Effect of Stabilization Heat Treatment Time on the Microstructures and Tensile Properties of Inconel 706 Alloy

This study investigates in detail the effects of different stabilization heat treatment times on the microstructures of Inconel 706 (IN706) alloy. In addition, we have thoroughly investigated the relationship between the microstructures and tensile properties of this alloy at room temperature. The results show that the yield and tensile strengths remain essentially unchanged and the plasticity decreases slightly with the gradual increase in the stabilization time. The stabilization treatment induces the precipitation of granular, rod-shaped and plate-like η phases at grain boundaries, accompanied by the emergence of a precipitate-free zone. With the prolongation of stabilization time, there is a concurrent enlargement in the size of the γ′–γ″ co-precipitates attributed to the precipitation of the η phase. The decrease in elongation of the stabilization heat treatment samples is due to the presence of η phase at the grain boundaries, leading to stress concentration and resulting in cracks at the grain boundaries.