Precipitation Kinetics and Morphology of Grain Boundary Carbides in Ni-Base Superalloy Haynes 282

Precipitation of grain boundary carbides in a mill-annealed Haynes 282 in the temperature range 650 °C to 1120 °C was investigated. The kinetics of M 23 C 6 was significantly faster than that of M 6 C. With increasing aging temperature, the morphology changes from continuous film to an interconnected brick wall structure and finally to discrete particles. No morphological changes were observed with aging time. Serrated grain boundaries formed during aging around 750 °C. The solvus temperature for both M 23 C 6 and M 6 C was approximately 1100 °C.