Comparative Study on the Corrosion Inhibitive Effect of 2-Mecraptobenzothiazole and Na2HPO4 on Industrial Conveying API 5L X42 Pipeline Steel

Abstract

Mild or low-carbon steel has an increasing utilization and is widely used for building construction, machinery parts, and pipelines, because it can be machined easily and has enhanced weldability as well as a low price. In any case, the corrosion resistance of mild steel under the conditions in industrial applications or in atmosphere is a thoughtful concern. This study inquires into the application of 2-mecraptobenzothiazole (MBT) and Na2HPO4 as corrosion inhibitors for the protection of API 5L X42 pipeline steel in 3.5 wt % NaCl as well as in water from the Athens city supply system. The electrochemical/morphological characterizations of the aforementioned mild steel proved that the corrosion protection mechanisms can be assigned to the protective layers created onto the metal surface because of the presence of the inhibitors, which prevent chloride’s penetration. The synergistic effect of the MBT and Na2HPO4 corrosion inhibition behavior, in a molar ratio of 1:1, revealed that the additives performed effectively with corrosion inhibition efficiency above 90%.