Home > News & Information >

News & Information

Corrosion principle of salt spray test machine

The salt spray test chamber uses a salt-containing solvent or an acid salt-containing solvent to accelerate corrosion of the material or product under a certain temperature and relative humidity to reproduce the degree of damage suffered by the material or product within a certain period of time. So what is the corrosion mechanism of the salt spray test machine?
The salt spray test chamber corrodes the metal material, mainly the conductive salt solvent penetrates into the metal to react electrochemically, forming a "low potential metal-electrolyte solvent-high potential impurity" micro-battery system, electron transfer occurs, and the metal as the anode appears. Dissolved to form a new compound, a corrosive.
Similarly, when the metal protective layer and the organic material protective layer are infiltrated into the inside, a microbattery in which a metal is used as an electrode and a metal protective layer or an organic material is used as another electrode is formed.
The salt spray test chamber plays a major role in the corrosion process of chloride ions. It has a strong penetrating power and easily penetrates the metal oxide layer into the metal interior, destroying the passive state of the metal. At the same time, the chloride ion has a small hydration energy and is easily adsorbed on the metal surface, replacing the oxygen in the oxide layer of the protective metal to destroy the metal.
In addition to chloride ions, the salt spray test chamber is also affected by oxygen dissolved in a salt solvent. Oxygen can cause the depolarization process of the metal surface, accelerate the dissolution of the anode metal, and continuously deposit on the surface of the sample due to continuous spraying during the salt spray test, so that the oxygen content is kept close to saturation.
The formation of corrosion products expands the volume of the salt solvent that penetrates into the metal defects, thus increasing the internal stress of the metal, causing stress corrosion, causing the protective layer to bulge.
For more details, please feel free to contact sales@lenpure.com
Please visit www.lenpure.com