Investigation on Effect of Cathodic Protection and Imidazoline Inhibitor on Electrochemical Performance of 20MnSi Steel under Alternating Temperature Condition

The failure of reinforcements in rammed earth has been paid more attention to. However, under the alternating temperature conditions, the effect of cathodic protection and inhibitor on reinforcements was doubtful. In this paper, 20MnSi steel was adopted as the research object, and the micro morphology and electrochemical tests were carried out to determine the effect of cathodic protection and inhibitor. The results showed that the number of pits on the surface of 20MnSi steel after 50 cycles of temperature alternation decreased and the corrosion area increased under the cathodic proteticon and inhibitor. Moreover, with the increase of CP potential, the number of pits and the maximum pit depth decreased significantly. Further, the cathodic protection can provide the electrochemical protection, while the synergistic effect of cathodic protection and inhibitor presented a resistance-electrochemical protection. Under the alternating temperature condition, the phase evolution caused by carbonation of 20MnSi steel was the main failure reason. However, the corrosion protection provided by cathodic protection and imidazoline inhibitor for 20MnSi steel can only be achieved by inhibiting the electrochemical reaction process.