Self-healing behavior of Inconel 617B superalloy

In the present study, the self-healing behavior of Inconel 617B superalloy (617B), used as a high-temperature material, was investigated through both preliminary test consisting of room-temperature tension and annealing and creep rupture test. Micro-cracks in the solution-treated specimen, which had been fractured at room temperature, were filled in by the precipitation of M23C6 and the segregation of B, C, and S after annealing at 800 °C for 16 h. Due to this healing effect and dislocation recovery, a 33% pre-strained and annealed specimen exhibited the longer total elongation, compared to the specimen strained until fracture without annealing after 33% pre-strain. Finally, creep rupture tests revealed that the creep strength of 617B is higher than Inconel 617 superalloy (617) due to the self-healing effect by the high-temperature precipitation of M23C6 and the segregation of B, C, and S as well as grain boundary strengthening of B and C. [Display omitted] •Self-healing was confirmed by high-temperature annealing in specimen with cracks.•Cracks were filled up by both precipitation of M23C6 and segregation of B, C, & S.•617B superalloy had higher creep strength than 617 superalloy due to self-healing.