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三、高温轴承钢 由于造纸机械、燃气涡轮机,喷气式发动机以及宇宙火箭,导弹等所用的轴承,工作温度很高（表17）,因此对这类轴承的材料就要求有足够的高温硬度、高温强度、耐磨性、抗氧化性、抗腐蚀性;低的膨胀系数和摩擦系数,高的比热、熔点和热传导率,良好的尺寸稳定性,以及高温下的长寿命。普通高碳铬轴承钢的最高使用温度为204℃, 表17 高温轴承的使用实例而实际使用温度仅能达到177℃。超过这一温度上限到接近工作温度230℃时,便迅速丧失了尺寸稳定性和硬度。但当这类轴承钢中加入一定量的Mo元素后（如TBS-600,TBS-1000）就可使用到更高的温度、或者加入一定量的Al(0.75～1.25％）以及同时提高硅含量至1.23％时（如Mh_7+Si）,在200℃时还呈现良好的尺寸稳定性,在250℃时硬度和机械性能都很稳定。它们的最高使用温度可提高到315℃,实际使用温度也可提高
Third, the high temperature bearing steel As papermaking machinery, gas turbines, jet engines and space rockets, missiles and other bearings used, the working temperature is high (Table 17), so the bearing material requires a sufficient high temperature hardness, high temperature Strength, wear resistance, oxidation resistance, corrosion resistance; low coefficient of expansion and friction, high specific heat, melting point and thermal conductivity, good dimensional stability, and long life at high temperature. Common high-carbon chromium bearing steel maximum temperature of 204 ℃, Table 17 examples of high temperature bearings and the actual use of the actual temperature can only reach 177 ℃. Exceeding this upper temperature limit to close to the operating temperature of 230 ° C rapidly loses dimensional stability and hardness. However, when a certain amount of Mo element (such as TBS-600, TBS-1000) is added to the bearing steel, a higher temperature can be used, or a certain amount of Al (0.75-1.25%) can be used and the silicon content To 1.23% (eg Mh_7 + Si), exhibits good dimensional stability at 200 ° C and very stable hardness and mechanical properties at 250 ° C. Their maximum operating temperature can be increased to 315 ℃, the actual use of temperature can be increased