Flow behavior study on fine-grain FGH96 P/M superalloy during hot deformation

The hot deformation behavior of FGH96 superalloy has been characterized in the temperature range of 1050-1100^DDGC and the strain rate range 0.001-0.1 /s by hot compressive simulation experiments on the fine-grain material. From the macroscopic and microscopic views, the correlation between flow stress of FGH96 and influencing factors (such as process parameters-deformation temperature, deformation rate and deformation degree, Zener-Hollomon parameter and grain size) was analyzed systematically. Flow curves show that the material exhibits dynamic recovery and dynamic recrystallization during deformation. The influences of deformation temperature, deformation rate and deformation degree on the flow stress and grain size are different. The deformation degree mainly influences the shape of flow curves. On the basis of systematic analysis and study, a phenomenological constitutive relationship model is established through a mathematical regression by taking the strain as a modification factor. The calculated and experimental values are in good agreement. Therefore, the essential prerequisite is created for the improvement of numerical simulation accuracy and for the rational choice of process parameters for FGH96 superalloy.