Chemical reaction in which an atom loses an electron. The consequence is that that atom forms a new structure, causing oxidation.
In order to have a reduction-oxidation reaction there must be one element that loses electrons and another that accepts them. These two reactions always occur together.
The oxidizing agent is the chemical element that tends to capture these electrons, remaining in a lower oxidation state than it had.
In the processes of rolling and forging of steels, due to the action of oxygen in the air, surface oxidation occurs. This oxidation consists of the formation of the scale or iron oxide on the surface of steel. During the process oxidation must be controlled because it can produce losses of material. The resulting scale in the final product is usually removed before cold transformations are carried out on these products.
In the heat treatment, controlling the atmosphere in the furnace is critical to avoid oxidation.