Nonlinear ultrasonic characterization of precipitation in 17-4PH stainless steel

Abstract

This research is part of a broader effort to develop a nondestructive evaluation technique to monitor radiation damage in reactor pressure vessel steels, the main contributor being copper-rich precipitates. In this work, 17-4PH stainless steel is thermally aged to study the effects of copper precipitates on the acoustic nonlinearity parameter. Nonlinear ultrasonic measurements using Rayleigh waves are performed on isothermally aged 17-4PH. Results showed a decrease in the acoustic nonlinearity parameter with increasing aging time, consistent with evidence of copper precipitation from hardness, thermo-electric power, transmission electron microscopy, and atom probe tomography measurements.

Evolution of the microstructure of a 15-5PH martensitic stainless steel during precipitation hardening heat treatment

“…Tailoring the characteristics of this precipitation in terms of volume fraction and size allows adjusting the balance of the steel in terms of yield strength (or ultimate tensile strength) and fracture toughness [2,3]. Thus, the Cu precipitation sequence in Fe based alloys [1,[4][5][6][7][8] and its impact on mechanical properties of PH stainless steels 17-4PH and 15-5PH [3,[9][10][11][12][13][14] has been thoroughly investigated during the last decades.…”

Propagation of Non-Linear Lamb Waves in Adhesive Joint with Micro-Cracks Distributing Randomly

“…According to different non-linear effects, sub-harmonic technology, acoustoelasticity, harmonic generation, and wave mixing are common methods for measuring the non-linearity in solids. Both experimental investigations and theoretical studies show that these techniques can detect and evaluate micro damages effectively, and the sensitivity is much higher than traditional linear ultrasonic techniques [19][20][21][22].…”

Wavelet based harmonics decomposition of ultrasonic signal in assessment of plastic strain in aluminum

“…Using ultrasonic testing, the material nonlinearity can be measured by two means: the stressdependent ultrasonic wave speed known as acoustoelasticity [8][9][10][11] and the detection of higher harmonics [12][13][14][15]. The acoustoelastic effect is negligibly small when the stress level is far below the yield point, which is beyond the scope of this paper.…”

“…The solution of the nonlinear wave equation resulting from the summation of the first and second harmonic waves is presented in section 2. To date, there are several applications of nonlinear ultrasonics to assess microstructural changes in metallic alloys, such as fatigue damage [18,19], creep damage [20][21][22], radiation damage [15], thermal aging [23,24], and cold work [25].…”