Both corrosion and erosion happen due to certain external actions on a surface. Corrosion means the destruction of materials through chemical reactions whereas erosion means the carrying away of the topsoil from the surface of the earth.
Corrosion normally happens because of chemical reactions. Erosion occurs by chemical reactions and by certain forces of nature. Corrosion also means the loss of electrons from the metals when it comes in contact with the moisture and oxygen in the atmosphere. Erosion happens because of natural forces like water and wind. Other factors such as acid rain, salt effects and oxidation of materials are also known to cause erosion.
In terms of the process, corrosion is an electro chemical process whereas erosion is a physical process. The corrosion of metals is often referred to as rusting and it is evident in the material itself. Erosion is a natural process that removes or carries away materials from one place to another. For instance, when sand is carried away from the beach or riverbanks, it is still sand even after erosion. Corrosion isn’t like that. When corrosion takes place, the material will be transformed to another chemical compound known as rust.
Various types of corrosion include galvanic, crevice, pitting, intergranular and selective leaching. Erosion also involves several different processes like weathering, transportation, and dissolution. Both corrosion and erosion can be prevented. To prevent corrosion, a protective layer is coated on the surface of the metal that constantly comes in contact with the atmosphere. Terracing the terrain or planting more trees on the surfaces where erosion is likely to happen can prevent erosion.