A synergistic effect of dissolved oxygen, $$HCO_3^-$$, and Cl− on the electrochemical corrosion behavior of X70 pipeline steel in the oilfield soil environment

2020 ◽  
Vol 126 (11) ◽  
Author(s):  
Fei Xie ◽  
Zeqi Wang ◽  
Dan Wang ◽  
Siwen Yin
Keyword(s):  
Synergistic Effect ◽  
Dissolved Oxygen ◽  
Corrosion Behavior ◽  
Pipeline Steel ◽  
Electrochemical Corrosion ◽  
Soil Environment ◽  
X70 Pipeline Steel ◽  
Electrochemical Corrosion Behavior

Study of Electrochemical Behavior, Hydrogen Permeation and Diffusion in Pipeline Steel

2021 ◽  
Vol 1019 ◽  
pp. 145-156
Author(s):  
Swapna Dey ◽  
Seetharaman Sivaprasad ◽  
Nityananda Das ◽  
Indranil Chattoraj
Keyword(s):  
Corrosion Behavior ◽  
Hydrogen Permeation ◽  
Pipeline Steel ◽  
Electrochemical Corrosion ◽  
Hydrogen Distribution ◽  
X70 Pipeline Steel ◽  
Hydrogen Flux ◽  
Hydrogen Damage ◽  
Internal Surfaces ◽  
Neutral Soil

The pipeline steels which are used for transportation of natural gas and crude oil suffer from hydrogen damage at their internal as well as external surfaces. The internal surfaces of pipelines are generally affected due to hydrogen induced cracking and the external surfaces due to the soil environmental conditions which cause stress corrosion cracking. In the present investigation, the electrochemical corrosion behavior of X70 pipeline steel was studied in sour environment and near neutral soil environment. To assess the mechanism of hydrogen damage in steel, electrochemical hydrogen charging and permeation techniques were used to characterize the hydrogen distribution, trapping and its diffusion in X70 pipeline steel. It has been found that corrosion behavior of pipeline steel in the sour environment is higher than the near neutral soil solution. From the hydrogen permeation study it is established that the hydrogen permeation rate increases with the square root of the charging current density, and the increase of hydrogen flux is directly proportional to the subsurface hydrogen concentration.

Effects of Temperature on Corrosion Behavior of X70 Steel in Halons

2011 ◽  
Vol 311-313 ◽  
pp. 996-1000 ◽  
Author(s):  
Jing Xu ◽  
Jian Wei Yang ◽  
Jian Ping Cao ◽  
Chen Chen
Keyword(s):  
Corrosion Behavior ◽  
Polarization Curve ◽  
Corrosion Test ◽  
Electrochemical Impedance ◽  
Pipeline Steel ◽  
Electrochemical Corrosion ◽  
Corrosion Current ◽  
X70 Pipeline Steel ◽  
Cathode Reaction ◽  
Immersion Corrosion

The corrosion behavior of X70 pipeline steel in 0.5% NaC1 solution in different temperature of 25°C、35°C and 55°C was studied by dynamic potential polarization curve and electrochemical impedance spectroscopy（EIS）method. The corrosion topography of X70 pipeline steel in normal temperature and 30°C was also compared in immersion corrosion test after 25 days. The results show that when the temperature rises, the corrosion current density Icorr increases, the linear polarization resistance reduces, cathode polarization curve right shift, caused corrosion rate increases which primarily by the increasing the transmission of reactant in the cathode reaction. Pitting corrosion developed after 25 days immersion corrosion in 30°C solution which proved the promoter action of temperature to pit corrosion, and which is agreed with the electrochemical corrosion test results.

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