Distilled water, lacking the salts necessary to form protective films, exhibits significant corrosion potential toward zinc coatings. Its corrosiveness ranks second only to rainwater, being slightly higher than soft water and approximately three-quarters of the corrosion rate observed in tap water environments.
When a very thin aqueous film forms on the zinc surface, oxygen concentration reaches its maximum within the water film, leading to particularly aggressive corrosion conditions under such circumstances.
Generally, the corrosion rate of zinc coatings in distilled water ranges from 50 to 200 mg/dm²·day.
