The principle of sodium chloride causing corrosion in carbon steel
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We all know that an aqueous solution of sodium chloride is corrosive to carbon steel. What I would like to understand is the mechanism of this corrosion. Could anyone help me? Thank you in advance!
The corrosion of carbon steel in NaCl solution is oxygen-depolarized corrosion. The cathodic process of oxygen depolarization can be divided into two basic steps: the transport of oxygen to the metal surface and the ionization reaction of oxygen. For specific corrosion mechanisms, you can refer to some books on corrosion
Agree with what was said above; another reason why electrolyte solutions accelerate corrosion is that they increase the conductivity of the solution
I agree with the answers from the two people above. The electrochemical corrosion mechanism of carbon steel in sodium chloride solution is the same as that in water; it is oxygen-polarized corrosion. Both sodium chloride solution and water act as ionic conductors, but the conductivity of the sodium chloride solution is higher than that of water, which facilitates corrosion. Furthermore, due to the composition of carbon steel, a short-circuited galvanic cell is formed, resulting in rapid corrosion; the anode is carbon, the cathode is iron, and sodium chloride solution serves as the electrolyte.
One more thing to add: one is oxygen-polarized electrochemical corrosion, and the other is chloride ion corrosion
Upvote, great material! Thank you!
Could you please provide the corrosion rates at various temperatures? Thank you