CONTINUOUS GAS CARBURIZING METHOD AND CONTINUOUS GAS CARBURIZING FURNACE THEREFOR

摘要

PURPOSE:To perform carburization treatment of members to be carburized at different depths in a single continuous gas carburizing furnace by providing a mechanism to control adequately the holding time in a diffusion stage according to the carburizing depths required for said members. CONSTITUTION:Trays 2 carrying members to be carburized are charged into a continuous gas carburizing furnace and are pushed into the inside part a1 of the furnace by a main pusher 1 so that the trays are passed through a heating up zone (a), a carburizing zone (b) and a diffusing zone (c). When the tray 2 existing in the part c1 of the carburizing furnace is pushed to the position c2, said tray is transferred to the position c3 by a side pusher 3 if the carburizing depth required for the members to be carburized is shallow. The tray is immediately fed by a pusher 4 to the cooling zone (d) where the materials are put into an oil tank 10 and are hardened. If the required carburizing depth is deep, the tray 2 is transferred to the position c4 by the side pusher 3 and is stagnated there till the next cycle so that the materials are deeply carburized to carburize deeply the carbon carburized into the members in the zone (b). The tray is then fed to the cooling zone (e) by a pusher 5.