| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an inexpensive thrust needle roller bearing with a long service life wherein abrasion and separation are hardly found even when it is used under a severe lubricating condition. <P>SOLUTION: A rolling face 1a of a rolling element 1 of this thrust needle roller bearing comprises a carbonitrided layer, and satisfies following five conditions; A: the amount of remaining austenite in a surface layer portion as a part from a surface to a depth 100μm is 5-30 vol%, B: hardness of the surface layer portion is Hv700 or more, C: nitrogen concentration of a most surface portion as a part from the surface to a depth 1μm is 0.3 mass% or more, D: the sum of nitrogen concentration and carbon concentration of the most surface portion is 1-1.8 mass%, and E: concentration of nitride or carbonitride of the surface layer portion is 0.5% or more in area ratio. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
