• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.6
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• pp.545-551
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• 2020

Cause analysis of surface pitting crack on a waterjet impeller was conducted. The waterjet impeller was made from stainless steel duplex 2205, which is more resistant to corrosion and local corrosion than typical stainless steel 316L and 317L, and has high mechanical strength, making it a useful material in various marine structures and seawater desalination facilities. The measurements were taken by scanning electron microscopy (SEM) and molecular ecological detection. The chemical composition of S was examined by SEM in the area of pitting corrosion. The dsrAB gene was detected on the sample of the pitting corrosion of the impeller through molecular ecological detection. Therefore, pitting corrosion on the surface of a waterjet impeller was caused by sulphite-reducing bacteria (SRB). To prevent the spread of SRB, management is required through high temperature treatments (over 65℃), pH management, or the insulation of a hull and waterjet.