Abstract: Vacuum carburizing of ferrous workpieces is performed at low pressure in a vacuum furnace using an unsaturated aromatic such as benzene as the carburizing medium. The unsaturated aromatic is gas phase hydrogenated into naphthenes, such as cyclohexane, which is metered into the furnace chamber proper and functions as the carburizing gas. The furnace is constructed to be generally transparent to the naphthenes so that cracking tends to occur at the workpiece which functions as a catalyst to minimize carbon deposits. The unsaturated aromatic is supplied in liquid form to fuel injectors which inject the liquid aromatic as a vapor at duty cycles and firing orders to produce a uniform dispersion of the hydrocarbon gas about the work resulting in uniform carburizing of the workpieces. An in-situ methane infrared sensor controls the process.

Abstract: Vacuum carburizing of ferrous workpieces is performed at low pressure in a vacuum furnace using a carburizing hydrocarbon as the carburizing medium. The furnace is constructed to be generally transparent to the carburizing hydrocarbon so that cracking tends to occur at the workpiece which functions as a catalyst to minimize carbon deposits. The carburizing hydrocarbon is supplied in liquid form to an injector which injects the liquid carburizing hydrocarbon as a vapor to produce a uniform dispersion of the carburizing hydrocarbon about the workpiece, resulting in uniform carburizing of the workpieces.

Abstract: A heat treat process is disclosed for use in an ion glow discharge chamber for carburizing ferrous workpieces. The process provides rapid carburizing cycles by optimizing the power supplied to the glow discharge correlated to temperature and desired uniformity of the carbon gradient profile while also optimizing the mass flow of the substantially pure carbon bearing gas which is correlated to the desired uniformity of the carbon gradient profile.

Abstract: A heat treat process is disclosed for use in an ion glow discharge chamber for carburizing ferrous workpieces. The process provides rapid carburizing cycles by optimizing the power supplied to the glow discharge correlated to temperature and desired uniformity of the carbon gradient profile while also optimizing the mass flow of the substantially pure carbon bearing gas which is correlated to the desired uniformity of the carbon gradient profile.