Effect of heat treatment process parameters on the mass stability of DFY250 gear reducer

There is currently no specific study on the impact of heat treatment process parameters on the mass stability of DFY250 gear reducer, but the general impact of heat treatment process parameters on gear reducer can be analyzed from the perspective of the general impact of heat treatment process parameters on gear reducer, as follows:

• Heating temperature and time

• Effect on gear hardness and wear resistance : Heating temperature and insulation time are key factors affecting gear hardness. For example, during the quenching process, appropriately increasing the heating temperature and maintaining sufficient time can make the gear material fully austenitized, and a higher hardness can be obtained after quenching, thereby improving the wear resistance of the tooth surface. However, if the heating temperature is too high or the time is too long, it may cause coarse grains, causing the toughness of the gears to decrease and cracks are prone to occur.

• Effect on gear deformation : Uneven heating temperature will cause inconsistent expansion of various parts of the gear, resulting in thermal stress, and thus deformation. For the gears of the DFY250 gear reducer, the higher the carburization temperature, the thicker the carburization layer, and the greater the possibility of gear deformation. Excessive insulation time can also increase the risk of deformation.

• Cooling medium and cooling rate

• Effect on gear deformation : Cooling medium and cooling rate are the most important factors affecting gear deformation. For example, the cooling capacity of oil is crucial to deformation. Hot oil quenching is less deformation than cold oil quenching, and is generally controlled at 100℃±20℃. At the same time, the unevenness of the cooling rate will also cause the gear to deform. For example, if the cooling rate difference between the surface and the core during the cooling process of the gear is too large, a large tissue stress will be generated, causing the gear to deform.

• Effect on gear structure and performance : Rapid cooling (such as quenching) allows the gear to obtain martensite structure, increasing hardness and strength, but also increasing internal stress and brittleness. Slow cooling (such as normalizing and annealing) will result in softer tissues, such as pearlite, ferrite, etc., which will reduce hardness, but can improve toughness and eliminate internal stress.

• Temperature and time of tempering

• Influence on gear toughness : The gears after quenching have high hardness but high brittleness. Residual stress can be eliminated and toughness can be improved through tempering. For the gears of the DFY250 gear reducer, the appropriate tempering temperature and time can make the gears maintain high hardness to cope with friction and wear, and have sufficient toughness to withstand alternating loads, greatly extending their service life.

• Influence on gear dimensional stability : Tempering can make the internal structure of the gear more stable, reducing dimensional changes during use, thereby ensuring the quality stability of the reducer. If the tempering is insufficient or the tempering process parameters are improper, the gear may change in size due to internal stress release during subsequent use, affecting the transmission accuracy of the reducer.

• Carburizing process parameters (such as carburizing temperature, time, carbon potential, etc.)

• Effect on the depth and hardness of the carburized layer : the higher the carburized temperature and the longer the time, the higher the carbon potential, the thicker the carburized layer, and the higher the surface hardness. However, too thick carburized layer may lead to increased brittleness in the gear surface and prone to failure forms such as peeling.

• Effects on gear deformation : Temperature uniformity, carbon layer uniformity and cooling medium temperature uniformity all affect gear deformation during carburization. Uneven carburizing will cause inconsistent tissue transformation of the gear parts, creating internal stress, and thus causing deformation.