| 摘要 |
PURPOSE:To reduce the amt. of the gaseous atmosphere to be used in the stage of performing heat treatment such as carburizing and nitriding in a heat treatment furnace by using gaseous atmospheres other than air by controlling the gaeous pressure in the furnace high while the door of the treatment furnace is open and controlling the same slightly higher than the atmospheric pressure while the door is held closed. CONSTITUTION:In subjecting steel materials to surface treatments such as carburizing and nitriding by putting the steel materials into a heat treatment furnace, supplying a gaseous atmosphere such as propane or ammonia cracking gas into the furnace and heating the steel materials, the gaseous atmosphere is so supplied that the pressure of the gaseous atmosphere in the furnace is made slightly higher than the atmopsheric pressure on the outside of the heating furnace while the door of the heating furnace is held closed and in the case of putting the steel materials to be treated into and out from the furnace by opening the door thereof, a larger amt. of the gaseous atmosphere is supplied into the furnace. The outbreak of explosion accidents in the heating furnace by the entry of the air into the heating furnace from the outside is prevented, the heat treating work is accomplished safely and the total amt. of the gaseous atmosphere to be used is reduced. |
