Effect of Temperature on Corrosion and Cathodic Protection of X65 Pipeline Steel in 3.5% NaCl Solution

In this investigation, polarization curve, electrochemical impedance spectroscopy and hydrogen permeation measurements were used to observe the corrosion behavior and cathodic protection of X65 under the influence of temperature. The results show that, with an increase in temperature, Icon- increased. Ecorr decreased and electrochemical impedance decreased, which indicates that corrosion resistance of X65 steel was weakened. As the temperature was increased, De deceased and c0 increased. The defects in X65 steel can block the hydrogen diffusion, but the hydrogen concentration in the specimen increased, which increased the risk of hydrogen embrittlement of X65 steel. As the hydrogen charge potential was shifted negatively, the current density first decreased and then increased, which indicated that the influence of hydrogen air masses in X65 is limited.