EP2268841A1 - A bearing component - Google Patents
A bearing componentInfo
- Publication number
- EP2268841A1 EP2268841A1 EP09726170A EP09726170A EP2268841A1 EP 2268841 A1 EP2268841 A1 EP 2268841A1 EP 09726170 A EP09726170 A EP 09726170A EP 09726170 A EP09726170 A EP 09726170A EP 2268841 A1 EP2268841 A1 EP 2268841A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- bearing component
- bainite
- cobalt
- aluminium
- chromium
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/34—Ferrous alloys, e.g. steel alloys containing chromium with more than 1.5% by weight of silicon
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
- C21D9/40—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for rings; for bearing races
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/22—Ferrous alloys, e.g. steel alloys containing chromium with molybdenum or tungsten
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/24—Ferrous alloys, e.g. steel alloys containing chromium with vanadium
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/30—Ferrous alloys, e.g. steel alloys containing chromium with cobalt
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/38—Ferrous alloys, e.g. steel alloys containing chromium with more than 1.5% by weight of manganese
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
- F16C33/00—Parts of bearings; Special methods for making bearings or parts thereof
- F16C33/30—Parts of ball or roller bearings
- F16C33/58—Raceways; Race rings
- F16C33/62—Selection of substances
Definitions
- the present invention relates generally to the field of metallurgy and to a bearing component such as a rolling element or ring formed from a bearing steel comprising lower bainite as the predominant phase.
- Rolling element bearings are devices that permit constrained relative motion between two parts.
- Rolling element bearings comprise inner and outer raceways and a plurality of rolling elements (balls or rollers) disposed therebetween.
- rolling elements balls or rollers
- Through-hardened components differ from case-hardened components in that the hardness is uniform or substantially uniform throughout the component. Through-hardened components are also generally cheaper to manufacture than case-hardened components because they avoid the complex heat-treatments associated with carburizing, for example.
- two heat- treating methods are available: martensite hardening or austempering. Component properties such as toughness, hardness, microstructure, retained austenite content, and dimensional stability are associated with or affected by the particular type of heat treatment employed.
- the martensite through-hardening process involves austenitising the steel prior to quenching below the martensite start temperature.
- the steel may then be low- temperature tempered to stabilize the microstructure.
- the bainite through-hardening process involves austenitising the steel prior to quenching above the martensite start temperature. Following quenching, an isothermal bainite transformation is performed. Bainite through-hardening is sometimes preferred in steels instead of martensite through- hardening. This is because a bainitic structure may possess superior mechanical properties, for example toughness and crack propagation resistance.
- WO 01/79568 describes a method for the production of a part for a rolling bearing. Summary
- the present invention provides a bearing component formed from a steel composition comprising:
- the bearing component is formed from the alloy as herein described and preferably comprises lower bainite as the main phase (typically at least 60% bainite, more typically at least 80% bainite) or as essentially the only phase (i.e. > 95% bainite) .
- Bainite is preferably obtained by carrying out the transformation at a relatively low temperature, typically less than 350 0 C, more typically from 110 to 325°C.
- the low transformation temperature is that the plates of bainite are very fine.
- the material preferably has a microstructure comprising plates of bainite of less than 100 nm, typically from 10 to 50 nm, more typically from 20 to 40 nm.
- the plates of bainite are typically interspersed with retained austenite.
- the bainite typically forms at least 60% of the microstructure, more typically at least 80%.
- the steel is preferably essentially carbide-free.
- the microstructure will comprises less than 5% carbides, more typically less than 3%.
- the steel typically has an ultimate tensile strength of 2500 MPa, a hardness at 600-670 HV, and toughness in excess of 30-40 MPam 1/2 .
- the microstructure and resulting mechanical properties lead to improved rolling contact fatigue performance in the bearing component.
- the steel composition preferably comprises 0.7 - 1.1 wt . % carbon, more preferably from 0.75 to 1.05 wt . % carbon. In combination with the other alloying elements, this results in the desired fine (lower) bainite microstructure. Carbon acts to lower the bainite transformation temperature.
- the steel composition preferably comprises 0.25 - 2 wt . % silicon, more preferably from 0.25 - 1 wt . % silicon, still more preferably from 0.4 - 1 wt.% silicon. In combination with the other alloying elements, this results in the desired fine carbide-free microstructure (or essentially carbide-free) . Silicon helps to suppress the precipitation of cementite. However, too high a silicon content may result in undesirable surface oxides and a poor surface finish. For this reason, the maximum silicon content is 2 wt.%, more preferably 1 wt.%.
- the steel composition preferably comprises 0.25 - 1.9 wt.% manganese, more preferably from 0.25 - 1.8 wt.% manganese, still more preferably from 0.25 - 1.7 wt.% manganese.
- Manganese acts to increase the stability of austenite relative to ferrite.
- the steel composition preferably comprises 0.95 to 2.05 wt . % chromium, more preferably from 0.95 - 1.5 wt.% chromium, still more preferably from 0.95 - 1.4 wt.% chromium, still more preferably 0.95 - 1.3 wt.% chromium. Chromium acts to increase hardenability and reduce the bainite start temperature .
- the steel composition comprises one or both of:
- the steel composition comprises one or both of:
- the steel composition comprises one or both of:
- the steel composition comprises one or both of:
- Aluminium has been found to improve the intrinsic toughness of the bearing component, possibly due to it suppressing carbide formation.
- Cobalt has been found to improve the corrosion resistance of the bearing component. This is very important for bearing components for wind turbines or marine pods, for example. Such bearings may become contaminated by sea water, which can drastically reduce the service life of the bearing.
- the alloy preferably also comprises from 0.05 - 0.5 wt . % molybdenum.
- Molybdenum acts to avoid austenite grain boundary embrittlement owing to impurities such as, for example, phosphorus. Molybdenum also acts to increase hardenability and reduce the bainite start temperature
- the steel for use in the bearing component according to the present invention may contain unavoidable impurities, although, in total, these are unlikely to exceed 0.5 wt . % of the composition.
- the alloys Preferably, contain unavoidable impurities in an amount of not more than 0.3 wt . % of the composition, more preferably not more than 0.1 wt . % of the composition.
- the phosphorous and sulphur contents are preferably kept to a minimum.
- the alloys according to the present invention may consist essentially of the recited elements. It will therefore be appreciated that in addition to those elements which are mandatory other non-specified elements may be present in the composition provided that the essential characteristics of the composition are not materially affected by their presence .
- the bearing component according to the present invention is formed from a steel that transforms to bainite at a temperature of typically 110 to 350 0 C, more typically 115 to 250 0 C.
- the transformation time for complete bainite formation is typically from 3 hours to 80 days, more typically from 6 hours to 60 days.
- the transformation time depends on the transformation temperature: the time is longer for lower temperatures.
- the amount of bainite that is formed depends on the transformation temperature: more bainite is formed at lower temperatures.
- the amount of retained austenite increases for higher transformation temperatures .
- the process for the manufacture of the steel for the bearing component avoids rapid cooling so that residual stresses can be avoided in large component pieces.
- Suitable bainitic steel compositions for use in the present invention include (the balance being Fe) :
- various mechanical properties can be improved by carrying out any of the conventional post-bainite transformation steps.
- the yield strength can be improved by carrying out a post-bainite transformation deformation step followed by tempering.
- the bearing component may be part of a rolling element bearing, for example the bearing inner or outer ring, or the ball or roller element.
- the bearing component could also be part of a linear bearing such as ball and roller screws.
- the present invention also provides a bearing comprising a bearing component as herein described.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- General Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Rolling Contact Bearings (AREA)
- Heat Treatment Of Articles (AREA)
Abstract
Description
Claims
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP09726170A EP2268841A1 (en) | 2008-03-25 | 2009-03-25 | A bearing component |
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP08251054 | 2008-03-25 | ||
EP09726170A EP2268841A1 (en) | 2008-03-25 | 2009-03-25 | A bearing component |
PCT/EP2009/002176 WO2009118166A1 (en) | 2008-03-25 | 2009-03-25 | A bearing component |
Publications (1)
Publication Number | Publication Date |
---|---|
EP2268841A1 true EP2268841A1 (en) | 2011-01-05 |
Family
ID=40757182
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP09726170A Withdrawn EP2268841A1 (en) | 2008-03-25 | 2009-03-25 | A bearing component |
Country Status (4)
Country | Link |
---|---|
US (1) | US20110052442A1 (en) |
EP (1) | EP2268841A1 (en) |
CN (1) | CN102046828A (en) |
WO (1) | WO2009118166A1 (en) |
Families Citing this family (26)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP2310545B1 (en) * | 2008-07-31 | 2013-10-23 | The Secretary of State for Defence | Super bainite steels and methods of manufacture thereof |
EP2458023B1 (en) * | 2009-07-22 | 2016-02-10 | NTN Corporation | Method for heat-treating a ring-shaped member, method for producing a ring-shaped member, ring-shaped member, bearing ring, rolling bearing, and method for producing a bearing ring |
CN102251197B (en) * | 2010-05-20 | 2013-01-23 | 宝山钢铁股份有限公司 | High-carbon chromium bearing steel and preparation method thereof |
BR112013013783A2 (en) * | 2010-12-13 | 2016-09-13 | Skf Ab | steel and component suitable for high temperature joining processes |
US9487843B2 (en) | 2011-01-21 | 2016-11-08 | Ntn Corporation | Method for producing a bearing ring |
CN103547696A (en) * | 2011-05-17 | 2014-01-29 | Skf公司 | Improved bearing steel |
CN102268601B (en) * | 2011-08-09 | 2013-02-20 | 上海捷如重工机电设备有限公司 | 50Cr3MoV steel for back-up roll and heat treatment method for steel |
WO2013060866A1 (en) * | 2011-10-28 | 2013-05-02 | Aktiebolaget Skf | A bearing component |
DE102012204618A1 (en) * | 2012-03-22 | 2013-09-26 | Schaeffler Technologies AG & Co. KG | Rolling bearing with a bearing ring with hardened edge zone |
DE102012017143B3 (en) * | 2012-08-30 | 2014-03-27 | Technische Universität Clausthal | Manufacturing component with bainitic microstructure, comprises preparing component blank comprising steel having manganese, cooling component blank at cooling rate to suppress ferrite and/or perlite formation, and bainite hardening |
CN102953006B (en) * | 2012-10-19 | 2014-08-06 | 燕山大学 | Integral hard bainite bearing steel and manufacture method thereof |
WO2015113574A1 (en) * | 2014-01-29 | 2015-08-06 | Aktiebolaget Skf | Steel alloy |
RU2578873C1 (en) * | 2014-11-25 | 2016-03-27 | федеральное государственное бюджетное образовательное учреждение высшего профессионального образования "Пермский национальный исследовательский политехнический университет" | Steel with bainite structure |
GB2532761A (en) * | 2014-11-27 | 2016-06-01 | Skf Ab | Bearing steel |
GB201421047D0 (en) * | 2014-11-27 | 2015-01-14 | Skf Ab | Bearing steel |
GB2535782A (en) * | 2015-02-27 | 2016-08-31 | Skf Ab | Bearing Steel |
DE102016208682A1 (en) * | 2015-05-25 | 2016-12-15 | Aktiebolaget Skf | A method for improving the structure of a steel component after heating and steel component obtained by the method |
GB201521947D0 (en) * | 2015-12-14 | 2016-01-27 | Skf Ab | Bearing steel |
CN105387073A (en) * | 2015-12-30 | 2016-03-09 | 哈尔滨工业大学 | Cobalt system conical roller bearing with high temperature-resistant fixing frame |
CN105908075A (en) * | 2016-05-31 | 2016-08-31 | 安徽潜山轴承制造有限公司 | Casting technology of alloy steel bearing block |
DE102016223680A1 (en) * | 2016-11-29 | 2018-05-30 | Schaeffler Technologies AG & Co. KG | Process for producing a rolling bearing component |
CN108061097A (en) * | 2017-12-14 | 2018-05-22 | 昆山拓可机械有限公司 | A kind of unleaded Sliding bush and production technology |
CN110029272B (en) * | 2019-04-17 | 2020-07-03 | 燕山大学 | Structure regulating method of high-toughness bearing and steel for nano bainite bearing |
KR102239184B1 (en) * | 2019-09-04 | 2021-04-12 | 주식회사 포스코 | Steel plate having excellent strength and low-temperature impact toughness and method for manufacturing thereof |
DE102020202739A1 (en) * | 2020-03-04 | 2021-09-09 | Mahle International Gmbh | Sintered bearing bushing material, plain bearings, internal combustion engines and electrical machines |
CN111763889A (en) * | 2020-06-02 | 2020-10-13 | 钢铁研究总院 | High-carbon bearing steel and preparation method thereof |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2352726A (en) | 1999-08-04 | 2001-02-07 | Secr Defence | A steel and a heat treatment for steels |
Family Cites Families (15)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2639985A (en) * | 1951-04-30 | 1953-05-26 | United States Steel Corp | Bearing and steel therefor |
US4992111A (en) * | 1988-08-15 | 1991-02-12 | N.T.N. Corporation | Bearing race member and method of fabrication |
JPH0633190A (en) * | 1992-07-14 | 1994-02-08 | Sumitomo Metal Ind Ltd | Long-life bearing steel |
JPH06271982A (en) * | 1993-03-23 | 1994-09-27 | Kawasaki Steel Corp | Bearing steel excellent in property of retarding change in microstructure due to repeated stress load |
JPH06293939A (en) * | 1993-04-07 | 1994-10-21 | Kobe Steel Ltd | Bearing parts excellent in high temperature rolling fatigue characteristic |
JPH07252595A (en) * | 1994-03-11 | 1995-10-03 | Kawasaki Steel Corp | Bearing member excellent in delaying property in change of microstructure caused by repeated stress load |
JP3243366B2 (en) * | 1994-04-20 | 2002-01-07 | 川崎製鉄株式会社 | Bearings with excellent microstructure change delay characteristics due to repeated stress loading |
JPH1030150A (en) * | 1996-07-19 | 1998-02-03 | Nippon Seiko Kk | Rolling bearing |
JP3687275B2 (en) * | 1997-05-19 | 2005-08-24 | 大同特殊鋼株式会社 | Non-tempered steel for induction hardening |
US6224688B1 (en) * | 1997-08-18 | 2001-05-01 | Nsk Ltd. | Rolling bearing |
NL1011806C2 (en) * | 1999-04-15 | 2000-10-17 | Skf Engineering & Res Services | Ball bearing steel with a surface with an underbainitic structure and a method of manufacturing it. |
NL1011807C2 (en) * | 1999-04-15 | 2001-02-05 | Skf Engineering & Res Services | Machine steel and part of a rolling bearing. |
JP3997662B2 (en) * | 1999-08-09 | 2007-10-24 | 株式会社ジェイテクト | Rolling bearing |
WO2005106059A1 (en) * | 2004-04-28 | 2005-11-10 | Jfe Steel Corporation | Parts for machine construction and method for production thereof |
WO2007058364A1 (en) * | 2005-11-21 | 2007-05-24 | National Institute For Materials Science | Steel for warm working, method of warm working of the steel, and steel material and steel part obtained by the same |
-
2009
- 2009-03-25 US US12/933,909 patent/US20110052442A1/en not_active Abandoned
- 2009-03-25 EP EP09726170A patent/EP2268841A1/en not_active Withdrawn
- 2009-03-25 CN CN2009801190049A patent/CN102046828A/en active Pending
- 2009-03-25 WO PCT/EP2009/002176 patent/WO2009118166A1/en active Application Filing
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2352726A (en) | 1999-08-04 | 2001-02-07 | Secr Defence | A steel and a heat treatment for steels |
Non-Patent Citations (3)
Title |
---|
"Cobalt", HUMAN HEALTH FACT SHEET - ARGONNE NATIONAL LABORATORY EVS, August 2005 (2005-08-01), pages 1 - 2, XP003028348 |
BROWN P.M. AND BAXTER D.P.: "Hyper-strength bainitic steels", AIST PROCESS METALLURGY, PRODUCT QUALITY AND APPLICATIONS PROCEEDINGS. MATERIALSSCIENCE AND TECHNOLOGY CONFERENCE, 26 September 2004 (2004-09-26), pages 433 - 436, XP009130518 |
See also references of WO2009118166A1 |
Also Published As
Publication number | Publication date |
---|---|
US20110052442A1 (en) | 2011-03-03 |
CN102046828A (en) | 2011-05-04 |
WO2009118166A1 (en) | 2009-10-01 |
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