Chloride corrosion

Chloride corrosion is a specific form of corrosion caused by the presence of chloride ions (Cl-) in the environment. It occurs mainly in metals such as steel, stainless steel, aluminum and copper and can cause serious damage, especially if the material is used in humid or salty environments. Chloride corrosion is a common problem in areas such as shipping, the offshore industry, construction and the chemical industry.

The chloride ions attack the passive layer that protects many metals from corrosion. Once this protective oxide layer is damaged, localized corrosion can occur, such as pitting or crevice corrosion. These forms of corrosion are particularly dangerous as they often go unnoticed until the material has already been significantly weakened.

Chloride corrosion is favored by various factors, including high chloride concentrations (e.g. from salt water or road salt), high temperatures and low pH values. Stresses in the material, such as those caused by mechanical loads, can also increase susceptibility to chloride corrosion.

Various measures are taken to protect against chloride corrosion, such as the selection of corrosion-resistant materials (e.g. high-alloy stainless steels), the use of protective coatings, cathodic corrosion protection or the avoidance of chloride sources. Regular inspections and maintenance are also important in order to detect and rectify damage at an early stage.