Definition - What does Reducing Atmosphere mean?
A reducing atmosphere is an atmospheric condition in which oxidation is prevented by removal of oxygen and other oxidizing gases or vapors. It lacks free oxygen, and may contain such reactive gases as hydrogen and/or carbon monoxide that oxidize in the presence of oxygen, such as hydrogen sulfide.
In metal processing, a reducing atmosphere is used in annealing ovens for relaxation of metal stresses without corroding the metal.
Reducing atmospheric principles apply to commercial incinerators as well as planets. The early atmosphere of the Earth was a reducing atmosphere, meaning there was little to no oxygen.
A reducing atmosphere is also known as a reduction atmosphere.
Corrosionpedia explains Reducing Atmosphere
A reducing atmosphere is an atmosphere of hydrogen (or other constituent that willingly provides electrons) surrounding a chemical reaction or physical device; the effect is the reverse of an oxidizing atmosphere.
Variances between oxidizing and reducing atmospheres depend on the composition of the surface and atmospheric gases. An oxidation atmosphere has ample oxygen for the fuel to burn; a reduction atmosphere occurs when the amount of available oxygen is lessened.
In a commercial incinerator, a reducing atmosphere is made by depriving the it of oxygen, inspiring the release of carbon-bearing fumes. These fumes are then oxidized in reburn tunnels where oxygen is injected gradually. This system allows lower temperatures to be employed in the incinerator section, where the solids are volumetrically reduced.
In the case of brazing operations not confined within an inert or reducing atmosphere environment (such as a furnace), flux is prerequisite to avoid oxides from forming while the metal is heated.