1. High-carbon chromium bearing steel
Are equivalent to the world of just GCr15 bearing steel as its base, to increase the hardenability of direction in order to adapt to the needs of thick-walled bearing parts, the practice is an appropriate increase in the components of the mass fraction of molybdenum (0.1%, 0.2%, ..., ranging from 0.6 percent), chromium mass fraction of a slight adjustment or change in order to develop a series of high-hardenability of high carbon chromium bearing steel. These apply not only to steel quenching martensite, but also to thick-walled bainite hardening of bearing parts.
High-carbon chromium bearing steel Another development is appropriate to reduce hardenability and medium-frequency induction heating imposed by the limited hardenability and hardening the surface of the overall quenching only. It carburizing steel carburizing quenching both superior performance and saving the steel alloy carburizing steel costs and the high cost of the carburizing heat treatment. Steel rail used to obtain good results bearing.
2. Non-chromium bearing steel
Non-chromium bearing steel in China's domestic resources in accordance with the characteristics of self-developed chromium bearing steel in place of the new steel, including GSiMnV, GSiMnMoV, GSiMnMoV, GSiMnMoVR, GMnMoV, GMnMoVR six steel grade. They have better hardenability, hardened, anti-fatigue properties and wear resistance of contacts. Compared with the chromium bearing steel, the larger the sensitivity of the surface decarburization, corrosion and mechanical properties of less processing performance, but to take appropriate measures to replace the use of such steel bearing chrome bearing steel production is totally feasible.
3. Carbon Steel Bearings
Foreign academics believe that bearing steel bearing steel alloy elements in the main role is to improve the hardenability, high strength, high hardness, wear resistance, fatigue performance and other key elements of the role of carbon. Vacuum degassing technology development and to this day, the purity of carbon steel can also be the same degree of increased wall thickness is not for the use of vacuum degassing of the bearings of the high-carbon steel, fully able to meet its performance requirements. There are further expanding the scope of the trend of carbon steel.
4. Carburizing bearing steel
With the development of high-speed aero-engine, all the fracture toughness of hardened steel is completely unable to meet the requirements. To this end the
5. Stainless steel bearings
Thick stainless steel carbide 9Gr18 be harmful, study abroad, is committed to reducing carbon mass fraction to 0.5 ~ 0.7, improved the overall performance 9Gr18 steel. At present, some countries are for research of stainless steel containing a larger force. United States, Germany Cronidur30 the development of a common nitrogen bearing stainless steel, the German Research LNS a low-nitrogen steel for aero-engine and aerospace bearings, France XD15N the development of a high nitrogen martensitic stainless steel bearings used in aerospace, the United States to develop a carburization of high-performance stainless steel CSS-42L, also successfully used in aerospace bearings.
6. Ceramic materials
Bearings used in the ceramic material is mainly Si3N4 and ZrO2 and their series combination of products. With the density of small, small friction factor, particularly high hardness, high temperature, corrosion resistance strong, with moderate resistance to impact toughness, in the middle have a higher contact stress under the fatigue life, etc., so in high-temperature, high-speed, corrosive medium, powerful state of the work of friction bearings, better selection of ceramic materials. At present, the types of ceramic bearings are mainly deep groove ball bearings, angular contact ball bearings and cylindrical roller bearings. Completely from the use of ceramic materials is divided into two types: one is the inside and outside the ring of steel with ceramic ball, known as the compound; the other is both rings and rolling ceramic body, known as the all-ceramic type . Full ceramic bearings in the application of the difficulties is due to meet with the axis of the expansion coefficient of different materials caused by fragmentation
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Author：mosbearing 2009-7-13 Source: View(1145) Comment(0)