## 2 Experimental Details  
Cavitation erosion experiments were conducted using a vibrating apparatus equipped with piezoceramic crystals, fully complying with the requirements of the ASTM G32-2016 standard [24]. The purpose of the test is to simulate this process under accelerated conditions conducted in the laboratory. The experimental setup is schematically shown in Figure 1. The cavitation process was rigorously controlled through software implemented on the computer operating the system, which ensured the maintenance of prescribed operating parameters: vibration amplitude (50 \(\upmu\)m), resonance frequency (20 \(\pm\) 0.3 kHz), water temperature (22 \(\pm\) 1 \({}^{\circ}\)C), and power of the ultrasonic generator (500 W). The pH of the drinking water was measured using a PH TESTER--POMETER, before, at the beginning, and at the end of each intermediate testing period, without observing any differences that could affect the degree of material degradation. The pH values measured during the testing days ranged from 6.98 to 7.11. No measurements were taken regarding the dissolved gas content due to the short duration of the intermediate periods (maximum 15 min). The sonotrode has an exponential shape, and the quartz transducer is fused to its terminal end. The test specimen is attached to the terminal part of the exponentially shaped sonotrode. The working parameters generate longitudinal vibrations, which are amplified and transmitted into the liquid as ultrasonic waves. The bubbles formed during these vibrations cause implosions at the surface of the specimens, leading to a cumulative effect that has a destructive impact on the surface. To eliminate any doubts regarding the chemical and structural homogeneity of the material, the specimens were taken from the same round bar made of the Ni-based alloy, INCONEL 625. The nominal chemical composition of the material is shown in Table 1, and its mechanical properties at room temperature for the as-delivered state (as rolled) are presented in Table 2.  
Figure 1: Schematic diagram of the testing apparatus. \begin{table}
\begin{tabular}{c c} \hline \hline Chmonium (Cr) & 22.01 \\ \hline Iron (Fe) & 4.48 \\ \hline Molybdenum & 9.20 \\ \hline Niobium (Nb) + Tantalum (Ta) & 3.39 \\ \hline Carbon (C) & 0.018 \\ \hline Manganese (Mn) & 0.12 \\ \hline Silicon (Si) & 0.14 \\ \hline Sulfur (S) & 0.002 \\ \hline Phosphorus (P) & 0.008 \\ \hline Aluminum (Al) & 0.28 \\ \hline Titanium (Ti) & 0.31 \\ \hline Cobalt (Co) & 0.07 \\ \hline Nickel (Ni) & Balance \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Chemical composition of researched alloy, wt. %. \begin{table}
\begin{tabular}{c|c} \hline \hline Ultimate tensile strength, R\({}_{\text{m}}\) & 948 N/mm\({}^{2}\) \\ \hline Yield strength, R\({}_{\text{p0.2}}\) & 527 N/mm\({}^{2}\) \\ \hline Elongation at break, A\({}_{5}\) & 46\% \\ \hline Reduction in area, Z & 51\% \\ \hline Hardness, HV & 236 daN/mm\({}^{2}\) \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Mechanical characteristics of INCONEL 625 at room temperature. Figure 2: Cyclogram of applied heat treatment. simultaneously and uniformly across all microvolumes or macroscopic regions of the parts. Instead, they are constrained, meaning that variations occurring in some microvolumes or regions hinder the free variation of neighbouring ones, and vice versa. As a result, a portion of the volumetric change is realized through plastic deformation, while the rest remains in the form of elastic deformation, which, according to Hooke's Law, is associated with residual stress--either normal (\(\sigma_{\text{res}}=\varepsilon_{\text{res}}\bullet\text{E}\)) or shear (\(\tau_{\text{res}}=\gamma_{\text{res}}\bullet\text{G}\)). These elastic deformations and residual stresses have varying magnitudes and signs and balance each other out, such that the metallic part retains its integrity, thus forming a mechanically stable system.