Determination of causes of accelerated local corrosion of austenitic steels in water supply systems

• This research presents a case study of accelerated local corrosion of water supply system pipeline.
• Presence of weld decay on AISI 304 steel was shown and its consequences were revealed.
• Formation of galvanic cells related to chromium depletion as a result of sensitisation was studied.

This paper concerns an inspection of a water supply system, made of AISI 304 steel, which showed signs of local corrosion at the weld. Such corrosion caused material perforation after very short periods of operation. It was revealed that steel was sensitised during the welding process. It was also proven that chromium micro-segregation occurred in the alloy leading to galvanic cell formation which initialised the process of pitting corrosion. This paper is a study of corrosion attack types due to negligence during and after the process of welding of the system.