运用扫描俄歇微区探针检测贝氏体预转变过程奥氏体晶界附近碳原子的分布，发现碳原子在晶界富集，近晶界区贫碳。建立了考虑晶界的贝氏体预转变热力学模型。计算结果表明，晶界附近贫碳区的形成满足热力学条件。 Scanning Auger microdialysis probe was used to detect the distribution of carbon atoms in the austenite grain boundary during the pre-transformation of bainite. It was found that carbon atoms were enriched in the grain boundary and lean in the grain boundary region. A thermodynamic model of bainite pre-transformation considering the grain boundary was established. The calculated results show that the formation of lean carbon near the grain boundary satisfies the thermodynamic conditions.