Pitting Corrosion
Pitting corrosion is a localized corrosion on passivated metals caused by chlorides, which eats deep into the material and leads to wear spots.
Physicochemical mechanism of action
Pitting corrosion occurs when chloride ions act on passivated metals. These ions react with the metal, strip off its protective oxide, and enable a continuous corrosion reaction at the attack points.
Metallurgical relevance & risks in welding
This corrosion can lead to localized wear and cracks, especially in highly stressed areas. It reduces the strength and service life of the material, which is especially dangerous for critical components or under high loads.
Workshop practice & action guidelines
To avoid pitting corrosion, chloride-containing substances should be removed from the weld zone. This can be achieved by careful cleaning and using corrosion-resistant protective agents. For heavily stressed parts, periodic inspection for corrosion is necessary to take early action.