Non-destructive evaluation techniques for assessment of creep and fatigue damage in materials and components

Abstract

In this article, application of various non-destructive evaluation (NDE) techniques for assessment of creep and fatigue damage in materials and components has been discussed. X-ray diffraction technique has been used for finding fabrication-induced residual stresses in components. Ultrasonic and magnetic techniques have been applied for characterizing changes in microstructures due to creep and fatigue. Crack closure phenomenon and fatigue crack growth have been studied in austenitic stainless steels using acoustic emission technique. Dual-frequency eddy current technique has been used for high sensitive detection of fatigue cracks in compressor discs of aeroengines.

A new methodology for identification of β-transus temperature in α + β and β titanium alloys using ultrasonic velocity measurement

“…However, this has been verified for two elastically anisotropic materials, AISI type 304 stainless steel with face-centred cubic structure and natural uranium with an orthorhombic structure. Jayakumar and co-workers [10,11] studied the effect of cold work in AISI type 304 stainless steel -transus temperature in titanium alloys 335 on ultrasonic velocities in three orthogonal directions, i.e. thickness, rolling and transverse directions, which were found to increase by 0.64 and 0.71% in the thickness direction on 40 and 50% cold work, respectively.…”

“…As ultrasonic velocity is a function of elastic properties in the direction of wave propagation and vibration, it has also been used for characterization of texture and assessment of recrystallization in various elastically anisotropic materials, such as austenitic stainless steel [11] and uranium [12]. In modified 9Cr-1Mo ferritic steel, Kumar et al [5] studied the influence of microstructure on ultrasonic velocity and attenuation for the specimens heat-treated at various temperatures followed by water quenching.…”

Evolution and characterization of dynamically recrystallized microstructure in a titanium-modified austenitic stainless steel using ultrasonic and EBSD techniques

“…Further, reduction in misorientation between the adjacent grains by rotation of the grains may happen during grain elongation in order to accommodate strain [25]. This may enable the ultrasonic beam to channel through the specimen [26]. However, the influence of the above two factors on ultrasonic attenuation seems to be less pronounced in our study.…”