Influence of Surface Condition on the Electrochemical Behavior of Alloy Steel in Saturated Ca(OH)2 Solution

Abstract

The electrochemical behavior of a novel alloy steel (Cr1MoV) in the conditions of as-received with mill scale and pickled without mill scale in saturated Ca(OH)2 solution was assessed using various electrochemical measurements. Backscattered electron (BSE) images and elemental mapping were employed to characterize the distribution of mill scale and rust layer on the surface of corroded steel in the presence of chlorides. Compared with pickled Cr1MoV steel, much lower passivation capability was observed for as-received Cr1MoV steel due to the depletion of alloying element Cr in the defective mill scale. However, in the presence of chlorides, the high corrosion resistance of passivated pickled Cr1MoV steel was less pronounced. Therefore, it was confirmed that the surface imperfections possibly formed during the pickling process had a negative impact on the chloride-induced corrosion behavior of pickled Cr1MoV steel.