Gas carburizing of steel with furnace atmospheres formedIn Situ from propane and air: Part III. Control of furnace atmosphere composition with a zirconia oxygen sensor

Gas carburizing experiments were conducted in a batch-type sealed-quench furnace using furnace atmospheres produced by the reaction of propane and air within the furnace. The air-propane ratio of the inlet gases was automatically controlled to maintain a constant oxygen potential, as measured by a zirconia oxygen sensor, within the furnace. The results of carburizing trials at 843 and 927 °C are described. The effect of inlet gas flow rate on furnace atmosphere composition and the amount of carburizing is illustrated.