抄録
Local area fatigue crack propagation resistance of a retired gas turbine vane made of a Ni-based superalloy which had been operating for about 20000 h. in a 1100 °C level land-based gas turbine, was experimentally evaluated. Here, special efforts were made to build up a new testing apparatus to assess the fatigue crack propagation resistance, using the miniature size specimens extracted from the vane. The miniature specimens were extracted from the leading and the trailing edges, respectively. It was shown that the fatigue crack grew associating with the rate significantly higher at the trailing than at the leading edge part. It was also indicated that the crack propagation rates in the miniature specimen were generally higher than those in the standard size specimen. Furthermore, it was also shown that an application of a simple reheat treatment was effective to recover the crack propagation resistance for the post service vane.
