1. The working environment of automobile gears is harsh, and the stress is complex, which requires high gear materials. As gears, there are many materials, such as 45# steel, 40Cr, 18CrMnTi and so on. From the first three materials, the strength of 45# steel and 40Cr is very high, and it is even stronger after heat treatment and quenching, but at the same time, the plasticity and toughness of these two materials are relatively reduced. The overall effect of using these two materials is not good, and it is easy to damage teeth, but 18CrMnTi. First of all, this is a high-quality low-carbon alloy steel. After carburizing and quenching, better comprehensive mechanical properties can be obtained, not only with high hardness, but also with good plasticity and toughness. After this treatment, the gear is wear-resistant and has a long service life, and basically does not appear.

2. Because the general working environment of machine tool gears is good, the force is uniform and stable, and lubrication measures are guaranteed, so the cost and processing technology should be considered when selecting gears. The gears of general equipment can be directly quenched to HRC48 after 45# machining, and the gears of heavy machine tools can be quenched to HRC50 after 40Cr machining. The process is simple, good mechanical properties can be obtained, and the economy is good.