In the entire process of shaft processing, sufficient heat treatment procedures should be arranged to ensure the mechanical properties of the gear shaft and the processing accuracy requirements, and to improve the machining performance of the workpiece.

Generally, normalizing treatment is arranged first after the shaft blank forging to eliminate the internal stress of forging, refine the grain and improve the cutting performance during machining. Arrange tempering treatment after roughing. In the roughing stage, after roughing, drilling and other processes, most of the machining allowance of the gear shaft is cut out.

Roughing process cutting force and heat are very large, under the action of force and heat, the shaft produces a lot of internal stress, through the tempering treatment can eliminate the internal stress, instead of aging treatment, at the same time can get the required toughness.

After semi-machining, except for important surfaces, other surfaces have reached the design size. Important surfaces only have finishing allowance, then arrange local quenching treatment at the teeth, so as to meet the hardness requirements of the design and ensure the wear resistance of these surfaces. Subsequent finishing processes can eliminate quenching deformation.