scholarly journals Digital Holographic Study of pH Effects on Anodic Dissolution of Copper in Aqueous Chloride Electrolytes

Metals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 487
Author(s):  
Changqi Yan ◽  
Boyu Yuan ◽  
Zhenhui Li ◽  
Liang Li ◽  
Chao Wang
Keyword(s):  
Dissolution Rate ◽  
Anodic Dissolution ◽  
Digital Holography ◽  
Acidic Solution ◽  
Ph Effects ◽  
Salt Layer ◽  
Aqueous Chloride ◽  
Cu2o Film ◽  
Pit Initiation ◽  
Holographic Study

The anodic dissolution of copper in chloride electrolytes with different pH has been investigated by using polarization measurements and digital holography. In acidic and neutral NaCl solutions, the oxidation processes of copper are almost the same: copper firstly dissolves as cuprous ions, which then produces the CuCl salt layer. The dissolution rate in the acidic solution is a little higher than that in the neutral. However, the mechanism is quite different in the alkaline NaCl solution: copper turns passive easily due to the formation of a relatively stable Cu2O film which results in pitting, and the dissolution rate of copper decreases before pit initiation.

Modeling the Interactions of Hydrogen, Stress and Dissolution in Near-Neutral pH Stress Corrosion Cracking of Pipelines

2006 ◽  
Author(s):  
Frank Y. Cheng
Keyword(s):  
Stress Corrosion ◽  
Dissolution Rate ◽  
Crack Growth ◽  
Anodic Dissolution ◽  
Hydrogen Concentration ◽  
Stress Corrosion Cracking ◽  
Crack Tip ◽  
Corrosion Cracking ◽  
Neutral Ph ◽  
Ph Stress

A thermodynamic model was developed to determine the interactions of hydrogen, stress and anodic dissolution at the crack-tip during near-neutral pH stress corrosion cracking in pipelines. By analyzing the free-energy of the steel in the presence and absence of hydrogen and stress, it is demonstrated that a synergism of hydrogen and stress promotes the cracking of the steel. The enhanced hydrogen concentration in the stressed steel significantly accelerates the crack growth. The quantitative prediction of the crack growth rate in near-neutral pH environment is based on the determination of the effect of hydrogen on the anodic dissolution rate in the absence of stress, the effect of stress on the anodic dissolution rate in the absence of hydrogen, the synergistic effect of hydrogen and stress on the anodic dissolution rate at the crack-tip and the effect of the variation of hydrogen concentration on the anodic dissolution rate.

scholarly journals Application of in situ digital holography to the study of the effect of a magnetic field on the anodic dissolution of iron in thichloroacetic acid

2006 ◽  
Vol 71 (1) ◽  
pp. 67-73 ◽  
Author(s):  
Xuegeng Yang ◽  
Shenhao Chen ◽  
Chao Wang ◽  
LI. Liang
Keyword(s):  
Magnetic Field ◽  
Acid Solution ◽  
Anodic Dissolution ◽  
Potentiodynamic Polarization ◽  
Trichloroacetic Acid ◽  
Digital Holography ◽  
Polarization Method ◽  
Trichloroacetic Acid Solution ◽  
The Magnetic Field

The effect of a magnetic field on the anodic dissolution of iron in 1.0 mol dm-3 trichloroacetic acid solution was studied by the potentiodynamic polarization method and in situ digital holography. It was found that the magnetohydrodynamic force increased the mass transport, which resulted in a faster anodic dissolution of iron. The effect of the magnetic field was analyzed by holograms and is discussed in terms of the magnetohydrodynamic force.

scholarly journals Investigation into the Anodic Dissolution Processes of Copper in Neutral and Acidic Sulfate Solutions with the In-line Digital Holography

2016 ◽  
Vol 84 (6) ◽  
pp. 378-382 ◽  
Author(s):  
Yongpan HU ◽  
Xijiao LI ◽  
Zhijuan JIAO ◽  
Guifei GAO ◽  
Boyu YUAN ◽  
...  
Keyword(s):  
Anodic Dissolution ◽  
Digital Holography ◽  
Sulfate Solutions ◽  
Acidic Sulfate

Surface modification of ferrosilide alloys for anode earthing

2020 ◽  
Vol 25 (3) ◽  
Keyword(s):  
Dissolution Rate ◽  
Anodic Dissolution ◽  
Silicon Content ◽  
Silicon Oxide ◽  
Iron Silicide ◽  
Mechanical Damage ◽  
High Porosity ◽  
Rate Of Dissolution ◽  
Magnetite Fe3o4 ◽  
The Relationship

It is known that the disadvantages of ferrosilide earthing devices are their fragility, which leads to their frequent mechanical damage. Their fragility is increased with increasing silicon content. The solution to this problem is to reduce the content of silicon in the alloy, but this greatly increases the rate of dissolution of the resulting alloy. As a result, the possibility of reducing the dissolution rate of ferrosilides with a silicon content of 9…12% due to thermal oxidation and treatment in a phosphoric acid medium was studied. The most promising method for anode grounding conductors is the method of processing materials in orthophosphoric and metaphosphoric acids with the formation on the surface of a phase of iron silicide highly resistant to anodic dissolution due to selective etching of the alloy. The relationship between the phase composition of the films showed that mainly phases of silicon oxide (SiO2) and magnetite (Fe3O4) predominate in the alloys, as a result of which the dissolution rate is significantly reduced. As a result of heat treatment of ferrosilide alloys with a silicon content of less than 14%, a decrease in the dissolution rate does not occur due to the high porosity of the formed films and the presence of phases that do not have protective properties. The anodic dissolution rate is the lower, when the grain size of the alloy used is the larger.

A Salt Layer Model for the Active Anodic Dissolution to Passive Transition of Nickel in Presence of Chloride

2019 ◽  
Vol 16 (48) ◽  
pp. 49-56
Author(s):  
Jerónimo Agrisuelas ◽  
José Juan García-Jareño ◽  
David Giménez-Romero ◽  
Joan Gregori ◽  
Michel Keddam ◽  
...  
Keyword(s):  
Anodic Dissolution ◽  
Layer Model ◽  
Salt Layer ◽  
Passive Transition
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