Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8110034 | Natural Gas Industry B | 2016 | 6 Pages |
Abstract
Oil and gas line pipes are laid underground and run through different areas in the laying process, so they will be subjected to different degrees of corrosion and even crack, leading to enormous casualties and economic losses. In order to guarantee the safe operation of line pipes, therefore, it is significant to investigate the electrochemical corrosion behaviors of pipe steel in a simulated soil environment. In this paper, the electrochemical corrosion behaviors of the base metals and welding materials of API 5L X90 steel longitudinally submerged arc welding pipes in near-neutral simulated soil solution (NS4) were studied by means of the electrochemical impedance spectroscopy (EIS) and the potentiodynamic polarization testing technology. It is shown that the typical characteristic of anodic dissolution is presented but with no passivation phenomenon when X90 linepipe steel is put in NS4 solution. The base material is thermodynamically more stable than the seam weld material. The base material and seam weld samples were polarized under â850Â mV polarization potential for different durations. It is demonstrated that with the proceeding of polarization, the polarization resistance and the corrosion resistance increase while the corrosion current density decreases. And the corrosion resistance of base material is better than that of seam weld material.
Keywords
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Physical Sciences and Engineering
Energy
Energy Engineering and Power Technology
Authors
Jinheng Luo, Liang Zhang, Lifeng Li, Fengping Yang, Weifeng Ma, Ke Wang, Xinwei Zhao,