Corrosion inhibition of 304 stainless steel by Paecilomyces variotii and Aspergillus niger in aqueous environment

Abstract

The presence of microorganisms influences corrosion of metallic materials by either an accelerating or an inhibiting effect. While most studies have focused on corrosion influenced by bacteria, especially sulphate-reducing bacteria, fungus (or mould) is another form of microorganisms which can significantly affect corrosion processes. This study investigated the effects of two common fungi, Paecilomyces variotii and Aspergillus niger, on corrosion of 304 stainless steel immersed in aqueous environment for up to 28 days. Biofilm formation was observed by SEM. Instead of accelerating corrosion, electrochemical studies such as potentiodynamic polarisation and electrochemical impedance spectroscopy have shown inhibitive effects of these fungi to corrosion of 304 stainless steel.