Influence of low-temperature carburising on metal release from AISI316L austenitic stainless steel in acetic acid

• Influence of low-temperature carburising (LTC) on metal release in acetic acid 3 vol.%.
• LTC-treated steel releases higher alloying metal amounts than untreated steel.
• Fe, Cr, Ni and Mn release higher than the WHO guideline values for drinking-water quality.

AISI316L austenitic stainless steel is widely used in the food industry, usually in contact with aggressive environments. Low-temperature carburising (LTC) is a treatment increasingly applied to this steel in order to harden the surface without decreasing corrosion resistance. In the present work, electrochemical and immersion tests were carried out in acetic acid 3 vol.% (reference environment for metals in contact with acetic foodstuffs), so as to investigate the influence of LTC on metal release. The results showed that the LTC-treated steel is less passivable in this environment, producing higher alloying metal release than the untreated steel.