US6126897A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Carburizing steel and steel products manufactured making use of the carburizing steel
Assignee: NTN Corp
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Filing: 1998-08-21
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Granted: 2000-10-03
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Expires: 2018-08-21
Abstract
Abstract A carburizing steel having the following chemical composition: C: 0.1 to 0.25%, Si: 0.2 to 0.4%, Mn: 0.3 to 0.9%, P: 0.02% or less, S: 0.001 to 0.15%, Cr: 0.5 to 0.9%, Mo: 0.15 to 1%, Al: 0.01 to 0.1%, B: 0.0005 to 0.009%, N: less than 0.006%, and the balance of Fe and incidental impurities, wherein % is on a weight basis. Also disclosed are a method for the manufacture of the carburizing steel, parts of constant velocity universal joints for drive shafts made of the carburizing steel, as well as a method for the manufacture of such parts. The carburizing steel may further contain Ni: 0.3-4.0%, and one or more elements selected from the group consisting of Ti, Nb, V and Zr: 0.01-0.3% for each. The parts of constant velocity universal joints for drive shafts are manufactured using the carburizing steel of the present invention as a material. When they are carburized and quenched, they exhibit a surface hardness (Hv) of 650-800, core hardness (Hv) of 250-450, and carburized case depth of 0.2-1.2 mm.
Inventors
- 👤 Kenji Aihara
- 👤 Yasuhide Fujioka
- 👤 Kazuhiko Yoshida
- 👤 Tatsuhiro Goto
- 👤 Akira Wakita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 14:47
CPC Classifications
C; C22; C22C; C22C38/00; C22C38/18; C22C38/22; C22C38/32; C23; C23C; C23C8/00; C23C8/02; C23C8/06; C23C8/08; C23C8/20; C23C8/22; F; F16; F16D; F16D3/00; F16D3/16; F16D3/20; F16D3/22; F16D3/223
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
64 words
A carburizing steel consisting essentially of the following elements: C: 0.1 to 0.25%, Si: 0.2 to 0.4%, Mn: 0.3 to 0.9%, P: 0.02% or less, S: 0.001 to 0.15%, Cr: 0.5 to 0.9%, Mo: 0.15 to 1%, Al: 0.01 to 0.1%, B: 0.0005 to 0.009%, N: 0.004 to 0.0059%, and the balance of Fe and incidental impurities, wherein % is on a weight basis.
Claim 2
Dependent Claim
64 words
A carburizing steel consisting essentially of the following elements: C: 0.1 to 0.25%, Si: 0.2 to 0.4%, Mn: 0.3 to 0.9%, P: 0.02% or less, S: 0.001 to 0.15%, Cr: 0.5 to 0.9%, Mo: 0.15 to 1%, Al: 0.01 to 0.1%, B: 0.0005 to 0.009%, N: 0.004 to 0.0059%, and the balance of Fe and incidental impurities, wherein % is on a weight basis.
Claim 3
Dependent Claim
68 words
A carburizing steel consisting essentially of the following elements: C: 0.1 to 0.25%, Si: 0.2 to 0.4%, Mn: 0.3 to 0.9%, P: 0.02% or less, S: 0.001 to 0.15%, Cr: 0.5 to 0.9%, Ni: 0.3 to 4.0%, Mo: 0.15 to 1%, Al: 0.01 to 0.1%, B: 0.0005 to 0.009%, N: 0.004 to 0.0059%, and the balance of Fe and incidental impurities, wherein % is on a weight basis.
Claim 4
Dependent Claim
68 words
A carburizing steel consisting essentially of the following elements: C: 0.1 to 0.25%, Si: 0.2 to 0.4%, Mn: 0.3 to 0.9%, P: 0.02% or less, S: 0.001 to 0.15%, Cr: 0.5 to 0.9%, Ni: 0.3 to 4.0%, Mo: 0.15 to 1%, Al: 0.01 to 0.1%, B: 0.0005 to 0.009%, N: 0.004 to 0.0059%, and the balance of Fe and incidental impurities, wherein % is on a weight basis.
Claim 5
Dependent Claim
82 words
A carburizing steel consisting essentially of the following elements: C: 0.1 to 0.25%, Si: 0.2 to 0.4%, Mn: 0.3 to 0.9%, P: 0.02% or less, S: 0.001 to 0.15%, Cr: 0.5 to 0.9%, Mo: 0.15 to 1%, Al: 0.01 to 0.1%, B: 0.0005 to 0.009%, N: less than 0.006%, one or more elements selected from the group consisting of Ti, Nb, V and Zr: 0.01-0.3% for each, and the balance of Fe and incidental impurities, wherein % is on a weight basis.
Claim 6
Dependent Claim
82 words
A carburizing steel consisting essentially of the following elements: C: 0.1 to 0.25%, Si: 0.2 to 0.4%, Mn: 0.3 to 0.9%, P: 0.02% or less, S: 0.001 to 0.15%, Cr: 0.5 to 0.9%, Mo: 0.15 to 1%, Al: 0.01 to 0.1%, B: 0.0005 to 0.009%, N: less than 0.006%, one or more elements selected from the group consisting of Ti, Nb, V and Zr: 0.01-0.3% for each, and the balance of Fe and incidental impurities, wherein % is on a weight basis.
Claim 7
Dependent Claim
86 words
A carburizing steel consisting essentially of the following elements: C: 0.1 to 0.25%, Si: 0.2 to 0.4%, Mn: 0.3 to 0.9%, P: 0.02% or less, S: 0.001 to 0.15%, Cr: 0.5 to 0.9%, Ni: 0.3 to 4.0%, Mo: 0.15 to 1%, Al: 0.01 to 0.1%, B: 0.0005 to 0.009%, N: less than 0.006%, one or more elements selected from the group consisting of Ti, Nb, V and Zr: 0.01-0.3% for each, and the balance of Fe and incidental impurities, wherein % is on a weight basis.
Claim 8
Dependent Claim
86 words
A carburizing steel consisting essentially of the following elements: C: 0.1 to 0.25%, Si: 0.2 to 0.4%, Mn: 0.3 to 0.9%, P: 0.02% or less, S: 0.001 to 0.15%, Cr: 0.5 to 0.9%, Ni: 0.3 to 4.0%, Mo: 0.15 to 1%, Al: 0.01 to 0.1%, B: 0.0005 to 0.009%, N: less than 0.006%, one or more elements selected from the group consisting of Ti, Nb, V and Zr: 0.01-0.3% for each, and the balance of Fe and incidental impurities, wherein % is on a weight basis.
Claim 9
Dependent Claim
54 words
A method for the manufacture of steel pipe comprising the steps of cold-working, with a percentage reduction in cross section of not more than 50%, steel pipe which is made of the carburizing steel as defined in claim 1, and annealing the resultant cold-worked pipe at a temperature ranging from 650 to 950° C.
Claim 10
Dependent Claim
54 words
A method for the manufacture of steel pipe comprising the steps of cold-working, with a percentage reduction in cross section of not more than 50%, steel pipe which is made of the carburizing steel as defined in claim 2 and annealing the resultant cold-worked pipe at a temperature ranging from 650 to 950° C.
Claim 11
Dependent Claim
54 words
A method for the manufacture of steel pipe comprising the steps of cold-working, with a percentage reduction in cross section of not more than 50%, steel pipe which is made of the carburizing steel as defined in claim 3 and annealing the resultant cold-worked pipe at a temperature ranging from 650 to 950° C.
Claim 12
Dependent Claim
54 words
A method for the manufacture of steel pipe comprising the steps of cold-working, with a percentage reduction in cross section of not more than 50%, steel pipe which is made of the carburizing steel as defined in claim 4 and annealing the resultant cold-worked pipe at a temperature ranging from 650 to 950° C.
Claim 13
Dependent Claim
45 words
A method as defined in claim 5, further comprising the steps of: subjecting the steel pipe to a carburizing treatment at a temperature between 880 and 930° C. for 1-3 hours, and quenching the carburized steel pipe from a temperature between 800 and 870° C.
Claim 14
Dependent Claim
41 words
A method as defined in claim 5, further comprising the step of: subjecting the steel pipe to a carburizing treatment which forms a carburized layer on the steel pipe, the carburized layer having a case depth of 0.2 to 1.2 mm.
Claim 15
Dependent Claim
70 words
A carburizing steel consisting essentially of the following elements: C: 0.1 to 0.25%, Si: 0.2 to 0.4%, Mn: 0.3 to 0.9%, P: 0.02% or less, S: 0.001 to 0.15%, Cr: 0.5 to 0.9% Mo: 0.15 to 1%, Al: 0.01 to 0.1%, B: 0.0005 to 0.009%, N: less than 0.006%, and the balance of Fe and incidental impurities, wherein % is on a weight basis and the carburizing steel is Ti-free.
Claim 16
Dependent Claim
70 words
A carburizing steel consisting essentially of the following elements: C: 0.1 to 0.25%, Si: 0.2 to 0.4%, Mn: 0.3 to 0.9%, P: 0.02% or less, S: 0.001 to 0.15%, Cr: 0.5 to 0.9% Mo: 0.15 to 1%, Al: 0.01 to 0.1%, B: 0.0005 to 0.009%, N: less than 0.006%, and the balance of Fe and incidental impurities, wherein % is on a weight basis and the carburizing steel is Ti-free.
Claim 17
Dependent Claim
14 words
The carburizing steel as defined in claim 3, wherein Cr is 0.5 to 0.65%.
Claim 18
Dependent Claim
19 words
The carburizing steel as defined in claim 3, having an ultimate tensile strength of over 120 kgf/mm 2 .
Claim 19
Dependent Claim
21 words
The carburizing steel as defined in claim 3, having a rolling contact fatigue strength of at least 300 kg/mm 2 .
Claim 20
Dependent Claim
56 words
The carburizing steel as defined in claim 3, having a carburized layer and wherein Mo is present in an amount which elevates C content of the carburized layer, Cr is present in an amount which prevents embrittlement of grain boundaries and N is present in an amount which prevents precipitation of carbides on the grain boundaries.
Claim 21
Dependent Claim
20 words
The carburizing steel as defined in claim 3, wherein C is 0.10 to 0.20% and Si is 0.23 to 0.4%.
Claim 22
Dependent Claim
19 words
The carburizing steel as defined in claim 1, wherein C is 0.10 to 0.20% and the steel is Ti-free.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2003-10-03 | 2004-04-03 | 2004-10-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-10-03 | 2008-04-03 | 2008-10-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-10-03 | 2012-04-03 | 2012-10-03 | $7700.00 | Window Closed / Lapsed |