## 1 Introduction  
Commercially available 316L stainless steel (316L SS) is employed in various industries including aeronautic, chemical, maritime, automotive, and biomedical. This is due to its good mechanical properties, moderate corrosion resistance, and acceptable chemical inertness [1, 2]. One area of application is filtration components for industrial installations, such as desalination plants. The filtration components often require complex shapes to match the industrial necessities such as size, efficiency, and maintenance requirements. Laser additive manufacturing technology allows the generation of unique products with complex morphologies in metallic material with high energy efficiency, low cost, and low environment impact. This process can be carried out with different methods such as laser powder bed fusion (LPBF) and powder or wire-fed directed energy deposition [3]. LPBF is commonly used in industry owing to the high resolution and excellent control of the size and internal passages [4, 5]. Some features induced by LPBF (e.g., porosity, cracksand dissimilar chemical composition in the samples) can, however, reduce the corrosion resistance that is a key property of the filter [6]. In 2016, [PERSON] et al. [6] compared the corrosion resistance in hydrochloric acid of the wrought 316L SS and other steels generated with laser additive manufacturing using potentiodynamic polarisation curves. The corrosion resistance of the LPBF samples was reported to be 83% lower than that of the wrought samples. This is due to the heterogeneous microstructure and the segregation of the molybdenum. Although the [PERSON] study provides information about the importance of the laser parameters on the corrosion, the corrosion resistance study was only focused on the potentiodynamic polarisation curve. [PERSON] at al. [7] also evaluated the corrosion resistance of LPBF 316L SS in a saltwater environment. The Nie assessments were carried out with open-circuit potential, potentiodynamic polarisation curves, and electrochemical impedance spectroscopy. The [PERSON] work showed that the passive film of the LPBF samples was more stable than that of the wrought samples due to the sub-grain size. The [PERSON] study gave important information about LPBF 316L SS corrosion, but the evolution of the corrosion mechanism over time was absent. In 2021, [PERSON] et al. [8] also investigated the influence of the laser parameters on the corrosion resistance of the LPBF 316L SS in saltwater. The cycle voltammetry was utilised to assess the corrosion. [PERSON] et al. observed that LPBF samples produced at high speed were more susceptible to the pitting corrosion due to the large numbers of dislocations, carbide formations, and intermetallic formations. [PERSON] et al., however, indicated the necessity of carrying out more experiments. In the same year, [PERSON] et al. [1] also investigated the corrosion resistance of the LPBF 316L SS but in alkaline saltwater. Open-circuit potential, cyclic voltammetry, potentiodynamic polarisation curve, and the Mott-Schottky method were used to analyse the corrosion process. LPBF samples had the capacity of generating a passive film with high stability due to the formation of \(\gamma\)-iron and the reduction in detrimental inclusions. The passive film had a lower electron donor capacity than that of the wrought samples. The [PERSON] study about the passive film was exhaustive, but the evolution of the corrosion mechanism with time was not reported. One year later, [PERSON] et al. [2] analysed the influence of the energy density on the corrosion resistance of the LPBF 316L SS in deaerated saltwater. The potentiodynamic polarisation curve determined that the LPBF samples produced at medium energy had the best corrosion resistance because of the low porosity. Although [PERSON] et al. defined the sample with the best corrosion resistance, an exhaustive study of the corrosion (e.g., corrosion mechanism evolution) was absent.