Definition - What does Rust mean?
Rust is a coating that occurs on the surface of iron as it oxidizes. Rust is also known as iron oxide and corrosion. This chemical compound comes in many different combinations of iron and oxygen. Rust is reddish-orange in color. The speed of rust formation can be increased if the iron alloy is placed in corrosive environments.
Rust can have catastrophic effects on iron-based alloys. The rusting process can eventually thin the iron alloy until it is unsuitable for its original intended purpose. Excessive rusting can cause structures to collapse and pipelines to burst. Rust can also ruin the aesthetic appeal of iron components.
Corrosionpedia explains Rust
Rust forms as iron oxidizes. Oxidation occurs when there is an electrolyte and an electrical potential difference between two materials, which creates an anode and a cathode. During the rusting process, the oxygen atoms from the atmosphere or the electrolyte itself are transferred through the electrolyte and react with the iron to form iron oxide. Removing the electrolyte prevents the reaction from occurring.
Frequently, corrosion/rust prevention methods are initiated because of the detrimental effects that rust can have on iron structures and components. Paints and coatings are materials that prevent contact between the iron and an electrolyte. Paints and coatings also prevents excessive oxygen from contacting the iron.
Another method used for rust prevention is galvanic protection. This involves placing a sacrificial anode in contact with the iron component. The sacrificial anode will be more likely to absorb the oxygen molecules than the iron, which prevents the formation of iron oxide. Adding additional alloying elements to an iron-based alloy can also help prevent rust. Sufficient additions of chromium and nickel are used in stainless steel to prevent rust formation.