merged

Biocorrosion Performance of Stainless Steel and Mild Steel in Marine
Environment
Nur Alia Binti Johari
Supervisor: Dr Wan Rafizah binti Wan Abdullah
Bachelor of Technology (Environment)
School of Ocean Engineering
Universiti Malaysia Terengganu
Biocorrosion occurs as microorganism starting to attach on metal, colonize and form
a biofilm layer. In short period of time, metal with low corrosion resistant will start to
corrode and deposit metal deposition. Hence, this study was performed to investigate
the biocorrosion behaviour of Stainless steel 316L (SS 316L) and mild steel coupons
upon immersion in medium 3.5% NaCl and natural seawater for 60 days according to
standard ASTM G31-2004. The selected steel substrates were also subject to
biocorrosion test in agar media containing Staphylococcus aureus (S.aureus) and
Escherichia coli (E.coli) for 7 consecutive days. The observations from SEM analysis
revealed that both SS 316L and mild steel experienced pitting corrosion after
immersion in all tested media. Based on corrosion rate value, the mild steel has higher
tendency to corrode either in medium with or without bacteria. The presence of E.coli
has induced more corrosion on tested substrates rather than S.aureus.
65 | U M T U N D E R G R A D U A T E R E S E A R C H D A Y 2019