Corrosion Resistance of Weathering Steels with Different Cr Content in Simulated High Temperature and Humidity Environment

Cyclic wet-dry corrosion testing was conducted on weathering steels containing Cr with two mass fractions (1.990%, 3.194%) in simulated high temperature and humidity environment of the South China Sea with a periodic wheel immersion accelerated corrosion chamber. Then electrochemical tests were conducted on the weathering steels after cyclic wet-dry corrosion for different times. The corrosion resistance of the weathering steels was studied and compared with that of Q235 steel (Cr mass fraction of 0.164%). The results show that the higher the Cr content, the lower the corrosion rate of the tested steel. In the initial stage of corrosion, the steel containing 3.194% Cr had the smallest free-corrosion current density, relatively large capacitance arc radius and the largest charge transfer resistance and total resistance (rust layer resistance+charge transfer resistance), showing the best corrosion resistance. In the final stage of corrosion, due to accelerated corrosion, the rust layer resistance, charge transfer resistance and total resistance of the steel containing 3.194% Cr were lower than those of the steel containing 1.990% Cr.