What Does Dry Corrosion Mean?
Dry corrosion, sometimes also called chemical corrosion, is a type of corrosion that occurs without moisture or water, which are the main drivers of the conventional types of corrosion. In dry corrosion, metal oxidizes with only the atmosphere, in a process sensitive to temperature. Dry corrosion, therefore, refers to an oxidation process sustained by oxygen in the air without a liquid solution.
At ambient temperatures, most engineering metals have slow oxidation rates in a given atmosphere with different mechanisms. When oxygen gets in contact with a metal surface, an oxide layer forms slowly with time. The layer restricts oxygen from reaching the metal surface, decreasing the corrosion rate.
Dry corrosion is not as severe as wet corrosion in most cases, and it occurs with mechanisms dependent of temperature and type of materials.
Corrosionpedia Explains Dry Corrosion
Corrosion of metals is defined as the spontaneous deterioration caused by the chemical interaction of metal with the surrounding environment. Because most corrosion is the formation of metal oxides, any metal can oxidize if oxygen is present, whether water is present or not.
Dry corrosion is sustained by oxygen, but also atmospheric gases such as hydrogen, sulphide, nitrogen, halogens, or anhydrous inorganic fluids.
Under hot conditions, dry corrosion occurs at a much faster rate than in normal conditions. However, alloys with oxidation reactions develop protective scales against further corrosion, including sulfidation and carburization, and other high-temperature attacks.
Corrosion is a worldwide problem that costs billions of dollars. Corrosion incidents in industry cause shutdowns of chemical plants, human and financial losses and property destruction. This is why chemical plants enforce safety precautions extending to ensure proper materials selection, quality control during manufacturing and fabrication, and routine maintenance.