Constitutive equations to correlate uniaxial creep behaviour vs stress and temperature for inconel 718

The paper presents uniaxial creep tests conducted on Inconel 718 superalloy, reporting and describing the results obtained. The creep strain curves have been examined in different scenarios: by varying the initial applied stress, by varying the initial test temperature, and by considering the orientation of the specimens with respect to the direction of the material processing. Finally, ductility and deformation accumulation rate have been evaluated to highlight the effect of the precipitation anisotropy on the creep behaviour. Given the complexity of the creep phenomenon, each phase of the creep strain curves of Inconel 718 has been analysed independently, using constitutive models taken from the literature that allow to describe the phenomenon in pure metals and in some alloys.