Forced-convection fuel gas toughening furnace

The invention relates to a forced-convection fuel gas toughening furnace, which comprises a furnace body steel structure and an insulating layer, wherein the furnace body steel structure is formed by an upper-part furnace body and a lower-part furnace body in a butt joint way; a ceramic roller is arranged between the upper-part furnace body and the lower-part furnace body; convection boxes are respectively arranged in the upper-part furnace body and the lower-part furnace body; injection holes are densely distributed on panels, close to the ceramic roller, of the convection boxes; a high-temperature circulating fan and a gas burner with abuilt-in heat exchanger are respectively arranged on the side walls of the upper-part furnace body and the lower-part furnace body; a spiral case of the high-temperature circulating fan is arranged inside the furnace body steel structure; an air outlet of the spiral case is communicated with the convection boxes through pipelines. According to the forced-convection fuel gas t