Question

How Corrosion can be prevented?

Answer 1

Corrosion is a natural process that transforms refined metals into more chemically stable forms such oxide, hydroxide, carbonate, or sulphide. It refers to the slow decomposition of things (typically metals) due to chemical and/or electrochemical reactions with their surroundings. Corrosion engineering is the science of preventing and controlling corrosion.

Complete answer:
Electroplating: It's an electrolysis-based technique that coats a metal (I) with a thin coating of another metal (II). The new metal covering protects the metal (I) against corrosion in this way. Metal (I) (metal to be plated) is used as the anode and metal (I) (metal to be plated) is used as the cathode in this procedure. Metal 'I' is linked to the negative terminal, whereas metal 'II' is connected to the positive terminal. When electricity is applied to these two electrodes, oxidation occurs in the anode, resulting in the dissolution of metal II ions in the electrolyte. At the cathode, these dissolved metal II ions are reduced, resulting in a coating on metal I.

Cathodic Protection: The base metal is linked to a sacrificial metal that corrodes instead of the base metal in this procedure. This sacrificial metal (which is more reactive than the base metal) will release electrons and get oxidised as a result. The ions generated as a result of this process participate in corrosion processes, sparing the base metal.

Galvanization: This procedure includes applying a thin layer of zinc on iron. In most cases, this is accomplished by dipping iron in molten zinc. As a result, the zinc layer shields the iron against corrosion.

Painting and Greasing: Applying a coating of paint or grease to the metal can keep it from coming into contact with the outside world, avoiding corrosion.

Using Corrosion Inhibitor: Corrosion inhibitors are substances that, when introduced into a corrosion environment, reduce the rate of corrosion.

Use the Appropriate Material: Corrosion can also be avoided by selecting the correct material. Aluminium and stainless steel, for example, are extremely corrosion resistant.

Note:
Many structural alloys erode simply by being exposed to moisture in the air, but exposure to specific chemicals can have a significant impact on the process. Corrosion can be localised locally, forming a pit or fracture, or it can spread over a large region, corroding the surface more or less evenly. Corrosion happens on exposed surfaces because it is a diffusion-controlled process. As a result, techniques like passivation and chromate conversion that lower the activity of the exposed surface might improve a material's corrosion resistance. Some corrosion mechanisms, on the other hand, are less apparent and predictable.