Bluing is a means of making use of a protecting end to metal to stop rust and corrosion. It’s generally used on firearms, in addition to different steel objects. The method entails creating a skinny layer of magnetite (Fe3O4) on the floor of the steel. Magnetite is a black oxide of iron that’s extremely proof against corrosion.
There are a number of totally different strategies for bluing a gun. The commonest methodology is scorching bluing, which entails heating the steel to a excessive temperature after which making use of a bluing resolution. Different strategies embody chilly bluing, which is completed at room temperature, and rust bluing, which makes use of a chemical response to create the magnetite layer.