铁基合金中马氏体形核动力学探讨

The Kinetics of Martensitic Nucleation in Iron Based Alloys

根据马氏体相变的经典形核理论 ,重新估算了铁基合金中马氏体均匀形核激活能 ,研究了激活能与界面能和相变驱动力的关系。结果表明 ,热激活形核具有很低的形核激活能 ;热激活能形核动力学与马氏体形核动力学实验研究结果一致。在动力学研究的基础上 ,提出了马氏体相变的形核机制。在该形核机制中 ,除了热激活形核 ,还考虑了应力对马氏体形核的作用 ,特别是在低温时由于急冷导致的内应力对形核的贡献。

WT5BZ]On the basis of the classical martensitic nucleation theory, the activation energy of homogeneous nucleation in iron based alloys were reconsidered A extensive study was made to determine the dependence of activation energy on the interfacial energy and the driving force of martensitic transformation It is indicated that thermal activated nucleation possesses very small activation energy, which is compatible with relevant experimental investigations On this context, a nucleation mechanism was developed, attempting to explain the origin of martensitic nucleation in iron based alloys In this mechanism, in addition to thermal activation, the contribution of mechanical driving force to the nucleation was taken into account, particular in the case of martensitic transformation at low temperature