金属材料热变形中的塑性流动失稳研究进展

Plastic flow instability is an important fundamental problem in controlling microstructure homogeneity and improving the comprehensive mechanical properties of components during hot deformation of metal materials. The research progresses made so far on the experiments and modelling of flow instability during hot deformation of metal materials were summarized and analyzed. It is indicated that the main types of plastic flow instability are flow localization, macro shear band and micro cracks. And the formation mechanisms of different types of instability were analyzed respectively; the influence rules of deformation temperature, strain rate, deformation reduction and initial microstructure on different types of flow instability were summarized; the existing prediction criterion and models of flow instability were reviewed and compared from the aspects of theory and application. Besides, for the hot deformation of metal materials, how to achieve the flow instability prediction considering the effect of heterogeneity of the microstructure before deformation under complex loading paths becomes an impartant trend of further development.