Endo And Exo Gas Generators In view of fundamental importance of carbon in determining the mechanical properties of steel, special attention has been devoted to those controlled atmosphere processes requiring control of carbon exchange between the furnace atmosphere and work being treated. To characterize the carbon exchange, the term carbon potential has been introduced (this denotes the carbon content which a pure iron specimen takes up in equilibrium with thw furnace atmosphere). The endothermic gas yields a potential between 0.7 to 0.9 which corresponds to the surface carbon content aimed at in the majority of processes. Endothermic atmospheres are used principally in the heat treatment of carbon steels and may be slightly carburizing to low carbon steels. These atmospheres have sufficient reducing constituent to prevent effectively any oxidation of the material being processed. They are substantially neutral to carbon steels. Endothermic gas is produced by the reaction of an air-gas mixture ranging from 25 to 40 % of perfect combustion. Since reaction in this range is endothermic, it is necessary to supply external heat.

Endo And Exo Gas Generators In view of fundamental importance of carbon in determining the mechanical properties of steel, special attention has been devoted to those controlled atmosphere processes requiring control of carbon exchange between the furnace atmosphere and work being treated. To characterize the carbon exchange, the term carbon potential has been introduced (this denotes the carbon content which a pure iron specimen takes up in equilibrium with thw furnace atmosphere). The endothermic gas yields a potential between 0.7 to 0.9 which corresponds to the surface carbon content aimed at in the majority of processes. Endothermic atmospheres are used principally in the heat treatment of carbon steels and may be slightly carburizing to low carbon steels. These atmospheres have sufficient reducing constituent to prevent effectively any oxidation of the material being processed. They are substantially neutral to carbon steels. Endothermic gas is produced by the reaction of an air-gas mixture ranging from 25 to 40 % of perfect combustion. Since reaction in this range is endothermic, it is necessary to supply external heat.