Definition - What does Oxygenation mean?
Oxygenation is an electrochemical process by which a temperature rise provides enough additional energy to accelerate reactions on metal surfaces, resulting in rapid and severe corrosion.
Oxygen attack is the most common cause of corrosion inside boilers. Dissolved oxygen in feedwater can become very aggressive when heated and reacts with the boiler’s internal surface to form corrosive components on the metal surface. Oxygenation can cause further damage to:
- Steam drums
- Mud dams
- Boiler headers
- Condensate piping
The entire boiler system is susceptible to oxygenation. Oxygen attack leads to:
- Failure of critical parts of the boiler system
- Deposition of corrosion products in critical heat exchange areas
- Overall efficiency loss
Petropedia explains Oxygenation
Oxygenation may lead to corrosion on a metal surface caused by dissolved oxygen in water. For example, internal boiler corrosion is normally the result of oxygen attack and/or low pH, and is potentially dangerous due to the pressures and temperatures associated with an operating boiler.
Every metal surface of the boiler system is vulnerable to oxygenation. Oxygen forms localized corrosion areas referred to as pits. Oxygen pits can rapidly "drill" through metal surfaces, leading to metal fatigue and failure. As oxygen corrodes the boiler metal, it dissolves the iron surface. This weakens the metal site, but more importantly, it sends dissolved iron into the boiler. This dissolved iron is deposited on boiler tubes, causing overheating and tube failure.
The following are three critical factors govern the onset and progress of oxygenation:
- Presence of moisture or water
- Presence of dissolved oxygen
- Unprotected metal surface
The corrosiveness of water increases as temperature and dissolved solids increase, and as pH decreases. Aggressiveness generally increases with an increase in oxygen.