Effects of sensitized under different temperature and composition of condensate on electrochemical behavior of 430 ferritic stainless steel

Electrochemical behavior of the 430 ferritic stainless steel (FSS), sensitized under different temperature, and the effect of composition of condensate on the electrochemical behavior are investigated in simulated automotive condensate environment. Results show that the 430 FSS sensitized under temperature within range of 850℃ to 1 150 is ℃ characterized by increasing grain size along with sensitization temperature, and both the corrosion potential and the charge transfer resistance of it decreases in the simulated solution, in solution containing Cl-ion, the existence of SO₄^2-or SO₃^2-is found to be able to accelerate corrosion processes of 430 FSS other than that of CO32-. In solution with Cl^-, SO₃^2- plays an important role in accelerating the occurrence of corrosion, which results in the increase of passive current density and the corrosion rate with the increase of concentration of SO₃^2-. In addition, the solution contains both Cl-and SO₃^2-, SO₃^2- inhibites the corrosion process of the ferritic stainless steel to reduce the corrosion rate, while SO₄^2- increases the corrosion rate.