| 摘要 |
PROBLEM TO BE SOLVED: To provide a conical roller bearing having excellent wear resistance and seizure resistance, and having a long service life even if being used under severe conditions such as a high speed rotary condition and a foreign matter-intruded lubricating environment. SOLUTION: The rolling element 3 of a conical roller bearing is composed of steel comprising silicon and manganese, and in which the content of silicon is≥0.4 mass%, the content of manganese is≥0.4 mass%, and also, the total content of silicon and manganese is≥1 mass%. Then, nitriding treatment or carbonitriding treatment, quenching and tempering are successively performed thereto. Regarding the rolling element 3 produced in this way, Si-Mn based nitrides with the maximum diameter of≤1μm are precipitated over the surface layer part to a depth of 0.01 mm from the surface, and the amount thereof is 1 to 10% by area ratio. Further, the ratio between the minimum value and the maximum value of the Si-Mn based nitrides in the surface layer part or the ratio between the minimum value and the maximum value of the nitrogen concentration in the surface layer part is≥0.9. COPYRIGHT: (C)2009,JPO&INPIT
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