关键词: 碳化硅, 耐火材料, 水蒸气, 抗氧化性

Abstract: The oxidation tests of different SiC refractories including Si₃N₄-SiC bricks,Si₃N₄-Si₂N₂O-SiC bricks from domestic and abroad,SiAlON-SiC bricks,oxides bonded SiC bricks,self-bonded SiC bricks as well as SiC castables were carried out in the steam atmosphere (1 000 ℃,32 kg·m^-3·h^-1) for 100,200,300,400 and 500 h,respectively.The mass,the volume,the bulk density and the apparent porosity before and after oxidation were tested.The XRD and SEM analyses were conducted.The results indicate that:(1)under the steam atmosphere condition (1 000 ℃,32 kg·m^-3·h^-1),along the oxidation time from 0 to 500 h,the volume and the mass of the silicon carbide refractories increase,while the bulk density decreases;in terms of the apparent porosity,oxides bonded SiC bricks and SiC castables present an increasing trend,Si₃N₄-SiC bricks,SiAlON-SiC bricks and self-bonded SiC bricks present an increasing trend first,and then a decreasing trend,and Si₃N₄-Si₂N₂O-SiC bricks present a decreasing trend or a trend of decreasing first and then increasing.(2)As for Si₃N₄-Si₂N₂O-SiC bricks,SNO-1 from domestic and SNO-2 from abroad with basically the same chemical and phase composition,the mass change rate of SNO-2 is less than that of SNO-1 during the 200-500 h oxidation,which indicates that the steam oxidation resistance of SNO-2 is better than that of SNO-1.

Key words: silicon carbide, refractory, steam, oxidation resistance