Author: Site Editor Publish Time: 2024-08-23 Origin: Site
There is essentially no difference between train wheels and subway wheels, except for the variation in diameter. Forging train wheels involves using forging machinery to induce plastic deformation in metal billets, thereby imparting specific mechanical properties and shapes. During the forging process, defects such as porosity, which can occur during metal smelting, are eliminated, optimizing the internal structure and maintaining the metal’s continuous grain flow. As a result, forged wheels have significantly superior mechanical properties compared to cast wheels made from the same materials.
As long as the design of the preformed die cavity and the forging die cavity is reasonable, the forged piece will fill the mold effectively during the forging process. The preforming is done on a shaped anvil with a single step of free upsetting, eliminating the need for a large hydraulic press. This way, the forging process for the first half of wheel manufacturing requires only two steps, performed on two different sizes of hydraulic presses, forming a production line with a productivity of up to 120 wheels per hour. If the quality of the steel billet is ensured, machining allowance can be reduced, and energy consumption can be saved.
The diagram for hot forged wheels is usually calculated by multiplying the cold forged wheel diagram by the thermal expansion factor. However, when there is a significant difference in dimensions between different parts of the precision forged wheel, the smaller parts cool faster, leading to a noticeable difference in final forging temperature compared to larger parts. In such cases, different thermal expansion coefficients can be used for different parts of the hot forged wheel diagram.
After the forged piece has cooled and passed inspection, rough machining can be performed, which includes drilling lifting holes and machining key slots. The piece then undergoes comprehensive heat treatment processes such as quenching, normalizing, and tempering. Heat treatment involves heating, holding, and cooling the material in its solid state to achieve the desired microstructure and properties. After heat treatment, the product undergoes hardness testing and flaw detection before entering the finishing stage, where high-speed CNC lathes are used to control the final dimensions to meet the drawing requirements, with a precision margin of 0.02mm to 0.03mm.
Forged wheels are much lighter than most cast wheels, making them very convenient to replace. They also offer other advantages, such as having a higher density grain structure compared to cast wheels. Cast wheels tend to be more porous, which means that forged wheels maintain their polished luster longer than similarly polished cast wheels.
MTJ has extensive forging experience and selects suitable forging processes according to different product structures, quantities, and material requirements, thereby achieving cost savings and improving efficiency. For inquiries, please contact tj-marketing@tj-wheel.com.
