The corrosion resistance of API 5L X52 pipeline in sulfide contaminated environment has the following characteristics:
When the sulfide ion content is lower than 0.4mM, the corrosion rate of API 5L X52 carbon steel will increase with the increase of sulfide concentration; when the sulfide ion content is higher than 0.4mM, it has an inhibitory effect on the corrosion behavior of carbon steel, and the corrosion rate will decrease with the further increase of sulfide concentration.
Through scanning electron microscopy (SEM) and energy spectrum analysis (EDAX) and other methods, it was found that in sulfide contaminated environment, corrosion product deposits will form on the surface of API 5L X52 carbon steel. As the sulfide concentration increases from 0.4mM to 4mM Na₂S, the Fe/S ratio in the corrosion product decreases from 12.02 to 2.6, which indicates that sulfide is involved in the formation process of corrosion products, and in a high concentration sulfide environment, the formed corrosion products may have a certain protective effect on the pipeline surface, thereby slowing down the corrosion rate.
Therefore, in order to improve the corrosion resistance of API 5L The corrosion resistance of X52 corrosion-resistant pipes in sulfide-polluted environments is usually improved by using anti-corrosion coatings and adding corrosion inhibitors. The common 3PE anti-corrosion coating can effectively isolate the contact between the pipe and the corrosive medium, significantly improving the corrosion resistance of the pipe. The addition of corrosion inhibitors can inhibit the corrosion reaction by adsorbing on the pipe surface or reacting chemically with the corrosive medium.
API 5L X52 Seamless Steel Pipe
