Study on Natural Passivation Behavior of Corrosion-resistant Steel Rebars in the Mortar

Abstract

The passivation behavior of HRB400 carbon steel rebar, 304 austenitic stainless steel rebar and 2304 austenitic-ferritic duplex stainless steel rebar during curing stage of mortar was studied by electrochemical testing techniques such as open-circuit potential, electrochemical impedance spectroscopy and linear polarization curve, and the corrosion resistance of the passivation film of the three rebars was compared to provide a reference for the practical engineering application of corrosion-resistant steel rebars. The study shows that all three types of steel rebars can be passivated during the 28 days curing stage of mortar, and 2304 duplex stainless steel rebars have the best passivation film corrosion resistance, followed by 304 stainless steel rebars, and HRB400 steel rebar was the worst.

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