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 a napthenes, 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 napthenes 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 napthene hydrocarbon as the carburizing medium. The furnace is constructed to be generally transparent to the napthene so that cracking tends to occur at the workpiece which functions as a catalyst to minimize carbon deposits. The napthene is supplied in liquid form to fuel injectors which inject the liquid napthene 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. Hydrogen is added to the napthene to either assure full carbon potential and produce methane or to perform variable carburizing.

Abstract: Vacuum carburizing of ferrous workpieces is performed at low pressure in a vacuum furnace using a napthene hydrocarbon as the carburizing medium. The furnace is constructed to be generally transparent to the napthene so that cracking tends to occur at the workpiece which functions as a catalyst to minimize carbon deposits. The napthene is supplied in liquid form to fuel injectors which inject the liquid napthene 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. Hydrogen is added to the napthene to either assure full carbon potential and produce methane or to perform variable carburizing.

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 a napthenes, 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 napthenes 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.