Impressed current anode
An insoluble electrode tied to an external DC source to protect a structure cathodically from corrosion. It barely wears out compared to sacrificial anodes.
Physical-Chemical Mechanism of Action
The impressed current anode is an electrode tied to an external DC source. It draws electrical charges away from the structure (sacrificial anode) and thus prevents the structure from corroding. The electrolysis is activated by the current flow between the impressed current anode and the sacrificial anode.
Metallurgical Relevance & Risks in Welding
Using impressed current anodes in welding is important to protect the weldment from corrosion. If the electrode is not correctly set up or the current is not sufficient, the structure may still be prone to corrosion. A missing or defective impressed current anode can also cause damage to the weldment.
Workshop Practice & Action Instructions
When connecting an impressed current anode, make sure the electrode is correctly positioned and the current is sufficient. Always tie the electrode to an external DC source and ensure the structure is protected so that no corrosion can occur. Also regularly check the condition of the impressed current anode and adjust if needed.