JP2013112827A - Gear excellent in pitching resistance and manufacturing method therefor - Google Patents
Gear excellent in pitching resistance and manufacturing method therefor Download PDFInfo
- Publication number
- JP2013112827A JP2013112827A JP2011257490A JP2011257490A JP2013112827A JP 2013112827 A JP2013112827 A JP 2013112827A JP 2011257490 A JP2011257490 A JP 2011257490A JP 2011257490 A JP2011257490 A JP 2011257490A JP 2013112827 A JP2013112827 A JP 2013112827A
- Authority
- JP
- Japan
- Prior art keywords
- gear
- furnace
- quenching
- carburizing
- treatment
- 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.)
- Granted
Links
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 15
- 238000005255 carburizing Methods 0.000 claims abstract description 50
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims abstract description 32
- 238000005496 tempering Methods 0.000 claims abstract description 28
- 239000002344 surface layer Substances 0.000 claims abstract description 22
- 238000005121 nitriding Methods 0.000 claims abstract description 21
- 238000001816 cooling Methods 0.000 claims abstract description 16
- 239000000203 mixture Substances 0.000 claims abstract description 16
- 229910052757 nitrogen Inorganic materials 0.000 claims abstract description 16
- 229910052804 chromium Inorganic materials 0.000 claims abstract description 13
- 238000010438 heat treatment Methods 0.000 claims abstract description 11
- 238000005242 forging Methods 0.000 claims abstract description 7
- 238000003754 machining Methods 0.000 claims abstract description 6
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 5
- 239000012535 impurity Substances 0.000 claims abstract description 5
- 229910052748 manganese Inorganic materials 0.000 claims abstract description 3
- 229910052750 molybdenum Inorganic materials 0.000 claims abstract description 3
- 229910052759 nickel Inorganic materials 0.000 claims abstract description 3
- 238000010791 quenching Methods 0.000 claims description 39
- 230000000171 quenching effect Effects 0.000 claims description 39
- 229910000831 Steel Inorganic materials 0.000 claims description 32
- 239000010959 steel Substances 0.000 claims description 32
- 229910000859 α-Fe Inorganic materials 0.000 claims description 19
- 239000000463 material Substances 0.000 claims description 18
- 229910001566 austenite Inorganic materials 0.000 claims description 15
- 239000010410 layer Substances 0.000 claims description 12
- 230000000717 retained effect Effects 0.000 claims description 12
- 238000005480 shot peening Methods 0.000 claims description 12
- 229910000734 martensite Inorganic materials 0.000 claims description 11
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 6
- 238000005256 carbonitriding Methods 0.000 claims description 4
- 229910052796 boron Inorganic materials 0.000 claims description 3
- 229910052742 iron Inorganic materials 0.000 claims description 3
- 229910052758 niobium Inorganic materials 0.000 claims description 3
- 229910052719 titanium Inorganic materials 0.000 claims description 3
- 229910052720 vanadium Inorganic materials 0.000 claims description 3
- 238000003303 reheating Methods 0.000 claims description 2
- 230000009545 invasion Effects 0.000 abstract description 4
- 238000012360 testing method Methods 0.000 description 47
- 238000005452 bending Methods 0.000 description 38
- 230000000052 comparative effect Effects 0.000 description 20
- 230000000694 effects Effects 0.000 description 17
- 230000003247 decreasing effect Effects 0.000 description 10
- 239000013078 crystal Substances 0.000 description 8
- 238000009661 fatigue test Methods 0.000 description 8
- 238000011161 development Methods 0.000 description 7
- 230000007423 decrease Effects 0.000 description 5
- 238000000034 method Methods 0.000 description 5
- 230000009466 transformation Effects 0.000 description 5
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 3
- 239000007789 gas Substances 0.000 description 3
- 238000009863 impact test Methods 0.000 description 3
- 229910052760 oxygen Inorganic materials 0.000 description 3
- 239000001301 oxygen Substances 0.000 description 3
- 238000005498 polishing Methods 0.000 description 3
- 229920006395 saturated elastomer Polymers 0.000 description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- 238000011835 investigation Methods 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- 230000035515 penetration Effects 0.000 description 2
- 239000000047 product Substances 0.000 description 2
- 229910000760 Hardened steel Inorganic materials 0.000 description 1
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 1
- 238000002441 X-ray diffraction Methods 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 239000001273 butane Substances 0.000 description 1
- 229910052791 calcium Inorganic materials 0.000 description 1
- 238000012937 correction Methods 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 230000006378 damage Effects 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 238000005098 hot rolling Methods 0.000 description 1
- 229910052745 lead Inorganic materials 0.000 description 1
- 239000000314 lubricant Substances 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- IJDNQMDRQITEOD-UHFFFAOYSA-N n-butane Chemical compound CCCC IJDNQMDRQITEOD-UHFFFAOYSA-N 0.000 description 1
- OFBQJSOFQDEBGM-UHFFFAOYSA-N n-pentane Natural products CCCCC OFBQJSOFQDEBGM-UHFFFAOYSA-N 0.000 description 1
- 150000004767 nitrides Chemical class 0.000 description 1
- 238000010606 normalization Methods 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 230000000644 propagated effect Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000005204 segregation Methods 0.000 description 1
- 229910052711 selenium Inorganic materials 0.000 description 1
- 238000007711 solidification Methods 0.000 description 1
- 230000008023 solidification Effects 0.000 description 1
- 238000004901 spalling Methods 0.000 description 1
- 238000005482 strain hardening Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 229910052717 sulfur Inorganic materials 0.000 description 1
- 230000001629 suppression Effects 0.000 description 1
- 238000004381 surface treatment Methods 0.000 description 1
- 230000002195 synergetic effect Effects 0.000 description 1
- 238000012422 test repetition Methods 0.000 description 1
- 230000001131 transforming effect Effects 0.000 description 1
Images
Abstract
Description
本発明は、耐ピッチング性に優れた歯車およびその製造方法に関する。 The present invention relates to a gear excellent in pitting resistance and a manufacturing method thereof.
自動車等に用いられている歯車は、近年、省エネルギー化による車体重量の軽量化に伴い小型化が要求され、またエンジンの高出力化による負荷の増大が起っている。 In recent years, gears used in automobiles and the like have been required to be reduced in size as the weight of the vehicle body has been reduced due to energy saving, and the load has increased due to higher output of the engine.
歯車の耐久性は、主に歯元の曲げ疲労破壊ならびに歯面の面圧疲労破壊の発生によって決まる。面圧がヘルツ応力で２８００ＭＰａを超えるような歯車の場合は、歯元の曲げ疲労強度が高い事に加えて歯面の耐ピッチング性が高いことが特に要求される。 The durability of a gear is mainly determined by the occurrence of bending fatigue failure of the tooth root and surface fatigue failure of the tooth surface. In the case of a gear whose surface pressure exceeds 2800 MPa in Hertzian stress, it is particularly required that the tooth surface has high pitting resistance in addition to high bending fatigue strength at the root.
従来は、ＪＩＳＳＣＭ４２０Ｈ，ＳＣＭ８２２Ｈ等の肌焼鋼を用いて歯車を成形し、浸炭等の表面処理を行い製造されてきたが、最近の高応力下での使用に耐えられるものでは無く、鋼材の変更、熱処理方法の変更、表面の加工硬化処理により歯元曲げ疲労強度、耐ピッチング性を向上させる開発が進められている。 Conventionally, gears were molded using case-hardened steel such as JIS SCM420H, SCM822H, etc., and surface treatment such as carburizing was carried out, but it is not able to withstand the use under the recent high stress, the steel material change Development of improving the root bending fatigue strength and pitting resistance by changing the heat treatment method and the work hardening treatment of the surface is being promoted.
特許文献１は、歯元曲げ疲労特性および面圧疲労特性に優れた歯車用鋼ならびに歯車に関し、本発明者等が開発した、特定成分のうち、焼戻し軟化抵抗を上げるのに有効なＳｉ，Ｃｒの含有量を更にパラメータ式で規定した耐ピッチング性に優れる歯車が記載されている。 Patent Document 1 relates to a steel for gears and a gear excellent in tooth root bending fatigue characteristics and surface pressure fatigue characteristics, and among the specific components developed by the present inventors, Si and Cr effective for increasing temper softening resistance. A gear having excellent pitching resistance, in which the content of is further defined by a parameter formula, is described.
しかしながら、近年においては上述したように面圧が高くなったのでより優れた耐ピッチング性が要求されるようになり、特許文献１記載の発明による歯車では要求特性を満足することが出来無くなっているのが現状である。そこで、本発明は、面圧疲労特性言い換えれば耐ピッチング性に優れた歯車および当該歯車の量産が可能な製造方法を提供することを目的とする。 However, in recent years, as described above, since the surface pressure has increased, better pitting resistance has been required, and the gear according to the invention described in Patent Document 1 cannot satisfy the required characteristics. is the current situation. Therefore, an object of the present invention is to provide a gear having excellent surface pressure fatigue characteristics, in other words, excellent pitching resistance, and a manufacturing method capable of mass production of the gear.
本発明者等は、上記課題を解決するために、鋭意研究を行い、以下のことを見出した。
１．鋼材（歯車の素材）の成分調整だけでは耐ピッチング性の向上に限界があり、鋼材成分と製造工程の相乗効果が必要である。
２．具体的には、耐ピッチング対策として従来から実施されている鋼材自体の低温域での焼戻し軟化抑制のための成分コントロールと歯車作成後の表面硬化部分の焼戻し軟化抵抗増大のため、窒化処理を行うことが有効で、特に、鋼材成分に応じて表面最大侵入窒素量をコントロールする事が有効である。
３．また、浸窒処理における侵入窒素の微量コントロールは、メタンガスやブタンガス雰囲気中で行うガス浸炭後では不可能で、浸炭処理を真空炉内で行い、表層付近の酸化を抑制し、窒素と結合しやすい元素の変動を抑える事で可能である。
４．非浸炭部（歯内部組織のうち浸炭処理による炭素が侵入していない部分）の金属組織を従来のマルテンサイト単相組織から、マルテンサイトとフェライトを含む２相組織とすることで、変態膨張が小さくなるため、歯車の熱処理変形が小さくなり、歯面を研磨することなく、歯面同士の接触が適正化され、さらに耐ピッチング強度を向上させることが可能である。
In order to solve the above-mentioned problems, the present inventors have conducted intensive research and found the following.
1. There is a limit to the improvement of the pitting resistance only by adjusting the components of the steel (gear material), and a synergistic effect between the steel components and the manufacturing process is necessary.
2. Specifically, as a countermeasure against pitting, the nitriding treatment is performed to increase the resistance to temper softening of the surface hardened portion after making the gear and to control the component for suppressing the temper softening in the low temperature region of the steel material, which has been conventionally performed. In particular, it is effective to control the surface maximum intrusion nitrogen amount according to the steel material composition.
3. In addition, minute control of intrusion nitrogen in nitrogen treatment is not possible after gas carburization performed in methane gas or butane gas atmosphere, carburization treatment is performed in a vacuum furnace, and oxidation near the surface layer is suppressed and it is easy to combine with nitrogen This is possible by suppressing the variation of elements.
4). By transforming the metal structure of the non-carburized part (the part of the tooth internal structure where carbon does not penetrate through the carburizing process) from a conventional martensite single-phase structure to a two-phase structure containing martensite and ferrite, transformation expansion is achieved. Therefore, the heat treatment deformation of the gears is reduced, the contact between the tooth surfaces is optimized without polishing the tooth surfaces, and the pitting resistance can be further improved.
本発明は得られた知見を基に更に検討を加えてなされたもので、すなわち、本発明は、 １．鍛造あるいは機械加工により歯車形状とした後、真空中で浸炭処理を行い、その後炉内で冷却後に焼入れする際、前記炉内での、浸炭後の炉内冷却から焼入れ前の加熱保持の間に、窒化処理を行い、前記焼入れ後に焼戻し処理される歯車であって、
成分組成が質量％で、Ｃ：０．１５〜０．３５％、Ｓｉ：０．７０〜２．５０％、Ｍｎ：０．２０〜１．００％、Ｎｉ：０．０１〜０．８０％、Ｃｒ：０．１０〜１．５０％、Ｍｏ：０．０１〜０．８０％、Ａｌ：０．００５〜０．２００％、残部鉄および不可避不純物からなり、前記成分組成におけるＳｉ、Ｃｒと前記浸窒処理による表層最大侵入窒素量による焼戻し軟化抵抗パラメータＨＳｉＣｒＮが（１）式を満たす事を特徴とする耐ピッチング性に優れた歯車。
ＨＳｉＣｒＮ（＝５８Ｓｉ＋４２×（Ｎｓ−Ｃｒ×１４／５２））≧８０・・・（１）
ここで、Ｓｉ，Ｃｒは含有量（質量％）Ｎｓ：表層最大侵入窒素量（質量％）とする。
２．前記成分組成が、更に、質量％で、Ｎｂ：０．０１０〜０．１００％、Ｖ： ０．００１〜０．１５０％、Ｔｉ：０．００５〜０．０５０％、Ｂ：０．０００５〜０．０１００％を１種または２種以上を含有することを特徴とする１記載の耐ピッチング性に優れた歯車。
３．前記焼入れ後に焼戻し処理した後の、浸炭層の組織がマルテンサイトと残留オーステナイトからなり、前記残留オーステナイトの体積率は表層から０．１ｍｍ深さの範囲内において最大値が１５〜４５％の範囲で、非浸炭部の組織はマルテンサイトとフェライトから成り、前記フェライトの体積率が１０〜４５％である事を特徴とする１または２に記載の耐ピッチング性に優れた歯車。
４．１または２に記載の成分組成の鋼材を鍛造あるいは機械加工により歯車形状とした後、真空中で浸炭処理を行い、その後炉内で冷却後に焼入れする際、前記炉内での、浸炭後の炉内冷却から焼入れ前の加熱保持の間に、窒化処理を行い、前記焼入れ後に焼戻し処理を行う歯車の製造方法であって、
前記浸炭処理は、（２）式にて計算される浸炭温度Ｔ（℃）の範囲に制御された真空中で行い、
前記浸炭処理後は、７２０℃〜８５０℃の温度範囲まで炉内で冷却して保持し、前記焼戻し処理は１００℃〜２５０℃の温度まで再加熱して行うことを特徴とする耐ピッチング性に優れた歯車の製造方法。
８８０−Ａ≦Ｔ（℃）≦９８０−Ａ ・・・（２）
Ａ＝２０３√Ｃ−１５．２Ｎｉ−４４．７Ｓｉ−１０４Ｖ ＋３０Ｍｎ＋１１Ｃｒ−４００Ａｌ−３１．５Ｍｏ （各成分記号は含有量（質量％）を示す）
５．浸炭窒化処理し、焼入れ焼戻し処理後、更に、アークハイト０．３ｍｍＡ以上のショットピーニングを行うことを特徴とする４記載の耐ピッチング性に優れた歯車の製造方法。
The present invention has been made by further study based on the obtained knowledge. After forging or machining to form a gear, carburizing treatment is performed in a vacuum, and then quenching is performed after cooling in the furnace, between the cooling in the furnace after carburizing and the heating before quenching in the furnace. , A gear that performs nitriding and is tempered after the quenching,
Component composition is mass%, C: 0.15-0.35%, Si: 0.70-2.50%, Mn: 0.20-1.00%, Ni: 0.01-0.80% Cr: 0.10 to 1.50%, Mo: 0.01 to 0.80%, Al: 0.005 to 0.200%, balance iron and inevitable impurities, and Si, Cr in the above component composition A temper softening resistance parameter H SiCrN based on the maximum amount of nitrogen entering the surface layer by the nitriding treatment satisfies the formula (1), and has excellent pitching resistance.
H SiCrN (= 58Si + 42 × (Ns−Cr × 14/52)) ≧ 80 (1)
Here, Si and Cr are made into content (mass%) Ns: surface layer maximum penetration | invasion nitrogen amount (mass%).
2. The component composition is further in mass%, Nb: 0.010 to 0.100%, V: 0.001 to 0.150%, Ti: 0.005 to 0.050%, B: 0.0005 The gear having excellent pitting resistance according to 1, wherein 0.0100% is contained in one kind or two or more kinds.
3. The structure of the carburized layer after tempering after quenching is composed of martensite and retained austenite, and the volume ratio of the retained austenite is in the range of 15 to 45% in the range of 0.1 mm depth from the surface layer. The gear having excellent pitting resistance according to 1 or 2, wherein the structure of the non-carburized portion is composed of martensite and ferrite, and the volume ratio of the ferrite is 10 to 45%.
4.1 After steel material having the composition described in 1 or 2 is made into a gear shape by forging or machining, carburizing treatment is performed in a vacuum, and after cooling in the furnace, after quenching in the furnace A method of manufacturing a gear for performing nitriding during the heating and holding before quenching from furnace cooling, and performing a tempering after quenching,
The carburizing treatment is performed in a vacuum controlled to a range of carburizing temperature T (° C.) calculated by equation (2),
After the carburizing treatment, it is cooled and held in a furnace to a temperature range of 720 ° C. to 850 ° C., and the tempering treatment is performed by reheating to a temperature of 100 ° C. to 250 ° C. Excellent gear manufacturing method.
880-A ≦ T (° C.) ≦ 980-A (2)
A = 203√C-15.2Ni-44.7Si-104V + 30Mn + 11Cr-400Al-31.5Mo (Each component symbol indicates content (% by mass))
5. 5. The method for producing a gear excellent in pitting resistance according to 4, wherein carbonitriding, quenching and tempering, and then shot peening with an arc height of 0.3 mmA or more are performed.
本発明によれば、自動車、産業機械用としての曲げ疲労特性を備え、更に面圧が２８００ＭＰａ以上となる高面圧下においても優れた耐ピッチング性を有する歯車および当該歯車を量産可能な製造方法が得られ、産業上極めて有用である。 According to the present invention, there is provided a gear having bending fatigue characteristics for automobiles and industrial machines and having excellent pitting resistance even under high surface pressure where the surface pressure is 2800 MPa or more, and a manufacturing method capable of mass-producing the gear. And is extremely useful industrially.
本発明に係る歯車の成分組成、好ましい組織について説明する。 The component composition and preferred structure of the gear according to the present invention will be described.
［素材の成分組成］
以下に限定理由について説明する。説明において％は質量％とする。
Ｃ：０．１５〜０．３５％
Ｃは強度確保のために必要であり、その含有量は浸炭焼戻し後の内部硬さを決定する。含有量が０．１５％に満たないと内部の硬さが低下しすぎるために歯車としての強度を確保できない。一方、０．３５％より多いと靭性低下、加工性の劣化が起る。よってＣ含有量は０．１５〜０．３５％とする。
[Component composition of the material]
The reason for limitation will be described below. In the description,% is mass%.
C: 0.15-0.35%
C is necessary for securing the strength, and its content determines the internal hardness after carburizing and tempering. If the content is less than 0.15%, the hardness as a gear cannot be ensured because the internal hardness is too low. On the other hand, if it exceeds 0.35%, the toughness is lowered and the workability is deteriorated. Therefore, the C content is 0.15 to 0.35%.
Ｓｉ：０．７０〜２．５０％
Ｓｉは焼戻し軟化抵抗を高めるのに有効な元素である。その含有量が０．７０％に満たないと、焼戻し軟化抵抗に効果が無く、耐ピッチング性が向上しない。一方、２．５０％より多くても焼戻し軟化抵抗への効果が飽和されるだけでなく、靭性が劣化する。このため、Ｓｉ含有量は０．７０〜２．５０％とする。
Si: 0.70 to 2.50%
Si is an element effective for increasing the temper softening resistance. If the content is less than 0.70%, the temper softening resistance is not effective, and the pitting resistance is not improved. On the other hand, if it exceeds 2.50%, not only the effect on the temper softening resistance is saturated, but also the toughness deteriorates. For this reason, Si content shall be 0.70-2.50%.
Ｍｎ：０．２０〜１．００％
Ｍｎは焼入れ性を高める元素であり、その効果を得るため、０．２０％以上が必要である。しかし、焼入れ性を高める効果は１．００％超えで飽和する。このため、Ｍｎ含有量は０．２０〜１．００％とする。
Mn: 0.20 to 1.00%
Mn is an element that enhances hardenability, and 0.20% or more is necessary to obtain the effect. However, the effect of improving hardenability is saturated at over 1.00%. For this reason, the Mn content is set to 0.20 to 1.00%.
Ｎｉ：０．０１〜０．８０％
Ｎｉは焼入れ性を高める元素であり、その効果を得るため、０．０１％以上が必要である。しかし、０．８０％を超えると焼入れ性が過度なり硬度が高くなりすぎて被削性が劣化する。また高価な元素であるため、０．０１〜０．８０％とする。
Ni: 0.01-0.80%
Ni is an element that enhances hardenability and needs to be 0.01% or more in order to obtain the effect. However, if it exceeds 0.80%, the hardenability becomes excessive, the hardness becomes too high, and the machinability deteriorates. Moreover, since it is an expensive element, it is 0.01 to 0.80%.
Ｃｒ：０．１０〜１．５０％
Ｃｒは焼入れ性向上元素であるとともに、焼戻し軟化抵抗を高める元素でもある。これらの効果を得るため、０．１０％以上が必要である。しかし、１．５０％を超えると表層浸炭部にＣｒＮが多量に析出して靭性の低下を起こし、疲労強度が低下するため、０．１０〜１．５０％とする。
Cr: 0.10 to 1.50%
Cr is an element that improves hardenability and also increases resistance to temper softening. In order to obtain these effects, 0.10% or more is necessary. However, if it exceeds 1.50%, a large amount of CrN precipitates in the surface carburized part, causing a decrease in toughness and a decrease in fatigue strength, so the content is made 0.10 to 1.50%.
Ｍｏ：０．０１〜０．８０％
Ｍｏは焼入れ性向上元素である。その効果を得るため、０．０１％以上が必要である。しかし、０．８０％を超えるとその効果が無くなり、靭性が低下して疲労強度が低下するため、０．０１〜０．８０％とする。
Mo: 0.01 to 0.80%
Mo is a hardenability improving element. In order to obtain the effect, 0.01% or more is necessary. However, if it exceeds 0.80%, the effect is lost, and the toughness is lowered and the fatigue strength is lowered. Therefore, the content is made 0.01 to 0.80%.
Ａｌ：０．００５〜０．２００％
Ａｌは脱酸に有効な元素であり、その効果を得るため、０．００５％以上が必要である。また、Ｎと結合してＡｌＮを生成し、結晶粒の粗大化を抑えて靭性を向上させるが、０．２００％を超えると粗大粒が発生して靭性が低下するため、０．００５〜０．２００％とする。本発明ではＡｌはｓｏｌ．Ａｌとする。
Al: 0.005 to 0.200%
Al is an element effective for deoxidation, and 0.005% or more is necessary to obtain the effect. Moreover, it combines with N to produce AlN and suppresses the coarsening of crystal grains to improve toughness. However, if it exceeds 0.200%, coarse grains are generated and the toughness is lowered. 200%. In the present invention, Al is sol. Al.
ＨＳｉＣｒＮ（＝５８Ｓｉ＋４２ｘ（Ｎｓ−Ｃｒｘ１４／５２））≧８０
ここで、Ｓｉ，Ｃｒは含有量（質量％）Ｎｓ：表層最大侵入窒素量（質量％）とする。
ＨＳｉＣｒＮは歯車表層部分が低温焼戻しされた場合の、焼戻し後の軟化の程度を示す焼戻し軟化抵抗パラメータである。焼戻し後の軟化にはＳｉ、Ｃｒ、窒化処理による表層部の侵入Ｎ量の最大値：Ｎｓが影響する。ＨＳｉＣｒＮの値が８０未満では、高面圧下でギヤを駆動させた時のギヤ同士の接触面の軟化が大きくなって、ピッチングが発生しやすくなり、耐久性が低下するため８０以上とする。
H SiCrN (= 58Si + 42x (Ns−Crx14 / 52)) ≧ 80
Here, Si and Cr are made into content (mass%) Ns: surface layer maximum penetration | invasion nitrogen amount (mass%).
H SiCrN is a temper softening resistance parameter indicating the degree of softening after tempering when the gear surface layer portion is tempered at low temperature. Softening after tempering is affected by the maximum value of the amount of intrusion N in the surface layer portion by Si, Cr, and nitriding treatment: Ns. If the value of H SiCrN is less than 80, softening of the contact surfaces between the gears when the gears are driven under high surface pressure increases, pitching is likely to occur, and durability is reduced, so 80 or more.
尚、上記パラメータの管理は浸炭後に窒素を添加するとともに酸素の影響を避けて他の合金元素の酸化を押さえる事が必要である。よって、後述する製造方法において、浸炭窒化（浸炭処理と窒化処理）は真空中で行うものとする。 Note that the above parameters must be controlled by adding nitrogen after carburizing and avoiding the influence of oxygen to suppress oxidation of other alloy elements. Therefore, in the manufacturing method described later, carbonitriding (carburizing treatment and nitriding treatment) is performed in a vacuum.
以上が本発明の基本成分組成で残部鉄及び不可避的不純物である。不可避不純物にはＰ、酸素、Ｎなどで、Ｐ、酸素の含有量は、出来るだけ低いほうが望ましい。Ｎは結晶粒を微細化させるので、０．２０％までの含有が許される。更に特性を向上させる場合、Ｎｂ、Ｖ、Ｔｉ、Ｂを１種または２種以上を含有する。また、被削性を向上させる場合、Ｓ、Ｐｂ、Ｓｅ、Ｃａ等の快削元素を含有させてもよい。 The above is the basic composition of the present invention and the balance iron and unavoidable impurities. Inevitable impurities are P, oxygen, N, etc., and the content of P and oxygen is preferably as low as possible. Since N refines crystal grains, it is allowed to contain up to 0.20%. Furthermore, when improving a characteristic, Nb, V, Ti, and B contain 1 type, or 2 or more types. Moreover, when improving machinability, you may contain free-cutting elements, such as S, Pb, Se, and Ca.
Ｎｂ：０．０１０〜０．１００％
Ｎｂは炭窒化物形成により結晶粒を微細化させて歯元曲げ疲労強度を向上させる。その効果を得るために０．０１０％以上とする。しかし、０．１００％を超えると粗大な炭窒化物を形成するようになって靭性を低下させるため、含有する場合は、０．０１０〜０．１００％とする。
Nb: 0.010 to 0.100%
Nb refines crystal grains by forming carbonitride and improves the root bending fatigue strength. In order to obtain the effect, the content is made 0.010% or more. However, if it exceeds 0.100%, coarse carbonitrides are formed and the toughness is lowered, so when contained, the content is made 0.010 to 0.100%.
Ｖ：０．００１〜０．１５０％
ＶもＳｉ，Ｃｒと同じく焼戻し軟化抵抗を高める。また、同時に炭窒化物を形成して結晶粒の微細化を行いＳｉの偏析を抑制する効果も持っている。その効果を発揮させるために０．００１％以上とする。しかし、０．１５０％を超えると粗大な炭窒化物を形成するようになって靭性を低下させるため、含有する場合は、０．００１〜０．１５０％とする。
V: 0.001 to 0.150%
V also increases the temper softening resistance like Si and Cr. At the same time, carbonitrides are formed to refine crystal grains and to suppress the segregation of Si. In order to exhibit the effect, it is made 0.001% or more. However, if it exceeds 0.150%, coarse carbonitrides are formed and the toughness is lowered, so when contained, the content is made 0.001 to 0.150%.
Ｔｉ：０．００５〜０．０５０％
ＴｉはＮｂと同様に炭窒化物を形成する元素で、結晶粒を微細化して歯元曲げ疲労強度を向上させる。その効果を得るために０．００５％以上とする。しかし、０．０５０％を超えて添加した場合は凝固時に粗大な窒化物が大量に生成して歯元曲げ疲労強度を低下させるので、添加する場合は、０．００５〜０．０５０％とする。
Ti: 0.005 to 0.050%
Ti is an element that forms carbonitrides like Nb, and refines crystal grains to improve the root bending fatigue strength. In order to acquire the effect, it is made 0.005% or more. However, if added over 0.050%, a large amount of coarse nitride is generated during solidification and lowers the root bending fatigue strength. Therefore, when added, the content is set to 0.005 to 0.050%. .
Ｂ：０．０００５〜０．０１００％、
Ｂは焼入れ性を向上させるのに有効で、その効果を得るために０．０００５％以上とする。０．０１００％を超えると焼入れ性を向上させる効果が飽和するようになるため、添加する場合は、０．０００５〜０．０１００％とする。
B: 0.0005 to 0.0100%,
B is effective in improving the hardenability, and is 0.0005% or more in order to obtain the effect. If it exceeds 0.0100%, the effect of improving hardenability comes to be saturated, so when added, the content is made 0.0005 to 0.0100%.
本発明に係る歯車は、浸炭処理を行い、その後炉内で冷却後に焼入れする際、前記炉内での、浸炭後の炉内冷却から焼入れ前の加熱保持の間に、窒化処理を行い、前記焼入れ後に焼戻し処理した後の、浸炭層および非浸炭層の組織が以下のようであることが好ましい。なお、組織の同定方法は実施例において説明する。 The gear according to the present invention performs carburizing treatment, and then performs nitriding treatment between the cooling in the furnace after carburizing and the heating before quenching in the furnace when quenching after cooling in the furnace, The structure of the carburized layer and the non-carburized layer after tempering after quenching is preferably as follows. In addition, the identification method of a structure | tissue is demonstrated in an Example.
浸炭層の表層から０．１ｍｍ深さまでの領域における残留オーステナイト量の最大値（体積率）：１５〜４５％
残留オーステナイト自体は軟質だが、歯面の表層付近に存在している場合、歯車の駆動中の応力によりマルテンサイトに変態して硬化するので、曲げおよび面圧疲労で発生する疲労き裂の進展を抑制する。その抑制効果は表層付近（表層から０．１ｍｍ深さまで）の最大値が１５％以上で大きくなる。
Maximum amount of retained austenite in the region from the surface layer of the carburized layer to a depth of 0.1 mm (volume ratio): 15 to 45%
Residual austenite itself is soft, but when it exists near the surface layer of the tooth surface, it transforms into martensite due to stress during driving of the gear and hardens, so the fatigue cracks that occur during bending and surface pressure fatigue are propagated. Suppress. The suppression effect becomes large when the maximum value near the surface layer (from the surface layer to a depth of 0.1 mm) is 15% or more.
一方、残留オーステナイト量が４５％を超えると表層の硬さの低下が大きくなり過ぎて面圧疲労特性が悪化するようになるため、最大値を１５〜４５％の範囲内とすることが好ましい。 On the other hand, if the amount of retained austenite exceeds 45%, the decrease in the hardness of the surface layer becomes too large and the surface pressure fatigue characteristics deteriorate, so the maximum value is preferably in the range of 15 to 45%.
非浸炭部のフェライト体積率：１０〜４５％
非浸炭部（本発明では、歯内部組織のうち浸炭処理による炭素が侵入していない部分）の組織がマルテンサイトとフェライトからなり、当該フェライト体積％が１０〜４５％であることが好ましい。歯内部組織中にフェライトを混在させて、変態膨張による変形を少なくすると、噛み合う歯車の歯面同士の接触が適正化され、面疲労強度を向上させる。
Ferrite volume ratio of non-carburized part: 10 to 45%
It is preferable that the structure of the non-carburized portion (in the present invention, the portion of the internal tooth structure where carbon is not penetrated by carburization treatment) is composed of martensite and ferrite, and the ferrite volume% is 10 to 45%. If ferrite is mixed in the tooth internal structure and deformation due to transformation expansion is reduced, the contact between the tooth surfaces of the meshing gears is optimized and the surface fatigue strength is improved.
フェライトが組織中に１０％以上含まれると面疲労強度を向上させる効果が大きくなるが、４５％を超えて存在すると、非浸炭部の硬さが低下しすぎるため、面疲労においてはスポーリングを起こしやすくなり、また曲げ疲労強度も不足となり耐久性が劣るようになって好ましくない。よって、非浸炭部のフェライト体積率は１０〜４５％とすることが好ましい。 If ferrite is contained in the structure at 10% or more, the effect of improving the surface fatigue strength is increased, but if it exceeds 45%, the hardness of the non-carburized part is excessively lowered. This is not preferable because it tends to occur, and the bending fatigue strength is insufficient, resulting in poor durability. Therefore, the ferrite volume ratio of the non-carburized portion is preferably 10 to 45%.
本発明に係る歯車は、鍛造あるいは機械加工により歯車形状とした後、真空中で浸炭処理を行い、その後炉内で冷却後に焼入れする際、前記炉内での浸炭後の炉内冷却から焼入れ前の加熱保持の間に、窒化処理を行い、前記焼入れ後に焼戻し処理されて製造される。 The gear according to the present invention is formed into a gear shape by forging or machining, and then carburized in vacuum, and then quenched after cooling in the furnace, before cooling from in-furnace cooling after carburizing in the furnace. During the heating and holding, nitriding treatment is performed, and tempering treatment is performed after the quenching.
[浸炭処理]
上述したように、焼戻し軟化抵抗パラメータ：ＨＳｉＣｒＮの値を８０以上とするため、浸炭処理は真空中で行う。浸炭温度（Ｔ℃）は疲労強度が低下しないように浸炭深さを調整するため、（１）式を満足するように設定する。
[Carburization]
As described above, in order to set the value of the temper softening resistance parameter H SiCrN to 80 or more, the carburizing process is performed in a vacuum. The carburizing temperature (T ° C.) is set so as to satisfy the formula (1) in order to adjust the carburizing depth so that the fatigue strength does not decrease.
８８０−Ａ≦Ｔ（℃）≦９８０−Ａ ・・・（１）
ここで、Ａ＝２０３√Ｃ＋１５．２Ｎｉ−４４．７Ｓｉ−１０４Ｖ＋３０Ｍｎ＋１１Ｃｒ−４００Ａｌ−３１．５Ｍｏ（各成分記号は含有量（質量％）を示す）
浸炭深さを調整するため、浸炭温度Ｔ（℃）を鋼材成分により変える。浸炭温度Ｔ（℃）が８８０−Ａ未満の場合には浸炭深さが浅く、疲労強度が低下する。一方、９８０−Ａ超えの場合には結晶粒が粗大化して疲労強度がやはり低下する。
880-A ≦ T (° C.) ≦ 980-A (1)
Here, A = 203√C + 15.2Ni-44.7Si-104V + 30Mn + 11Cr-400Al-31.5Mo (each component symbol indicates content (mass%))
In order to adjust the carburizing depth, the carburizing temperature T (° C.) is changed depending on the steel material component. When the carburizing temperature T (° C.) is less than 880-A, the carburizing depth is shallow, and the fatigue strength decreases. On the other hand, when it exceeds 980-A, the crystal grains become coarse and the fatigue strength is also lowered.
[窒化処理]
窒化処理は、真空炉で浸炭処理を行った後、浸炭後の炉内冷却から焼入れ前の加熱保持の間に、前記真空炉内に窒素を導入して窒化処理を行う。窒化処理は、上述したＨＳｉＣｒＮ（＝５８Ｓｉ＋４２ｘ（Ｎｓ−Ｃｒｘ１４／５２））が８０以上となるように、Ｎｓ：表層最大侵入窒素量（質量％）を調整して行う。
[Nitriding treatment]
In the nitriding treatment, after performing the carburizing treatment in a vacuum furnace, the nitriding treatment is performed by introducing nitrogen into the vacuum furnace between cooling in the furnace after carburizing and heating and holding before quenching. The nitriding treatment is performed by adjusting Ns: surface layer maximum intrusion nitrogen amount (mass%) so that the above-mentioned H SiCrN (= 58Si + 42x (Ns−Crx14 / 52)) is 80 or more.
[焼入れ-焼戻し処理]
真空炉内で浸炭処理および窒化処理を行った後、同じ炉内で焼入れのための加熱保持を行う。焼入れ後は焼戻し処理を行う。
[Quenching-tempering]
After carburizing and nitriding in a vacuum furnace, heating and holding for quenching is performed in the same furnace. Tempering is performed after quenching.
以上の製造方法で製造された歯車は、所望の特性を備えているが、更に曲げ疲労強度、面圧疲労強度を向上させる場合、ショットピーニングを行う。 The gear manufactured by the above manufacturing method has desired characteristics, but shot peening is performed when the bending fatigue strength and the contact pressure fatigue strength are further improved.
ショットピーニングを行う場合、アークハイトが０．３ｍｍＡ以下では圧縮残留応力の付与が少なくて曲げ疲労強度、面圧疲労強度を向上させることが出来ないため、アークハイト０．３ｍｍＡ以上で施すことが好ましい。以下、本発明の効果を実施例を用いて、詳細に説明する。 When shot peening is performed, it is preferable that the arc height is 0.3 mmA or more because when the arc height is 0.3 mmA or less, compressive residual stress is hardly applied and bending fatigue strength and surface pressure fatigue strength cannot be improved. . Hereinafter, the effects of the present invention will be described in detail with reference to examples.
表１に示す化学成分を有する鋼を溶解した。溶製されたインゴットを熱間圧延により直径３２〜７０ｍｍの丸棒鋼に調製し、得られた丸棒鋼に対し９２５℃で１時間保持後に室温まで空冷する焼準処理を実施した。 Steels having chemical components shown in Table 1 were melted. The melted ingot was prepared into a round bar steel having a diameter of 32 to 70 mm by hot rolling, and the obtained round bar steel was subjected to a normalizing treatment in which it was kept at 925 ° C. for 1 hour and then air-cooled to room temperature.
焼準処理後の丸棒から、焼入れ歪量試験片，および小野式回転曲げ疲労試験片，ローラーピッチング試験片を採取した。焼入れ歪、各疲労試験片に対して図１に示す条件で真空炉内で浸炭処理し、窒化処理後に焼入れし、焼戻し処理を施した後、小野式回転曲げ疲労試験片，ローラーピッチング試験片の半数はアークハイト０．６ｍｍAのショットピーニングを行い、浸炭焼入れ歪量試験，回転曲げ疲労試験およびローラーピッチング試験を実施した。 Quenching strain amount test pieces, Ono type rotary bending fatigue test pieces, and roller pitching test pieces were collected from the round bars after the normalizing treatment. The quenching strain and fatigue test specimens were carburized in a vacuum furnace under the conditions shown in FIG. 1, quenched after nitriding, tempered, and then subjected to Ono-type rotary bending fatigue test specimens and roller pitching specimens. Half performed shot peening at an arc height of 0.6 mmA, followed by carburizing and quenching strain tests, rotating bending fatigue tests, and roller pitching tests.
さらに、焼準後の３２ｍｍ径の丸棒鋼について、浸炭焼入れ・焼戻し処理後に内部（非浸炭部）より衝撃試験片および硬さ試験片を採取し、内部硬さと内部靭性を調べた。 Further, with regard to the round bar steel having a diameter of 32 mm after normalization, impact test pieces and hardness test pieces were collected from the inside (non-carburized part) after carburizing and tempering treatment, and the internal hardness and internal toughness were examined.
浸炭条件は、Ｎｏ．１〜４１のいずれの試験片においても、表１に示したとおり、（１）式を用いて浸炭の上限、下限温度を算出し、下限温度と上限温度のほぼ中央の温度：Ｘ℃にて浸炭を行った。 The carburizing conditions are No. In any test piece of 1-41, as shown in Table 1, the upper limit and the lower limit temperature of carburization were calculated using the formula (1), and the temperature at the approximate center between the lower limit temperature and the upper limit temperature: X ° C. Carburized.
その後、炉内に窒素を充眞させながら、鋼材を炉内で８３０℃まで冷却した後に３０分〜２時間保持して窒化処理により侵入窒素量を調整し、焼入れを行った。但し従来例４２，４３については一般的な浸炭温度である９２０℃で浸炭を実施し、その後は本発明範囲ならびに比較例と同様の窒化処理・焼入れ・焼戻しを行った。 Thereafter, while the furnace was filled with nitrogen, the steel material was cooled to 830 ° C. in the furnace and then held for 30 minutes to 2 hours, and the amount of intruded nitrogen was adjusted by nitriding treatment, followed by quenching. However, for the conventional examples 42 and 43, carburizing was performed at 920 ° C., which is a general carburizing temperature, and thereafter nitriding, quenching, and tempering were performed in the same manner as in the scope of the present invention and the comparative example.
尚、第１表に示すＮｏ．１〜２３（開発例）は本発明範囲であり、本発明の条件（成分範囲組成，焼戻し軟化抵抗パラメータ：ＨｓｉＣｒＮ≧８０のいずれも）を満たしている。Ｎｏ．２４〜４１（比較例）は本発明の条件範囲外になるもので、本発明の条件（成分範囲組成，焼戻し軟化抵抗パラメータ：ＨｓｉＣｒＮ≧８０）の少なくとも一つの条件を満たしておらず、比較例である。 No. shown in Table 1 1 to 23 (development examples) are within the scope of the present invention and satisfy the conditions of the present invention (component range composition, temper softening resistance parameter: any of HsiCrN ≧ 80). No. 24 to 41 (comparative example) is outside the condition range of the present invention, and does not satisfy at least one of the conditions of the present invention (component range composition, temper softening resistance parameter: HsiCrN ≧ 80). It is.
また、Ｎｏ．４２，４３は従来使用されている鋼材で、それぞれＪＩＳＳＣＭ８２２Ｈ，ＳＣＭ４２０Ｈであり、焼戻し軟化抵抗パラメータ：ＨｓｉＣｒＮ≧８０を満たしておらず、本発明範囲外である。各試験の詳細について説明する。 No. 42 and 43 are steel materials conventionally used, which are JIS SCM822H and SCM420H, respectively, which do not satisfy the temper softening resistance parameter: HsiCrN ≧ 80 and are outside the scope of the present invention. Details of each test will be described.
[焼入れ歪量]
焼準された直径７０ｍｍの丸棒鋼からネイビーＣ試験片を加工した。図２にネイビーＣ試験片の正面図を、図３にその側面図を示す。ネイビーＣ試験片１は、両図に示したように、円盤状体に開口部２および円盤状空間３を有し、試験片各部の寸法は、次の通りである。
[Quenching strain]
Navy C specimens were machined from normalized round bar steel with a diameter of 70 mm. FIG. 2 shows a front view of the Navy C test piece, and FIG. 3 shows a side view thereof. As shown in both drawings, the navy C test piece 1 has an
試験片直径（ａ）：６０ｍｍ、厚さ（ｂ）：１２ｍｍ、円盤状空間の直径（Ｃ）：３４．８ｍｍ、開口部間隔（ｄ）：６ｍｍ、試験片中心と開口部円中心との距離（ｐ）：１０．２ｍｍ。 Test piece diameter (a): 60 mm, thickness (b): 12 mm, disk space diameter (C): 34.8 mm, opening interval (d): 6 mm, distance between test piece center and opening circle center (P): 10.2 mm.
浸炭焼入れ・焼戻しによる焼入れ歪量測定の試験は、上記のネイビーＣ試験片１を各鋼材当たり１０個作製し、この試験片を浸炭焼入れ・焼戻しをした後にこの試験片の開口部間隔（ｄ）の、浸炭焼入れ・焼戻し前後の変化率を測定し、この値を焼入れ歪量と定義した。 In the test for measuring the amount of quenching strain by carburizing and tempering, 10 navy C test pieces 1 are prepared for each steel material, and the test piece is subjected to carburizing and tempering, and the opening interval (d) between the test pieces. The rate of change before and after carburizing and tempering was measured, and this value was defined as the amount of quenching strain.
ネイビーＣ試験片による浸炭焼入れ・焼戻し後の変形量が、２．０％を超えるような大きな値を示す鋼材を用いて浸炭歯車を作製した場合は、歯車の歯面表層近傍に存在する残留オーステナイトが、ショットピーニングや、歯車として稼動させた後の応力により、マルテンサイト変態をした時に、歯面の変形が大きくなり過ぎて、面圧疲労特性が悪化する。 When a carburized gear is made using a steel material having a large deformation value after carburizing and tempering with a Navy C test piece exceeding 2.0%, residual austenite existing near the tooth surface of the gear However, when a martensitic transformation occurs due to shot peening or stress after operating as a gear, the tooth surface deformation becomes too large, and the surface pressure fatigue characteristics deteriorate.
よって、焼入れ歪量は２．０％以下が望ましい。さらに、浸炭焼入れ・焼戻しによるオーステナイト組織からマルテンサイト組織への変態による変形と、歯車駆動での残留オーステナイト組織からマルテンサイト組織への変態による歯面の変形の両方を少なくし、浸炭焼入れ・焼戻し後に歯車の歯型修正研削をしなくても面圧疲労特性の良好な歯車を得るには、この試験による歪量が１．０％以下であることが望ましい。 Therefore, the quenching strain amount is desirably 2.0% or less. Furthermore, both deformation due to transformation from austenite structure to martensite structure due to carburizing and tempering and deformation of tooth surfaces due to transformation from retained austenite structure to martensite structure during gear drive are reduced, and after carburizing and tempering. In order to obtain a gear having good surface pressure fatigue characteristics without performing gear tooth profile correction grinding, it is desirable that the strain amount by this test is 1.0% or less.
焼入れ歪量の試験結果を、試験繰り返し数ｎ＝１０の平均値で表して、表２に示す。 Table 2 shows the quenching strain test results, which are expressed as an average value of the number of test repetitions n = 10.
[残留オーステナイト量（体積率（％））]
次に浸炭焼入れ歪量測定済みの試験片を用いて、各供試鋼の試験片１０個中の２個を抜き出し、そのうちの１個の試験片正面部分にアークハイト０．６ｍｍＡのショットピーニング（Ｓ／Ｐと略す場合もある。）を施した。
[Amount of retained austenite (volume ratio (%))]
Next, using the test pieces for which the carburizing and quenching strain has been measured, 2 out of 10 test pieces of each test steel were extracted, and shot height peening (with an arc height of 0.6 mmA) was performed on the front part of one of the test pieces. S / P may be abbreviated.).
そして、各供試鋼のショットピーニング実施試験片１個、ショットピーニング未実施試験片１個それぞれについて、正面部分の表層〜１００μｍ深さ位置までの２０μｍ深さごとに残留オーステナイト量を測定し、その平均値を求めた。尚、測定面の研磨には電解研磨を使用し、測定にはＸ線回折回折装置を使用した。 And about each one shot peening execution test piece of each test steel, and one shot peening non-execution test piece, the amount of retained austenite is measured every 20 μm depth from the surface layer of the front part to the 100 μm depth position, The average value was obtained. Incidentally, electrolytic polishing was used for polishing the measurement surface, and an X-ray diffraction diffractometer was used for measurement.
[非浸炭部のフェライト量（体積率（％））]
浸炭焼入れ歪量、表層残留オーステナイト量測定済みの試験片の１個を切断して、各鋼材の浸炭焼入れ・焼戻しにおける内部（非浸炭部）のフェライトーマルテンサイト二相組織を検鏡試験で各鋼材ともに１０視野づつ観察し、各視野中でフェライトの占める比率を画像処理装置にて測定し、その１０視野の平均値を求め、フェライト体積率（％）と定義した。
[Amount of ferrite in non-carburized part (volume ratio (%))]
Cut one of the specimens that have been measured for carburizing and quenching strain and the amount of retained austenite on the surface layer. Each steel material was observed with 10 fields of view, and the ratio of ferrite in each field of view was measured with an image processing apparatus. The average value of the 10 fields of view was determined and defined as the ferrite volume ratio (%).
[回転曲げ疲労特性]
直径３２ｍｍの丸棒鋼から、平行部直径１０ｍｍの試験片を採取し、平行部にこれと直角方向の深さ３ｍｍの切り欠き（切り欠き係数：１．４）を全周にわたってつけた回転曲げ疲労試験片を調製した。
[Rotating bending fatigue characteristics]
Rotating bending fatigue where a specimen with a diameter of 10 mm was taken from a round steel bar with a diameter of 32 mm, and a notch (notch coefficient: 1.4) with a depth of 3 mm in the direction perpendicular to the parallel part was made in the parallel part. A test piece was prepared.
得られた試験片全数に対し、ネイビーＣ試験片に施した条件で浸炭焼入れ・焼戻し処理を行った。その後、各鋼の試験片について半数にショットピーニング処理（アークハイト：０．６ｍｍＡ）を行った。そして、各鋼のショットピーニング実施品、未実施品について、小野式回転曲げ疲労試験機を使用して１０７回を疲労限度として回転曲げ疲労試験を行い、回転曲げ疲労強度を測定した。 Carburizing quenching / tempering treatment was performed on the total number of the obtained test pieces under the conditions applied to the Navy C test piece. Thereafter, half of the test pieces of each steel were subjected to shot peening treatment (arc height: 0.6 mmA). The shot peening embodiment sample of the steel, the incomplete product, performs a rotational bending fatigue test as fatigue limit of 10 7 times using fatigue tester Ono-type rotating bending was measured rotating bending fatigue strength.
[ピッチング試験（面圧疲労特性）]
直径３２ｍｍの丸棒鋼から図４に示す試験面の直径が２６ｍｍ、幅が２８ｍｍの円筒部を有するローラー状試験片4を作製した。さらに直径７０ｍｍの丸棒鋼を用いて、鍛造により直径１３５ｍｍとした後、焼準処理を行い、直径１３０ｍｍ、幅１８ｍｍの大ローラー5を作製した。
[Pitching test (surface fatigue characteristics)]
A roller-shaped test piece 4 having a cylindrical part with a test surface diameter of 26 mm and a width of 28 mm shown in FIG. 4 was prepared from a round steel bar having a diameter of 32 mm. Further, using a round steel bar having a diameter of 70 mm, the diameter was set to 135 mm by forging, and then a normalizing process was performed to produce a
次いでローラー状試験片4および大ローラー5をネイビーＣ試験片，回転曲げ疲労試験片と同じ条件で浸炭焼入れ・焼戻し処理を行った。その後、それぞれの半数について回転曲げ疲労試験片と同じ条件でショットピーニング処理（アークハイト：０．６ｍｍＡ）を実施した。
Next, the carburizing and tempering treatment was performed on the roller-shaped test piece 4 and the
そして、各鋼のショットピーニング実施品（Ｓ／Ｐ材）、未実施品について、コマツエンジニアリング製ローラーピッチング試験機を使用して１０７回を疲労限度として試験を行った。試験条件は回転数：１５００ｒ．ｐ．ｍ、すべり率４０％、潤滑剤：ミッショオイル、油温：１２０℃とした。 Then, shot peening the embodiment sample of each steel (S / P material), about the un-implemented product, was tested as a fatigue limit of 10 7 times using the Komatsu Engineering Co. roller pitching test machine. The test condition is the number of revolutions: 1500 r. p. m, slip ratio of 40%, lubricant: mission oil, oil temperature: 120 ° C.
[浸炭有効硬化層深さ、内部硬さおよび内部靭性]
浸炭焼入れ・焼戻し後の直径３２ｍｍの丸棒鋼について、垂直断面にて表層部分から所定ピッチにて試験荷重２．９４Nでビッカース硬度を測定し、硬さが５５０Ｈｖとなる深さを有効硬化層深さとした。次いで非浸炭部である内部のビッカース硬さを測定してその値で歯車芯部の強度を評価した。
[Carburized effective hardened layer depth, internal hardness and internal toughness]
With respect to a round steel bar having a diameter of 32 mm after carburizing and tempering, the Vickers hardness is measured at a predetermined pitch from the surface layer portion at a predetermined pitch in a vertical section, and the depth at which the hardness becomes 550 Hv is defined as the effective hardened layer depth. did. Subsequently, the internal Vickers hardness which is a non-carburized part was measured, and the strength of the gear core part was evaluated based on the measured value.
また、非浸炭部よりＪＩＳ３号衝撃試験片を調製し、衝撃試験を行いその結果により歯車芯部の靭性を評価した。同じ丸棒について部分的にショットピーニングを施し、ショットピーニング未実施部位と実施部位の各１断面について垂直断面内の表層の粒界酸化層を検鏡観察により調べた。以上の試験結果を表２に併せて示す。表２においてショットピーニングを行わなかった試験片を浸炭材、行った試験片をＳ／Ｐ材と表示した（以下の表も同様とする）。 Further, a JIS No. 3 impact test piece was prepared from the non-carburized portion, an impact test was performed, and the toughness of the gear core portion was evaluated based on the result. The same round bar was partially shot peened, and the grain boundary oxide layer in the vertical section was examined by microscopic observation for each section of the shot peened non-executed part and the executed part. The above test results are also shown in Table 2. In Table 2, the test pieces that were not shot peened were indicated as carburized materials, and the test pieces that were performed were indicated as S / P materials (the same applies to the following tables).
表１および表２から下記事項が明らかである。比較例Ｎｏ．２４はＣ量が本発明範囲よりも低いために内部の硬さが低下しすぎており、そのため内部起点の破壊であるスポーリングが発生して面疲労強度が低下した。比較例２５はＣ量が本発明範囲よりも高くなってしまい、そのために靭性が低下しすぎており、そのために回転曲げ疲労強度および面疲労強度が低下した。 From Tables 1 and 2, the following matters are clear. Comparative Example No. In No. 24, the amount of C was lower than the range of the present invention, so the internal hardness was too low. Therefore, spalling, which is destruction of the internal origin, occurred, and the surface fatigue strength was reduced. In Comparative Example 25, the amount of C was higher than the range of the present invention, so that the toughness was too low, and therefore the rotary bending fatigue strength and the surface fatigue strength were reduced.
比較例２６はＳｉ量が本発明範囲よりも低いために焼戻し軟化抑制効果が小さすぎて面疲労強度が低下した。比較例２７はＳｉ量が本発明範囲よりも高いために靭性が劣化して、疲労試験において亀裂の進展が促進されたために回転曲げ疲労強度および面疲労強度が低下した。 In Comparative Example 26, since the Si amount was lower than the range of the present invention, the effect of suppressing temper softening was too small, and the surface fatigue strength was reduced. In Comparative Example 27, since the Si amount was higher than the range of the present invention, the toughness was deteriorated, and the progress of cracks was promoted in the fatigue test, so that the rotational bending fatigue strength and the surface fatigue strength were reduced.
比較例２８はＭｎ量が本発明範囲よりも低いために焼入れ性が不足し、有効硬化層が浅くなり、内部硬さも低くなっており、そのために回転曲げ疲労強度および面疲労強度が低下した。比較例２９はＮｉ添加量が本発明範囲よりも低いために焼入れ性が不足し、有効硬化層が浅くなり、内部硬さも低くなっており、そのために回転曲げ疲労強度および面疲労強度が低下した。 In Comparative Example 28, since the amount of Mn was lower than the range of the present invention, the hardenability was insufficient, the effective hardened layer became shallow, and the internal hardness was also low, so that the rotary bending fatigue strength and the surface fatigue strength were reduced. In Comparative Example 29, the Ni addition amount is lower than the range of the present invention, so that the hardenability is insufficient, the effective hardened layer is shallow, and the internal hardness is also low, so that the rotary bending fatigue strength and the surface fatigue strength are reduced. .
比較例３０はＮｉ添加量が本発明範囲よりも高いために内部硬度が高くなりすぎており、靭性が不足して面疲労強度が低下した。比較例３１はＣｒ添加量が本発明範囲よりも低いために焼入れ性が不足するとともに焼戻し軟化抑制効果が得られず、内部硬度が低くなり、硬化層深さも浅くなり、回転曲げ疲労強度および面疲労強度が低下した。 In Comparative Example 30, since the amount of Ni added was higher than the range of the present invention, the internal hardness was too high, the toughness was insufficient and the surface fatigue strength was lowered. In Comparative Example 31, since the Cr addition amount is lower than the range of the present invention, the hardenability is insufficient and the temper softening suppressing effect cannot be obtained, the internal hardness is lowered, the hardened layer depth is also shallow, the rotational bending fatigue strength and the surface are reduced. Fatigue strength decreased.
比較例３２はＣｒ添加量が本発明範囲よりも高いために粗大なＣｒＮが多く析出して靭性が低下し、回転曲げ疲労強度および面疲労強度が低下した。比較例３３はＭｏ添加量が本発明範囲よりも高くなっており、内部硬度が高くなり、靭性が低下した。そのため回転曲げ疲労強度および面疲労強度が低下した。 In Comparative Example 32, since the amount of Cr added was higher than the range of the present invention, a large amount of coarse CrN was precipitated and the toughness was lowered, and the rotary bending fatigue strength and the surface fatigue strength were lowered. In Comparative Example 33, the amount of Mo added was higher than the range of the present invention, the internal hardness increased, and the toughness decreased. Therefore, rotational bending fatigue strength and surface fatigue strength decreased.
比較例３４はＭｏ添加量が本発明範囲より低くなったおり、焼入れ性が不足したために回転曲げ疲労強度および面疲労強度が低下した。比較例３５はＡｌ添加量が本発明範囲よりも低くなっており、脱酸が不足したために介在物による破壊が発生して回転曲げ疲労強度が低下した。 In Comparative Example 34, the amount of Mo added was lower than the range of the present invention, and the hardenability was insufficient, so that the rotational bending fatigue strength and the surface fatigue strength were reduced. In Comparative Example 35, the amount of Al added was lower than the range of the present invention, and because deoxidation was insufficient, fracture due to inclusions occurred and rotational bending fatigue strength decreased.
比較例３６はＡｌ添加量が本発明範囲よりも高くなっており、そのために結晶粒が粗大化して回転曲げ疲労強度および面疲労強度が低下した。比較例３７はＮｂ添加量が本発明範囲よりも高くなっており、そのために結晶粒が粗大化して回転曲げ疲労強度および面疲労強度が低下した。 In Comparative Example 36, the amount of Al added was higher than the range of the present invention, and as a result, the crystal grains became coarse, and the rotational bending fatigue strength and the surface fatigue strength decreased. In Comparative Example 37, the amount of Nb added was higher than the range of the present invention. For this reason, the crystal grains were coarsened, and the rotational bending fatigue strength and the surface fatigue strength were reduced.
比較例３８はＶ添加量が本発明範囲よりも高くなっており、そのために靭性が低下して回転曲げ疲労強度および面疲労強度が低下した。比較例３９はＴｉ添加量が本発明範囲よりも高くなっており、粗大なＴｉＮが多く存在して、疲労の起点や亀裂進展を促進して回転曲げ疲労強度が低下した。 In Comparative Example 38, the amount of V added was higher than the range of the present invention, and as a result, the toughness decreased and the rotary bending fatigue strength and the surface fatigue strength decreased. In Comparative Example 39, the amount of Ti added was higher than the range of the present invention, and a large amount of coarse TiN was present. The fatigue starting point and crack propagation were promoted, and the rotational bending fatigue strength was reduced.
比較例４０はＢ添加量が本発明範囲よりも低くなっており、焼入れ性が不足したために、有効硬化層が浅くなっており、そのために回転曲げ疲労強度および面疲労強度が低下した。比較例４１の各種成分は本発明範囲内であるものの、焼戻し軟化パラメータであるＨＳｉＣｒＮが本発明範囲よりも低くなっており、そのために面疲労強度が低下した。 In Comparative Example 40, the amount of addition of B was lower than the range of the present invention, and the hardened property was insufficient, so that the effective hardened layer was shallow, and thus the rotational bending fatigue strength and the surface fatigue strength were reduced. Although the various components of Comparative Example 41 were within the scope of the present invention, H SiCrN, which is a temper softening parameter, was lower than the scope of the present invention, so that the surface fatigue strength was reduced.
従来鋼の４２，４３はＳｉ添加量、ＨＳｉＣｒＮが本発明範囲よりも低くなっており、そのために面疲労強度が低下した。 In conventional steels 42 and 43, the amount of Si added and H SiCrN were lower than the range of the present invention, and the surface fatigue strength was reduced.
一方、本発明鋼であるＮｏ．１〜２３は従来鋼Ｎｏ．４２、４３に比べて、内部衝撃値、内部硬度、γ粒度は同等の値が得られており、そのため、回転曲げ疲労強度は同等以上であるが、焼戻し軟化パラメーター（ＨＳｉＣｒ）が高く、非浸炭部のフェライトによる熱変形量が少ないために、面疲労強度は著しく上昇した。 On the other hand, no. 1 to 23 are conventional steel Nos. Compared to 42 and 43, the internal impact value, internal hardness, and γ grain size are equivalent, and therefore the rotational bending fatigue strength is equivalent or higher, but the temper softening parameter (HSiCr) is high, and it is not carburized. The surface fatigue strength significantly increased because of the small amount of thermal deformation caused by ferrite in the part.
表１に記載の開発例２０の材料を用いて浸炭・拡散時間を調整して残留オーステナイト量を変化させて、各種調査を実施した。表３に結果を示す。表３より以下のことが明らかである。開発例２０−１〜５は本発明範囲であり、従来鋼よりも高い面疲労強度を有しているものの、残留オーステナイトの体積率が表層から０．１ｍｍ深さの範囲内において最大値が１５〜４５％の２０−１、２、３はさらに高い面疲労強度が得られた。 Various investigations were carried out by changing the amount of retained austenite by adjusting the carburization / diffusion time using the materials of Development Example 20 shown in Table 1. Table 3 shows the results. From Table 3, the following is clear. Although the development examples 20-1 to 5 are within the scope of the present invention and have higher surface fatigue strength than conventional steel, the maximum value is 15 in the range where the volume ratio of retained austenite is 0.1 mm deep from the surface layer. Even higher surface fatigue strength was obtained with ˜45% 20-1, 2, 3.
表１に記載の開発例２０、２３の鋼材を用いて浸炭温度ならびに焼入れ温度を調整して残留γ体積率、フェライト体積率を変えた試験片を作成して各種調査を実施した。表３に開発例２０を用いて残留γ体積率を変えた結果を示す。表３より以下のことが明らかである。Ｎｏ．２０−１〜２０−５はいずれも高い面疲労強度が得られているが、残留γ体積率が本発明範囲である２０−１〜２０−３はさらに高い面疲労強度が得られた。 Using the steel materials of development examples 20 and 23 shown in Table 1, the carburizing temperature and the quenching temperature were adjusted to prepare test pieces in which the residual γ volume fraction and ferrite volume fraction were changed, and various investigations were carried out. Table 3 shows the results of changing the residual γ volume fraction using the development example 20. From Table 3, the following is clear. No. Although 20-1 to 20-5 all have high surface fatigue strength, 20-1 to 20-3, in which the residual γ volume fraction is in the range of the present invention, have higher surface fatigue strength.
表４に開発例２３を用いてフェライト体積率を変えた結果を示す。表４より以下のことが明らかである。Ｎｏ．２３−１〜２３−５はいずれも高い面疲労強度が得られているが、フェライト体積率が本発明範囲であるＮｏ．２３−１、３、４はさらに高い面疲労強度が得られた。 Table 4 shows the results of changing the ferrite volume fraction using Development Example 23. From Table 4, the following is clear. No. Nos. 23-1 to 23-5 all have high surface fatigue strength, but the ferrite volume ratio is No. 1 in the range of the present invention. In 23-1, 3, and 4, higher surface fatigue strength was obtained.
それに対してフェライト量が０のＮｏ．２３−２では内部硬さが硬すぎて面疲労強度が低下した。フェライト量が多すぎたＮｏ．２３−５では内部硬さが低下しすぎて回転曲げ疲労強度および面疲労強度が低下した。 On the other hand, no. In 23-2, the internal hardness was too hard and the surface fatigue strength decreased. No. with too much ferrite In 23-5, the internal hardness decreased too much, and the rotary bending fatigue strength and the surface fatigue strength decreased.
Claims (5)
成分組成が質量％で、Ｃ：０．１５〜０．３５％、Ｓｉ：０．７０〜２．５０％、Ｍｎ：０．２０〜１．００％、Ｎｉ：０．０１〜０．８０％、Ｃｒ：０．１０〜１．５０％、Ｍｏ：０．０１〜０．８０％、Ａｌ：０．００５〜０．２００％、残部鉄および不可避不純物からなり、前記成分組成におけるＳｉ、Ｃｒと前記窒化処理による表層最大侵入窒素量による焼戻し軟化抵抗パラメータＨＳｉＣｒＮが（１）式を満たすことを特徴とする耐ピッチング性に優れた歯車。
ＨＳｉＣｒＮ（＝５８Ｓｉ＋４２×（Ｎｓ−Ｃｒ×１４／５２））≧８０・・・（１）
ここで、Ｓｉ，Ｃｒは含有量（質量％）Ｎｓ：表層最大侵入窒素量（質量％）を示す。 After forging or machining to form a gear, carburizing treatment is performed in a vacuum, and then quenching is performed after cooling in the furnace, between the cooling in the furnace after carburizing and the heating before quenching in the furnace. , A gear that performs nitriding and is tempered after the quenching,
Component composition is mass%, C: 0.15-0.35%, Si: 0.70-2.50%, Mn: 0.20-1.00%, Ni: 0.01-0.80% Cr: 0.10 to 1.50%, Mo: 0.01 to 0.80%, Al: 0.005 to 0.200%, balance iron and inevitable impurities, and Si, Cr in the above component composition A temper softening resistance parameter H SiCrN according to the surface layer maximum intrusion nitrogen amount by the nitriding treatment satisfies the formula (1), and has excellent pitching resistance.
H SiCrN (= 58Si + 42 × (Ns−Cr × 14/52)) ≧ 80 (1)
Here, Si and Cr indicate content (mass%) Ns: surface layer maximum intrusion nitrogen quantity (mass%).
前記浸炭処理は、（２）式にて計算される浸炭温度Ｔ（℃）の範囲に制御された真空中で行い、
前記浸炭処理後は、７２０℃〜８５０℃の温度範囲まで炉内で冷却して保持したのち焼入れを行い、前記焼戻し処理は１００℃〜２５０℃の温度まで再加熱して行うことを特徴とする耐ピッチング性に優れた歯車の製造方法。
８８０−Ａ≦Ｔ（℃）≦９８０−Ａ ・・・（２）
Ａ＝２０３√Ｃ−１５．２Ｎｉ−４４．７Ｓｉ−１０４Ｖ＋３０Ｍｎ＋１１Ｃｒ−４００Ａｌ−３１．５Ｍｏ （各成分記号は含有量（質量％）を示す） After the steel material having the component composition according to claim 1 or 2 is formed into a gear shape by forging or machining, carburizing treatment is performed in a vacuum, and then, after cooling in the furnace, after quenching in the furnace. A method of manufacturing a gear for performing nitriding during the heating and holding before quenching from furnace cooling, and performing a tempering after quenching,
The carburizing treatment is performed in a vacuum controlled to a range of carburizing temperature T (° C.) calculated by equation (2),
After the carburizing treatment, it is cooled and held in a furnace to a temperature range of 720 ° C. to 850 ° C. and then quenched, and the tempering treatment is performed by reheating to a temperature of 100 ° C. to 250 ° C. A gear manufacturing method with excellent pitting resistance.
880-A ≦ T (° C.) ≦ 980-A (2)
A = 203√C-15.2Ni-44.7Si-104V + 30Mn + 11Cr-400Al-31.5Mo (Each component symbol indicates content (% by mass))
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2011257490A JP5872863B2 (en) | 2011-11-25 | 2011-11-25 | Gear having excellent pitting resistance and method for producing the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2011257490A JP5872863B2 (en) | 2011-11-25 | 2011-11-25 | Gear having excellent pitting resistance and method for producing the same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2013112827A true JP2013112827A (en) | 2013-06-10 |
| JP5872863B2 JP5872863B2 (en) | 2016-03-01 |
Family
ID=48708664
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2011257490A Active JP5872863B2 (en) | 2011-11-25 | 2011-11-25 | Gear having excellent pitting resistance and method for producing the same |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP5872863B2 (en) |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2015010250A (en) * | 2013-06-27 | 2015-01-19 | 愛知製鋼株式会社 | Vacuum carbonitriding method |
| CN104625665A (en) * | 2014-12-30 | 2015-05-20 | 宁波职业技术学院 | Alloy material and production process of gear |
| JP2018053337A (en) * | 2016-09-30 | 2018-04-05 | Ｊｆｅスチール株式会社 | Carburized component excellent in wear resistance and fatigue characteristic, and process for producing the same |
| JP2018053338A (en) * | 2016-09-30 | 2018-04-05 | Ｊｆｅスチール株式会社 | Carburized component excellent in wear resistance, and process for producing the same |
| JP2019007063A (en) * | 2017-06-27 | 2019-01-17 | 新日鐵住金株式会社 | Steel for vacuum carburization and carburization component |
| JP2020033637A (en) * | 2018-08-27 | 2020-03-05 | Ｊｆｅスチール株式会社 | Component and manufacturing method thereof |
| KR20200104080A (en) * | 2019-02-26 | 2020-09-03 | 주식회사 퓨트로닉 | Manufacturing method of Spur Gear |
| CN113832404A (en) * | 2021-09-23 | 2021-12-24 | 马鞍山钢铁股份有限公司 | Boron-containing high-performance gear forging and production method thereof |
| CN114058827A (en) * | 2021-11-26 | 2022-02-18 | 西安煤矿机械有限公司 | Method for controlling hardness of spline after gear carburization integral quenching |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH07138696A (en) * | 1993-11-11 | 1995-05-30 | Sumitomo Metal Ind Ltd | Steel parts excellent in fatigue strength |
| JPH09287644A (en) * | 1996-04-23 | 1997-11-04 | Toa Steel Co Ltd | High strength low heat treatment deformation gear and manufacture thereof |
| JP2002121645A (en) * | 2000-10-17 | 2002-04-26 | Nkk Bars & Shapes Co Ltd | Steel for gear having excellent dedendum bending fatigue characteristic and facial pressure fatigue characteristic and gear |
| JP2006322036A (en) * | 2005-05-18 | 2006-11-30 | Kobe Steel Ltd | Vacuum-carburized parts and manufacturing method therefor |
| JP2008121075A (en) * | 2006-11-13 | 2008-05-29 | Kobe Steel Ltd | Gear part excellent in fitness |
| JP2008163414A (en) * | 2006-12-28 | 2008-07-17 | Komatsu Ltd | Rolling member and manufacturing method for the same |
| US20110129382A1 (en) * | 2009-12-01 | 2011-06-02 | Hyundai Motor Company | Alloy steel for low temperature vacuum carburizing |
-
2011
- 2011-11-25 JP JP2011257490A patent/JP5872863B2/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH07138696A (en) * | 1993-11-11 | 1995-05-30 | Sumitomo Metal Ind Ltd | Steel parts excellent in fatigue strength |
| JPH09287644A (en) * | 1996-04-23 | 1997-11-04 | Toa Steel Co Ltd | High strength low heat treatment deformation gear and manufacture thereof |
| JP2002121645A (en) * | 2000-10-17 | 2002-04-26 | Nkk Bars & Shapes Co Ltd | Steel for gear having excellent dedendum bending fatigue characteristic and facial pressure fatigue characteristic and gear |
| JP2006322036A (en) * | 2005-05-18 | 2006-11-30 | Kobe Steel Ltd | Vacuum-carburized parts and manufacturing method therefor |
| JP2008121075A (en) * | 2006-11-13 | 2008-05-29 | Kobe Steel Ltd | Gear part excellent in fitness |
| JP2008163414A (en) * | 2006-12-28 | 2008-07-17 | Komatsu Ltd | Rolling member and manufacturing method for the same |
| US20110129382A1 (en) * | 2009-12-01 | 2011-06-02 | Hyundai Motor Company | Alloy steel for low temperature vacuum carburizing |
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2015010250A (en) * | 2013-06-27 | 2015-01-19 | 愛知製鋼株式会社 | Vacuum carbonitriding method |
| CN104625665A (en) * | 2014-12-30 | 2015-05-20 | 宁波职业技术学院 | Alloy material and production process of gear |
| JP2018053337A (en) * | 2016-09-30 | 2018-04-05 | Ｊｆｅスチール株式会社 | Carburized component excellent in wear resistance and fatigue characteristic, and process for producing the same |
| JP2018053338A (en) * | 2016-09-30 | 2018-04-05 | Ｊｆｅスチール株式会社 | Carburized component excellent in wear resistance, and process for producing the same |
| JP2019007063A (en) * | 2017-06-27 | 2019-01-17 | 新日鐵住金株式会社 | Steel for vacuum carburization and carburization component |
| JP2020033637A (en) * | 2018-08-27 | 2020-03-05 | Ｊｆｅスチール株式会社 | Component and manufacturing method thereof |
| KR20200104080A (en) * | 2019-02-26 | 2020-09-03 | 주식회사 퓨트로닉 | Manufacturing method of Spur Gear |
| KR102207374B1 (en) * | 2019-02-26 | 2021-01-26 | 주식회사 퓨트로닉 | Manufacturing method of Spur Gear |
| CN113832404A (en) * | 2021-09-23 | 2021-12-24 | 马鞍山钢铁股份有限公司 | Boron-containing high-performance gear forging and production method thereof |
| CN114058827A (en) * | 2021-11-26 | 2022-02-18 | 西安煤矿机械有限公司 | Method for controlling hardness of spline after gear carburization integral quenching |
| CN114058827B (en) * | 2021-11-26 | 2023-05-26 | 西安煤矿机械有限公司 | Method for controlling hardness of spline after gear carburization integral quenching |
Also Published As
| Publication number | Publication date |
|---|---|
| JP5872863B2 (en) | 2016-03-01 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5872863B2 (en) | Gear having excellent pitting resistance and method for producing the same | |
| JP5958652B2 (en) | Soft nitrided induction hardened steel parts with excellent surface fatigue strength | |
| EP2966189B1 (en) | Semi-finished material for induction hardened component and method for producing same | |
| JP5530763B2 (en) | Carburized steel parts with excellent low cycle bending fatigue strength | |
| JP5635316B2 (en) | Gear having excellent fatigue strength and method for manufacturing the same | |
| WO2015098106A1 (en) | Carburized-steel-component production method, and carburized steel component | |
| JP4385019B2 (en) | Manufacturing method for steel nitrocarburized machine parts | |
| US9200354B2 (en) | Rolled steel bar or wire for hot forging | |
| WO2019244503A1 (en) | Mechanical component | |
| JP6772499B2 (en) | Steel parts and their manufacturing methods | |
| JP4609585B2 (en) | Soft nitriding steel, soft nitriding steel and crankshaft | |
| JP5206271B2 (en) | Carbonitriding parts made of steel | |
| JP2018141216A (en) | Component and manufacturing method thereof | |
| JP6601358B2 (en) | Carburized parts and manufacturing method thereof | |
| JP4798963B2 (en) | High strength gear and manufacturing method thereof | |
| TWI544088B (en) | Vacuum carburizing steel and its manufacturing method | |
| JP4504550B2 (en) | Steel for gears and gears with excellent root bending fatigue and surface fatigue properties | |
| JP7013833B2 (en) | Carburized parts | |
| JP6447064B2 (en) | Steel parts | |
| JP5272609B2 (en) | Carbonitriding parts made of steel | |
| JP7063070B2 (en) | Carburized parts | |
| JP6922415B2 (en) | Carburized parts | |
| JP5131770B2 (en) | Non-tempered steel for soft nitriding | |
| JP5151323B2 (en) | Machine structural parts | |
| JP7063071B2 (en) | Carburized parts |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20140709 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20150311 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20150324 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20150423 |
|
| A711 | Notification of change in applicant |
Free format text: JAPANESE INTERMEDIATE CODE: A711 Effective date: 20150710 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20150825 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20151026 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20160105 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20160114 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 5872863 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |