In addition to stress-relief annealing, what other methods can be used to reduce the stress in the gearbox housing?

In addition to stress relief annealing, the following methods can also be used to reduce the stress on the gearbox housing:

Vibration aging method: By using specialized equipment to induce resonance in the box under periodic external forces, the internal microstructure of the box undergoes grain slip and twinning, thereby reducing residual stress peaks and improving stress distribution. This method can usually eliminate about 50% of residual stress or reduce 50% of the peak residual stress within one hour, with high processing efficiency and cost savings. It is generally carried out after rough machining and before precision machining.

Natural aging method: Place the gear reducer housing outdoors and gradually relax the stress in a natural environment by utilizing changes in climate and temperature. This method takes a long time, usually more than a year, and the stress relief effect is limited, only able to reduce residual stress by 2% -10%. However, it can still be used for some enclosures that do not require extremely high accuracy.

Ultrasonic impact method: By generating compressive plastic deformation on the metal surface through high-frequency impact, the stress field is changed, beneficial compressive stress is introduced, and the strength and fatigue resistance of the material are improved. The working principle of ultrasonic impact is to use high-power energy to push the impact head and impact the metal surface at a frequency of about 20000 times per second. It is particularly suitable for post weld treatment of welded structures and can effectively eliminate welding residual stress.

Hammer striking method: Using a steel hammer to strike the areas of residual stress accumulation in the box, causing compressive stress on the metal surface that receives the hammer strike, resulting in local plastic deformation, thereby reducing the peak value of residual stress, improving and balancing the distribution of original residual stress. This method is particularly suitable for welding parts and is widely used in welding processing.

Cold processing stretching method: By stretching or rolling the box material, it undergoes plastic deformation to adjust the grain structure and eliminate internal stress. But this method may generate new stresses and is not suitable for all types of metal materials, especially those sensitive to cold working.