Effect of Ni on Corrosion Resistance of Weathering Steels in Wet/Dry Environments

Corrosion behavior of a low alloy steel A with 3% nickel content was studied by a wet/dry cyclic test. A commercial weathering steel Q450NR1 was used for comparison. The classical weight loss method was used to evaluate the weatherability of weathering steel, while the iron rust layers formed on weathering steel were analyzed by using SEM, XRD and electrochemical measurements. The results indicated that the corrosion resistance of steels A was better than that of commercial weathering steel Q450NR1 in the wet/dry cyclic test. The addition of Ni promoted the formation of α-FeOOH so as to improve the resistance of the rust. The EIS results indicated that the charge transfer resistance of steel A was bigger than that of steel Q450NR1.