Small Punch Test Enables Southern Company And Transcanada To Determine Remaining Life Of Turbine Rotor Wheels

Southern Company and TransCanada Energy used a noninvasive, small sample test technique, called a small punch test, to determine the fracture toughness of low-pressure steam turbine rotor wheels. This test, which was developed through EPRI research, provided information that could be used as part of a larger crack growth and lifing model to more accurately predict the behavior of the turbine components and to determine their remaining life.

The ability to make these determinations from small specimens enables non-disruptive small sample removal from operating components to provide additional, more precise, unit- and location-specific data for life assessment. In these cases, the findings allowed the utilities to better manage risk of continued operation and to maximize utilization of the turbine rotor wheels.

“EPRI research has developed the small punch fracture toughness technique to a level where the end user can have significant confidence in the results. This confidence in the input data has provided greater clarity in the decision-making process around our turbine life evaluations.”

 ~ David Downs
Principal Engineer and Supervisor,
Metallurgy and Material Application
Southern Company

Download Success Story