Claims
- 1. A rolling bearing comprising a race and a roller, at least one of said race and said roller essentially consisting of an alloy steel which contains 0.1-1.2% by weight C, 1-3% by weight Cr and 0.33-2.0% by weight Mo, at least one of said race and said roller has being subjected to carburizing, quenching and tempering or carbonitriding, quenching and tempering to form a rolling surface, wherein said rolling surface has a residual austenite content (.gamma..sub.R) which is 20%-40% by volume, a maximum particle size of at least one of fine grain carbides and carbonitrides being not more than about 2.3 .mu.m, and wherein Cr is contained in an amount ranging no more than three times as much as the Mo content by weight.
- 2. A rolling bearing as claimed in claim 1 wherein said rolling surface has the following range of Vickers hardness (Hv) in relation to the residual austenite content:
- -4.7.times.(.gamma..sub.R vol %)+920.ltoreq.H.sub.V .ltoreq.-4.7.times.(.gamma..sub.R vol %)+1020.
- 3. A rolling bearing according to claim 2, wherein an average particle size of said least one of fine-grained carbides and carbonitrides is in the range of 0.5-1.5 .mu.m.
- 4. A rolling bearing according to claim 2, wherein said rolling surface has a content of at least one of fine-grained carbides and carbonitrides in the surface layer of said rolling surface is in the range of 10-30% by area.
- 5. A rolling bearing according to claim 1, wherein an average particle size of said least one of fine-grained carbides and carbonitrides is in the range of 0.5-1.5 .mu.m.
- 6. A rolling bearing according to claim 1, wherein said rolling surface has a content of at least one of fine-grained carbides and carbonitrides in the surface layer of said rolling surface is in the range of 10-30% by area.
- 7. A rolling bearing according to claim 1, wherein that said rolling elements are made of a high-carbon chromium steel.
- 8. A rolling bearing comprising track rings, namely, inner and outer races, and rolling elements set between said inner and outer races, wherein
- the amount of residual austenite (.gamma..sub.R vol %) in the surface layer of at least one of said inner and outer races is in a range of 25 to 40 vol %, and the surface hardness (Hv) thereof meets the following condition:
- -4. 7.times.(.gamma..sub.R vol %)+900.ltoreq.Hv.ltoreq.-4.7.times.(.gamma..sub.R vol %)+1000
- and
- the hardness of said rolling elements is higher by H.sub.R C of 1 to 2 than that of said one of the inner and outer races.
Priority Claims (2)
Number |
Date |
Country |
Kind |
3-178191 |
Jul 1991 |
JPX |
|
4-274465 |
Oct 1992 |
JPX |
|
Parent Case Info
This is a Continuation-in-Part of Application No. 07/915,503 filed Jul. 20, 1992, abandoned.
US Referenced Citations (2)
Number |
Name |
Date |
Kind |
4904094 |
Furumura et al. |
Feb 1990 |
|
5137375 |
Murakami et al. |
Aug 1992 |
|
Foreign Referenced Citations (2)
Number |
Date |
Country |
4194415 |
Jul 1992 |
JPX |
2244103 |
Nov 1991 |
GBX |
Continuation in Parts (1)
|
Number |
Date |
Country |
Parent |
915503 |
Jul 1992 |
|