Definition - What does Erosion Corrosion mean?
Erosion corrosion is the combined effect that occurs due to corrosion and erosion and is caused by the rapid flow of any turbulent fluid on a metal surface. Pitting, which is often found on the inner surfaces of pipes, is the main cause of turbulence.
The rate of erosion increases in turbulent conditions and can result in leakages in tubes and pipes.
Erosion corrosion can also result from poor workmanship. When burrs in the tubes are not removed during installation, these inner burrs cause localized turbulence and hinder the smooth flow of the fluid.
This leads to high rates of pitting in the tubes.
Corrosionpedia explains Erosion Corrosion
When fluid is flowing through a pipe, the velocity of the fluid and the physical effect of the fluid moving against the surface is combined with the corrosive action of the moving fluid. This in turn causes an accelerated loss of metal.
The metal usually has a protective film, which is the first part to be eroded by the fluid. Once the film is gone, the bare metal is exposed to corrosion. This type of corrosion is common in constriction areas. These are areas where there are blockages, inlet ends, pump impellers as well as other places where there are high rates of flow.
Cultivation corrosion is a form of erosion corrosion. This is a special type caused by water bubbles produced by high-speed impellers. This causes the formation of pits on the surface of the metal.
Erosion corrosion can be prevented or reduced through any of the following methods:
- Reduce the turbulence of the fluid in the tube by streamlining the piping.
- Control the velocity of the fluid to reduce high-flow velocities.
- Use corrosion-resistant materials.
- Use corrosion inhibitors and cathodic protection.
- Ensure that the entire piping system has been de-burred.
- Replace sharp angles in the piping system with gentler angles to avoid constrictions.
- Reduce the amount of oxygen dissolved in the fluid.
- Adjust the pH value of the fluid.
- Change the metal alloy.