Comparative Corrosion Behavior of Five Different Microstructures of Rebar Steels in Simulated Concrete Pore Solution with and Without Chloride Addition

The present work discusses the effect of five different microstructures, coarse, fine and very fine ferrite–pearlite, martensite and tempered martensite, made by furnace cooling, air cooling, forced air-cooling, water quenching and tempering, respectively, of a rebar steel on its corrosion performance in freely aerated with and without chloride-contaminated simulated concrete pore solution using the dynamic polarization and electrochemical impedance spectroscopy. The corrosion performance of the steels with five different microstructures relates to the polarization resistance, protective ability of rusts and the extent of the galvanic attack. The corrosion rate of the steels has been found to be comparable in the simulated concrete pore (SCP) solution. However, in chloride-containing SCP solution, corrosion rate has been found to increase in the following sequence: forced air-cooled–air-cooled–quenched–furnace-cooled–tempered steels.