What defects often occur after gears are quenched by electromagnetic induction heating equipment? How to prevent it?

After the gear is quenched by the electromagnetic induction heating equipment, some quality inspections are first carried out, such as the composition of the raw material steel, the hardness of the core of the gear, the surface hardness, structure and quality, and the depth of the hardened layer, etc., to see if it meets the technical requirements of the standard. But not all quenched gears will be qualified, because during the process of quenching heat treatment, some common quality defects may appear in the gears due to materials, operation and other reasons. For this, we will take some corresponding measures to solve them.

1. The surface hardness is uneven. This is due to the uneven distance between the inductor and the gear during induction hardening. The raw material steel used has a band structure precipitated inside, and the phenomenon of oxidative decarburization occurs locally. When heating and cooling , the temperature is too high or too low, and the gear is not evenly heated. In this regard, we need to check the quality of the steel before production, and clean the gears before quenching to remove oil and rust on the surface. The water spray holes of the sensor should be evenly distributed, and timely check whether the holes are damaged Blockage. When quenching, heating and cooling, the temperature should be uniform, and the operation should be carried out in accordance with the requirements of the standard.

2. Quenching cracks appear on the surface of the gear. This is because the quenching temperature is too high, local overheating occurs, and the carbon content of the selected production material is too high, and the composition is uneven. During tempering, sufficient tempering was not carried out in time deal with. In this regard, we should choose the appropriate quenching medium according to the raw materials, and carry out cooling treatment according to the standard specifications. The quenching temperature must be strictly controlled, not too high or too low, and the shape of the inductor of the electromagnetic induction heating equipment should be adjusted in time according to the shape of the gear. 

3. The hardness of the gear surface is too high or too low, which is due to the high or low carbon content of the raw material; the temperature is not suitable for quenching and heating; the heating is not strictly in accordance with the required temperature and time during tempering. In this regard, we need to adjust according to the required hardness; reasonably select the cooling medium, and perform tempering treatment according to the required tempering process specifications.

4. The depth of the hardened layer is not deep. This is because the frequency of the induction heating equipment is too high, the heating time is too short, and the gear does not choose a suitable cooling medium when cooling. In this regard, we need to choose the appropriate electromagnetic induction heating equipment, adjust the heating parameters in time to meet the standard requirements; we must choose a suitable cooling medium for cooling treatment.

5. Deformation, this is due to irregular heating and inappropriate cooling medium. In this regard, we have to operate in accordance with standard heating specifications, choose a suitable cooling medium, and ensure that the heating and cooling of the gear can be carried out evenly.