Effect of Cl- concentration on the corrosion mechanism for N80 tubing steel.

This article used a high-temperature and high-pressure Hastelloy reactor to simulate the harsh corrosion environment. The effects of different Cl- concentrations(0, 5 000, 10 000, 15 000 mg/L)on the corrosion mechanism of N80 tubing steel in the extraction fluid was studied. The corrosion rate, corrosion morphology and corrosion film structure of N80 tubing steel was analyzed using a combination of macroscopic and microscopic means. The variability of corrosion in different Cl- content environments was clarified. The results showed that the corrosion rate rose significantly with the elevation of Cl- concentration, and the pits on the surface of the corrosion products gradually increased. The large amount of Cl- enrichment destroyed the originally dense corrosion film, exposing N80 tubing steel to the corrosion solution. The presence of trace O2 made the concentration difference battery occur, accelerating the corrosion process. [ABSTRACT FROM AUTHOR]