Rust is also known as iron oxide. Iron oxide is extremely common and it has the chemical signature, Fe203. Iron oxide is almost everywhere because iron reacts easily with oxygen. The reaction happens so easily that it's difficult to find pure iron in nature. Iron or steel which rusts is metal which is experiencing corrosion. This is an electrochemical process which involves an electrolyte, a cathode and an anode.
These three elements must be in place before rust can happen on iron. When iron, water in the air and oxygen are all present, as they so often are, rust may begin. This is why car owners who love their vehicles try to shield their cars from moisture when they can. The chassis of autos are very susceptible to corrosion. There are rust-proofing procedures which may help cars to stay free of iron oxide for longer.
The most common form of rust is red oxide, which forms when there is a redoc reaction between air and iron, while water is present or air moisture is present. Many types of rust may be classified by their appearance.
If rust goes untreated for long enough and the same three elements which caused it to start continue to be present, it may convert the entire metal piece to rust and then disintegrate.
Rust on a surface may flake and be friable. It won't protect the iron which is underneath. Patina on copper is protective. However, this isn't the case with rust. Rust is just not a good thing in any way.
There is also green rust, which is formed when rebar which is utilised for underwater construction experiences corrosion
Prevention is the best defence. Keeping metal dry is important. As well, you should treat rust right away. For example, if you notice rust forming on your car, be sure to do something about it. Don't procrastinate, as rust never sleeps. If you don't treat it with a product or device, it may become a big problem. It will eat away at the structural integrity of the metal and it won't look very nice, either.
Now that you know why metal rusts and which three elements need to be present before rust begin. It's safe to say that no one likes rust. It takes a toll on metal like nothing else.