Effect of natural seawater salinity on stainless steel corrosion : Enhanced resistance in seawater bittern

Gudić, Senka (avtor), Ćorić, Mislav (avtor), Vrsalović, Ladislav (avtor), Nagode, Aleš (avtor), Krolo, Jure (avtor), Jakić, Jelena (avtor)

Stainless steels are commonly used in coastal structures and in seawater desalination and treatment systems, so understanding their corrosion behaviour under different salinity conditions is important to ensure the durability and reliability of the material. In this study, the behaviour of AISI 304L, AISI 316L, and 2205 duplex stainless steels (DSS) was tested in three media with different salinities: brackish water (BSW), seawater (SW), and concentrated seawater bittern (CSW). Testing was conducted using classical electrochemical methods (open circuit potential, linear, and potentiodynamic polarization) supplemented by surface analyses (optical microscopy, SEM/EDS, and optical profilometry). Corrosion resistance increased in the order AISI 304L < AISI 316L < 2205 DSS. Duplex steel 2205 performed best in all media: it exhibited the most positive open circuit potential, the highest polarization resistance, the lowest corrosion current density, and the widest passive range. Unexpectedly, CSW showed improved corrosion resistance compared to SW, which is explained by the reduced chloride content characteristic of seawater bittern after NaCl crystallisation and the presence of magnesium, calcium, and sulphate ions that promote the formation of protective deposits on the metal surface. Pronounced pitting was observed on AISI 304L steel in seawater, while surface degradation in brackish and concentrated seawater was significantly less, and 2205 DSS remained almost unchanged. The results obtained can serve as guidelines for the design and selection of materials for equipment and structures in industries operating in aggressive marine and coastal environments, such as desalination plants, shipbuilding, and energy systems.

• Jezik: Angleški jezik
• Ključne besede: corrosion, stainless steel, chloride media, electrochemical methodsa, surface investigation
• Vrsta gradiva: Članek v reviji
• Tipologija: 1.01 - Izvirni znanstveni članek
• Organizacija: NTF - Naravoslovnotehniška fakulteta
• Status publikacije: Objavljeno
• Različica publikacije: Objavljena publikacija
• Datum objave: 22.12.2025
• Leto izida: 2026
• Št. strani: Str. 1-21
• Številčenje: Vol. 16, iss. 1
• PID: 20.500.12556/RUL-177901
• UDK: 669
• ISSN pri članku: 2076-3417
• DOI: 10.3390/app16010109
• COBISS.SI-ID: 264376323
• Datum objave v RUL: 17.02.2026

Gradivo je del revije

• Naslov: Applied sciences
• Skrajšan naslov: Appl. sci.
• Založnik: MDPI
• ISSN: 2076-3417
• COBISS.SI-ID: 522979353

Licence

• Licenca: CC BY-NC 4.0, Creative Commons Priznanje avtorstva-Nekomercialno 4.0 Mednarodna
• Povezava: http://creativecommons.org/licenses/by-nc/4.0/deed.sl
• Opis: Licenca Creative Commons, ki prepoveduje komercialno uporabo, vendar uporabniki ne rabijo upravljati materialnih avtorskih pravic na izpeljanih delih z enako licenco.

Projekti

• Financer: MZOS - Ministry of Science, Education and Sports of the Republic of Croatia
• Naslov: ANTARES (IP-UNIST-28)