Corrosion behavior of the weld joint of X80 pipeline steel in an acidic red soil

Abstract

In this paper, the corrosion behavior of X80 pipeline steel weld joints in an acidic red soil solution was studied. The results show that uniform corrosion occurs on the entire surface of the weld joint after 840 h immersion. The corrosion degree of heat affected zone (HAZ) is more serious than that of base metal (BM) and weld zone (WZ). The corrosion rate of HAZ specimen is always higher than those of WZ and BM specimens throughout the separated immersion. The accelerating corrosion of HAZ may come from its microstructure change, its corrosion sensitivity and the deterioration of mechanical performance of corrosion product on it.

Keywords

• X80 pipeline steel
• weld joint
• red soil
• soil corrosion
• electrochemical impedance spectroscopy