Sacrificial anodic protection
Sacrificial anode corrosion protection connects a less noble metal to the part being protected so that the anode corrodes preferentially and the part stays safe.
Physical-Chemical Mechanism of Action
A less noble metal (sacrificial anode) is electrically connected to the part to be protected. The sacrificial anode corrodes preferentially, while the higher metal (cathode) stays protected.
Metallurgical Relevance & Risks in Welding
Wrong selection or use of the sacrificial anode can lead to unwanted corrosion of the part. It’s important to ensure the correct electrochemical potential sequence and material compatibility.
Shop Practice & Instructions
1. Determine the right less noble metal as the sacrificial anode for the part to be protected.
2. Connect the two materials electrically, e.g., with a bolt or bonding wire.
3. Check the corrosion situation regularly and adjust protection measures if needed.