Degradation of Creep Resistant Ni - alloy During Aging at Elevated Temperature Part I: Mechanical Properties

The results of experimental study of mechanical properties degradation of creep resistant Ni-base alloy are presented. The material studied was subjected to long-term influence of high pressure hydrogen atmosphere at temperature 750K and 850K. The mechanical properties of specimens taken at different distance from inner surface of thick wall tube were evaluated. The results of mechanical testing showed distinct influence of the temperature on mechanical properties of Ni creep resistant alloy. Moreover, the mechanical properties of studied alloy depend on the location of the specimen with respect to the dissociated ammonia source i.e. distance from the inner surface of the chamber. The results of mechanical testing show that the higher the distance from inner surface of the chamber the better mechanical properties of studied Ni base super-alloy.