首先利用层错能的热力学模型计算了Mn 含量分别为5%、7%的中锰Q&P 钢中残余奥氏体的层错能，并分析了热处理过程中碳配分对层错能的影响; 然后通过XRD、SEM 及TEM 分析等研究了中锰Q&P 钢拉伸变形过程中的变形机制; 最后将层错能与实测变形机制相结合分析了两者的关系． 结果表明: 中锰Q&P 钢残余奥氏体的层错能计算必须考虑碳的配分; 7Mn － 1． 5Si － 0． 2C 试样的层错能为4． 55 mJ /m²，5Mn － 1． 5Si － 0． 2C试样的层错能为17． 8 mJ /m² ; 钢中残余奥氏体含量的对数与变形量成线性关系; 中锰Q&P 钢的残余奥氏体在变形过程中主要发生的是TRIP 效应，这与通过层错能判别的结果相吻合．

In this paper,first,the stacking fault energy of the retained austenite in medium manganese Q&P steels respectively with a Mn content of 5% and 7% were calculated by using the thermodynamic model of stacking fault energy,and the effect of carbon partition during the heat treatment on the stacking fault energy was analyzed.Then,the deformation mechanism of the steel under tensile strain was investigated by means of XRD,SEM and TEM,and the relationship between the stacking fault energy and the deformation mechanism was explored.The results show that ( 1) carbon partition should be considered during the calculation of the stacking fault energy of medium manganese Q&P steels; ( 2) the stacking fault energy of 7Mn-1. 5Si-0. 2C sample is 4. 55mJ /m²,and that of 5Mn-1. 5Si-0. 2C sample is 17. 8 mJ /m² ; ( 3) there is a linear relationship between the natural logarithm of retained austenite content and the deformation; and ( 4) TRIP effect is the main deformation mechanism of medium manganese Q&P steels,which is also verified by the calculated results of the stacking fault energy.