Influence of Hydrostatic Pressure on the Pitting Corrosion Behavior of API X80 Steel

Abstract

In this research, the effect of hydrostatic pressure on metastable and stable pitting corrosion of API X80 steel was investigated by using electrochemical method in simulated deep-sea environment. Cumulative probability distribution analysis of metastable pitting events revealed that hydrostatic pressure promoted the occurrence of metastable pitting corrosion and transformation trend of metastable pitting corrosion to stable pitting corrosion. Moreover, according to the results of scanning Kelvin probe force microscopy(SKPFM) tests, pitting corrosion of test steel can be confirmed to originate from the position of the interface between the inclusion and the substrate. Finally, combined with finite element analysis, the mechanism by which hydrostatic pressure promotes the occurrence and expansion of stable pitting corrosion of test steel in simulated deep -sea environment is explained.