Industry | The global cost of corrosion is about 4 trillion US dollars How to deal with the challenge of ocean corrosion?

In 2018, global natural disaster losses totaled 160 billion U.

75em; text-indent: 2em; font-family: ; font-size: 16px; box-sizing: border-box; -webkit-tap-highlight-color: rgba(0, 0, 0, 0);">Anti-corrosion measures should consider cost and convenience

75em; text-indent: 2em; font-family: ; font-size: 16px; box-sizing: border-box; -webkit-tap-highlight-color: rgba(0, 0, 0, 0);">Anti-corrosion measures should consider cost and convenience

75em; text-indent: 2em; font-family: ; font-size: 16px; box-sizing: border-box; -webkit-tap-highlight-color: rgba(0, 0, 0, 0);">Anti-corrosion measures should consider cost and convenience

Anti-corrosion measures should consider cost and convenience.

Anti-corrosion measures should consider cost and convenience.
The main countermeasures for equipment failure due to corrosion are various, including coating /plating, corrosion-resistant materials , surface treatment and modification, cathodic protection, corrosion inhibitors, Structural health monitoring and testing, safety evaluation and reliability analysis, and life assessment, etc.
Coating anti-corrosion materials "The measures adopted depend on the cost and the service conditions during actual use.
" Han Enhou introduced the protective effects of different measures.
Coating treatment is the mainstream.
Academician Ke Wei’s survey results show that it accounts for 75.
6% of corrosion control measures in my country.
Most of the corrosion that people see is electrochemical corrosion, and the occurrence of electrochemical corrosion requires conductors of water, ions and electrons, and the coating can block the diffusion of water, oxygen and corrosive ions into the protected material to achieve With the effects of anti-corrosion, anti-fouling, and drag reduction, marine steel structures such as ships, containers, bridges, docks, and offshore platforms all adopt this protective measure.
Corrosion-resistant materials account for 12.
5% ​​of corrosion control measures.
Passive metals such as stainless steel and titanium alloys are corrosion-resistant materials.
In the marine environment, because there is a passivation film layer of several nanometers thick, it can protect the base metal well; non-passive metals can form a stable rust layer , Based on uniform corrosion, life can be monitored.
In terms of surface modification, chemical and physical methods are used to change the chemical composition or structure of the surface of the material or workpiece to improve the corrosion resistance of the component.
Surface modification generally includes chemical heat treatment, laser remelting composite, ion implantation, nanometerization and so on.
In terms of cathodic protection, it is pursued to reduce the corrosion current.
"From the corrosion thermodynamic curve, once it enters the non-corrosive zone, no corrosion will occur.
" But Han Enhou also said that too low a control potential will also cause hydrogen to enter and make the material brittle, so the cathodic protection potential should be appropriate.
In terms of corrosion inhibitors, chemical substances with surface activity are first physically adsorbed on the metal surface, and then converted into chemical adsorption, occupying the active points on the metal surface, thereby achieving the effect of inhibiting corrosion.
Life expectancy is the most difficult in the entire corrosion control process.
Only by mastering the corrosion kinetics process, especially the process of local corrosion development kinetics, finding out the law and establishing a model, can accurate prediction be made.
Han Enhou said, “Accelerating material performance tests under simulated service environment conditions in the laboratory is the key to understanding the law and obtaining predictive models.
”