The influence of passivation temperature on the corrosion resistance of passivation film for Q235 steel in simulated pore solution of concrete with chloride or/and sulfate ions

The effect of temperature on the corrosion resistance performance of the passivation film (PF) formed at 20 °C to 60 °C was investigated systematically in Cl− ion or/and SO42− ion solution. It is found that the temperature accelerates the growth rate of PF and increases the thickness of PF. In addition, the critical chloride ion concentration of PF at 20 °C to 40 °C, and that of PF at 50 °C and 60 °C, which is increased by 15.8%. In the single SO42−, all the PF were not depassivated with the increased concentration of SO42−. However, at the presence of Cl−, the PF were depassivated once the concentration of SO42− reaches 0.18 mol/L. These results show that in a single ion environment, the corrosion resistance of PF increased with the passivation temperature, while the impact of temperature on the corrosion resistance of PF is negligible in the combine solution of 3.5 wt% Cl− and SO42− ions.