| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a bearing material having a long rolling fatigue life, and to provide a method of manufacturing the bearing material. <P>SOLUTION: The bearing material having the following properties has excellent rolling fatigue life. When an area to be tested is 3,000 mm<SP POS="POST">2</SP>, the total number of oxide-based nonmetallic inclusions and sulfide-containing oxide-based nonmetallic inclusions in which the average diameter of the inclusions calculated by (length×width)<SP POS="POST">1/2</SP>is equal to or larger than 3 μm is equal to or smaller than 100 pieces per 1,000 mm<SP POS="POST">2</SP>, and the total number of the oxide-based nonmetallic inclusions and the sulfide-containing oxide-based nonmetallic inclusions in which the average diameter of the inclusions is equal to or larger than 10 μm is equal to or larger than 2 pieces per 1,000 mm<SP POS="POST">2</SP>. Furthermore, in 90% or more of the whole of the oxide-based nonmetallic inclusions and the sulfide-containing oxide-based nonmetallic inclusions in which the average diameter of the inclusions is equal to or larger than 3 μm, a magnesium oxide concentration is equal to or lower than 5 mass%. <P>COPYRIGHT: (C)2012,JPO&INPIT |
