Common types of metal corrosion in heat exchangers

Metal corrosion refers to the destruction of metal produced by the chemical or electrochemical action of the surrounding medium, and often in conjunction with physical, mechanical or biological factors, that is, the destruction of metal under the action of its environment.

The common types of metal corrosion of plate heat exchanger are as follows:

Uniform corrosion in the entire surface exposed to the medium, or in a larger area, the macro uniform corrosion damage is called uniform corrosion.

Crevice corrosion Severe crevice corrosion occurs in the crevices and covered parts of the metal surface.

Contact corrosion Two kinds of metal or alloy with different potential contact each other, and immersed in electrolyte solutive solution, there is a current between them, the corrosion rate of positive metal potential decreases, the corrosion rate of negative metal potential increases.

Erosion corrosion Erosion corrosion is a kind of corrosion that accelerates the corrosion process due to the relative motion between the medium and the metal surface.

Selective corrosion The phenomenon that an element in an alloy is corroded into the medium is called selective corrosion.

Pitting corrosion concentrated on individual small spots on the metal surface of greater depth of corrosion is called pitting corrosion, or pore corrosion, pitting corrosion.

Intergranular corrosion Intergranular corrosion is a kind of corrosion that preferentially corrodes the grain boundary and the area near the grain boundary of a metal or alloy, while the grain itself is less corroded.

Hydrogen Destruction Destruction of metals in electrolyte solutions by hydrogen infiltration can occur as a result of corrosion, pickling, cathodic protection, or electroplating.

Stress corrosion fracture (SCC) and corrosion fatigue are the material fracture caused by the joint action of corrosion and tensile stress in a certain metal-medium system.

Post time: Aug-20-2022