Chloride-induced macro-cell corrosion behavior of a novel alloyed-steel rebar and its inhibition strategy

Abstract A new type of corrosion-resistant alloyed-steel rebar, Cr10MoV, was researched using techniques such as corrosion electrochemistry, X-ray computed tomography, and zero resistance ammeter to systematically study the macro-cell corrosion behavior and corrosion resistance of alloyed-steel rebar in mortar and concrete samples induced by chloride ion concentration in the marine environment. The macro-cell corrosion characteristics and development patterns induced by chloride ion concentration in alloyed-steel rebar were preliminarily revealed. In the macro-cell corrosion system of rebar mortar samples induced by 29 times chloride ion concentration, the corrosion current density of the alloyed-steel rebar combination stabilizes at 1.6–2.4 μA/cm 2 , which is only one-third of that of the carbon-steel rebar combination, while the dissimilar steel rebar combination stabilizes at 0–0.4 μA/cm 2 . Alloyed-steel rebar and carbon-steel rebar are configured in high concentration and low concentration chlorine salt areas, respectively. With the help of high corrosion resistance, the long-term stable corrosion resistance of alloyed-steel rebar is ensured. The potential difference between carbon-steel rebar and alloyed-steel rebar is reduced to weaken the driving force of macro-cell corrosion. It is a useful way to inhibit the macro-cell corrosion of dissimilar steel rebar and ensure the high corrosion resistance and durability of marine reinforced concrete structures.