Kloriidmiljöer

Kloriidmiljöer, or chloride environments, refer to chemical environments where chloride ions (Cl-) are present in significant concentrations. Chloride ions originate from salts such as sodium chloride, calcium chloride, or seawater and can influence corrosion, chemical reactions, and material compatibility. These environments can be acidic, neutral, or alkaline, but the presence of chlorides often accelerates localized attack on metals.

Common sources and settings include seawater and brackish water, road and bridge de-icing salts, brines used in food processing or chemical industries, and certain industrial or marine atmospheres. Factors such as temperature, humidity, pH, oxygen availability, and the total chloride concentration determine the severity of the exposure.

The most affected materials are metals, particularly steels and stainless steels, as well as certain aluminum and magnesium alloys. In chloride environments, metals may experience uniform corrosion, pitting corrosion, crevice corrosion, or, in some cases, stress corrosion cracking. Stainless steels are vulnerable to pitting and crevice corrosion initiated at chloride-rich regions, while plain carbon steels can suffer rapid pitting and accelerated corrosion in seawater or saline environments. In reinforced concrete, chlorides penetrate the concrete and depassivate the steel reinforcement, leading to localized corrosion and potential structural weakening.

Mitigation strategies include selecting corrosion-resistant materials or alloys, applying protective coatings or sealants, using cathodic protection, and limiting chloride ingress through design, coatings, moisture control, and concrete mix optimization. Regular inspection and monitoring help detect early signs of chloride-induced attack.