Effect of alloyed Cr on corrosion behavior of low‐alloy steel in wet atmosphere

Abstract

The effect of 1.5% Cr on the corrosion resistance of low‐alloy steel in a simulated mine environment was studied. To clarify the effect of Cr on the corrosion of low‐alloy steel in the wet environment at the initial stage of corrosion, salt spray corrosion tests were performed to simulate the corrosion process in the field, and the bare steel and corrosion products were characterized. The results showed that the addition of 1.5% Cr reduced the surface potential and the kinetic tendency of the corrosion reaction, making the corrosion rate at the initial stage of the test lower than anticipated. An increase in Cr content significantly elevates the level of α‐FeOOH. The corrosion product film (CPF) had a bilayer structure, with α‐FeOOH of Cr‐rich and Cr(OH)3 were found in the inner layer and at the junction of the inner and outer layer. The CPF had a dense structure that effectively reduced electrochemical reaction activity and improved corrosion resistance.