Abstract. An accelerated creep test was implemented to study the effects of heat treatment on the creep properties of INCONEL 617. Three heat treatment conditions were set on the test specimens, including 1) as-received, 2) aged as the simulation of service conditions at 650°C for 1,000 h and 3) solutionised. The accelerated creep test was performed at 700, 750, 800 and 900°C with applied stress at 80% and 90% of the yield stress (YS) at tested temperatures. The results were analysed for both time to rupture and % RA, which showed that there was a significant drop in time to rupture and % RA at 750°C. Subsequently, the % RA increased while the time to rupture gradually decreased. The Larson Miller curve for all heat treatment conditions could be plotted with an interest in the presence of an intersection zone. This indicated the possibility of failure behaviour changes from a creep mode to an overload mode at low applied loads to high applied loads, respectively.