Nitrogen for Heat Treating avoids edge oxidation and decarburisation during the process, a shielding nitrogen atmosphere is used. The heat-treating process involves both heat and pressure. Heat treating entails warming the metal to a designated degree and maintaining that hot temperature. The high heat changes the microstructure or physical properties of the metal. Once the desired effect is obtained, the metal is set to cool. This method is used to make different metals, alloys and other materials. More about the industry here.