Corrosion behavior of X65 steel at different depths of pitting defects under local flow conditions

Abstract

The electrochemical corrosion behavior and the development mechanism of the local corrosion of X65 steel under different defect depths were studied by using macroscopic electrochemical measurements and characterization techniques. A CO2-saturated NACE solution was used to study electrochemical corrosion characteristics in the single-phase flow-accelerated corrosion test loop system. Changes in the flow characteristic around the defects at different depths were characterized by COMSOL. The results indicated that samples with lower depth defects tend to deepen towards the radial direction both in the deep defects and shallow defects. Moreover, the upper and trailing edge of the defect has a tendency to deepen and expand the region of the defect under the influence of higher turbulent kinetic energy (TKE) and the shearing rate.