Known as the industrial pearl on the crown of aeroengine bearings is what material made of? - bearing knowledge

Traditional air launch main bearing materials is more M50. In the 1980 s, on the basis of M50 developed M50NiL, it adds a nickel, reduces the carbon, is a kind of surface carburizing steel. Two is the main ingredient in the diagram below. M50NiL surface hardness can be up to 60 ~ 64 HRC. Figure, M50 and M50NiL composition profiles aircraft engine in order to ensure the bearing working under high DN value, high temperature and load, its inner and outer ring and roller material hardness is not less than RC58, or bearing 'crushed' damage will occur. As working temperature has increased, the hardness of materials will gradually decline. Is usually the most common use of SAE 52100 bearing steel, when the working environment more than 175 degrees Celsius, hardness is lower than RC58, it already can not adapt to the modern course of main bearing demand, as shown in the figure below, WB - high temperature bearing steel 49 the maximum service temperature can reach 537 degrees Celsius. Aircraft engine rotation speed and turbine gas temperature before the increasingly rising, the work of the main bearing temperature rising, too. Bearing working temperature range is quite broad, and it can in - which requires 55 degrees Celsius is easy to start to work at high temperature, also need to adapt to the temperature change after parking. When the engine after parking, bearing lubricating oil cooling circulatory system to stop working, turbine blades, wheel and axle bearing on residual heat conduction gradually to the turbine, its temperature is increased with the increase of parking time gradually enhanced. General parking in 40 minutes later, the temperature of the turbine bearing can also higher than that of normal working temperature of 100 ~ 150 degrees Celsius. When the bearing working temperature is below 175 degrees Celsius, can use ordinary SAE52100 bearing steel. MHT bearing steel is added in the SAE52100 1. 3% of aluminum, its working temperature can ascend to 260 degrees Celsius. M - 50 applicable temperature at 170 ~ 315 degrees Celsius. M1 and M2 hardness can meet the requirements in 500 degrees Celsius, but it has also reached their limits of oxidation resistance. WB- Although 49 carburizing steel high temperature performance is good, can work at 537 degrees Celsius, but the current manufacturing process is not enough to make reliable ball, and can only be used for inner and outer ring. M1 material will be used on ball.