Specific Corrosion Behavior of 316L Stainless Steel in Mineral Water

The comparative assessment of the corrosion sensitivity of a pipe and its welds made of 316L stainless steel in a mineral water is performed under different electrochemical conditions. The study shows that this steel demonstrates an unusual electrochemical behavior and the typical passive region in the anodic polarization curve is practically absent. Thus, the analyzed steel is electrochemically active in the given environment, which provokes its sensitivity to corrosion. It has been found that the preliminary holding of the specimens in demineralized water saturated with oxygen leads to the appearance of a passive region (plateau) in the anodic polarization curve of steel in mineral water. The length of this plateau significantly increases with holding time and also with the additional application of anodic polarization current. Similar trends are also observed for the welded joints of 316L steel. The preliminary treatments of the internal pipeline surface prior to use are proposed and discussed.