Ultrasonic creep damage detection by frequency analysis for boiler piping

Boiler piping of fossil-fuel combustion power generation plants are exposed to high-temperature and high-pressure environments, and failure of high-energy piping due to creep damage has been a concern. Therefore, a precise creep damage assessment method is needed. This paper proposes a nondestructive method for creep damage detection of piping in fossil-fuel combustion power generation plants by ultrasonic testing. Ultrasonic signals are transformed to signals in a frequency domain by Fourier transform, and a specific frequency band is chosen. To determine the creep damage, the spectrum intensities are calculated. Calculated intensities have a good correlation to life consumption of the weld joints, and this method is able to predict the remaining life of high-temperature piping, which has been already installed. [DOI: 10.1115/1.2767364] Keywords: nondestructive testing, frequency analysis, creep damage, maintenance, fossil-fuel combustion power generation plants, boiler piping, frequency spectral intensity, life consumption, ultrasonic testing