Hydrostatic pressure effects on corrosion behaviour of X80 steel in artificial sea water

ABSTRACT

The effect of hydrostatic pressure (HP) on the corrosion behaviour of X80 steel is investigated to assist the development of deep-sea oil and gas resources. The results show that the corrosion current increases as HP increases whereas the charge transfer resistance follows the opposite trend. The corrosion products are composed of γ-FeOOH, α-Fe₂O₃ and α-FeOOH at atmospheric pressure, while Fe₃O₄ is only formed at a high HP. Additionally, the inner layer of the corrosion products contains more Fe₃O₄ compared with the surface corrosion layer. HP accelerates the corrosion rate of X80 steel due to its effect on the chemical and physical properties of the corrosion products, including the promoted reduction of γ-FeOOH and the formation of wider and deeper cracks on the corrosion product layer.

KEYWORDS:

• X80 steel
• hydrostatic pressure
• corrosion products
• deep-sea environment

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by Beijing Science and Technology Planning Project: [Grant Number Z201100004520011]; National Natural Science Foundation of China: [Grant Number U1837602]; Overseas Expertise Introduction Project for Discipline Innovation: [Grant Number B12012].