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

The effect of hydrostatic pressure on the metastable and stable pitting corrosion of API X80 steel was investigated in a simulated deep-sea environment. Cumulative probability distribution analysis of metastable pitting events revealed that hydrostatic pressure promoted the occurrence of metastable pitting corrosion and the transformation of metastable pitting corrosion to stable pitting corrosion. According to the results of scanning Kelvin probe force microscopy tests, pitting corrosion of the test steel originated at the interface between inclusions and the substrate. Combined with finite element analysis, the mechanism by which hydrostatic pressure promoted the occurrence and propagation of stable pitting corrosion of test steel in the simulated deep-sea environment was explained.