Hot tensile deformation and fracture behaviours of Hastelloy C-276 alloy

The uniaxial tensile tests of Hastelloy C-276 were performed under elevated temperature and strain rate. Considering the effects of different deformation parameters, the flow behaviour, microstructure and fracture characteristics were analysed based on the experimental data. From the rheological curves, the typical characteristics of dynamic recrystallisation were observed at a relatively high deformation temperature and low strain rate. Optical microstructures show that the degree of dynamic recrystallisation increases with an increase in temperature. The SEM micrographs show that the amount of precipitates increases with an increase in deformation temperature. Examination of the fracture morphology at high magnifications revealed that the coalescence of microscopic voids is responsible for the fracture failure.