... hydrogen, please inject the nitrogen)when heat, the furnace pressure can not exceed 0.3-0.35Mpa, ... .After finishing the heat, the pressure of the furnace will decrease owing to air’s contract, but ... the thermocouple and electroheat thread.Heat time: the furnace is kept in the hearth for 2-2.5hours ... setting the heat temperature, then is taken out the furnace and is cooled down naturally. In general, shall ...