Nitrogenation furnace

A nitrogenation furnace includes a furnace body, which comprises a furnace body thermal-insulating layer and a resistance wire layer arranged on an inner wall of the furnace body thermal-insulating layer. A furnace cover is installed at an opening of one end of the furnace body and comprises a furnace cover thermal-insulating layer, on which a gas inlet and a gas outlet are formed. An opening is arranged in the center of the furnace cover thermal-insulating layer. By means of the structure, when a portion requiring to be nitrogenated on a shaft body is inserted into the furnace through the opening of the furnace body, nitrogen is fed into the furnace through the gas inlet and the resistance wire layer can heat the interior of the furnace well, so that nitrogenation on the corresponding portion of the shaft can be carried out. The nitrogenation furnace allows the surface of the portion requiring to be nitrogenated on the shaft body to be nitrogenated without inserting the whole shaft into the furnace, thereby saving the size of the nitrogenation furnace and reducing the production cost and energy consumption of the nitrogenation furnace.