Influence of temperature on pitting corrosion of steel rebar in simulated concrete pore solution

The electrochemical behaviors of HRB400 steel rebar specimens were investigated by potentiodynamic polarization, electrochemical impendence spectroscopy (EIS), Mott-Schottky curve, constant potential polarization and immersion test in Ca(OH)₂ saturated solution containing 0.1% (by mass) NaCl. The results show that with the increase of the solution temperature, corrosion potential and pitting corrosion potential decrease, corrosion current density increases, the impedance of passive film decreases. The semi-conductive styles and properties of passive film change at different solution temperatures. The pregnancy time of pitting corrosion is shortened and the sensitivity of pitting corrosion increases remarkably as the solution temperature increases. In addition, with the increase of solution temperature, the uniform corrosion rate of HRB400 steel rebar increases, serious pitting corrosion appeares on the surface of the specimens at higher solution temperatures.