Corrosion Dynamics of Low Carbon Steel in Salt Spray Environment

In order to study the corrosion dynamics of low carbon steel in neutral salt spray environment, the low carbon steel samples were carried out neutral salt spray corrosion test (SST). The corrosive behavior of low carbon steel was examined by scan electron microscopy, electrochemical impedance spectra, and potentiodynamic polarization, and the salt spray corrosion dynamics laws of low carbon steel were discussed. SST results showed that as the corrosion progresses, the rust layers will become dense, forming a “scab” structure, and forming an occluded corrosion zone with the substrate, resulting in increased corrosion rate. The newly generated inner rust layers were loose and expanded outward, caused the “scab” structure to peel off, and this has a certain periodicity. After corrosion, the surface of the substrate is pit-shaped, which uniformity is poor. Electrochemical tests showed that the corrosion process of low carbon steel in salt spray environment was mainly controlled by cathode diffusion, and the corrosion rate was relatively stable.