INTERACTION BETWEEN OXIDATION AND THERMO-MECHANICAL FATIGUE IN IN738LC SUPERALLOY -I (original) (raw)

Turbine blades are subjected to severe cyclic thermal-me&an&l loading in a highly oxidizing environment. The en-damage is minim&d by coating the blades. Nevertheless, during the operation, the coating can be cracked and the base metal be exposed to the environment. There are experimental evidences that high tanperaane isothermal fatigue and temperature cycling enhance the oxidation process in different steels (1,2) and superalloys (3-7). The thermo-mechanical fatigue (TMF) test provides a laboratory simulation of the complex thermo-mechanical loading of the turbine blades leading and trailing edges. Therefore, the study of the interaction between oxidation and TMF loading will evidently result in a better understanding of the damage which occurs in real blades.