugs for steel ladles used in extra furnace steelmaking technology are considered. Results of a structural study of refractories based on electrofused corundum, crystalline silicon, and artificial graphite are reported. To improve the properties of corundum-carbon refractories, the sintering temperature should be increased to 1600°C.Blow plugs for steel ladles used in extra furnace steelmaking technology are fabricated from high-quality refractory materials. Under service conditions, the plugs are exposed to a number of factors that are capable of accelerating the wear of the plugs and finally lead to their failure. These factors are: inlet slit channels through which an inert gas is injected. The ingress of molten metal may cause irreparable damage to the blow facility;high temperature gradients and, consequently, high thermal stresses in the refractory material because of the cooling due to the injected gas; enhanced risk of erosion failure of the gas channel walls exposed to the gas jet and molten metal at the channel outlet in the steel ladle.In practice, blow facilities are subjected to a faster wear than nozzle blocks or ladle bottom lining and therefore require frequent replacement. Enhancing the service life of blow facilities is a challenging task; for its satisfactory solution, one will need innovative steps to be taken in both engineering design and advanced refractory materials. A step in this direction may be an adequate assessment of the physical, chemical, and mechanical properties of refractory materials potentially suitable for fabrication of blow facilities.