Behaviour of stainless steel in simulated concrete pore solution

The localised corrosion behaviour of austenitic, martensitic, and duplex stainless steels has been studied in several solutions simulating the liquid present in the pores of both alkaline and carbonated concrete in the presence of chloride ions. The work aimed to evaluate the suitability of these types of stainless steel as rebars in reinforced concrete structures exposed to very aggressive environments. Electrochemical tests have been performed in solutions with pH values in the range 7.6-13.9, chloride concentration in the range 0-10%, and temperatures of 20 and 40 degrees C. The adverse effect of a decrease in pH on the critical chloride content is discussed, as a function of stainless steel composition and temperature, and the inhibitive effect of high carbonate/bicarbonate concentrations is also shown.