Definition - What does Reducing Atmosphere mean?
A reducing atmosphere is a gaseous environment with a lessened amount of oxygen as a free-form vapor as a single unit or in a mixture. It often contains other reactive gaseous elements or compounds such as hydrogen or nitrogen. Such an atmosphere is used in annealing ovens to lessen the stress of a metal.
Corrosionpedia explains Reducing Atmosphere
A reducing atmosphere facilitates the occurrence of reduction reactions, which are achieved whenever an atom gains electrons and obtains a charge that is a reduction of the oxidation number. The atom or element that initiates a reduction reaction is known as the reducing agent.
For example, the corrosion of iron occurs in the presence of oxygen and water. Oxygen acts as the oxidizing agent while water acts as the reducing agent. Therefore, when a piece of iron is placed in a moist environment, the environment acts as a reducing atmosphere.