Erosion corrosion
Encyclopedia
Erosion corrosion is a degradation of material surface due to mechanical action, often by impinging liquid, abrasion by a slurry, particles suspended in fast flowing liquid or gas, bubbles or droplets, cavitation
, etc. The mechanism can be described as follows:
The mechanism of erosion corrosion, the materials affected by it, and the conditions when it occurs are generally different than that of flow-accelerated corrosion
, although the last one is sometimes classified as a sub-type of erosion corrosion.
Surface chemistry can play a role in erosion corrosion due to mechanochemical
effects.
Erosion corrosion is the second most common cause of copper tube failure
.
Cavitation
Cavitation is the formation and then immediate implosion of cavities in a liquidi.e. small liquid-free zones that are the consequence of forces acting upon the liquid...
, etc. The mechanism can be described as follows:
- mechanical erosion of the material, or protective (or passive) oxide layer on its surface,
- enhanced corrosion of the material, if the corrosion rate of the material depends on the thickness of the oxide layer.
The mechanism of erosion corrosion, the materials affected by it, and the conditions when it occurs are generally different than that of flow-accelerated corrosion
Flow-accelerated corrosion
Flow-accelerated corrosion , also known as flow-assisted corrosion, is a corrosion mechanism in which a normally protective oxide layer on a metal surface dissolves in a fast flowing water. The underlying metal corrodes to re-create the oxide, and thus the metal loss continues.By definition, the...
, although the last one is sometimes classified as a sub-type of erosion corrosion.
Surface chemistry can play a role in erosion corrosion due to mechanochemical
Mechanochemistry
Mechanochemistry is the coupling of the mechanical and the chemical phenomena on a molecular scale and includes mechanical breakage, chemical behaviour of mechanically-stressed solids , tribology, polymer degradation under shear, cavitation-related phenomena , shock wave chemistry and physics, and...
effects.
Erosion corrosion is the second most common cause of copper tube failure
Erosion corrosion of copper water tubes
Erosion corrosion, also known as impingement damage, is the combined effect of corrosion and erosion caused by rapid flowing turbulent water. It is probably the second most common cause of copper tube failures behind Type 1 pitting which is also known as Cold Water Pitting of Copper Tube.-Copper...
.
Further reading
- Alan Levy, "Solid Particle Erosion and Erosion-Corrosion of Materials", ASM International, 1995.