When you look at the ocean and see cruise liners or huge cargo vessels pass by, do you wonder if the metal structure of these ships ever rusts? It’s a basic principle that when metals are submerged in water, they will corrode. Even the metal strap of your wrist watch will develop rust over time because sweat rubs on it. Corrosion is a natural process that can weaken metal surfaces and form rust.
On a grander scale, the hulls and propellers of giant ships are no exceptions. Since they are perpetually immersed in the sea and travel long miles, corrosion can seriously damage and weaken their metal structures. Ships, boats, pipelines and storage tanks are all pre-disposed to corrosion.
Protection Against Corrosion
In the shipping industry, the aluminum sacrificial anode is the rescuer of the vital metal parts of the ships and boats. When exposed to the sea environment, steel and other metals break down electrochemically and eventually fail. The said anode is literally used as the sacrificial lamb.
Sacrificial anodes are called to active duty to serve a single, specific purpose. They are created and designed to corrode instead of the necessary metal parts of the ship. These sacrificial anodes are known as active metals, yet they are far cheaper compared to the propellers, rudder, and ship engines. What is interesting is that these cheap metals get eaten away by rust instead of the major parts.
What are Sacrificial Anodes Made of?
Sacrificial anodes are usually made of three active materials namely aluminium, magnesium, and zinc. Each has different properties that are effective to prevent destruction to the ship’s metal parts plunged underwater.
The shape and sizes of the sacrificial anodes vary but perform a common task. They need to be connected electrically, meaning metal to metal – the anode and the metal part that needs protection.
What Is the Best Sacrificial Anode Material?
The aluminium sacrificial anode is seen as the ideal protector since aluminum is more active than zinc or magnesium. Most manufacturers and shipbuilders regard aluminum as the best metal material to use. Unlike zinc and magnesium, the aluminum-made anode can be used safely in all types of water. Another salient characteristic of aluminum which makes it a better alternative than zinc is that it is not a pollutant of the environment.
The Cathodic Protection System is used in various industries like energy, marine, industrial and infrastructure. All of the mentioned industries have a need for the aluminum sacrificial anode to avert damage to metal structures. It’s an added learning if you’re not into the metal stuff.