## 1 Introduction
Some studies even suggest that the combined use of hardening techniques and coatings creates a synergistic effect, making the material even more resistant [6; 7; 8; 9; 10; 11; 12; 13; 14]. [PERSON] et al. [15] demonstrated that solution annealing (1040 \({}^{\circ}\)C) followed by artificial aging (480 \({}^{\circ}\)C) applied to 17-4 PH stainless steels has favorable effects on microstructure, reduces internal stresses, and improves resistance to both corrosion and cavitation erosion. [PERSON] et al. [16] studied the cavitation erosion resistance of AISI 420 stainless steel after applying quenching and partitioning heat treatment. The results suggest that resistance to cavitation erosion significantly increases due to the high hardness and the fraction of retained austenite. During cavitation, the retained austenite can absorb the energy from bubble collapse by transforming into strain-induced martensite. [PERSON] et al. [17] developed a super-austenitic stainless steel coating reinforced with SiC and applied via HVAF spraying to provide high resistance to both corrosion and cavitation. The improvement of these properties is attributed to low porosity, increased alloying, and refined grain structure. [PERSON] et al. [18] showed that layers consisting of CrC particles (12.5% and 6% vol.) in combination with INCONEL 625 (Inc-625) powder, deposited under specific carrier gas conditions on a cast A27 steel substrate, exhibit pronounced plastic deformation, grain refinement, and increased hardness--factors that justify the improvement in cavitation erosion resistance. [PERSON] et al. [19] determined the optimal values of linear energy used in the surface coating of the Hastelloy C-276 alloy via the CMT (cold metal transfer) technique, in order to prevent cavitation erosion damage in stainless steel components used in marine engineering. [PERSON] et al. [20] demonstrated that the incubation period and the maximum depth of erosion penetration (MDE) in the GH 4738 superalloy have more favorable values compared to those of the Inconel 601 superalloy. Additionally, they found that in the severe cavitation region of the GH 4738 superalloy, selective damage occurred, and the Mo element was preferentially removed. The material studied in the present work is an austenitic alloy that possesses an excellent combination of mechanical properties and high corrosion resistance. Its high mechanical strength is justified by the solid solution strengthening effect of its FCC crystal structure by Cr, Mo, and Nb [20]. Its chemical composition is responsible for resistance to pitting, crevice corrosion, intergranular corrosion, and stress corrosion cracking in chloride-ion environments [21]. Due to its favorable combination of properties, it is widely used in the manufacture of pressurized water nuclear reactor components, aerospace components, and other hydromechanical equipment [20; 21; 22; 23]. However, its range of applications can still be extended, particularly in cavitating environments, and the specialized literature contains limited data on its behavior in such conditions. Numerous components made from this material are manufactured through plastic deformation operations, machining, and/or welding. Following these processes--or even during the technological processing flow--stress-relief annealing heat treatment is applied in order to reduce residual stresses and increase dimensional stability. As a result of its application, equilibrium states are obtained that are stable from chemical, physical, mechanical, and structural points of view. In terms of origin, residual stresses can be: thermal, structural, and mechanical. Thermal stresses occur during non-uniform heating or cooling of the metallic product, which causes a thermal gradient across the section. Structural stresses are caused by phase transformations during heating or cooling, which involve changes in specific volume. Mechanical stresses are introduced by external actions inherent to technological processing operations.