# What is rust? Explained.



## Chris (Sep 15, 2003)

Here is my simple explanation of rust and why is occurs. Just fresh on my mind with my flail mower. Rust, Corrosion, is more properly called iron oxide. It is chemically the stable form of steel. Iron ore, the raw mineral we mine to make steel, is actually iron oxide. Rust! That's right, steel is made from rust. It spends the rest of its life trying to return to its natural state.

In order to have rusting take place, you need three things: Steel, Oxygen, and Heat. It's just like the three items needed for a fire: Fuel (the steel), Heat (any temperature above freezing), and Oxygen (to support the burning or rusting). In fact, rust can be thought of as a slow burn, like charcoal, where rust is the ash.

Various treatments are available that will slow, or seemingly eliminate the burning process. By converting the iron oxide to iron phosphate, we are converting the unstable oxide from to a stable inert metal. This is probably not a permanent solution but it does tell to cut the cycle off at the knees. 

Hope this helps. 
Andy


----------



## guest2 (Dec 27, 2003)

So where does water/moisture enter into the picture? I know bare steel will form a light rust w/o any moisture but it sure seems to speed the process.


----------



## CatDaddy (May 30, 2004)

> _Originally posted by sixchows _
> *So where does water/moisture enter into the picture? I know bare steel will form a light rust w/o any moisture but it sure seems to speed the process. *


Water is an oxidizer. That's why speeds up the 'rusting' process.

Angel


----------



## Chipmaker (Sep 16, 2003)

Just a smidgen of humidity is sufficient for rust or other corroision on other materials to start forming. Thats why the military stores its excess and old aircraft in the Arizona desert as it has the least amount of humidity in the US territory. When I was in Kuwait and some other desert countries, rust was virtually non-existent due to lack of humidity. Since humidity is comprised of water, and water is an oxidizer things are gonna rust.


----------



## jodyand (Sep 16, 2003)

Salt is one heck of an oxidizer. I was at Morton salt at Weeks island once and i asked one of the guy there what they did with the tractors down in the mine when they got new ones. He said they had a spot that that park them at under ground. He said that they would first have to cut them up to get them out (thats the only way to get new tractors down there is to take them apart and send them piece by piece down the elevator and put them back together down in the hole.) He said that they had so much salt soaked in the metal that if they were top side they would be a pile of rust in a week. Every thing metal we used there the next day was rusted and had to be clean and oil the next day.


----------



## luckycharms (Dec 4, 2003)

That is simply amazing, Jody. I have never seen or heard anything like that before. Sounds like a good feature story for Discovery Channel or something.

Thanks for sharing.
:lucky: :lucky: :lucky: 
-LC


----------



## Carm (May 27, 2004)

Salt needs moisture (humidity) to corrode something. It acts as an electrolyte to speed up the corrosion process. Galvanizing is meant to slow corrosion by having a ferrous metal coated in a more easily corroded substance, usually Zinc. The zinc will corrode away before the steel begins to. Also, there is cad plating, which is usually used on hardware and smaller parts. There are other methods for different types of metals.


----------

