Induction quenching soft belt reserving method for ultra-long machine tool guide rail

The invention discloses an induction quenching soft belt reserving method for a super-long machine tool guide rail, is suitable for a machine tool guide rail of which a starting end is easy to crack after quenching or needs machining (groove milling or drilling and the like), and belongs to the technical field of heat treatment. The method comprises the following steps: carrying out aging treatment, machining, destressing treatment, medium-frequency induction quenching and tempering treatment on the ultra-long machine tool guide rail. Wherein the medium-frequency induction quenching adopts double inductors for quenching, one inductor is a preheating inductor, the other inductor is a quenching inductor, the distance between the double inductors is 15-20mm, the distance between the surfaces of the inductors and the quenching surface is 4-6mm, and heating quenching is started at the position, which is more than 20mm away from the edge of the machine tool guide rail, of the quenching starting end. After the treat