Reza Javaherdashti - ParsCorrosion Consultants Co., Australia
Farzaneh Akvan - Young Researchers and Elite Club, North Tehran Branch, Iran

A composite fuzzy function model was developed to predict the corrosion resistance of carbon steel in three environment containing single-type and mixed cultures of corrosion-related bacteria such as sulphate reducing bacteria and iron reducing bacteria. Based on this model, it was predicted that the fuzzy probability of corroding carbon steel in the mixed environment is higher than that of the single-type environments and that this fuzzy probability for the single-type environments is almost equal. To validate the model, stress corrosion testing (slow strain rate test, SSRT) was conducted on carbon steel in these environments. The obtained results validated the predicted results by the model as measured by change of important mechanical features of carbon steel in these environments.

Corrosion; Microbiologically Influenced Corrosion (MIC); Steel; Fuzzy Composite Functions; Bacteria.