JP2022165628A - Carbonitriding steel material and carbonitrided steel material - Google Patents
Carbonitriding steel material and carbonitrided steel material Download PDFInfo
- Publication number
- JP2022165628A JP2022165628A JP2021071046A JP2021071046A JP2022165628A JP 2022165628 A JP2022165628 A JP 2022165628A JP 2021071046 A JP2021071046 A JP 2021071046A JP 2021071046 A JP2021071046 A JP 2021071046A JP 2022165628 A JP2022165628 A JP 2022165628A
- Authority
- JP
- Japan
- Prior art keywords
- mass
- carbonitriding
- steel material
- concentration
- present
- 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.)
- Pending
Links
- 238000005256 carbonitriding Methods 0.000 title claims abstract description 108
- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 102
- 239000010959 steel Substances 0.000 title claims abstract description 102
- 239000000463 material Substances 0.000 title claims abstract description 92
- 238000005496 tempering Methods 0.000 claims abstract description 16
- 239000012535 impurity Substances 0.000 claims abstract description 11
- 229910052742 iron Inorganic materials 0.000 claims abstract description 3
- 229910052799 carbon Inorganic materials 0.000 abstract description 7
- 229910052804 chromium Inorganic materials 0.000 abstract description 5
- 229910052757 nitrogen Inorganic materials 0.000 abstract description 5
- 229910052802 copper Inorganic materials 0.000 abstract description 3
- 229910052748 manganese Inorganic materials 0.000 abstract description 3
- 229910052750 molybdenum Inorganic materials 0.000 abstract description 3
- 229910052759 nickel Inorganic materials 0.000 abstract description 3
- 229910052698 phosphorus Inorganic materials 0.000 abstract description 3
- 229910052710 silicon Inorganic materials 0.000 abstract description 3
- 229910052782 aluminium Inorganic materials 0.000 abstract description 2
- 229910052717 sulfur Inorganic materials 0.000 abstract description 2
- 238000005255 carburizing Methods 0.000 description 16
- 238000000034 method Methods 0.000 description 12
- 239000007789 gas Substances 0.000 description 11
- 238000005121 nitriding Methods 0.000 description 11
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 8
- 238000005452 bending Methods 0.000 description 7
- 230000000052 comparative effect Effects 0.000 description 7
- 230000007423 decrease Effects 0.000 description 7
- 239000000203 mixture Substances 0.000 description 7
- 230000015572 biosynthetic process Effects 0.000 description 6
- 238000010791 quenching Methods 0.000 description 5
- 230000000171 quenching effect Effects 0.000 description 5
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 4
- 238000010521 absorption reaction Methods 0.000 description 4
- 235000013339 cereals Nutrition 0.000 description 4
- 239000013078 crystal Substances 0.000 description 4
- 239000002244 precipitate Substances 0.000 description 4
- 239000002344 surface layer Substances 0.000 description 4
- 229910021529 ammonia Inorganic materials 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 239000010410 layer Substances 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 150000004767 nitrides Chemical class 0.000 description 3
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- ATUOYWHBWRKTHZ-UHFFFAOYSA-N Propane Chemical compound CCC ATUOYWHBWRKTHZ-UHFFFAOYSA-N 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 238000009792 diffusion process Methods 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- 150000001247 metal acetylides Chemical class 0.000 description 2
- 229910052758 niobium Inorganic materials 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 238000001556 precipitation Methods 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 229910052719 titanium Inorganic materials 0.000 description 2
- 229910052720 vanadium Inorganic materials 0.000 description 2
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 1
- 240000007594 Oryza sativa Species 0.000 description 1
- 235000007164 Oryza sativa Nutrition 0.000 description 1
- 238000002441 X-ray diffraction Methods 0.000 description 1
- 229910052785 arsenic Inorganic materials 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 229910002091 carbon monoxide Inorganic materials 0.000 description 1
- 238000005266 casting Methods 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 238000004993 emission spectroscopy Methods 0.000 description 1
- 239000004744 fabric Substances 0.000 description 1
- 238000005242 forging Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 230000006698 induction Effects 0.000 description 1
- 230000013011 mating Effects 0.000 description 1
- 230000006911 nucleation Effects 0.000 description 1
- 238000010899 nucleation Methods 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 238000007517 polishing process Methods 0.000 description 1
- 239000001294 propane Substances 0.000 description 1
- 235000009566 rice Nutrition 0.000 description 1
- 238000007790 scraping Methods 0.000 description 1
- 238000004611 spectroscopical analysis Methods 0.000 description 1
- 239000013585 weight reducing agent Substances 0.000 description 1
Images
Classifications
-
- 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
- C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
- C21D1/06—Surface hardening
-
- 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
-
- 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
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/58—Ferrous alloys, e.g. steel alloys containing chromium with nickel with more than 1.5% by weight of manganese
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C8/00—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
- C23C8/06—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases
- C23C8/28—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases more than one element being applied in one step
- C23C8/30—Carbo-nitriding
- C23C8/32—Carbo-nitriding of ferrous surfaces
Abstract
Description
本発明は浸炭窒化処理用鋼材および浸炭窒化鋼材に関する。 TECHNICAL FIELD The present invention relates to a carbonitriding steel material and a carbonitriding steel material.
例えば自動車や産業機械の歯車、シャフト等の鋼製部品には高い面疲労強度が求められる。そこで、従来、当該部品として浸炭窒化部品が用いられている。鋼材を浸炭窒化することにより面疲労強度が向上することは、従来、広く知られている。
これに関連する従来法として、例えば特許文献１～５に記載のものが挙げられる
For example, high surface fatigue strength is required for steel parts such as gears and shafts for automobiles and industrial machinery. Therefore, conventionally, carbonitrided parts are used as such parts. Conventionally, it is widely known that surface fatigue strength is improved by carbonitriding steel materials.
Conventional methods related to this include those described in Patent Documents 1 to 5, for example.
例えば特許文献１、２には生地が、特定組成を備える鋼材であり、表面から深さ０．１ｍｍまでの領域において、平均のＣ濃度Ｃｓが０．６０～０．９０％、平均のＮ濃度Ｎｓが０．１５～０．３５％、Ｃｓ＋Ｎｓが０．８０～１．１０％で、かつ、各成分が特定の関係式を満たすことを特徴とする鋼製の浸炭窒化部品が記載されている。そして、このような浸炭窒化部品によれば、大幅なコストアップをすることなく、表面硬化処理として最も代表的な浸炭焼入れによって製造した場合に較べて大幅に優れた曲げ疲労強度および面疲労強度を有し、部品の軽量化、小型化、高応力負荷化の要求に応えることができる鋼製の浸炭窒化部品を提供することができると記載されている。
For example, in
また、特許文献３には、特定組成からなり、各成分が特定の関係式を満たすことを特徴とする浸炭窒化用鋼材が記載されている。そして、このような浸炭窒化鋼材によれば、部品形状への加工性に優れ、しかも浸炭窒化処理後の研磨工程を省略してもピッチング寿命に優れた鋼材、および該鋼材を用いた部品を提供できると記載されている。 Further, Patent Document 3 describes a carbonitriding steel material having a specific composition, wherein each component satisfies a specific relational expression. According to such a carbonitriding steel material, it is possible to provide a steel material that is excellent in workability into a part shape and has an excellent pitting life even if the polishing process after the carbonitriding treatment is omitted, and a part using the steel material. It is stated that it is possible.
また、特許文献４には、基地が、特定の組成を備える鋼材であり、表面から深さ５μｍの領域において、空隙の比率が１０％未満であり、表面から深さ１００μｍまでの領域において、平均のＣ濃度Ｃａｖｅが０．００５～０．８０％、平均のＮ濃度Ｎａｖｅが０．３０～０．７０％、Ｃａｖｅ＋Ｎａｖｅが０．５０～１．４０％であることを特徴とする鋼部品が記載されている。そして、このような鋼部品によれば、面疲労強度及び耐摩耗性が優れ、自動車や産業機械の歯車、クランクシャフト、カムシャフトなどの部品に利用できる鋼部品を提供することができると記載されている。 Further, in Patent Document 4, the base is a steel material having a specific composition, the ratio of voids is less than 10% in a region from the surface to a depth of 5 μm, and the average C concentration Cave is 0.005 to 0.80%, average N concentration Nave is 0.30 to 0.70%, and Cave + Nave is 0.50 to 1.40%. It is It is described that such steel parts have excellent surface fatigue strength and wear resistance, and can be used for parts such as gears, crankshafts, and camshafts of automobiles and industrial machinery. ing.
さらに特許文献５には、平坦部及びエッジ部を有する表面を含む表層部と、前記表層部よりも内部の芯部とを備え、前記芯部は、特定組成を備え、前記平坦部から深さ０．０５ｍｍまでの領域における炭素濃度ＣＰ１は０．７０～０．８９％であり、窒素濃度は０．１０～０．８０％であり、前記エッジ部から深さ０．０５ｍｍまでの領域における炭素濃度ＣＰ２は、前記炭素濃度ＣＰ１よりも高く１．２０％以下であり、前記平坦部から深さ０．３ｍｍ位置でのビッカース硬さがＨＶ６５０以上であり、前記表層部での粒界酸化層深さが３．０μｍ未満であり、前記芯部のビッカース硬さがＨＶ２６０以上である、浸炭窒化部品が記載されている。そして、このような浸炭窒化部品によれば、平坦部及びエッジ部を含む表面を含み、優れた曲げ疲労強度及びピッチング強度を有する浸炭窒化部品を提供することができると記載されている。 Furthermore, Patent Document 5 includes a surface layer portion including a surface having a flat portion and an edge portion, and a core portion inside the surface layer portion, the core portion having a specific composition, and a depth from the flat portion The carbon concentration CP1 in the region up to 0.05 mm is 0.70 to 0.89%, the nitrogen concentration is 0.10 to 0.80%, and the carbon in the region from the edge to a depth of 0.05 mm The concentration CP2 is higher than the carbon concentration CP1 and 1.20% or less, the Vickers hardness at a depth of 0.3 mm from the flat portion is HV650 or more, and the depth of the grain boundary oxide layer at the surface layer portion is is less than 3.0 μm and the core has a Vickers hardness of HV260 or higher. According to such a carbonitrided part, it is possible to provide a carbonitrided part having a surface including a flat portion and an edge portion and having excellent bending fatigue strength and pitting strength.
近年、自動車は電動化され、それに伴い一部の部品の摺動温度は従来よりも高温（例えば３００～５００℃程度）となる可能性がある。したがって、一部の部材には、高温に曝されても十分に硬いこと、すなわち、高温焼戻し硬さが求められる。 In recent years, automobiles have been electrified, and along with this, there is a possibility that the sliding temperature of some parts will be higher than before (for example, about 300 to 500° C.). Therefore, some members are required to be sufficiently hard even when exposed to high temperatures, that is, high temperature temper hardness.
一方、本発明者は、浸炭窒化の面疲労強度向上要因としてＣｒＮクラスターの生成が大きく寄与しているおり、面疲労強度を十分に向上させるためにはＣｒをある程度添加する必要があることを見出した。具体的には３００℃まではＮの添加が、３００℃よりも高温領域においてはＣｒ、Ｎの２元素の添加が有効であることを見出した。
さらに、本発明者はＣｒ、Ｎの添加量によっては高温（３００～５００℃程度）における焼戻し硬さが低下してしまうことを見出した。
すなわち、面疲労強度と高温焼戻し硬さとの両方を改善することは難しく、これらはトレードオフの関係にあることを見出した。
On the other hand, the present inventor found that the formation of CrN clusters greatly contributes to the improvement of the surface fatigue strength of carbonitriding, and that it is necessary to add Cr to a certain extent in order to sufficiently improve the surface fatigue strength. rice field. Specifically, it was found that the addition of N is effective up to 300°C, and the addition of Cr and N is effective in the temperature range above 300°C.
Furthermore, the inventors have found that the tempering hardness at high temperatures (about 300 to 500° C.) decreases depending on the amount of Cr and N added.
That is, it has been found that it is difficult to improve both surface fatigue strength and high-temperature tempering hardness, and that these are in a trade-off relationship.
本発明は上記のような課題を解決することを目的とする。
すなわち、本発明の目的は、面疲労強度が高く、かつ、高温焼戻し硬さが十分に高い浸炭窒化処理用鋼材およびそれを浸炭窒化処理してなる浸炭窒化鋼材を提供することである。
An object of the present invention is to solve the above problems.
That is, an object of the present invention is to provide a carbonitriding steel material having high surface fatigue strength and sufficiently high high-temperature tempering hardness, and a carbonitriding steel material obtained by carbonitriding the same.
本発明者は上記課題を解決するため鋭意検討し、本発明を完成させた。
本発明は下記（１）～（７）である。
（１）Ｃ：０．１～０．３質量％、
Ｓｉ：０．３質量％以下、
Ｍｎ：０．４～２．０質量％、
Ｐ：０．０３質量％以下、
Ｓ：０．０３質量％以下、
Ｃｕ：０．３質量％以下、
Ｎｉ：２．５質量％以下、
Ｃｒ：０．５～３．０質量％、
Ｍｏ：０．００１～１．０質量％、
Ａｌ：０．０１～０．０８質量％、
Ｎ：０．００５～０．０３質量％、
で含有し、残部はＦｅおよび不可避的不純物からなり、
浸炭窒化を施すことで、
式１：表面Ｃ濃度（質量％）＋１２／１４×表面Ｎ濃度（質量％）＝０．６～１．４
を満たし、
式２：１２９．７８０５×［Ｃｒ（質量％）］－７６．９７９７×［Ｃｒ（質量％）］2＋３３９．３３７５×［表面Ｎ濃度（質量％）］－５３９．３４５×［表面Ｎ濃度（質量％）］2＋１８１．４９８３×［Ｃｒ（質量％）］×［表面Ｎ濃度（質量％）］＋４３７．６７９９＞５６０
を満たし、
前記浸炭窒化を施した後に５００℃で焼戻し処理を施した場合に、表面から０．０５ｍｍの深さの部分における硬さが５６０ＨＶ以上である浸炭窒化鋼材が得られる、浸炭窒化処理用鋼材。
（２）Ｎｂ：０．００１～０．０８質量％、
Ｖ：０．５質量％以下、
Ｔｉ：０．０５質量％以下、および
Ｂ：０．０００５～０．００３質量％、
からなる群から選ばれる少なくとも一種をさらに含有する、上記（１）に記載の浸炭窒化処理用鋼材。
（３）Ｃ：０．１５～０．２５質量％、
Ｓｉ：０．０１～０．２４質量％、
Ｍｎ：０．５～１．８質量％、
Ｃｕ：０．００１～０．３質量％、
Ｎｉ：０．０１～０．６質量％、
Ｃｒ：０．６～１．８質量％、
Ｍｏ：０．０１～０．８質量％、
Ａｌ：０．０２～０．０５質量％、
Ｎ：０．０１～０．０２５質量％、
で含有し、
Ｎｂ：０．００１５～０．０６質量％、
Ｖ：０．２５質量％以下、
Ｔｉ：０．０１２～０．０４質量％、および
Ｂ：０．０００６～０．００２５質量％、
からなる群から選ばれる少なくとも一種をさらに含有し、残部はＦｅおよび不可避的不純物からなり、
前記浸炭窒化を施すことで、
式１：表面Ｃ濃度（質量％）＋１２／１４×表面Ｎ濃度（質量％）＝０．７～１．２を満たす浸炭窒化処理鋼材が得られる、上記（１）または（２）に記載の浸炭窒化処理用鋼材。
（４）Ｃｕ：０．０３～０．３質量％、
で含有する、上記（１）～（３）のいずれかに記載の浸炭窒化処理用鋼材。
（５）Ｓｉ：０．０１～０．１７質量％、
で含有する、上記（１）～（４）のいずれかに記載の浸炭窒化処理用鋼材。
（６）Ｃｕ：０．０３～０．２５質量％、
で含有する、上記（１）～（５）のいずれかに記載の浸炭窒化処理用鋼材。
（７）上記（１）～（６）のいずれかに記載の浸炭窒化処理用鋼材を浸炭窒化処理してなり、
式１：表面Ｃ濃度（質量％）＋１２／１４×表面Ｎ濃度（質量％）＝０．６～１．４
を満たし、
式２：１２９．７８０５×［Ｃｒ（質量％）］－７６．９７９７×［Ｃｒ（質量％）］2＋３３９．３３７５×［表面Ｎ濃度（質量％）］－５３９．３４５×［表面Ｎ濃度（質量％）］2＋１８１．４９８３×［Ｃｒ（質量％）］×［表面Ｎ濃度（質量％）］＋４３７．６７９９＞５６０
を満たし、
さらに５００℃で焼戻し処理を施した場合に、表面から０．０５ｍｍの深さの部分における硬さが５６０ＨＶ以上となる、浸炭窒化鋼材。
The present inventor has made intensive studies to solve the above problems, and completed the present invention.
The present invention provides the following (1) to (7).
(1) C: 0.1 to 0.3% by mass,
Si: 0.3% by mass or less,
Mn: 0.4 to 2.0% by mass,
P: 0.03% by mass or less,
S: 0.03% by mass or less,
Cu: 0.3% by mass or less,
Ni: 2.5% by mass or less,
Cr: 0.5 to 3.0% by mass,
Mo: 0.001 to 1.0% by mass,
Al: 0.01 to 0.08% by mass,
N: 0.005 to 0.03% by mass,
and the balance consists of Fe and unavoidable impurities,
By applying carbonitriding,
Formula 1: Surface C concentration (% by mass) + 12/14 x Surface N concentration (% by mass) = 0.6 to 1.4
The filling,
Formula 2: 129.7805×[Cr (mass%)]−76.9797×[Cr (mass%)] 2 +339.3375×[Surface N concentration (mass%)]−539.345×[Surface N concentration ( % by mass)] 2 +181.4983×[Cr (% by mass)]×[Surface N concentration (% by mass)]+437.6799>560
The filling,
A steel material for carbonitriding treatment, wherein a carbonitriding steel material having a hardness of 560 HV or more at a depth of 0.05 mm from the surface is obtained when tempering treatment is performed at 500° C. after the carbonitriding treatment.
(2) Nb: 0.001 to 0.08% by mass,
V: 0.5% by mass or less,
Ti: 0.05% by mass or less, and B: 0.0005 to 0.003% by mass,
The carbonitriding steel material according to (1) above, further containing at least one selected from the group consisting of:
(3) C: 0.15 to 0.25% by mass,
Si: 0.01 to 0.24% by mass,
Mn: 0.5 to 1.8% by mass,
Cu: 0.001 to 0.3% by mass,
Ni: 0.01 to 0.6% by mass,
Cr: 0.6 to 1.8% by mass,
Mo: 0.01 to 0.8% by mass,
Al: 0.02 to 0.05% by mass,
N: 0.01 to 0.025% by mass,
contains with
Nb: 0.0015 to 0.06% by mass,
V: 0.25% by mass or less,
Ti: 0.012 to 0.04% by mass, and B: 0.0006 to 0.0025% by mass,
further contains at least one selected from the group consisting of the balance consisting of Fe and inevitable impurities,
By applying the carbonitriding,
Formula 1: Surface C concentration (% by mass) + 12/14 x Surface N concentration (% by mass) = 0.7 to 1.2. Steel for carbonitriding.
(4) Cu: 0.03 to 0.3% by mass,
The steel material for carbonitriding treatment according to any one of the above (1) to (3), containing in.
(5) Si: 0.01 to 0.17% by mass,
The steel material for carbonitriding treatment according to any one of the above (1) to (4), containing in.
(6) Cu: 0.03 to 0.25% by mass,
The steel material for carbonitriding treatment according to any one of the above (1) to (5), containing in.
(7) Carbonitriding the steel material for carbonitriding according to any one of (1) to (6) above,
Formula 1: Surface C concentration (% by mass) + 12/14 x Surface N concentration (% by mass) = 0.6 to 1.4
The filling,
Formula 2: 129.7805×[Cr (mass%)]−76.9797×[Cr (mass%)] 2 +339.3375×[Surface N concentration (mass%)]−539.345×[Surface N concentration ( % by mass)] 2 +181.4983×[Cr (% by mass)]×[Surface N concentration (% by mass)]+437.6799>560
The filling,
A carbonitrided steel material which, when further tempered at 500° C., has a hardness of 560 HV or more at a depth of 0.05 mm from the surface.
本発明によれば、面疲労強度が高く、かつ、高温焼戻し硬さが十分に高い浸炭窒化処理用鋼材およびそれを浸炭窒化処理してなる浸炭窒化鋼材を提供することができる。 According to the present invention, it is possible to provide a carbonitriding steel material having high surface fatigue strength and sufficiently high high-temperature tempering hardness, and a carbonitriding steel material obtained by carbonitriding the same.
本発明について説明する。
本発明の浸炭窒化処理用鋼材は、Ｃ：０．１～０．３質量％、Ｓｉ：０．３質量％以下、Ｍｎ：０．４～２．０質量％、Ｐ：０．０３質量％以下、Ｓ：０．０３質量％以下、Ｃｕ：０．３質量％以下、Ｎｉ：２．５質量％以下、Ｃｒ：０．５～３．０質量％、Ｍｏ：０．００１～１．０質量％、Ａｌ：０．０１～０．０８質量％、Ｎ：０．００５～０．０３質量％、で含有し、残部はＦｅおよび不可避的不純物からなり、浸炭窒化を施すことで、式１：表面Ｃ濃度（質量％）＋１２／１４×表面Ｎ濃度（質量％）＝０．６～１．４を満たし、式２：１２９．７８０５×［Ｃｒ（質量％）］－７６．９７９７×［Ｃｒ（質量％）］2＋３３９．３３７５×［表面Ｎ濃度（質量％）］－５３９．３４５×［表面Ｎ濃度（質量％）］2＋１８１．４９８３×［Ｃｒ（質量％）］×［表面Ｎ濃度（質量％）］＋４３７．６７９９＞５６０を満たし、前記浸炭窒化を施した後に５００℃で焼戻し処理を施した場合に、表面から０．０５ｍｍの深さの部分における硬さが５６０ＨＶ以上である浸炭窒化鋼材が得られる、浸炭窒化処理用鋼材である。
The present invention will be described.
The carbonitriding steel material of the present invention has C: 0.1 to 0.3% by mass, Si: 0.3% by mass or less, Mn: 0.4 to 2.0% by mass, and P: 0.03% by mass. Below, S: 0.03% by mass or less, Cu: 0.3% by mass or less, Ni: 2.5% by mass or less, Cr: 0.5 to 3.0% by mass, Mo: 0.001 to 1.0 % by mass, Al: 0.01 to 0.08% by mass, N: 0.005 to 0.03% by mass, the balance being Fe and unavoidable impurities. : Surface C concentration (% by mass) + 12/14 x surface N concentration (% by mass) = 0.6 to 1.4, formula 2: 129.7805 x [Cr (mass%)] -76.9797 x [ Cr (mass%)] 2 + 339.3375 × [Surface N concentration (mass%)] - 539.345 × [Surface N concentration (mass%)] 2 + 181.4983 × [Cr (mass%)] × [Surface N Concentration (% by mass)]+437.6799>560, and when tempering is performed at 500° C. after the carbonitriding, the hardness at a depth of 0.05 mm from the surface is 560 HV or more. It is a carbonitriding steel material from which a carbonitriding steel material can be obtained.
また、本発明の浸炭窒化鋼材は、本発明の浸炭窒化処理用鋼材を浸炭窒化処理してなり、式１：表面Ｃ濃度（質量％）＋１２／１４×表面Ｎ濃度（質量％）＝０．６～１．４を満たし、式２：１２９．７８０５×［Ｃｒ（質量％）］－７６．９７９７×［Ｃｒ（質量％）］2＋３３９．３３７５×［表面Ｎ濃度（質量％）］－５３９．３４５×［表面Ｎ濃度（質量％）］2＋１８１．４９８３×［Ｃｒ（質量％）］×［表面Ｎ濃度（質量％）］＋４３７．６７９９＞５６０を満たし、さらに５００℃で焼戻し処理を施した場合に、表面から０．０５ｍｍの深さの部分における硬さが５６０ＨＶ以上となる、浸炭窒化鋼材である。 Further, the carbonitriding steel material of the present invention is obtained by carbonitriding the steel material for carbonitriding treatment of the present invention. 6 to 1.4, Formula 2: 129.7805 × [Cr (mass%)] −76.9797 × [Cr (mass%)] 2 + 339.3375 × [Surface N concentration (mass%)] −539 .345×[Surface N concentration (mass%)] 2 +181.4983×[Cr (mass%)]×[Surface N concentration (mass%)]+437. The carbonitrided steel material has a hardness of 560 HV or more at a depth of 0.05 mm from the surface.
本発明の浸炭窒化処理用鋼材の組成について説明する。 The composition of the carbonitriding steel material of the present invention will be described.
＜Ｃ＞
本発明の浸炭窒化処理用鋼材におけるＣ含有率は０．１～０．３質量％であり、０．１５～０．２５質量％であることが好ましい。
このようなＣ含有率であると、本発明の浸炭窒化処理用鋼材の焼入れ性が向上し、また表面部および芯部の硬さが確保される。Ｃ含有率が高すぎると靭性および熱間加工性が低下する可能性がある。
<C>
The carbonitriding steel material of the present invention has a C content of 0.1 to 0.3% by mass, preferably 0.15 to 0.25% by mass.
With such a C content, the hardenability of the carbonitriding steel material of the present invention is improved, and the hardness of the surface portion and the core portion is ensured. If the C content is too high, toughness and hot workability may deteriorate.
＜Ｓｉ＞
本発明の浸炭窒化処理用鋼材におけるＳｉ含有率は０．３質量％以下であり、０．０１～０．２４質量％であることが好ましく、０．０１～０．１７質量％であることがより好ましく、０．０１～０．１６質量％であることがさらに好ましい。
このようなＳｉ含有率であると、本発明の浸炭窒化処理用鋼材での窒化物の析出（Ｓｉ3Ｎ4、ＳｉＭｎＮ2等）の析出が抑制され、疲労強度の低下を防ぐことができる。
<Si>
The Si content in the carbonitriding steel material of the present invention is 0.3% by mass or less, preferably 0.01 to 0.24% by mass, and more preferably 0.01 to 0.17% by mass. More preferably, it is 0.01 to 0.16% by mass.
With such a Si content, the precipitation of nitrides (Si 3 N 4 , SiMnN 2 , etc.) in the carbonitriding steel material of the present invention is suppressed, and a decrease in fatigue strength can be prevented.
＜Ｍｎ＞
本発明の浸炭窒化処理用鋼材におけるＭｎ含有率は０．４～２．０質量％であり、０．５～２．０質量％であることが好ましく、０．５３～２．０質量％であることがより好ましく、０．５～１．８質量％であることがより好ましく、０．５～１．４質量％であることがより好ましく、０．５３～１．５質量％であることがさらに好ましい。
このようなＭｎ含有率であると、焼入れ性が向上することで芯部硬さが向上し、疲労強度が向上する。また、切削性、焼入性、製造性が良好となる。Ｍｎ含有率が低すぎると焼入れ性向上効果が得られない。また、Ｍｎ含有率が高すぎると製造性を損なう可能性がある。
<Mn>
The Mn content in the carbonitriding steel material of the present invention is 0.4 to 2.0% by mass, preferably 0.5 to 2.0% by mass, and more preferably 0.53 to 2.0% by mass. More preferably, 0.5 to 1.8% by mass, more preferably 0.5 to 1.4% by mass, and 0.53 to 1.5% by mass is more preferred.
With such a Mn content, the hardenability is improved, the core hardness is improved, and the fatigue strength is improved. In addition, machinability, hardenability and manufacturability are improved. If the Mn content is too low, the effect of improving hardenability cannot be obtained. Also, if the Mn content is too high, there is a possibility that the manufacturability will be impaired.
＜Ｐ＞
本発明の浸炭窒化処理用鋼材におけるＰ含有率は０．０３質量％以下％であり、０．０２０質量％以下であることが好ましい。Ｐは鋼に含有される不純物であり、結晶粒界に偏析して鋼を脆化させ、特に、その含有量が０．０３０質量％を超えると、脆化の程度が著しくなる場合がある。従って、本発明の浸炭窒化処理用鋼材におけるＰ含有率は０．０３質量％以下％とする。
<P>
The P content in the carbonitriding steel material of the present invention is 0.03% by mass or less, preferably 0.020% by mass or less. P is an impurity contained in steel, and segregates at grain boundaries to embrittle the steel. In particular, when the content exceeds 0.030% by mass, the degree of embrittlement may become significant. Therefore, the P content in the carbonitriding steel material of the present invention is set to 0.03% by mass or less.
＜Ｓ＞
本発明の浸炭窒化処理用鋼材におけるＳ含有率は０．０３質量％以下であり、０．０２０質量％以下であることが好ましい。
このようなＳ含有率であると、ＭｎＳを形成し、被削性を向上させる作用がある。一方で、Ｓの含有量が０．０３０質量％を超えると、粗大なＭｎＳを形成して、熱間鍛造性および曲げ疲労強度が低下する傾向がある。そのため、０．００５～０．０３０質量％であることが好ましい。熱間鍛造性および曲げ疲労強度をより重視する場合、Ｓの含有量は０．０２０質量以下が好ましい。
<S>
The S content in the carbonitriding steel material of the present invention is 0.03% by mass or less, preferably 0.020% by mass or less.
Such a S content has the effect of forming MnS and improving the machinability. On the other hand, when the S content exceeds 0.030% by mass, coarse MnS tends to be formed and the hot forgeability and bending fatigue strength tend to decrease. Therefore, it is preferably 0.005 to 0.030% by mass. When more emphasis is placed on hot forgeability and bending fatigue strength, the S content is preferably 0.020 mass or less.
＜Ｃｕ＞
本発明の浸炭窒化処理用鋼材におけるＣｕ含有率は０．３質量％以下％であり、０．００１～０．３質量％であることが好ましく、０．０３～０．３質量％であることがより好ましく、０．０３～０．２５質量％であることがさらに好ましい。
このようなＣｕ含有率であると炭化物の生成が抑制され、焼入れ性が向上する。Ｃｕ含有率が高すぎると熱間加工性が低下する可能性がある。
<Cu>
The Cu content in the carbonitriding steel material of the present invention is 0.3% by mass or less, preferably 0.001 to 0.3% by mass, and 0.03 to 0.3% by mass. is more preferable, and 0.03 to 0.25% by mass is even more preferable.
With such a Cu content, the formation of carbides is suppressed and the hardenability is improved. If the Cu content is too high, the hot workability may deteriorate.
＜Ｎｉ＞
本発明の浸炭窒化処理用鋼材におけるＮｉ含有率は２．５質量％以下であり、０．０１～０．６質量％であることが好ましく、０．０５～０．６質量％であることがより好ましい。
このようなＮｉ含有率であると焼入れ性が高まり、靭性が向上する。また、非酸化性の元素であり、浸炭時に粒界酸化層の深さを増大せずに鋼表面を強靭化することができる。
<Ni>
The Ni content in the carbonitriding steel material of the present invention is 2.5% by mass or less, preferably 0.01 to 0.6% by mass, and more preferably 0.05 to 0.6% by mass. more preferred.
With such a Ni content, hardenability increases and toughness improves. In addition, it is a non-oxidizing element and can toughen the steel surface without increasing the depth of the grain boundary oxide layer during carburizing.
＜Ｃｒ＞
本発明の浸炭窒化処理用鋼材におけるＣｒ含有率は０．５～３．０質量％であり、０．５～２．５質量％であることが好ましく、０．６～１．８質量％であることがより好ましい。
このようなＣｒ含有率であると焼入れ性が向上し、被切削性も確保され、ピッチング疲労強度が向上し、靭性も向上する。
Ｃｒ含有率が高すぎると、硬度大きくなり、被削性が低下し、また、浸炭時に粗大なＣｒ炭化物が生成することで、また、浸炭窒化時に結晶粒界に沿って粗大なＣｒＮ生成し、曲げ強度が低下する可能性がある。
<Cr>
The Cr content in the carbonitriding steel material of the present invention is 0.5 to 3.0% by mass, preferably 0.5 to 2.5% by mass, and more preferably 0.6 to 1.8% by mass. It is more preferable to have
With such a Cr content, hardenability is improved, machinability is ensured, pitting fatigue strength is improved, and toughness is also improved.
If the Cr content is too high, the hardness increases, the machinability decreases, and coarse Cr carbides are formed during carburizing, and coarse CrN is formed along grain boundaries during carbonitriding, Bending strength may decrease.
＜Ｍｏ＞
本発明の浸炭窒化処理用鋼材におけるＭｏ含有率は０．００１～１．０質量％であり、０．０１～０．８質量％であることが好ましく、０．０５～０．６質量％であることがより好ましい。
このようなＭｏ含有率であると、焼入れ性が向上することで焼入れ処理した部品の芯部硬さが向上し、疲労強度が向上する。また、表面硬さ及び硬化層硬さを向上させる。
Ｍｏ含有率が低すぎると熱間鍛造後の強度が高くなり、切削加工性が加工する可能性がある。また、Ｍｏ含有率が高すぎると、析出核生成サイトを生成し、炭窒化物等の析出物の生成を促進してしまう傾向がある。また、未固溶の粗大な炭窒化物等が鋼中に残存し、浸炭窒化焼入れ時において、粗大な炭窒化物がさらに成長し粗大化し、これにより疲労強度が低下する可能性がある。
<Mo>
The Mo content in the carbonitriding steel material of the present invention is 0.001 to 1.0% by mass, preferably 0.01 to 0.8% by mass, and 0.05 to 0.6% by mass. It is more preferable to have
With such a Mo content, the hardenability is improved, so that the core hardness of the quenched part is improved, and the fatigue strength is improved. It also improves surface hardness and hardened layer hardness.
If the Mo content is too low, the strength after hot forging increases, and machinability may deteriorate. On the other hand, if the Mo content is too high, there is a tendency to generate precipitation nucleation sites and promote the formation of precipitates such as carbonitrides. In addition, undissolved coarse carbonitrides and the like remain in the steel, and during carbonitriding and quenching, the coarse carbonitrides grow further and coarsen, which may reduce the fatigue strength.
＜Ａｌ＞
本発明の浸炭窒化処理用鋼材におけるＡｌ含有率は０．０１～０．０８質量％であり、０．０２～０．０５質量％であることが好ましい。
このようなＡｌ含有率であると、ＡｌはＮと結合しやすく、ＡｌＮを形成し、結晶粒を微細化して鋼を強化する作用を奏する。
Ａｌ含有率が高すぎると、硬質で粗大なＡｌ2Ｏ3の形成により被削性が低下する可能性があり、また、大型硬質介在物としてのＡｌ2Ｏ3が疲労破壊の起点となり、曲げ疲労強度やピッチング強度の低下の原因となる可能性がある。
<Al>
The Al content in the carbonitriding steel material of the present invention is 0.01 to 0.08% by mass, preferably 0.02 to 0.05% by mass.
With such an Al content, Al easily bonds with N, forms AlN, refines crystal grains, and strengthens the steel.
If the Al content is too high, there is a possibility that the machinability will decrease due to the formation of hard and coarse Al 2 O 3 , and Al 2 O 3 as large hard inclusions will become the origin of fatigue fracture, resulting in bending failure. It may cause a decrease in fatigue strength and pitting strength.
＜Ｎ＞
本発明の浸炭窒化処理用鋼材におけるＮ含有率は０．００５～０．０３質量％であり、０．０１～０．０２５質量％であることが好ましく、０．０１～０．０２０質量％であることがより好ましく、０．０１～０．０１５質量％であることがさらに好ましい。
このようなＮ含有率であると窒化物形成により結晶粒が微細化し、曲げ疲労強度が向上する。
Ｎ含有率が高すぎると粗大窒化物が形成することで靭性が低下する可能性がある。
<N>
The N content in the carbonitriding steel material of the present invention is 0.005 to 0.03% by mass, preferably 0.01 to 0.025% by mass, and more preferably 0.01 to 0.020% by mass. more preferably 0.01 to 0.015% by mass.
With such an N content, the crystal grains are refined by the formation of nitrides, and the bending fatigue strength is improved.
If the N content is too high, formation of coarse nitrides may reduce the toughness.
＜Ｎｂ＞
本発明の浸炭窒化処理用鋼材はＮｂを含んでもよい。
本発明の浸炭窒化処理用鋼材におけるＮｂ含有率は０．００１～０．０８質量％であることが好ましく、０．００１５～０．０６質量％であることがより好ましい。
このようなＮｂ含有率であると微細な析出物（ＮｂＣ）が生成することで、浸炭時の結晶粒が粗大化し難くなる。
<Nb>
The carbonitriding steel material of the present invention may contain Nb.
The Nb content in the carbonitriding steel material of the present invention is preferably 0.001 to 0.08% by mass, more preferably 0.0015 to 0.06% by mass.
With such an Nb content, fine precipitates (NbC) are generated, making it difficult for crystal grains to coarsen during carburizing.
＜Ｖ＞
本発明の浸炭窒化処理用鋼材はＶを含んでもよい。
本発明の浸炭窒化処理用鋼材におけるＶ含有率は０．５質量％以下であることが好ましく、０．２５質量％以下であることがより好ましい。
このようなＶ含有率であるとＶ析出物が分散して現れ、破壊特性が向上する。
<V>
The carbonitriding steel material of the present invention may contain V.
The V content in the carbonitriding steel material of the present invention is preferably 0.5% by mass or less, more preferably 0.25% by mass or less.
With such a V content, V precipitates appear dispersedly, and the fracture characteristics are improved.
＜Ｔｉ＞
本発明の浸炭窒化処理用鋼材はＴｉを含んでもよい。
本発明の浸炭窒化処理用鋼材におけるＴｉ含有率は０．０５質量％以下であることが好ましく、０．０８質量％以下であることがより好ましく、０．０１２～０．０４質量％であることがさらに好ましい。
このようなＴｉ含有率であると微細な析出物（ＴｉＣ）が生成することで、浸炭時の結晶粒が粗大化し難くなる。
<Ti>
The carbonitriding steel material of the present invention may contain Ti.
The Ti content in the carbonitriding steel material of the present invention is preferably 0.05% by mass or less, more preferably 0.08% by mass or less, and 0.012 to 0.04% by mass. is more preferred.
With such a Ti content, fine precipitates (TiC) are generated, making it difficult for crystal grains to coarsen during carburizing.
＜Ｂ＞
本発明の浸炭窒化処理用鋼材はＢを含んでもよい。
本発明の浸炭窒化処理用鋼材におけるＢ含有率は０．０００５～０．００３質量％であることが好ましく、０．０００６～０．００２５質量％であることがより好ましい。
このようなＢ含有率であると焼入れ性が大幅に向上し、また割れ加工性が改善する。
Ｂ含有率が高すぎると、ＢＮを形成し、深部での焼入れ性向上の効果が低下する。
<B>
The carbonitriding steel material of the present invention may contain B.
The B content in the carbonitriding steel material of the present invention is preferably 0.0005 to 0.003% by mass, more preferably 0.0006 to 0.0025% by mass.
With such a B content, the hardenability is greatly improved, and the crack workability is improved.
If the B content is too high, BN is formed and the effect of improving the hardenability at deep portions is reduced.
本発明の浸炭窒化処理用鋼材は上記のような含有率でＣ、Ｓｉ、Ｍｎ、Ｐ、Ｓ、Ｃｕ、Ｎｉ、Ｃｒ、Ｍｏ、Ａｌ、Ｎを含有し、さらに任意成分としてＮｂ、Ｖ、ＴｉおよびＢからなる群から選ばれる少なくとも１種を特定の含有率で含有してよい。そして、残部はＦｅおよび不可避的不純物からなる。
ここで不可避的不純物とは、意図的に添加しなくても原料や製造過程から混入する可能性がある成分を意味する。不可避的不純物として、具体的にはＯ、Ａｓ等が挙げられる。
The steel material for carbonitriding treatment of the present invention contains C, Si, Mn, P, S, Cu, Ni, Cr, Mo, Al and N in the above contents, and further optionally includes Nb, V and Ti. and B may be contained at a specific content rate. The balance consists of Fe and unavoidable impurities.
Here, the unavoidable impurities mean components that may be mixed from raw materials or manufacturing processes even if they are not intentionally added. Specific examples of unavoidable impurities include O, As, and the like.
本発明の浸炭窒化処理用鋼材が含有する各成分の含有率は、次の方法によって測定して得た値を意味するものとする。
Ｓｉ、Ｍｎ、Ｐ、Ｃｕ、Ｎｉ、Ｃｒ、Ｍｏ、Ｖ、Ｔｉ、Ｎｂは蛍光Ｘ線分析法によって求めた値、Ａｌは発光分光分析法、Ｏは不活性ガス中溶解－赤外線吸収法、Ｃ、Ｓは燃焼赤外線吸収法によって求めた値を意味するものとする。また、Ｎは不活性ガス中融解－熱伝導法、Ｂは発光分光分析法によって求めた値を意味するものとする。
The content of each component contained in the steel material for carbonitriding treatment of the present invention means the value obtained by measuring by the following method.
Si, Mn, P, Cu, Ni, Cr, Mo, V, Ti, Nb are values determined by fluorescent X-ray analysis, Al is by emission spectrometry, O is dissolved in an inert gas-infrared absorption method, C , S denote values determined by the combustion infrared absorption method. Further, N means the value obtained by melting in an inert gas-thermal conduction method, and B means the value obtained by the emission spectroscopic analysis method.
本発明の浸炭窒化処理用鋼材の製造方法は特に限定されない。例えば従来公知の方法によって本発明の浸炭窒化処理用鋼材を製造することができる。 The method for producing the carbonitriding steel material of the present invention is not particularly limited. For example, the steel material for carbonitriding treatment of the present invention can be produced by a conventionally known method.
上記のような組成を備える本発明の浸炭窒化処理用鋼材について、浸炭窒化処理を施すことで、本発明の浸炭窒化鋼材を得ることができる。
ここで浸炭窒化処理は特に限定されず、本発明の浸炭窒化処理用鋼材から本発明の浸炭窒化鋼材を得ることができる浸炭窒化処理であればよいが、例えば次のような浸炭窒化処理Ｘであってよい。
浸炭窒化処理Ｘは、ガス浸炭窒化、真空浸炭窒化の何れでもよい。また、浸炭窒化処理の諸条件（浸炭温度、浸炭ガスの種類、浸炭ガス圧、浸炭工程での処理時間、拡散工程での処理時間、冷却工程での冷却速度、窒化工程での窒化ガス圧、アンモニアガス量、処理時間、焼入れ温度等）は、浸炭窒化部品において要求される表層部の硬さ、焼戻し硬さに応じて適宜決定でき、特に限定されない。例えば、ガス浸炭窒化処理では、通常ＣＰ＝０．５～１．０に制御し、浸窒ガスとしてアンモニアを使用し、アンモニア流量、炉内アンモニア濃度、拡散時間、焼入れ温度を調整することで、表面Ｎ濃度を制御し、焼入れを実施する。その後、１００℃～３００℃に加熱、１～３時間保持し、焼戻しを実施する。
The carbonitriding steel material of the present invention can be obtained by subjecting the steel material for carbonitriding treatment of the present invention having the above composition to carbonitriding treatment.
Here, the carbonitriding treatment is not particularly limited, and any carbonitriding treatment that can obtain the carbonitriding steel material of the present invention from the steel material for carbonitriding treatment of the present invention can be used. It's okay.
The carbonitriding treatment X may be either gas carbonitriding or vacuum carbonitriding. In addition, various conditions of carbonitriding (carburizing temperature, type of carburizing gas, carburizing gas pressure, treatment time in the carburizing process, treatment time in the diffusion process, cooling rate in the cooling process, nitriding gas pressure in the nitriding process, Ammonia gas amount, treatment time, quenching temperature, etc.) can be appropriately determined according to the surface layer hardness and tempering hardness required for carbonitriding parts, and are not particularly limited. For example, in gas carbonitriding, CP is usually controlled to 0.5 to 1.0, ammonia is used as the nitriding gas, and the ammonia flow rate, ammonia concentration in the furnace, diffusion time, and quenching temperature are adjusted. Hardening is performed by controlling the surface N concentration. Then, it is tempered by heating to 100° C. to 300° C. and holding for 1 to 3 hours.
本発明の浸炭窒化鋼材について説明する。
本発明の浸炭窒化鋼材は、上記のような本発明の浸炭窒化処理用鋼材について浸炭窒化処理（例えば上記の浸炭窒化処理Ｘ）を施すことで得ることができる。
The carbonitriding steel material of the present invention will be described.
The carbonitriding steel material of the present invention can be obtained by subjecting the steel material for carbonitriding treatment of the present invention as described above to a carbonitriding treatment (for example, the carbonitriding treatment X described above).
＜表面Ｃ濃度＞
本発明の浸炭窒化鋼材において表面Ｃ濃度は０．４～０．８質量％であることが好ましく、０．４５～０．７０質量％であることがより好ましい。
ここで表面Ｃ濃度は、本発明の浸炭窒化鋼材を、その表面から１００μｍの深さまで削り、得られた切り屑（ダライ粉）について燃焼－赤外線吸収法を適用して求めたＣ濃度を意味するものとする。
<Surface C concentration>
The carbonitrided steel material of the present invention preferably has a surface C concentration of 0.4 to 0.8% by mass, more preferably 0.45 to 0.70% by mass.
Here, the surface C concentration means the C concentration obtained by applying the combustion-infrared absorption method to the obtained chips (turning powder) by scraping the carbonitriding steel material of the present invention from the surface to a depth of 100 μm. shall be
＜表面Ｎ濃度＞
本発明の浸炭窒化鋼材において表面Ｎ濃度は０．２５～０．８質量％であることが好ましく、０．３０～０．７０質量％であることがより好ましい。
ここで表面Ｎ濃度は、本発明の浸炭窒化鋼材を、その表面から１００μｍの深さまで削り、得られた切り屑（ダライ粉）について融解－熱伝導度測定を適用して求めたＮ濃度を意味するものとする。
<Surface N concentration>
The carbonitrided steel material of the present invention preferably has a surface N concentration of 0.25 to 0.8% by mass, more preferably 0.30 to 0.70% by mass.
Here, the surface N concentration means the N concentration obtained by cutting the carbonitrided steel material of the present invention from the surface to a depth of 100 μm and applying the fusion-thermal conductivity measurement to the obtained chips (turning powder). It shall be.
本発明の浸炭窒化鋼材は、上記のような表面Ｃ濃度および表面Ｎ濃度が、次の式１を満たす。
式１：表面Ｃ濃度（質量％）＋１２／１４×表面Ｎ濃度（質量％）＝０．６～１．４
式１の計算結果は０．７～１．２であることが好ましい。
In the carbonitrided steel material of the present invention, the surface C concentration and the surface N concentration as described above satisfy the following formula 1.
Formula 1: Surface C concentration (% by mass) + 12/14 x Surface N concentration (% by mass) = 0.6 to 1.4
The calculation result of Equation 1 is preferably 0.7 to 1.2.
本発明の浸炭窒化鋼材は、上記のような表面Ｃ濃度および表面Ｎ濃度ならびにＣｒ含有率が、次の式２を満たす。
式２：１２９．７８０５×［Ｃｒ（質量％）］－７６．９７９７×［Ｃｒ（質量％）］2＋３３９．３３７５×［表面Ｎ濃度（質量％）］－５３９．３４５×［表面Ｎ濃度（質量％）］2＋１８１．４９８３×［Ｃｒ（質量％）］×［表面Ｎ濃度（質量％）］＋４３７．６７９９＞５６０
In the carbonitrided steel material of the present invention, the surface C concentration, the surface N concentration, and the Cr content as described above satisfy the following
Formula 2: 129.7805×[Cr (mass%)]−76.9797×[Cr (mass%)] 2 +339.3375×[Surface N concentration (mass%)]−539.345×[Surface N concentration ( % by mass)] 2 +181.4983×[Cr (% by mass)]×[Surface N concentration (% by mass)]+437.6799>560
本発明の浸炭窒化処理用鋼材について前述の浸炭窒化処理Ｘを施すことで得られた本発明の浸炭窒化鋼材は、その表面から０．０５ｍｍの深さの部分における硬さが６００ＨＶ以上であることが好ましい。 The carbonitriding steel material of the present invention obtained by subjecting the carbonitriding steel material of the present invention to the carbonitriding treatment X described above has a hardness of 600 HV or more at a depth of 0.05 mm from the surface. is preferred.
本発明の浸炭窒化処理用鋼材について、前述の浸炭窒化処理Ｘを施すことで得られた本発明の浸炭窒化鋼材について、さらに５００℃で焼戻し処理を施した場合に、表面から０．０５ｍｍの深さの部分における硬さが５６０ＨＶ以上となる。 For the steel material for carbonitriding treatment of the present invention, when the steel material for carbonitriding treatment of the present invention obtained by applying the carbonitriding treatment X described above is further subjected to tempering treatment at 500 ° C., a depth of 0.05 mm from the surface The hardness of the thin portion is 560 HV or more.
＜試験片の製造＞
以下、本発明の実施例について説明する。
第１表に示す実施例１～３１および比較例１～１９の各々について、表１および表２に示す組成（単位は質量％であり、残部はＦｅ及び不可避不純物）となるように原料を混合し、１５０ｋｇ高周波誘導炉を用いて溶製し、鋳造して鋼塊Ａを得た。
<Production of test piece>
Examples of the present invention will be described below.
For each of Examples 1 to 31 and Comparative Examples 1 to 19 shown in Table 1, the raw materials were mixed so as to have the compositions shown in Tables 1 and 2 (the unit is mass%, the balance being Fe and unavoidable impurities). Then, a steel ingot A was obtained by melting using a 150 kg high-frequency induction furnace and casting.
次に、鋼塊Ａを熱間圧延または熱間鍛造し、断面直径が１２５ｍｍの丸棒を得た後、さらに熱間鍛造して、断面直径が３２ｍｍの丸棒を得た。そして、焼きならし処理を施し（９２５℃×１ＨｒＡＣ）、得られた丸棒から、断面直径１５ｍｍの丸棒（長さ２１０ｍｍ）を切り出した。 Next, the steel ingot A was hot-rolled or hot-forged to obtain a round bar with a cross-sectional diameter of 125 mm, and then hot-forged to obtain a round bar with a cross-sectional diameter of 32 mm. Then, a normalizing treatment was applied (925° C.×1 HrAC), and a round bar (length: 210 mm) with a cross-sectional diameter of 15 mm was cut out from the obtained round bar.
次に、丸棒に浸炭処理および窒化処理を施して、試験片を得た。ただし、一部の比較例においては浸炭処理のみを施し、窒化処理は施さなかった。 Next, the round bar was subjected to carburizing treatment and nitriding treatment to obtain a test piece. However, in some comparative examples, only the carburizing treatment was performed, and the nitriding treatment was not performed.
ここで浸炭処理は、次の処理である。
ガス浸炭窒化炉へ丸棒を載置し、９３０℃の温度で浸炭ガス（エンリッチガスとしてプロパンガスを使用）を導入し、一酸化炭素と二酸化炭素の分圧を調整することでＣＰ（カーボンポテンシャル）を０．７に制御し、浸炭を実施した。
Here, the carburizing treatment is the following treatment.
A round bar is placed in a gas carbonitriding furnace, a carburizing gas (propane gas is used as an enrichment gas) is introduced at a temperature of 930°C, and CP (carbon potential) is adjusted by adjusting the partial pressure of carbon monoxide and carbon dioxide. ) was controlled to 0.7, and carburization was carried out.
また、窒化処理は、次の処理である。
上記の浸炭処理を施した後の丸棒を８５０℃に降温し、ＣＰを一定に保った状態で窒化ガスとしてアンモニアガスを導入し、窒化処理を実施した。なお、窒化処理を実施した後、１２０℃のセミホット油で焼入れを行った。さらに次の処理として、焼入れを施した後の丸棒を１６０℃に調整した炉内に２時間裁置して加熱した後、炉から出し、室内で放冷する焼戻し処理を実施した。
Further, the nitriding treatment is the following treatment.
After the above carburizing treatment, the temperature of the round bar was lowered to 850° C., and ammonia gas was introduced as a nitriding gas while keeping the CP constant, and the nitriding treatment was performed. After the nitriding treatment, quenching was performed with semi-hot oil at 120°C. As the next treatment, the quenched round bar was placed in a furnace adjusted to 160° C. for 2 hours, heated, taken out of the furnace, and allowed to cool in a room for tempering.
＜表面Ｃ濃度、表面Ｎ濃度＞
上記の浸炭処理および窒化処理を施した試験片（一部は浸炭処理のみを施した試験片）について、その表面から１００μｍの深さまでを削り、得られた切り屑（ダライ粉）におけるＣ濃度およびＮ濃度を測定した。Ｃ濃度の測定には燃焼－赤外線吸収法を用い、Ｎ濃度の測定には融解－熱伝導度測定を用いた。
結果を第１表に示す。
<Surface C density, surface N density>
For the above carburized and nitrided test pieces (some of which were only carburized), the surface was scraped to a depth of 100 μm, and the C concentration and N concentration was measured. A combustion-infrared absorption method was used to measure the C concentration, and a fusion-thermal conductivity measurement was used to measure the N concentration.
The results are shown in Table 1.
＜常温での表面硬さ＞
上記の浸炭処理および窒化処理を施した試験片（一部は浸炭処理のみを施した試験片）について、その表面を鏡面研磨し、表面から０．０５ｍｍの位置の硬さをＪＩＳ Ｚ ２２４４に基づき、荷重２．９４Ｎで測定した。
結果を表１および表２に示す。
<Surface hardness at room temperature>
For the above carburized and nitrided test pieces (some of which were only carburized), the surface was mirror-polished, and the hardness at a position 0.05 mm from the surface was measured according to JIS Z 2244. , and a load of 2.94N.
Results are shown in Tables 1 and 2.
＜５００℃で焼戻し処理を施した場合の表面硬さ＞
上記の浸炭処理および窒化処理を施した試験片（一部は浸炭処理のみを施した試験片）を５００℃に調整した炉内に３時間載置して加熱した後、炉から出し、室内で放冷する焼戻し処理を施した。そして、その後、その表面を鏡面研磨し、表面から０．０５ｍｍの位置の硬さをＪＩＳ Ｚ ２２４４に基づき、荷重２．９４Ｎで測定した。
結果を表１および表２に示す。
<Surface hardness when tempered at 500°C>
The above carburized and nitrided test pieces (some of which were only carburized) were placed in a furnace adjusted to 500 ° C. for 3 hours and heated, then taken out of the furnace and placed in a room. A tempering treatment was performed by standing to cool. After that, the surface was mirror-polished, and the hardness at a position 0.05 mm from the surface was measured with a load of 2.94 N based on JIS Z 2244.
Results are shown in Tables 1 and 2.
＜疲労強度寿命比＞
上記の鋼塊Ａから同様の工程で丸棒を製造し、機械加工して小ロータを得た。小ローラ１は、図１に示すような直径２６ｍｍ、幅２８ｍｍの接触部２、その両側に配置される直径２２ｍｍの小径部４からなる。
そして、小ロータについて浸炭処理および窒化処理を施して、試験片を得た。
次に、試験片の相手側となる大ローラを用意した。大ローラは材質がＳＵＪ２でＨＲＣ６１となるように焼入れ焼戻し処理を実施した。なお、大ローラの曲率半径は１５０Ｒとした。
そして、ローラピッチング試験を行った。ローラピッチング試験では、試験片と相手側大ローラとを２．０～４．０ＧＰａの種々の面圧で、回転数：３０００ｒｐｍで接触させ、ローラピッチング試験機を用いてそれらを滑り率：－１００％で回転させ、１０7サイクルでピッチングを生じない負荷応力を面疲労強度（ピッチング疲労強度）とした。そしてＪＩＳ ＳＣＲ４２０の真空浸炭材に対する面疲労強度を、ぞれぞれの試験片において求めた。すなわち、疲労強度寿命比は（試験片の面疲労強度／ＪＩＳ ＳＣＲ４２０の真空浸炭材の面疲労強度）を意味する。
結果を表１および表２に示す。
<Fatigue strength life ratio>
A round bar was produced from the above steel ingot A in the same process and machined to obtain a small rotor. As shown in FIG. 1, the small roller 1 comprises a
Then, the small rotor was subjected to carburizing treatment and nitriding treatment to obtain a test piece.
Next, a large roller was prepared as the opposite side of the test piece. The large roller was made of SUJ2 and was quenched and tempered so as to have HRC61. The radius of curvature of the large roller was set to 150R.
Then, a roller pitching test was performed. In the roller pitching test, the test piece and the mating large roller are brought into contact with each other at various surface pressures of 2.0 to 4.0 GPa at a rotation speed of 3000 rpm, and a roller pitching tester is used to determine the slip rate: -100. %, and the load stress that does not cause pitting in 10 7 cycles was taken as the surface fatigue strength (pitting fatigue strength). Then, the surface fatigue strength against the vacuum carburized material of JIS SCR420 was determined for each test piece. That is, the fatigue strength life ratio means (surface fatigue strength of test piece/surface fatigue strength of vacuum carburized material of JIS SCR420).
Results are shown in Tables 1 and 2.
＜焼き付き限界荷重比＞
上記の鋼塊Ａを機械加工して負荷ローラー側、試験ローラー側の二つの試験片を得た。
試験片は直径７８ｍｍ、幅１８ｍｍからなり、負荷ローラー側の曲率半径は７００Ｒとした。
そして、試験片について、浸炭処理および窒化処理を施して、試験片を得た。
そしてローラーピッチング試験機を用いて焼付き試験を行った。
焼付き試験では上記で作製した二つの試験片をあるすべり速度下（２．０～２０．０ｍ／ｓ）で荷重を６０秒ごとに０．０５ＧＰａずつ段階的に増加させた。
焼付き判定は、負荷側に設置したトルク計のトルクが急上昇した時点とし、その際の荷重を焼付き荷重とした。
そして、ＪＩＳ ＳＣＲ４２０の真空浸炭材に対する面疲労強度を、それぞれの試験片において求めた。
すなわち、焼付き限界荷重比は「試験片の焼付き荷重／ＪＩＳ ＳＣＲ４２０の真空浸炭材の焼付き荷重」を意味する。
実施例１～３１および比較例１～１９の各々について焼付き限界荷重を測定した。
結果を表３および表４に示す。
<Seizure limit load ratio>
Steel ingot A was machined to obtain two specimens, one on the load roller side and one on the test roller side.
The test piece had a diameter of 78 mm and a width of 18 mm, and the radius of curvature on the load roller side was 700R.
Then, the test piece was subjected to carburizing treatment and nitriding treatment to obtain a test piece.
Then, a seizure test was conducted using a roller pitting tester.
In the seizure test, the load was increased stepwise by 0.05 GPa every 60 seconds under a certain sliding speed (2.0 to 20.0 m/s) on the two test pieces prepared above.
Seizure was determined at the time when the torque of the torque meter installed on the load side suddenly increased, and the load at that time was taken as the seizure load.
Then, the surface fatigue strength against the vacuum carburized material of JIS SCR420 was determined for each test piece.
That is, the seizure limit load ratio means "seizure load of test piece/seizure load of vacuum carburized material of JIS SCR420".
The seizure limit load was measured for each of Examples 1-31 and Comparative Examples 1-19.
The results are shown in Tables 3 and 4.
表１および表２に示した５００℃で焼戻し処理を施した場合の表面硬さと、疲労強度寿命比（高速度ローラーピッチング条件における寿命比）との関係を図２に示す。
図２から、実施例は比較例に対して、いずれもが向上していることを確認できる。
FIG. 2 shows the relationship between the surface hardness when tempering at 500° C. shown in Tables 1 and 2 and the fatigue strength life ratio (life ratio under high-speed roller pitting conditions).
From FIG. 2, it can be confirmed that the example is improved in all respects as compared with the comparative example.
また、表１および表２に示した５００℃で焼戻し処理を施した場合の表面硬さと、表３および表４に示した焼付き限界荷重比との関係を図３に示す。
図３から、実施例は比較例に対して、いずれもが向上していることを確認できる。
3 shows the relationship between the surface hardness when tempering at 500° C. shown in Tables 1 and 2 and the seizure limit load ratio shown in Tables 3 and 4. FIG.
From FIG. 3, it can be confirmed that the example is improved in all respects as compared with the comparative example.
１ 小ローラ
２ 接触部
４ 小径部
1
Claims (7)
Ｓｉ：０．３質量％以下、
Ｍｎ：０．４～２．０質量％、
Ｐ：０．０３質量％以下、
Ｓ：０．０３質量％以下、
Ｃｕ：０．３質量％以下、
Ｎｉ：２．５質量％以下、
Ｃｒ：０．５～３．０質量％、
Ｍｏ：０．００１～１．０質量％、
Ａｌ：０．０１～０．０８質量％、
Ｎ：０．００５～０．０３質量％、
で含有し、残部はＦｅおよび不可避的不純物からなり、
浸炭窒化を施すことで、
式１：表面Ｃ濃度（質量％）＋１２／１４×表面Ｎ濃度（質量％）＝０．６～１．４
を満たし、
式２：１２９．７８０５×［Ｃｒ（質量％）］－７６．９７９７×［Ｃｒ（質量％）］2＋３３９．３３７５×［表面Ｎ濃度（質量％）］－５３９．３４５×［表面Ｎ濃度（質量％）］2＋１８１．４９８３×［Ｃｒ（質量％）］×［表面Ｎ濃度（質量％）］＋４３７．６７９９＞５６０
を満たし、
前記浸炭窒化を施した後に５００℃で焼戻し処理を施した場合に、表面から０．０５ｍｍの深さの部分における硬さが５６０ＨＶ以上である浸炭窒化鋼材が得られる、浸炭窒化処理用鋼材。 C: 0.1 to 0.3% by mass,
Si: 0.3% by mass or less,
Mn: 0.4 to 2.0% by mass,
P: 0.03% by mass or less,
S: 0.03% by mass or less,
Cu: 0.3% by mass or less,
Ni: 2.5% by mass or less,
Cr: 0.5 to 3.0% by mass,
Mo: 0.001 to 1.0% by mass,
Al: 0.01 to 0.08% by mass,
N: 0.005 to 0.03% by mass,
and the balance consists of Fe and unavoidable impurities,
By applying carbonitriding,
Formula 1: Surface C concentration (% by mass) + 12/14 x Surface N concentration (% by mass) = 0.6 to 1.4
The filling,
Formula 2: 129.7805×[Cr (mass%)]−76.9797×[Cr (mass%)] 2 +339.3375×[Surface N concentration (mass%)]−539.345×[Surface N concentration ( % by mass)] 2 +181.4983×[Cr (% by mass)]×[Surface N concentration (% by mass)]+437.6799>560
The filling,
A steel material for carbonitriding treatment that provides a carbonitriding steel material having a hardness of 560 HV or more at a depth of 0.05 mm from the surface when tempering treatment is performed at 500° C. after the carbonitriding treatment.
Ｖ：０．５質量％以下、
Ｔｉ：０．０５質量％以下、および
Ｂ：０．０００５～０．００３質量％、
からなる群から選ばれる少なくとも一種をさらに含有する、請求項１に記載の浸炭窒化処理用鋼材。 Nb: 0.001 to 0.08% by mass,
V: 0.5% by mass or less,
Ti: 0.05% by mass or less, and B: 0.0005 to 0.003% by mass,
The carbonitriding steel material according to claim 1, further comprising at least one selected from the group consisting of:
Ｓｉ：０．０１～０．２４質量％、
Ｍｎ：０．５～１．８質量％、
Ｃｕ：０．００１～０．３質量％、
Ｎｉ：０．０１～０．６質量％、
Ｃｒ：０．６～１．８質量％、
Ｍｏ：０．０１～０．８質量％、
Ａｌ：０．０２～０．０５質量％、
Ｎ：０．０１～０．０２５質量％、
で含有し、
Ｎｂ：０．００１５～０．０６質量％、
Ｖ：０．２５質量％以下、
Ｔｉ：０．０１２～０．０４質量％、および
Ｂ：０．０００６～０．００２５質量％、
からなる群から選ばれる少なくとも一種をさらに含有し、残部はＦｅおよび不可避的不純物からなり、
前記浸炭窒化を施すことで、
式１：表面Ｃ濃度（質量％）＋１２／１４×表面Ｎ濃度（質量％）＝０．７～１．２を満たす浸炭窒化処理鋼材が得られる、請求項１または２に記載の浸炭窒化処理用鋼材。 C: 0.15 to 0.25% by mass,
Si: 0.01 to 0.24% by mass,
Mn: 0.5 to 1.8% by mass,
Cu: 0.001 to 0.3% by mass,
Ni: 0.01 to 0.6% by mass,
Cr: 0.6 to 1.8% by mass,
Mo: 0.01 to 0.8% by mass,
Al: 0.02 to 0.05% by mass,
N: 0.01 to 0.025% by mass,
contains with
Nb: 0.0015 to 0.06% by mass,
V: 0.25% by mass or less,
Ti: 0.012 to 0.04% by mass, and B: 0.0006 to 0.0025% by mass,
further contains at least one selected from the group consisting of the balance consisting of Fe and inevitable impurities,
By applying the carbonitriding,
The carbonitriding treatment according to claim 1 or 2, wherein a carbonitriding-treated steel material that satisfies Formula 1: surface C concentration (mass%) + 12/14 x surface N concentration (mass%) = 0.7 to 1.2 is obtained. steel material.
で含有する、請求項１～３のいずれかに記載の浸炭窒化処理用鋼材。 Cu: 0.03 to 0.3% by mass,
The steel material for carbonitriding treatment according to any one of claims 1 to 3, containing in.
で含有する、請求項１～４のいずれかに記載の浸炭窒化処理用鋼材。 Si: 0.01 to 0.17% by mass,
The steel material for carbonitriding treatment according to any one of claims 1 to 4, containing in.
で含有する、請求項１～５のいずれかに記載の浸炭窒化処理用鋼材。 Cu: 0.03 to 0.25% by mass,
The steel material for carbonitriding treatment according to any one of claims 1 to 5, containing in.
式１：表面Ｃ濃度（質量％）＋１２／１４×表面Ｎ濃度（質量％）＝０．６～１．４
を満たし、
式２：１２９．７８０５×［Ｃｒ（質量％）］－７６．９７９７×［Ｃｒ（質量％）］2＋３３９．３３７５×［表面Ｎ濃度（質量％）］－５３９．３４５×［表面Ｎ濃度（質量％）］2＋１８１．４９８３×［Ｃｒ（質量％）］×［表面Ｎ濃度（質量％）］＋４３７．６７９９＞５６０
を満たし、
さらに５００℃で焼戻し処理を施した場合に、表面から０．０５ｍｍの深さの部分における硬さが５６０ＨＶ以上となる、浸炭窒化鋼材。 Carbonitriding the steel material for carbonitriding according to any one of claims 1 to 6,
Formula 1: Surface C concentration (% by mass) + 12/14 x Surface N concentration (% by mass) = 0.6 to 1.4
The filling,
Formula 2: 129.7805×[Cr (mass%)]−76.9797×[Cr (mass%)] 2 +339.3375×[Surface N concentration (mass%)]−539.345×[Surface N concentration ( % by mass)] 2 +181.4983×[Cr (% by mass)]×[Surface N concentration (% by mass)]+437.6799>560
The filling,
A carbonitrided steel material which, when further tempered at 500° C., has a hardness of 560 HV or more at a depth of 0.05 mm from the surface.
Priority Applications (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2021071046A JP2022165628A (en) | 2021-04-20 | 2021-04-20 | Carbonitriding steel material and carbonitrided steel material |
| PCT/JP2022/017420 WO2022224849A1 (en) | 2021-04-20 | 2022-04-08 | Steel material for carbonitriding and carbonitrided steel material |
| CN202280029585.2A CN117222771A (en) | 2021-04-20 | 2022-04-08 | Steel material for carbonitriding treatment and carbonitriding steel material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2021071046A JP2022165628A (en) | 2021-04-20 | 2021-04-20 | Carbonitriding steel material and carbonitrided steel material |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2022165628A true JP2022165628A (en) | 2022-11-01 |
Family
ID=83722969
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2021071046A Pending JP2022165628A (en) | 2021-04-20 | 2021-04-20 | Carbonitriding steel material and carbonitrided steel material |
Country Status (3)
| Country | Link |
|---|---|
| JP (1) | JP2022165628A (en) |
| CN (1) | CN117222771A (en) |
| WO (1) | WO2022224849A1 (en) |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3538995B2 (en) * | 1994-09-29 | 2004-06-14 | 日本精工株式会社 | Rolling bearing |
| JP5272609B2 (en) * | 2008-09-22 | 2013-08-28 | 新日鐵住金株式会社 | Carbonitriding parts made of steel |
| KR20190028568A (en) * | 2014-07-29 | 2019-03-18 | 신닛테츠스미킨 카부시키카이샤 | Carbonitrided bearing member |
| JP7205112B2 (en) * | 2018-08-24 | 2023-01-17 | 大同特殊鋼株式会社 | carbonitriding steel |
| DE112019006482T5 (en) * | 2018-12-27 | 2021-11-04 | Jtekt Corporation | CARBONITRATED BEARING COMPONENT |
-
2021
- 2021-04-20 JP JP2021071046A patent/JP2022165628A/en active Pending
-
2022
- 2022-04-08 WO PCT/JP2022/017420 patent/WO2022224849A1/en active Application Filing
- 2022-04-08 CN CN202280029585.2A patent/CN117222771A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| WO2022224849A1 (en) | 2022-10-27 |
| CN117222771A (en) | 2023-12-12 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP3176276B1 (en) | Steel for carbonitrided bearing | |
| JP5449626B1 (en) | Soft nitriding steel and soft nitriding parts made from this steel | |
| WO2014136307A1 (en) | Semi-finished material for induction hardened component and method for producing same | |
| JP5567747B2 (en) | Soft nitriding steel, soft nitriding component and manufacturing method thereof | |
| JP5477111B2 (en) | Nitriding induction hardening steel and nitriding induction hardening parts | |
| JP2011153364A (en) | Crankshaft and method for producing the same | |
| JP6520347B2 (en) | Forming material of induction hardened parts, induction hardened parts, and manufacturing method thereof | |
| JP6772499B2 (en) | Steel parts and their manufacturing methods | |
| JP2001073072A (en) | Carbo-nitrided parts excellent in pitching resistance | |
| JP4737601B2 (en) | High temperature nitriding steel | |
| JP6055397B2 (en) | Bearing parts having excellent wear resistance and manufacturing method thereof | |
| JP2010189697A (en) | Crankshaft and method for producing the same | |
| JP6225965B2 (en) | Soft nitriding steel and parts, and methods for producing them | |
| JP7013833B2 (en) | Carburized parts | |
| WO2022224849A1 (en) | Steel material for carbonitriding and carbonitrided steel material | |
| JP6447064B2 (en) | Steel parts | |
| JP2021113338A (en) | Steel component and method for manufacturing the same | |
| JP7063070B2 (en) | Carburized parts | |
| JP6477614B2 (en) | Steel for soft nitriding and parts and method for manufacturing them | |
| JP6881496B2 (en) | Parts and their manufacturing methods | |
| WO2017146057A1 (en) | Cement steel component and steel material having excellent stability of rolling fatigue life, and method for manufacturing same | |
| JP6881498B2 (en) | Parts and their manufacturing methods | |
| JP6881497B2 (en) | Parts and their manufacturing methods | |
| JP3940322B2 (en) | Manufacturing method of steel part for machine structure and steel part for machine structure | |
| JP7275665B2 (en) | Steel for carbo-nitriding |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20240216 |