Enhanced corrosion resistance to molten iron of carbon bricks through nano-scale micropores and alumina addition

Abstract

The composition and micropores characteristics of carbon bricks have significant influence on their corrosion resistance to molten iron. In this study, the corrosion of an ultra-microporous carbon brick (MG carbon brick) in molten iron was studied by the rotating cylinder method. The results indicated that the corrosion resistance to molten iron of the MG carbon brick was better than that of the NMA carbon brick, especially under the conditions of low carbon, high sulfur and low titanium molten iron. The nano-scale micropores and the addition of Al2O3 were the main factors which made the MG carbon brick more resistant to corrosion by molten iron than the NMA carbon brick. In terms of chemical composition, the MG carbon brick contained 8.74 wt.% Al2O3 and 6.91 wt.% SiC, while their content in the NMA carbon brick was very little. The corrosion resistance to molten iron of carbon bricks can be enhanced by adding Al2O3. But it cannot be ignored that the thermal stability of the carbon brick would deteriorate due to the addition of Al2O3. Moreover, because of the better properties of the MG carbon brick in terms of average pore size and ≤1 μm pore volume, the MG carbon brick had better permeation resistance to molten iron than the NMA carbon brick.