It has been grand living about 2 football fields from the Gulf of Mexico. Not so much for our metal family members, namely bicycles, the hitch, and the underside of the truck. What was once shiny and chrome, or clean iron, is now a coppery-rust. Salt air is not their friend.
The purpose of this post is not to show you that metal rusts. We all know that. It's to remind you that being so close to seawater will speed up the process. And before you know it, all your iron is oxidizing.
Rust is the common name for a very common compound, iron oxide.
For iron to become iron oxide, three things are required: iron, water and oxygen. Here's what happens when the three get together:
When a drop of water hits an iron object, two things begin to happen almost immediately. First, the water, a good electrolyte, combines with carbon dioxide in the air to form a weak carbonic acid, an even better electrolyte. As the acid is formed and the iron dissolved, some of the water will begin to break down into its component pieces -- hydrogen and oxygen. The free oxygen and dissolved iron bond into iron oxide, in the process freeing electrons. The electrons liberated from the anode portion of the iron flow to the cathode, which may be a piece of a metal less electrically reactive than iron, or another point on the piece of iron itself.
The chemical compounds found in liquids like acid rain, seawater and the salt-loaded spray from snow-belt roads make them better electrolytes than pure water, allowing their presence to speed the process of rusting on iron and other forms of corrosion on other metals.
(Courtesy of http://science.howstuffworks.com/question445.htm)
Of course, chrome doesn't actually rust. Chrome is applied to metal and in doing so prohibits any oxygen from interacting with the metal, thus preventing oxidation from occurring. Oxidation is part of the rusting process.
The metal to which chrome is bonded rusts. Apparently, any tiny scratch in the chrome will allow oxygen and perhaps, water, in to make contact with the metal below.
You will see rust at these fissures. But below the chrome, the rust is consuming the metal.
Even our laundry drying rack wasn't safe.