Abstract: In order to improve the oxidation resistance test method for SiC refractories and to save testing time,the oxidation of two kinds of SiC refractories (Si₃N₄-SiC and Si₂N₂O/Si₃N₄-SiC) treated by 1 000 ℃ water vapor with different pressures (0.10,0.11,0.13,0.15,0.17,and 0.19 MPa,respectively) for different periods (20 and 40 h,respectively) was studied.The mass and the apparent porosity of the specimens before and after oxidation were measured,and the mathematical relationship between the mass change rate and the water vapor pressure was analyzed by the mathematical statistics method.The result indicates that the increase of the water vapor pressure accelerates the oxidation progress of Si₃N₄-SiC and Si₂N₂O/Si₃N₄-SiC refractories at 1 000 ℃;the square of the mass change rate has a highly significant linear relationship with the water vapor pressure after being oxidized for 20 or 40 h,which shows that the oxidation basically follows the classical parabolic kinetic equations.

Key words: silicon carbide, oxidation, water vapor, pressure

摘要： 为改进SiC质耐火材料的抗氧化性测试方法,节省测试时间,研究了Si₃N₄-SiC、Si₂N₂O/Si₃N₄-SiC两种SiC质耐火材料在1 000 ℃不同水蒸气压力(分别为0.10、0.11、0.13、0.15、0.17、0.19 MPa)下氧化不同时间(分别为20和40 h)后的氧化量,检测了氧化前后试样的质量和显气孔率,通过数理统计方法分析了质量变化率与水蒸气压力的数学关系。结果表明:Si₃N₄-SiC和Si₂N₂O/Si₃N₄-SiC质耐火材料在1 000 ℃水蒸气中的氧化速度随水蒸气压力的提高而增大;在氧化20和40 h后,其质量变化率的二次方与水蒸气压力具有高度显著的线性关系,表明它们的氧化基本遵循经典的抛物线动力学方程。

关键词: SiC, 氧化, 水蒸气, 压力