Research on High Performance Fe3Si-Si3N4-SiC Composite Used for Blast Furnace

ABSTRACT

Excellent Fe3Si-Si3N4-SiC composites were successfully prepared with FeSi75 and SiC as main starting materials by nitridation reaction(at 1300°C for 8Hrs). The material properties were studied; the ferrosilicon nitridation mechanism was analyzed through chemical thermodynamics; phase composition, microstructure, corrosion resistance of products were also investigated. The results are shown that the comprehensive properties of Fe3Si-Si3N4-SiC are outstanding. The nitridation products are fiber-like α-Si3N4 and rod-like β-Si3N4, which makes better mechanical behavior due to fiber reinforcement; a great deal of Fe3Si intermetallic compounds uniformly distribute in matrix, which is one of the products of Fe-Si nitridation and as a plastic phase forming in grain boundary optimizes the performance of products. Chemical thermodynamic analysis is shown that the fiber-like α-Si3N4 is formed by SiO(g) and N2(g) reaction which also increases the rate of nitridation. Fe3Si-Si3N4-SiC material has high corrosion resistance. Now it has been successfully applied to one 2000M3 domestic steel plant, the blast furnace operation goes well.