Definition - What does Base Metal mean?
A base metal is a metal that oxidizes or corrodes easily and reacts variably with hydrochloric acid to form hydrogen gas. The best examples of base metals are:
Copper is also included in this group because it oxidizes fairly easily, even though it does not react with hydrochloric acid. The oxidation of these metals forms oxides, which are commonly referred to as rust. Rusting is the common term for corrosion of iron and its alloys.
Corrosionpedia explains Base Metal
At the atomic level, iron combines readily with oxygen, forming a new compound called an oxide. The oxide weakens the bonds of the metal. In this case, the base metal is iron and therefore the resulting rust is called iron oxide. Water and oxygen are the main components for base metal oxidization. For instance, when water comes in contact with a base metal, it easily penetrates through the cracks of the metal and then the hydrogen atoms present in the water form carbonic acids, leading to the exposure of the metal.
In industrial settings, coatings are used to provide the highest level of corrosion resistance to various base metals used in industrial components, such as pipelines. This is done to preserve the integrity of the base metal and keep machinery, equipment and parts free of rust or any form of corrosion wear.