Gas leak was observed in the stainless steel tubes used for the transportation of natural gas in the power station. Tubes located in an open area near the quarries that produce lots of dust. A detailed failure analysis was conducted on the tube to determine the mode and the root cause of the failure. The analysis included both optical and scanning electron microscopy (SEM) of the inner and outer surfaces of the tube as well as characterization of the corrosion products using energy-dispersive X-ray spectroscopy (EDX). Results revealed that the corrosion attack was confined to the upper side of the outer service of the tube. It was evident that failure occurred due to pitting attack that penetrated the whole wall thickness and resulted in a leak failure. Some prevention measures are proposed to avoid this type of corrosion attack in the future.

failure analysis, stainless steel, tube, pitting.