METHOD FOR DROPPING AND RAISING TEMPERATURE OF GAS CARBURIZING FURNACE AND FOR REGULATING INTERNAL ATMOSPHERE OF SAID FURNACE

摘要

PURPOSE:To reduce the time required to operate a furnace again by keeping the inside of the furnace in an inert gaseous atmosphere until a carburizing gas is introduced after the beginning of a temp. drop when the operation of the furnace is suspended and started again. CONSTITUTION:When the temp. of a gas carburizing furnace is dropped to suspend the operation of the furnace, an inert gas is introduced into the furnace after the beginning of the temp. drop to remove the carburizing gas and to fill the inside of the furnace with an inert gaseous atmosphere. During the suspension of the furnace, the inside of the furnace is kept in the inert gaseous atmosphere. When the temp. of the furnace is raised to start the operation again, the temp. is raised in the inert gaseous atmosphere after ignition until a carburizing gas is introduced. The carburizing gas is then introduced by a larger volume than the volume during operation to regulate the internal atmosphere of the furnace. Thus, the time required to operate the furnace again is reduced.