Creep crack initiation life characteristics of solidification-controlled nickel-based superalloy notched specimens analyzed by misorientation analysis

Gas turbines require proper operation and maintenance, and predicting the creep crack initiation life of turbine blades made of a solidification-controlled Ni-based superalloy is crucial. A unified life assessment method was developed to assess creep crack initiation life at various stress-concentrated regions, using a misorientation parameter which is equivalent to the relative notch opening displacement. This parameter can predict creep crack initiation life using crystal orientation distribution measured by the EBSD method. In this study, the influence of the specimen plate thickness was investigated, and it was confirmed that there is no issues with practical applicability.