The development of bearing material

1. High carbon chromium bearing steel with equivalent of GCr15 in every country in the world just as the basis of bearing steel, to improve the hardenability of direction to meet the needs of the thick wall bearing parts, its practice is increasing mass fraction of molybdenum in the ingredients ( 0. 1%, 0. , 0. 6%) , the mass fraction of chromium slightly adjust or constant, so as to develop a series of high carbon chromium bearing steel high hardenability. The steel grade applies not only to martensitic hardening, also applies to bainite hardening of thick wall bearing parts. Another development of high carbon chromium bearing steel is appropriate to reduce the hardenability, medium frequency induction heating, and administered by limited hardenability and overall quenching surface hardening. It has better performance of carburizing steel carburizing and quenching, and save the cost of steel alloy carburizing steel and high carburizing heat treatment costs. Made of the steel rail bearing obtain good results. 2. Without chromium bearing steel chromium bearing steel is developed by our country according to the characteristics of domestic resources to replace the new steel grade chromium bearing steel, including GSiMnV, GSiMnMoV, GSiMnMoV, GSiMnMoVR, GMnMoV, GMnMoVR six kinds of steel grade. They have good hardenability, hardenability, contact fatigue resistance and wear resistance. Compared with chromium bearing steel, the surface decarburization sensitivity slightly larger, corrosion performance and machining performance slightly, but take appropriate measures to replace chromium bearing steel production with this kind of steel bearing is completely feasible. 3. Carbon bearing steel bearing steel abroad scholars think bearing steel main effect is to improve the hardenability of the alloy elements, high strength, high hardness, wear resistance, fatigue resistance and other main performance is a function of carbon element. And vacuum degassing technology development today, the carbon steel purity can also increased significantly, as the wall thickness is not bearing using vacuum degassing of high carbon steel, its performance can meet the requirements. There are further to enlarge the range of carbon steel using the trend. 4. Carburizing bearing steel with the development of high-speed aircraft engine, the fracture toughness of the hardened steel is completely unable to meet the requirements. For the United States developed high temperature resistant carburizing bearing steel M50NiL, its fracture toughness is very good, high temperature performance of high-speed performance impact toughness wear-resistant fatigue resistance is very superior. Super M50NiL carburizing steel at present and in the research. 5. 9 gr18 stainless steel stainless bearing steel thick carbide can be harmful, dedicated to the study abroad carbon mass fraction decreased to zero. 5 to 0. 7, improve the comprehensive performance of the 9 gr18 steel. Some countries are currently in the research of nitrogen stainless steel into a larger power. America and Germany jointly develop a Cronidur30 nitrogen stainless bearing steel, the German research a kind of low nitrogen steel LNS used for aviation engine and aerospace bearings, French develop a XD15N high nitrogen martensite stainless steel used for aerospace bearings, the United States to develop a high performance of carburizing CSS - stainless steel 42 l, also successfully used in aerospace bearings. 6. Ceramic materials used in main bearing of ceramic materials is Si3N4 and ZrO2 and its series products. Has small density, low friction factor, particularly high hardness, high temperature resistant, strong corrosion resistance, has a moderate impact resistance toughness, under the medium contact stress has the advantages of higher fatigue life, so in the high temperature, high speed, corrosive medium, strong bearing friction condition, choose ceramic material is better. The type of ceramic bearing at present mainly include deep groove ball bearings, angular contact ball bearings and cylindrical roller bearings. From whether adopt ceramic material completely partitioned into two types: one is inside and outside of steel ring and ceramic roller, called compound; The other is a race and rolling elements are made of ceramic, known as the ceramic type. The difficulty in the full ceramic bearing in application is when cooperate with shaft fracture caused by the expansion coefficient of different materials.