K. A. Connery, S. Ho, Praxair, Inc., Burr Ridge, IL
A method and system employing an oxygen free gas blend for use in carburizing and other heat treating applications is presented. The system uses model predictive software control with a gas mixing station to deliver precise amounts of a carbon-containing, nitrogen-based gas blend to an atmospheric pressure furnace throughout the heat treating process. The precise control, simplicity of the gas blend and absence of oxygen provide the process benefits of: traceability; low flammability and low toxicity; minimization of process cycle time, and minimization of intergranular oxidation (IGO) in the treated parts. These benefits are provided at a capital cost much lower than low-pressure systems since it can be retrofit to existing batch or continuous furnaces.
Summary: A method and system employing an oxygen free gas blend for use in carburizing and other heat treating applications that can be retrofit to existing batch or continuous furnaces is presented. Benefits include : traceability, low flammability and low toxicity, minimization of process cycle time, and minimization of intergranular oxidation (IGO).
