Automobile wheel hub is a kind of cylindrical metal part used to support the tire with axle as the center in automobile tire, that is, the component of axle installed in the center of wheel. They are important parts connecting brake drum or brake disc, wheel disc and axle shaft. Automobile wheel can be divided into steel wheel and alloy wheel according to material.

　　Because the steel wheels are ugly in appearance, heavy in weight, high in inertia resistance and easy to rust, alloy wheels can make up for this problem. Therefore, automobile manufacturers are increasingly using alloy materials to manufacture automobile wheels.

　　Due to the continuous improvement of vehicle utilization rate and the extension of driving mileage, the hardness of automobile is also higher and higher, which improves the wear resistance and tensile strength of automobile wheels. However, the alloy materials of automobile wheels can not fully meet the needs of people, which leads to the wheel damage easily and frequent replacement, which increases the maintenance cost of automobile.

　　Cleaning and polishing: the surface of the alloy blank after cutting is cleaned with water high-pressure spray gun, then mechanically polished and carburized: the alloy blank cleaned and polished in the above steps is put into the carburizing furnace for carburizing treatment. The carburizing temperature is 880 ℃～ 920 ℃, the carburizing time is 90min-120min, the tempering temperature is 360 ℃～ 400 ℃, and the tempering time is 50-60min.