Bearing steel production present situation and future development direction in China

China bearing steel production 2019 - present situation and future development direction 01 - 05 special steel is the major equipment manufacturing and the key material required for national key project construction, is the high technology content products in steel material, its production and application on behalf of a country's level of industrial development. Situation and development direction of bearing steel bearing is widely used in mining machinery, precision machine tools, metallurgical equipment, heavy equipment and luxury cars, and other areas of the major equipment and wind power, high-speed rail train and emerging industries such as aerospace field. China's production of bearings mainly for mid-range bearings and small medium-sized bearings, characterized by lack of low-end and high-end excess. Compared with abroad, in high-end bearing and large bearing larger gap. China's high-speed railway passenger dedicated supporting wheel bearing all need to be imported from abroad. In aerospace, high-speed rail, luxury cars, and other industrial sectors with the key on the bearing, China bearing in service life, reliability, Dn value and carrying capacity, etc, and advanced level there is a big gap. For example, the service life of the foreign auto gearbox bearing 500000 kilometers, the lowest 100000 km, and similar domestic bearing life and reliability and stability. 1 aviation as the key foundation of aircraft engine parts and components, is developing the thrust ratio of 15 to abroad 20 second generation of aircraft engine bearing, preparation before and after assembly in 2020 to the fifth generation fighter. Research and development in recent 10 years, the United States on the second generation of aircraft engine with bearing steel, the representative steel for corrosion resistance to 500 ℃ Gao Qiangnai CSS - bearing steel 42 l and 350 ℃ high nitrogen stainless bearing steel X30 ( Cronidur30） , China is in developing the second generation of bearing used for aviation engine. 2 cars for automobile wheel hub bearing, China is currently widely used is the first generation and second generation wheel hub bearing, The ball bearing) , which has been widely adopted by the third generation wheel hub bearings. The main advantage of the third generation wheel hub bearing is reliable and effective load distance short, easy to install, no adjustment, compact structure, etc. At present, China introduced most models use this lightweight wheel hub bearing and integration structure. Three aspects at present, the railway vehicles bearing used in China's railway heavy-duty train domestic esr G20CrNi2MoA carburizing steel manufacturing, and will have uhp bearing steel (abroad EP steel) The vacuum degassing of smelting technology, inclusion homogenization technology ( IQ steel) And long life span steel technology ( TF steel) , fine quality, and the heat treatment technology, surface hardening treatment technique and advanced sealing lubrication technology applied to the bearing production and manufacturing, thus greatly enhance the service life of bearing and reliability. China electric slag bearing steel low quality not only, and cost 2000 - higher than steel vacuum degassing 3000 yuan/ton, the future China needs to develop super high purity, fine quality, uniform and stable quality of vacuum degassed bearing steel to replace the current use of electroslag bearing steel. 4 wind energy for wind power bearing, China will not be in the production of high technical content and speeder bearing spindle bearing, basically rely on imports, supporting more than 3 mw wind turbines bearing the localization problem is still unsolved. Abroad in order to improve the strength and toughness of wind power bearing and service life, using a new type of special heat treatment steel SHX ( 40CrSiMo） For yaw bearing and pulp, through the surface induction hardening heat treatment to control the depth of hardening layer, surface hardness, soft belt width and surface crack; For speed increaser bearings and spindle bearings adopt carbonitriding, make parts surface gets more stable retained austenite volume fraction ( 30% - 35%) And a large number of fine carbide, carbon nitrides, improve the service life of the bearing lubrication conditions in pollution. In order to improve the service life of rolling mill bearing and running accuracy, future needs for rolling mill with GCr15SiMn and G20Cr2Ni4 uhp vacuum degassing of bearing steel smelting and austenite bearing surface larger size control of heat treatment technology research and development, etc. NSK and Japan NTN bearing company enhanced technology developed on the surface of austenitic respectively, namely austenitic content, by increasing the surface developed TF bearing and WTF bearing, thus improving the service life of bearing by 6 - 10 times. China's future development direction of the bearing steel is mainly reflected in four aspects: 1 under the premise of economic cleanliness considering economy, further improving steel cleanliness, reduce the oxygen in the steel and titanium content and achieve the oxygen in the bearing steel and titanium mass fraction of less than 6 & times; 10 - 6 and 15 & times; 10 - 6 levels, reduce the size, the content of inclusions in steel and improve the distribution uniformity. 2 organization refining and homogenizing by alloying design and the application of controlled rolling process of controlled cooling, further improve the uniformity of inclusions and carbide, reduce and eliminate the mesh and banded carbide, reduce the average size and the maximum particle size, achieve carbides average size less than 1 & mu; M's goal; To further improve the matrix organization grain size, grain size refinement of bearing steel. 3 macrostructure defect is reduced further reduce center loose, shrinkage cavity and the center of bearing steel composition segregation, improve the uniformity of macrostructure. 4 high toughness of bearing steel and heat treatment process are optimized by the new alloying, hot rolling process, improve the toughness of the steel bearings. （ Source: China steel enterprises association)