Abstract
Fatigue crack propagation property of the post-service gas turbine vane made of a Ni-based superalloy, 1N939, was experimentally evaluated at room temperature and 850℃. Special efforts were made to build up a new testing apparatus to assess the fatigue crack propagation resistance, using the miniature compact tension (CT) specimen extracted from a leading edge and a trailing edge of the post-service vane and the as-cast IN939. It was experimentally found that fatigue crack propagation rates (FCGR) were higher in a larger thickness CT specimen (thickness 2.0mm) compared with those in the miniature CT specimens (thickness 0.5mm). It was also shown that FCGR in the post-service trailing edge were higher than in the leading edge and the as-cast specimen.
