Journal
COATINGS
Volume 9, Issue 1, Pages -Publisher
MDPI
DOI: 10.3390/coatings9010029
Keywords
X80 pipeline steel; coating damage; DC stray current; anodic corrosion; cathodic disbondment
Categories
Funding
- National Natural Science Foundation of China [51471011]
- Rixin Scientist of the Beijing University of Technology
Ask authors/readers for more resources
The influence of a direct current (DC) stray current on the corrosion and cathodic disbondment of X80 steel coated with a polyethylene (3PE) coating in 3.5% NaCl solution was studied by immersion experiments, electrochemical tests, three-dimensional microscopy, and a surface analysis. The results showed that the potential of the X80 steel sample shifts under the direct current. After 100A/m(2) DC interference was applied, the potential of the sample in the anode region positively shifted from -0.68 to -0.43 V. At the same time, the sample in the cathode region negatively shifted to -1.45 V. Under the DC anode action, the X80 steel corrosion exhibited no passivation and followed Faraday's law of electrolysis, in which the corrosion rate is proportional to the current density. Three-dimensional (3D) digital microscopy showed that, as the DC current increased, the depth of the corrosion pit also increased (gradually), indicating a higher corrosion degree. The sample in the cathode region only underwent a hydrogen evolution reaction, which caused cathodic disbondment of the coating. The stray current had a critical current density for the coating disbonding: the coating delamination area reached its maximum and then remained unchanged.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available