By using materials with good wear resistance to replace the previously used gear materials, the wear resistance of the gear surface can be directly improved, and then the service life of the gear can be improved. For example, the wear resistance of 20CrMnTi gear material, which is widely used in automobile gears, is better than that of ordinary modulated steel and cast steel gear materials; The new automobile gear steel with high wear resistance newly developed by Baosteel Special Steel Branch uses titanium alloy (Ti6A14V) to manufacture high-performance automobile gears, but it also increases the manufacturing cost of gears; The internally lubricating wear-resistant thermoplastic modified plastics produced and developed by rtpcompany can improve the bending strength of gears used repeatedly and reduce the possibility of gear tooth fracture; Using powder metallurgy to manufacture gears can save a lot of raw materials and improve the wear resistance of gears; The relative wear resistance of quasi bainitic cast steel is 2 ~ 20 times that of high manganese steel. It has excellent mechanical properties of high strength, high toughness and high wear resistance. It has the characteristics of simple process and good welding performance. It saves energy, reduces cost and improves product quality and service life. It is an ideal high wear resistant material.
For heavy trucks, Cr Mo series, Cr Ni Mo series and mn-cr-b series gear steels are currently used. These steels have high hardenability and can improve the wear resistance and bending fatigue strength of gears within a certain range.
a. Compared with 20CrMnTi steel, Cr Mo steel improves the bending fatigue resistance and surface hardness of gear, and increases the wear resistance and contact fatigue performance of gear due to the increase of material hardenability.
b. Due to the addition of Ni, Cr Ni Mo steel increases the toughness and strength of the material. Compared with 20CrMnTi steel, Cr Ni Mo steel has higher hardenability, higher hardness and wear resistance of gears after carburizing and quenching. It is suitable for heavy transmission gears with high load and high requirements of bending fatigue performance and impact performance. For example, the steel SAE8620H for heavy-duty transmission gear of Eaton company of the United States requires J6 = 32 ~ 42 HRC, J9 = 27 ~ 35hrc and J24 ≥ 18 HRC. SAE8620H steel is equivalent to domestic 20crnimoh steel.
c. Mn-cr-b steel improves the hardenability of gear steel due to the addition of B. therefore, compared with 20CrMnTi steel, mn-cr-b steel improves the wear resistance, bending fatigue performance and contact fatigue performance of gear, and the price is low.