Bearings are widely used in major equipment fields such as mining machinery, precision machine tools, metallurgical equipment, heavy equipment, and high-end cars, as well as emerging industries such as wind power generation, high-speed trains, and aerospace. The bearings produced in China are mainly mid to low end bearings and small to medium-sized bearings, which are characterized by an excess of low-end and a lack of high-end. Compared with foreign countries, there is a significant gap in high-end bearings and large bearings.

All the specialized wheel bearings for high-speed railway passenger cars in China need to be imported from abroad. There is a significant gap between Chinese bearings and advanced levels in terms of service life, reliability, Dn value, and load-bearing capacity in key bearings used in aerospace, high-speed railways, high-end cars, and other industrial fields. For example, the minimum service life of foreign automotive gearbox bearings is 500000 kilometers, while similar bearings in China have a service life of about 100000 kilometers and poor reliability and stability.

1. Aviation aspect

As a key basic component of aviation engines, foreign countries are developing second-generation aviation engine bearings with a thrust ratio of 15-20, which are ready to be assembled into fifth generation fighter jets around 2020. In the past decade, the United States has developed the second generation of bearing steel for aircraft engines, with representative steel grades being the high-strength and corrosion-resistant bearing steel CSS-42L, which can withstand 500 ℃, and the high nitrogen stainless bearing steel X30 (Cronidur30), which can withstand 350 ℃. China is currently conducting research and development on bearings for the second generation of aircraft engines.

2. In terms of automobiles

For automotive wheel hub bearings, China currently widely uses the first and second generation wheel hub bearings (ball bearings), while Europe has widely adopted the third generation wheel hub bearings. The main advantages of third-generation wheel hub bearings are reliability, short effective load spacing, easy installation, no need for adjustment, and compact structure. At present, most imported car models in China use this lightweight and integrated structure wheel hub bearing.

3. In terms of railway vehicles

At present, the bearings used in China's railway heavy-duty trains are made of domestically produced electric slag remelted G20CrNi2MoA carburizing steel, while foreign countries have applied vacuum degassing smelting technology for ultra-high purity bearing steel (EP steel), inclusion homogenization technology (IQ steel), ultra long life steel technology (TF steel), refinement heat treatment technology, surface super hardening treatment technology, and advanced sealing lubrication technology to the production and manufacturing of bearings, greatly improving the life and reliability of bearings. Chinese electric slag bearing steel not only has low quality, but also has a cost 2000-3000 yuan/ton higher than vacuum degassing steel. In the future, China needs to develop ultra-high purity, finer, more uniform, and quality stable vacuum degassing bearing steel to replace the currently used electric slag bearing steel.

4. Wind power energy aspect

For wind turbine bearings, China is currently unable to produce technically advanced main shaft bearings and gearbox bearings, relying mainly on imports. The localization problem of supporting bearings for wind turbines with a capacity of over 3MW has not yet been solved. In order to improve the strength, toughness, and service life of wind power bearings abroad, a new type of special heat treated steel SHX (40CrSiMo) has been adopted. For yaw and pitch bearings, the depth and surface of the hardened layer are controlled by surface induction quenching heat treatment