Reducing Ammonia Consumption and Emissions Using Zero Flow Gas Nitriding

 Gas nitriding has been performed in many ways with many variations over the years (using NH₃ only, NH₃ + diss.NH₃ , and NH₃ + N₂).  Practical heat treating demands lower costs and consumption.  With the challenges of ammonia storage, costs and emissions, the Zero Flow process reduces ammonia consumption and still offers the same capability to affect the nitrided layer, resulting in lower emissions of ammonia and greenhouse gases.  The analysis contains: temperature of the process, chemical composition of the atmosphere in the retort of the furnace (nitriding potential), phase composition of the nitrided layer, its thickness and type of the atmosphere used for nitriding. Examples of experiences are shown in commercial production nitriding furnaces. It has been proven that this method of processing and atmosphere used for nitriding still allows for precision in controlling growth kinetics of the nitrided layer, yet has substantial impact on the ammonia consumption and emissions.