Sacrificial Anode Cathodic Protection
Sacrificial anode cathodic protection shields metal parts by using a less noble metal as the anode, which corrodes instead. This keeps the protected part from corroding.
Physical-Chemical Mechanism of Action
In sacrificial anode cathodic protection, a less noble metal (such as zinc or galvanized steel) acts as the anode. It gives up electrons while the protected metal (cathode) receives them. This prevents corrosion of the protected part.
Metallurgical Relevance & Risks in Welding
Wrong selection or application of the sacrificial metal can lead to insufficient protection and leave the part vulnerable to corrosion. It’s important that the sacrificial metal is in the right galvanic series and that the correct anode distribution is ensured.
Shop Practice & Instructions
Pick a less noble metal as the anode that can corrode more easily. Make sure the anode is well connected to the protected metal and provides enough surface area for electron transfer. Check the condition of the sacrificial metal regularly and replace it when needed.