利用扫描电镜及能谱分析研究了不同加热温度和保温时间对M2高速钢中M2C共晶碳化物分解行为的影响。结果表明,M2C共晶碳化物的分解程度随加热温度的升高和保温时间的延长而增加,但温度起主要作用。讨论了M2C共晶碳化物的分解过程,得出其分解特点:M2C共晶碳化物的分解受原子的扩散行为控制;通过原子扩散,在原始M2C共晶碳化物的外层形成M6C碳化物,内层形成MC碳化物。 The effect of different heating temperature and holding time on the decomposition behavior of M2C eutectic carbide in M2 high speed steel was studied by SEM and EDS. The results show that the decomposition degree of M2C eutectic carbide increases with the increase of heating temperature and holding time, but the temperature plays a major role. The decomposition process of M2C eutectic carbides was discussed and the decomposition characteristics of M2C eutectic carbides were obtained. The decomposition of M2C eutectic carbides was controlled by the diffusion behavior of atoms. By atom diffusion, M6C carbides were formed on the outer layer of original M2C eutectic carbides, The inner layer forms MC carbides.