A new approach to strengthen grain boundaries for creep improvement of a Ni-Cr-Co-Mo superalloy at 950 °C

Damage-tolerant microstructure containing serrated grain boundaries (GBs) has been developed in a solid-solution-strengthened Ni-Cr-Co-Mo superalloy by proprietary thermomechanical treatment. The creep life was found to be 2.8 times longer by mitigation of GB cavitational damage. The factors affecting creep properties at 950 °C are discussed in terms of GB strengthening.