Generally speaking, if the working temperature of bearing excess 150 degree, we call these bearing high temperature bearings. If chrome bearing steel is used under the temperature excess 150 degree, it rigidity will reduce rapidly, it size will become instable, so as to cause bearing can not work as common. Therefore, as to these bearing which need to work under the temperature between 150 degree to 250 degree, if ferrule and rolling element still use common chrome bearing steel as material., it is need to backfire the component of bearings specially, usually, the temperature of backfire should be 50 degree higher than working temperature. Bearing steel which is treated though backfire according to above requirements, can be used as usually in working temperature. But after backfire, there’s some decline on both the rigidity and assuage of bearings. When the working temperature of bearing is higher than 250 degree, it is need to use the material of high-temperature endurable bearing steel to produce bearings.

Besides the common performance of bearing steel, high-temperature bearings also have the advantage of high temperature rigidity, high temperature contact fatigue resistance, ant oxygenic property, high temperature impact resistance endurance, and high temperature size stability.

Common high temperature bearing steel are as following:

Mo series steel: Cr4M04V, Crl5M04, 9Crl8Mo, Crl4M04;

W series steel: W9Cr4V2Mo, W18Cr4V;

W and Mo series steel: W6MoSCr4V2

High temperature bearing steel W, Cr, V, Mo and so on can form insoluble carbide in high temperature, and can separate and disperse carbide during process of back fire, and cause the effct of secondary hardening, thus such steel can also have high rigidity, friction endurance, much stronger antioxygenic property, higher fatigue resistance and size stability. Cr4M04V and W18Cr4V are most popular ones among high temperature bearing steel.

As to bearing which have complicated structure and need to endure much higher amount of impact load, can use the material of high temperature cemented bearing steel. 12Cr2Ni3M05 is a kind of high temperature cemented steel with good performance, due to its carbon content is very low, 0.15% or so, without the disadvantage of asymmetric carbide, low rigidity during anneal, good capability of mach inability, at the same time, it also have better toughness, good forge ability, so that can magnify the ratio of forging reduction, which is also propitious to the working life of bearings, after commentate, bearings can satisfy to work under the temperature under 430 degree, moreover, it also have good capacity of impact endurance.

At present, H10Cr4M04Ni4VA is the best high temperature cemented bearing steel, but its price is very expensive. While the working temperature of bearings excess 500~E, common high temperature endurable bearings steel already can not meet the requirement, instead, should choose cobalt, nickel alloy steel or ceramics such high temperature endurable material.

High temperature bearings are mainly used in following areas, aero jet engine, gas turbine, nuclear reactor system, X-ray tube tungsten dish, high speed aero craft, rocket, and spacecraft and so on.