Electrochemical Behavior of Fine-Grained Steel in Alkaline Solutions in the Presence of Chlorides

Fine-grained (FG) steel is largely used for high-speed railway applications because of its high yield strength. Its corrosion behavior is equally critical to the service life of reinforced concrete structure, especially in severe environments. The corrosion resistance of FG steel and conventional low-carbon (LC) steel in simulated concrete interstitial electrolytes containing chlorides was investigated by using electrochemical measurements and microstructure characterization techniques. Two types of alkaline solutions, i.e.,high-alkaline simulated concrete pore solution (CP solution) and low-alkaline saturated Ca(OH)2 solution (CH solution) were used. The results indicate that, in CP solution with chlorides, FG steel exhibits lower corrosion resistance than LC steel but slightly higher corrosion resistance in CH solution. The corrosion resistance of FG steel appears to be dominated by the amount of corrosion pits in high-alkaline CP solution and by the compactness and adherence of corrosion products in low-alkaline CH solution.