Fretting Fatigue In-service Failure of X20CrMo13 Stainless Steel Turbine Blade

Abstract

The turbine blades play a crucial role in the efficiency of the steam turbines system, which can also lead to safety and economic implications in a catastrophic failure. The propagation of fatigue cracks is a relevant issue, especially if there are safety issues involving human life or the environment or significant economic losses. This work investigated the failure of a turbine blade of a 25 MW cogeneration power plant. One found several deformation marks and debris in the primary crack origin at the blade's base. They were responsible for the fretting fatigue type wear. The blade material matches the composition of X20CrMo13 steel; however, the hardness shows a higher average value (250±4.7) than typical standard values of 220–240 HB.

Keywords:
Fretting; Fatigue; Wear; Cracks; Turbine blades