Cause of Leakage on 316L Stainless Steel Corrugated Tube

The 316L stainless steel corrugated tube for ship perforated and leaked. The causes of leakage on corrugated tube were analyzed by macro analysis, chemical composition analysis, scanning electron microscope analysis, energy spectrum analysis and metallographic examination. The results show that the corrugated tube has corrosion under scale, and the corrosion leakage points are concentrated at the bottom of bellows. The main reason was that when the bellows was injected and discharged with seawater during use, the impurities in the seawater accumulated in the groove at the bottom of the bellows form scale. The corrosive elements sulfur and chlorine in the scale led to the corrosion under scale of the corrugated tube until penetrated the tube wall and leaked.