Water and steam react with most metals to form oxides or hydroxides. Formation of a protective oxide layer such as magnetite (Fe₃O₄) on the metal surface causes reaction rates to slow with time.
💧 Boiler cycle water treatment programs are designed to maintain such protective oxide films on internal surfaces and thus prevent corrosion in boilers and other cycle components. With adequate control of water and steam chemistry, internal corrosion of boiler circuitry can be minimized. Yet, chemistry upsets (transient losses of control) do occur.
⚙️ Vigilant monitoring of system chemistry permits quick detection of upsets and quick remedial action to prevent boiler damage. Where these measures fail and corrosion occurs, good monitoring and documentation of system chemistry can facilitate identification of the root cause, and identification of the cause can be an essential step toward avoiding further corrosion.
🔍 Where corrosion occurs and the origin is unknown, the documented water chemistry, location of the corrosion, appearance of the corrosion, and chemistry of localized deposits and corrosion products often suggest the cause.
🔥 Common causes are:
flow accelerated corrosion
oxygen pitting
chelant corrosion
caustic corrosion,
acid corrosion
organic corrosion
acid phosphate corrosion
hydrogen damage
corrosion assisted cracking
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