Corrosion is a natural process that affects our metals. The oxygen contained in the water, air, etc, could have been combined with the different metals, particularly ferrous metals like steel. The product of that process is the rust and the metal consumption. If we don´t take steps to stop, the process continues until the metal extinction. Keeping clean, painting, and electrostatic processes, like chroming, zinc plating, are the most common tools to preserve the metals.