Corrosion behaviour of AISI 348 stainless steel in simulated WWER environment and during LOCA conditions

This study investigates the corrosion and high-temperature oxidation behaviour of AISI 348 stainless steel under normal and extreme conditions for potential nuclear applications.Plate specimens were exposed to simulated WWER primary water conditions in an autoclave at 360 °C for extended duration, reaching up to 1659 days. In addition to long-term exposure testing, short-term high-temperature oxidation experiments were performed at temperatures up to 1 400 °C to evaluate oxide scale formation, spallation behaviour, and structural integrity. Characterization techniques included Mössbauer spectroscopy for oxide phase identification, microhardness measurements, and optical microscopy for grain size evaluation. Mechanical testing, including ductility assessment and microhardness measurements, was conducted after high-temperature exposure to evaluate the material’s ability to retain mechanical integrity under accidental conditions.