High Temperature Tensile Deformation Behavior of Inconel 690 Alloy

The high temperature tensile deformation behavior of Inconel 690 Ni-based alloy were studied by using Gleeble-3800 thermo-simulation machine in the temperature range of 1 000-1 250 ℃ and strain rates of 0.1-10 s-1. The variation of flow stress and fracture characteristics with deformation temperature and strain rate was obtained. The results show that the flow stress of the alloy decreased with increase of deformation temperature during high temperature tensile deformation, and increased with increase of the strain rate. The optimal plastic deformation region was 1 100-1 250 ℃. The flow stress of the alloy during tensile deformation could be described by constitutive equation in the form of hyperbolic sine, and its deformation activation energy was 654.7 kJ·mol-1 . With increase of deformation temperature and strain rate, the fracture mechanism changed from micro-void accumulation fracture to inter-granular fracture.