| 摘要 |
PURPOSE:To reduce considerably a treatment time, by using a heat treatment furnace of an indirect heating type with an electric heater which supplies a gaseous mixture for an atmosphere consisting essentially of gaseous N2 to a hearth packed therein with refractory powder and granules and forms a fluidized bed. CONSTITUTION:Refractory powder and granules of alumina, etc. are packed on the gas dispersion plate 3 in a heat treatment furnace 2 which can heat said powder and granules to a prescribed temp. with an electric heater 1. On the other hand, gaseous N2 is fed through a pipeline 9 to a mixer 4, gaseous hydrocarbon such as CH4, C3H8, C4H10 or the like through a pipeline 7 and gaseous methanol through a pipeline 8. The gaseous atmosphere mixed with such gases and consisting essentially of gaseous N2 is fed to a pressure chamber 5. The refractory powder and granules in the chamber 5 flow to form a fluidized bed 6. Thereupon the metallic object to be treated is immersed in the bed 6 heated with the heater 1 to a prescribed temp. and is thereby carburized. |
