Cathodic protection
Cathodic protection prevents corrosion attack by making the metal the cathode of a galvanic cell. This protects the metal from chemical change.
Physicochemical mechanism of action
Cathodic protection is based on the principles of galvanization. The metal to be protected is made the cathode of a galvanic cell. This interrupts electrolyte reactions at the component and prevents corrosion attack.
Metallurgical relevance & risks when welding
Incorrect application or lack of control of cathodic protection can lead to incomplete protective layer formation, which in turn impairs resistance to corrosion. This can lead to premature failure and cracks in the metal.
Workshop practice & instructions
To ensure effective cathodic protection, the following steps must be observed:
1. Prepare the weld pool: Make sure the weld pool is clean and free of impurities.
2. Insert cathode elements: Place cathode elements like silver or zinc into the weld pool.
3. Control the welding process: Keep the temperature constant and avoid rapid temperature changes to ensure uniform protective layer formation.