Effect of dynamic DC stray current on corrosion behavior of X70 steel

Abstract

Corrosion behavior of X70 steel under the application of dynamic DC stray current was investigated in simulated soil solution by immersion tests and electrochemical measurements. Experimental results indicated that the corrosion rate of X70 steel under dynamic DC stray current was strongly influenced by the dynamic period. When the dynamic period was <80 s, the corrosion rate was only approximately 1–7% of that caused by an equivalent amount of steady direct current. However, as the dynamic period became >80 s, the corrosion rate increased significantly with the dynamic period. And finally when the dynamic period was >1 hr, the corrosion rate was nearly equal to 100% of that caused by an equivalent amount of steady direct current. Meanwhile, the surface examination showed that the specimens experienced uniform corrosion under the experimental conditions. On the basis of the experiment results, the dynamic DC stray current corrosion mechanism of X70 steel under the experimental conditions was discussed, which was closely related to the electric double‐layer structure at the electrode/solution interface and dynamic electrochemical reactions under dynamic stray current.

Salt‐spray corrosion behavior of a Cu–Al composite plate under AC current

“…At present, research on the influence of current on metal corrosion has been carried out to a certain extent, especially the influence mechanism of DC current on the corrosion behavior of metal has obtained some highly recognized conclusions. Research by Zhang et al [16] and Qin et al [17] shows that under the action of the DC electric field, the corrosion of metal materials is accelerated, and the corrosion rate is proportional to the current density. However, the mechanism of AC current corrosion is still worth discussing, especially, the effect of current density on the corrosion rate is relatively complex.…”