Experimental design of Cu content in weathering resistance steel for industrial atmosphere application

In this paper, the effect of sulfur dioxide (SO2) on the corrosion behavior of weathering steel with different copper (Cu) contents in a simulated industrial environment was studied. The results showed that the corrosion occurred in three distinct stages with the corrosion kinetics characterized via the parameter of 'n'. For the first and second stage with n > 1 and n < 1, the corrosion of weathering steel was accelerated and reduced, respectively. The third stage witnessed the minimum value of n, indicating a lowest corrosion rate. As the Cu content increased from 0.15% to 0.50%, the corrosion weight gained and corrosion rate remarkably decreased. In contrast, when the Cu contents increased from 0.50% to 0.70%, the corrosion rate began to slightly decrease. With the Cu addition, the stable alpha-FeOOH phase in the rust layer was refined, which increased the electrochemical impedance accordingly lowered the electrochemical reaction rate and ultimately enhanced the corrosion resistance. In this work, we have studied the corrosion mechanism of Cu element on the weathering steel in the industrial atmosphere, and studied the effect of Cu content on the corrosion resistance of weathering steel. The research shows that the content of the effect is not great, so the recommended amount of Cu in weathering steel is not more than 0.50%.