Roller heat treatment zero decarbonization control method for mesh belt furnace

The invention discloses a roller heat treatment zero decarbonization control method for a mesh belt furnace, which comprises three steps as follows: quenching, tempering and detecting. The innovative point is characterized in that the quenching step is conducted in a quenching region of the mesh belt furnace; three atmospheres, namely methanol, nitrogen and propane are adopted to control the carbon potential; in the quenching and heating process, the atmosphere flow is controlled in the three regions; nitrogen and propane are introduced in a first region and a second region; propane are controlled by two parts, wherein a part of propane is controlled by a constant low flow of 0.5-1 L/min; the other part of propane is controlled by oxygen probe automatic compensation type; when the carbon potential is deficient, propane is introduced at 2-3 L/min; nitrogen and methanol are introduced to a third region, the flow is 6-6.4 m /h and 4-4.5 m /h respectively; the heating time of a roller is 52-60 min; the quenching temperature is 845-855 DEG C; the carbon potential is stabilized and controlled at 0.7-0.8 %; in the tempering process, the tempering temperature is 160-165 DEG C; the temperature preservation time is 180-210 min. According to the method, the problems in the normal controlling process that recarburization occurs in a high carbon potential and the carbon shortage occurs in a low carbon potential are solved.