WO2018051599A1 - Spring and spring material - Google Patents
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- WO2018051599A1 WO2018051599A1 PCT/JP2017/022834 JP2017022834W WO2018051599A1 WO 2018051599 A1 WO2018051599 A1 WO 2018051599A1 JP 2017022834 W JP2017022834 W JP 2017022834W WO 2018051599 A1 WO2018051599 A1 WO 2018051599A1
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- 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
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- 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
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
- F16F1/00—Springs
- F16F1/02—Springs made of steel or other material having low internal friction; Wound, torsion, leaf, cup, ring or the like springs, the material of the spring not being relevant
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
- C21D9/02—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for springs
Definitions
- austenite crystal grain in the present invention is a concept including so-called former austenite crystal grains, and refers to those defined in JIS G0202.
- the austenite grain size number can be measured by the method defined in JIS G 0551.
- the austenite grain size number in the spring material of the present invention is less than 10, and the austenite grain size is very large.
- a spring having excellent mechanical properties can be obtained as will be described in detail later.
- the spring of the present invention has a bainite structure suitable for a spring obtained by subjecting a spring material having a large austenite grain size to austempering, and has a Vickers hardness higher than that of a conventional spring.
- the Vickers hardness of the spring of the present invention is 400 Hv or more. If the Vickers hardness of the spring is large as described above, it is considered that the spring is bainite transformed at least over the entire region in the plate thickness direction. As a result, the spring of the present invention is considered to have excellent mechanical properties such as high strength and excellent fatigue resistance.
- the spring material of the present invention having an austenite grain size number of less than 10 when used, it can be said that an austempering treatment can be suitably performed and a spring having excellent hardness can be manufactured.
- the larger austenite crystal grains in the spring material of the present invention are better. Therefore, the austenite grain size number of the spring material of the present invention should be small, specifically, preferably austenite grain size number 9 or less, more preferably less than 9 and more preferably 8 or less. More preferably.
Abstract
In order to provide a technique whereby the mechanical characteristics of a spring having carbon steel as the material thereof can be further enhanced, a spring material is configured so as to contain, in terms of mass%, 0.4%-0.9% C, 0.1%-0.35% Si, more than 0% and no more than 1% Mn, more than 0% and no more than 0.03% P, more than 0% and no more than 0.25% Ni, and more than 0% and no more than 0.3% Cr, the remainder comprising Fe and unavoidable impurities, 0.005% or less of the impurities being Al, and the austenite crystal grain size number being less than 10. The spring according to the present invention is configured so as to contain, in terms of mass%, 0.4%-0.9% C, 0.1%-0.35% Si, more than 0% and no more than 1% Mn, more than 0% and no more than 0.03% P, more than 0% and no more than 0.25% Ni, and more than 0% and no more than 0.3% Cr, the remainder comprising Fe and unavoidable impurities, 0.005% or less of the impurities being Al, the spring having a bainite structure, and the Vickers hardness thereof being 400 Hv or greater.
Description
本発明は、ばね及び当該ばねの材料に関する。
The present invention relates to a spring and a material of the spring.
ホースクランプ等に代表されるばねは、一般に、炭素を含有する鋼つまり炭素鋼を材料とする。この種の炭素鋼をばね材料としてばねを製造する際には、ばねに必要な機械的特性を向上させることを目的として、オーステンパ処理と呼ばれる熱処理を施す場合がある。炭素鋼にオーステンパ処理を施すことで、炭素鋼の組織をベイナイト変態させ、強度や耐疲労特性等のばねの機械的特性を向上できると考えられる（例えば、特許文献１参照）。
The springs represented by hose clamps and the like are generally made of steel containing carbon, that is, carbon steel. When manufacturing a spring using this type of carbon steel as a spring material, a heat treatment called austempering may be applied for the purpose of improving the mechanical characteristics required for the spring. By performing austempering treatment on carbon steel, it is considered that the structure of carbon steel can be transformed into bainite and mechanical properties of the spring such as strength and fatigue resistance can be improved (see, for example, Patent Document 1).
しかし、近年では高性能のばねが要求されており、従来のばねよりも機械的特性の更に向上したばねが望まれている。
However, in recent years, a high-performance spring has been demanded, and a spring having further improved mechanical characteristics over the conventional spring is desired.
本発明は、上記事情を鑑みてなされたものであり、炭素鋼を材料とするばねの機械的特性の更なる向上を図り得る技術を提供することを目的とする。
The present invention has been made in view of the above circumstances, and an object thereof is to provide a technique capable of further improving the mechanical characteristics of a spring made of carbon steel.
本発明の発明者等は、鋭意研究の結果、ばね材料にオーステンパ処理を行う際のばね材料の内部における熱伝導の速度が充分でない可能性があることに気付いた。そして、このためにばね材料つまり炭素鋼の組織が均一にベイナイト変態せず、ばねの機械的特性に影響を及ぼすのではないかという着想を得た。そして、ばね材料の内部において熱伝導が充分な速度で行われていない理由がばね材料の組織にあることに想到し、本発明を完成した。
As a result of diligent research, the inventors of the present invention have found that the rate of heat conduction inside the spring material may not be sufficient when the spring material is subjected to austempering. For this reason, the idea is that the structure of the spring material, that is, the carbon steel, does not uniformly transform into bainite and affects the mechanical properties of the spring. The inventors have conceived that the reason why heat conduction is not performed at a sufficient speed inside the spring material is the structure of the spring material, and thus the present invention has been completed.
すなわち、上記課題を解決する本発明のばね材料は、
質量％で、Ｃ：０．４％以上０．９％以下、Ｓｉ：０．１％以上０．３５％以下、Ｍｎ：０％を超え１％以下、Ｐ：０％を超え０．０３％以下、Ｎｉ：０％を超え０．２５％以下、Ｃｒ：０％を超え０．３％以下を含有し、残部がＦｅ及び不純物からなり、前記不純物のうちＡｌ：０．００５％以下であり、
オーステナイト結晶粒度番号が１０番未満である、ばね材料である。 That is, the spring material of the present invention that solves the above problems is
In mass%, C: 0.4% to 0.9%, Si: 0.1% to 0.35%, Mn: more than 0% and 1% or less, P: more than 0% and 0.03% Hereinafter, Ni: more than 0% and not more than 0.25%, Cr: more than 0% and not more than 0.3%, with the balance being Fe and impurities, and among the impurities, Al: not more than 0.005% ,
A spring material having an austenite grain size number of less than 10.
質量％で、Ｃ：０．４％以上０．９％以下、Ｓｉ：０．１％以上０．３５％以下、Ｍｎ：０％を超え１％以下、Ｐ：０％を超え０．０３％以下、Ｎｉ：０％を超え０．２５％以下、Ｃｒ：０％を超え０．３％以下を含有し、残部がＦｅ及び不純物からなり、前記不純物のうちＡｌ：０．００５％以下であり、
オーステナイト結晶粒度番号が１０番未満である、ばね材料である。 That is, the spring material of the present invention that solves the above problems is
In mass%, C: 0.4% to 0.9%, Si: 0.1% to 0.35%, Mn: more than 0% and 1% or less, P: more than 0% and 0.03% Hereinafter, Ni: more than 0% and not more than 0.25%, Cr: more than 0% and not more than 0.3%, with the balance being Fe and impurities, and among the impurities, Al: not more than 0.005% ,
A spring material having an austenite grain size number of less than 10.
また、上記課題を解決する本発明のばねは、
質量％で、Ｃ：０．４％以上０．９％以下、Ｓｉ：０．１％以上０．３５％以下、Ｍｎ：０％を超え１％以下、Ｐ：０％を超え０．０３％以下、Ｎｉ：０％を超え０．２５％以下、Ｃｒ：０％を超え０．３％以下を含有し、残部がＦｅ及び不純物からなり、前記不純物のうちＡｌ：０．００５％以下であり、
ベイナイト組織を有し、
ビッカース硬さが４００Ｈｖ以上である、ばねである。 The spring of the present invention that solves the above problems is
In mass%, C: 0.4% to 0.9%, Si: 0.1% to 0.35%, Mn: more than 0% and 1% or less, P: more than 0% and 0.03% Hereinafter, Ni: more than 0% and not more than 0.25%, Cr: more than 0% and not more than 0.3%, with the balance being Fe and impurities, and among the impurities, Al: not more than 0.005% ,
Has a bainite structure,
A spring having a Vickers hardness of 400 Hv or more.
質量％で、Ｃ：０．４％以上０．９％以下、Ｓｉ：０．１％以上０．３５％以下、Ｍｎ：０％を超え１％以下、Ｐ：０％を超え０．０３％以下、Ｎｉ：０％を超え０．２５％以下、Ｃｒ：０％を超え０．３％以下を含有し、残部がＦｅ及び不純物からなり、前記不純物のうちＡｌ：０．００５％以下であり、
ベイナイト組織を有し、
ビッカース硬さが４００Ｈｖ以上である、ばねである。 The spring of the present invention that solves the above problems is
In mass%, C: 0.4% to 0.9%, Si: 0.1% to 0.35%, Mn: more than 0% and 1% or less, P: more than 0% and 0.03% Hereinafter, Ni: more than 0% and not more than 0.25%, Cr: more than 0% and not more than 0.3%, with the balance being Fe and impurities, and among the impurities, Al: not more than 0.005% ,
Has a bainite structure,
A spring having a Vickers hardness of 400 Hv or more.
本発明のばね材料によるとばねの機械的特性の更なる向上を図り得る。また、本発明のばねは機械的特性の向上したものである。
The spring material of the present invention can further improve the mechanical characteristics of the spring. The spring of the present invention has improved mechanical properties.
以下に、本発明を実施するための形態を説明する。なお、特に断らない限り、本明細書に記載された数値範囲「ａ～ｂ」は、下限ａ及び上限ｂをその範囲に含む。そして、これらの上限値及び下限値、並びに実施例中に列記した数値も含めてそれらを任意に組み合わせることで数値範囲を構成し得る。更に上記の各数値範囲内から任意に選択した数値を新たな範囲の上限、下限の数値とすることができる。
Hereinafter, modes for carrying out the present invention will be described. Unless otherwise specified, the numerical range “a to b” described in this specification includes the lower limit “a” and the upper limit “b”. A numerical range can be configured by arbitrarily combining these upper limit values and lower limit values and numerical values listed in the examples. Furthermore, numerical values arbitrarily selected from the numerical ranges described above can be used as the upper and lower numerical values of the new range.
本発明のばね材料は、炭素鋼の一種であり、Ｆｅ以外にもＣ、Ｓｉ、Ｍｎ、Ｐ、Ｎｉ、Ｃｒを必須構成元素として含み、更に、上記の必須構成元素以外の不純物を含む。
The spring material of the present invention is a kind of carbon steel, which contains C, Si, Mn, P, Ni, Cr as essential constituent elements in addition to Fe, and further contains impurities other than the above essential constituent elements.
本発明のばね材料におけるＦｅ以外の必須構成元素の含有量は、質量％で、Ｃ：０．４％以上０．９％以下、Ｓｉ：０．１％以上０．３５％以下、Ｍｎ：０％を超え１％以下、Ｐ：０％を超え０．０３％以下、Ｎｉ：０％を超え０．２５％以下、Ｃｒ：０％を超え０．３％以下である。これらの量で必須構成元素を含有するばね材料は、例えばＪＩＳ Ｇ ４４０１、ＪＩＳ Ｇ ３３１１、ＪＩＳ Ｇ ４０５１等に規格されている。
The content of essential constituent elements other than Fe in the spring material of the present invention is mass%, C: 0.4% to 0.9%, Si: 0.1% to 0.35%, Mn: 0 % Over 1%, P: over 0% over 0.03%, Ni: over 0% over 0.25%, Cr: over 0% over 0.3%. Spring materials containing essential constituent elements in these amounts are standardized in, for example, JIS G 4401, JIS G 3311, JIS G 4051, and the like.
不純物としては、炭素鋼の原料中に存在したり、炭素鋼の製造工程において不可避的に混入したりする元素であり、かつ、上記必須構成元素以外の元素が例示される。例えば、ばね材料の製造工程において用いられる脱酸剤、脱硫剤、脱燐剤の等の添加剤に含まれる元素が当該不純物に該当する。
Examples of the impurities include elements that are present in the raw material of carbon steel or are inevitably mixed in the manufacturing process of carbon steel, and elements other than the above essential constituent elements. For example, an element contained in an additive such as a deoxidizer, a desulfurizer, and a dephosphorizer used in the spring material manufacturing process corresponds to the impurity.
不純物としての元素は、例えば、後述するＡｌであれば０．００５質量％以下、Ｃａであれば５０質量ｐｐｍ以下と非常に少量であり、所謂不可避的不純物に相当すると言える。
The element as the impurity is, for example, a very small amount of 0.005 mass% or less for Al described later and 50 mass ppm or less for Ca, and can be said to correspond to a so-called unavoidable impurity.
ところで、既述したようにばねを製造する際には、ばね材料すなわち炭素鋼にオーステンパ処理を行い、当該炭素鋼の組織をベイナイト変態させる技術が用いられている。オーステンパ処理は、熱処理の一種であり、鋼を加熱してオーステナイト化し、その後Ar'とAr"変態点との間を急冷し、その温度で等温保持してオーステナイト化していた組織をベイナイト変態させる方法である。鋼をオーステナイト化する温度（所謂オーステナイト化温度）としては８２０℃～９００℃付近の温度が例示され、等温保持する温度（所謂テンパー温度）としては１５０℃～５５０℃付近の温度が例示される。また、急冷する際にはパーライト変態を起こさない程急速に冷却するのが良いとされている。
By the way, as described above, when manufacturing a spring, a technique is used in which an austempering process is performed on a spring material, that is, carbon steel, and the structure of the carbon steel is transformed to bainite. Austempering is a type of heat treatment in which steel is heated to austenite, then rapidly cooled between Ar 'and Ar "transformation points, and isothermally held at that temperature to austeniticize the bainite transformation. Examples of the temperature at which the steel is austenitized (so-called austenitizing temperature) include temperatures in the vicinity of 820 ° C. to 900 ° C., and examples of the temperature at which isothermal holding is performed (so-called tempering temperature) include temperatures in the vicinity of 150 ° C. to 550 ° C. In addition, it is said that it is good to cool rapidly so as not to cause pearlite transformation.
本発明の発明者等は、ばね材料に上記のオーステンパ処理を行って得られたばねの機械的特性は、ばね材料の種類によって異なることに気付き、この現象がばね材料のオーステナイト結晶粒度に依存することを見出した。詳しくは、本発明の発明者等は、オーステナイト結晶粒度が特定の範囲を上回るばね材料を用いた場合に、耐疲労特性や強度等の機械的特性に優れるばねを得ることができることを見出した。
The inventors of the present invention have noticed that the mechanical properties of the spring obtained by subjecting the spring material to the austempering treatment described above vary depending on the type of spring material, and this phenomenon depends on the austenite grain size of the spring material. I found. Specifically, the inventors of the present invention have found that when a spring material having an austenite grain size exceeding a specific range is used, a spring having excellent mechanical properties such as fatigue resistance and strength can be obtained.
その理由は定かではないが、大きなオーステナイト結晶粒同士の間では熱伝導が好適に行われるためであると予想される。つまり、オーステナイト結晶粒の大きなばね材料にオーステンパ処理を行うと、ばね材料内部での熱伝導が好適になされ、上記した急冷の速度が充分に速くなり、その結果、好適なベイナイト組織を有するばねが得られると考えられる。逆に、オーステナイト結晶粒の小さなばね材料にオーステンパ処理を行うと、急冷速度が遅く、好適なベイナイト組織が得られ難くなり、ばねに優れた機械的特性を付与し難いと考えられる。
The reason is not clear, but it is expected that heat conduction is suitably performed between large austenite crystal grains. In other words, when austempering is performed on a spring material having a large austenite crystal grain, the heat conduction inside the spring material is suitably performed, and the rapid cooling rate described above is sufficiently high. As a result, a spring having a suitable bainite structure It is thought that it is obtained. Conversely, when austempering is performed on a spring material having small austenite crystal grains, the rapid cooling rate is slow, and it is difficult to obtain a suitable bainite structure, and it is considered difficult to impart excellent mechanical properties to the spring.
なお、本発明におけるオーステナイト結晶粒とは所謂旧オーステナイト結晶粒を包含する概念であり、ＪＩＳ Ｇ ０２０２に規定されるものを指す。また、オーステナイト結晶粒度番号はＪＩＳ Ｇ ０５５１に規定される方法で測定できる。
In addition, the austenite crystal grain in the present invention is a concept including so-called former austenite crystal grains, and refers to those defined in JIS G0202. The austenite grain size number can be measured by the method defined in JIS G 0551.
更に具体的には、本発明の発明者等は、ばね材料のオーステナイト結晶粒の大きさには、炭素鋼つまりばね材料を製造する際の脱酸剤の種類が関与することを見出した。
More specifically, the inventors of the present invention have found that the size of the austenite crystal grains of the spring material is related to the type of deoxidizer used when producing the carbon steel, that is, the spring material.
つまり、脱酸剤として一般的に好適とされているＡｌを用いた場合には、オーステナイト結晶粒の小さなばね材料が得られる。そして、当該ばね材料にオーステンパ処理を行った場合には、好適なベイナイト組織が生成し難い。
That is, when Al, which is generally suitable as a deoxidizer, is used, a spring material with small austenite crystal grains can be obtained. And when an austempering process is performed to the said spring material, a suitable bainite structure is hard to produce | generate.
また、当該オーステナイト結晶粒の小さなばね材料においては、脱酸剤たるＡｌに由来して、Ａｌ２Ｏ３等の介在物が生成する。そして、当該オーステナイト結晶粒の小さなばね材料を材料とするばねにおいては、当該介在物が耐久疲労時における破断の原因となり得る。
In addition, in the spring material with small austenite crystal grains, inclusions such as Al 2 O 3 are generated due to Al as a deoxidizer. And in the spring which uses the spring material with the said small austenite crystal grain as a material, the said inclusion can cause a fracture | rupture at the time of a durable fatigue.
既述したように、従来、オーステナイト結晶粒は微細である方が良いとされていた。また、脱酸剤としては一般にＡｌが用いられていた。
As described above, conventionally, it was considered that fine austenite crystal grains should be fine. Moreover, Al was generally used as a deoxidizer.
例えば、特開平３－１３８３３３号公報には、ばね材料のオーステナイト結晶粒を微細化することが、ばねの優れた機械的特性に寄与することが開示されている。
For example, Japanese Patent Laid-Open No. 3-138333 discloses that refining austenite crystal grains of a spring material contributes to excellent mechanical properties of the spring.
本発明のばね材料におけるオーステナイト結晶粒度番号は１０番未満であり、オーステナイト結晶粒は非常に大きい。このようにオーステナイト結晶粒の大きな本発明のばね材料によると、追って詳説するように、優れた機械的特性を有するばねを得ることができる。
The austenite grain size number in the spring material of the present invention is less than 10, and the austenite grain size is very large. Thus, according to the spring material of the present invention having large austenite crystal grains, a spring having excellent mechanical properties can be obtained as will be described in detail later.
上記のように大きなオーステナイト結晶粒を得るために、本発明のばね材料を製造する際には、Ａｌを使用しないか又は非常に少量のＡｌを使用するに留める。したがって、本発明のばね材料のＡｌ含有量は非常に少ない。具体的には、本発明のばね材料におけるＡｌ含有量は、０．００５質量％以下であり、好ましくは０．００４質量％以下であり、より好ましくは０．００３質量％以下である。更に、本発明のばね材料はＡｌを含有しなくても良い。
In order to obtain large austenite crystal grains as described above, when the spring material of the present invention is manufactured, Al is not used or only a very small amount of Al is used. Therefore, the Al content of the spring material of the present invention is very small. Specifically, the Al content in the spring material of the present invention is 0.005% by mass or less, preferably 0.004% by mass or less, and more preferably 0.003% by mass or less. Furthermore, the spring material of the present invention may not contain Al.
一般に、Ａｌはばね材料を製造する際の脱酸剤として用いられている。したがって、Ａｌ含有量の少ない本発明のばね材料を製造する際には、Ａｌ以外の脱酸剤を用いる。Ａｌ以外の脱酸剤としては、「日立評論、昭和３４年６月、第４１巻、第６号、第８３２頁～第８３５頁」、「鉄と鋼、１９７０年、第３号、第３９１頁～第４０１頁」、「鉄と鋼、Ｖｏｌ．８３、１９９７年、Ｎｏ．１１、第７頁～第１２頁」等の公知の文献に開示されている公知の脱酸剤を用いることができる。当該公知の脱酸剤とは、例えば、単体Ｃａ、ＣａとＳｉとの混合物、ＣａとＳｉとの合金、Ｃａと微量のＡｌとの混合物等である。これらの公知の脱酸剤を用いた脱酸方法もまた、公知の方法に基づけば良い。
Generally, Al is used as a deoxidizer when manufacturing spring materials. Therefore, when producing the spring material of the present invention having a low Al content, a deoxidizer other than Al is used. Examples of deoxidizers other than Al include “Hitachi Review, June 1959, Vol. 41, No. 6, pages 832 to 835”, “Iron and Steel, 1970, No. 3, No. 391”. Page to page 401 "," Iron and steel, Vol. 83, 1997, No. 11, pages 7 to 12 ", etc., using a known deoxidizing agent disclosed in known documents. it can. The known deoxidizing agent is, for example, simple substance Ca, a mixture of Ca and Si, an alloy of Ca and Si, a mixture of Ca and a small amount of Al, or the like. The deoxidation method using these known deoxidizers may also be based on a known method.
ばね材料を製造する際に単体Ｃａ、ＣａとＳｉとの混合物、ＣａとＳｉとの合金等に代表されるＣａ系の脱酸剤を用いる場合、本発明のばね材料はＣａを含有する。この場合、本発明のばね材料のＣａの含有量は１０質量ｐｐｍ以上５０質量ｐｐｍ以下とすることができる。当該Ｃａの含有量は１５質量ｐｐｍ以上３０質量ｐｐｍ以下であるのが好ましく、後述する実施例のばね材料においては１９質量ｐｐｍ以上２３質量ｐｐｍ以下である。
When producing a spring material, when using a Ca-based deoxidizer represented by simple substance Ca, a mixture of Ca and Si, an alloy of Ca and Si, etc., the spring material of the present invention contains Ca. In this case, the Ca content of the spring material of the present invention can be 10 mass ppm or more and 50 mass ppm or less. The content of Ca is preferably 15 mass ppm or more and 30 mass ppm or less, and is 19 mass ppm or more and 23 mass ppm or less in the spring material of Examples described later.
上記した本発明のばね材料を用いて得られた本発明のばねは、上記した本発明のばね材料と同様の組成で必須構成元素及び不純物を含む。本発明のばねは、本発明のばね材料にオーステンパ処理を行うことで得られるために、ベイナイト組織を有する。当該ベイナイト組織は、オーステナイト結晶粒中のオーステナイトが変態したものであるため、本発明のばねのオーステナイト結晶粒の大きさ、つまり、オーステナイト結晶粒度は、本発明のばね材料のオーステナイト結晶粒度と同様に、オーステナイト結晶粒度番号１０番未満である。つまり、本発明のばね材料のオーステナイト結晶粒度番号とばねのオーステナイト結晶粒度番号とは共通する。
本発明のばねは、オーステナイト結晶粒度の大きなばね材料にオーステンパ処理を行って得られた、ばねに好適なベイナイト組織を有するものであり、従来のばねに比べてビッカース硬さが大きい。具体的には本発明のばねのビッカース硬さは４００Ｈｖ以上である。このようにばねのビッカース硬さが大きければ、ばねが少なくとも板厚方向の全域にわたってベイナイト変態していると考えられる。その結果、本発明のばねには高強度及び優れた耐疲労特性という、優れた機械的特性が付与されると考えられる。 The spring of the present invention obtained by using the spring material of the present invention described above contains essential constituent elements and impurities in the same composition as the spring material of the present invention described above. Since the spring of the present invention is obtained by subjecting the spring material of the present invention to austempering, it has a bainite structure. Since the austenite structure in the austenite crystal grains is transformed, the size of the austenite crystal grains of the spring of the present invention, that is, the austenite crystal grain size is the same as the austenite crystal grain size of the spring material of the present invention. The austenite grain size number is less than 10. That is, the austenite grain size number of the spring material of the present invention and the austenite grain size number of the spring are common.
The spring of the present invention has a bainite structure suitable for a spring obtained by subjecting a spring material having a large austenite grain size to austempering, and has a Vickers hardness higher than that of a conventional spring. Specifically, the Vickers hardness of the spring of the present invention is 400 Hv or more. If the Vickers hardness of the spring is large as described above, it is considered that the spring is bainite transformed at least over the entire region in the plate thickness direction. As a result, the spring of the present invention is considered to have excellent mechanical properties such as high strength and excellent fatigue resistance.
本発明のばねは、オーステナイト結晶粒度の大きなばね材料にオーステンパ処理を行って得られた、ばねに好適なベイナイト組織を有するものであり、従来のばねに比べてビッカース硬さが大きい。具体的には本発明のばねのビッカース硬さは４００Ｈｖ以上である。このようにばねのビッカース硬さが大きければ、ばねが少なくとも板厚方向の全域にわたってベイナイト変態していると考えられる。その結果、本発明のばねには高強度及び優れた耐疲労特性という、優れた機械的特性が付与されると考えられる。 The spring of the present invention obtained by using the spring material of the present invention described above contains essential constituent elements and impurities in the same composition as the spring material of the present invention described above. Since the spring of the present invention is obtained by subjecting the spring material of the present invention to austempering, it has a bainite structure. Since the austenite structure in the austenite crystal grains is transformed, the size of the austenite crystal grains of the spring of the present invention, that is, the austenite crystal grain size is the same as the austenite crystal grain size of the spring material of the present invention. The austenite grain size number is less than 10. That is, the austenite grain size number of the spring material of the present invention and the austenite grain size number of the spring are common.
The spring of the present invention has a bainite structure suitable for a spring obtained by subjecting a spring material having a large austenite grain size to austempering, and has a Vickers hardness higher than that of a conventional spring. Specifically, the Vickers hardness of the spring of the present invention is 400 Hv or more. If the Vickers hardness of the spring is large as described above, it is considered that the spring is bainite transformed at least over the entire region in the plate thickness direction. As a result, the spring of the present invention is considered to have excellent mechanical properties such as high strength and excellent fatigue resistance.
なお、ビッカース硬さは、ＪＩＳ Ｚ ２２４４、ＩＳＯ ６５０７－１、ＩＳＯ ６５０７－４の何れかにより規定される。本発明のばねのビッカース硬さは４５０Ｈｖ以上であるのがより好ましい。
The Vickers hardness is defined by any one of JIS Z 2244, ISO 6507-1, and ISO 6507-4. The Vickers hardness of the spring of the present invention is more preferably 450 Hv or more.
上記したように、ばね材料のオーステナイト結晶粒度が小さければ、オーステンパ処理の際に、ばね材料内部での熱伝導が好適になされないと考えられる。したがって、厚肉のばね材料は薄肉のばね材料に比べて、ベイナイト変態が好適に行われ難いと考えられる。具体的には、例えば板厚１ｍｍ程度の薄肉のばねに比べて、板厚１．５ｍｍ以上の比較的厚肉のばねは、好適なベイナイト組織を有すると言い難い。また、特に板厚２ｍｍ以上の厚肉のばねは、より一層、好適なベイナイト組織を有するとは言い難い。
As described above, if the austenite grain size of the spring material is small, it is considered that the heat conduction inside the spring material is not suitably performed during the austempering process. Therefore, it is considered that the bainite transformation is not easily performed in the thick spring material as compared with the thin spring material. Specifically, it is difficult to say that a relatively thick spring having a plate thickness of 1.5 mm or more has a suitable bainite structure as compared with a thin spring having a plate thickness of about 1 mm. In particular, it is difficult to say that a thick spring having a plate thickness of 2 mm or more has a more suitable bainite structure.
本発明のばねは、板厚１．５ｍｍ以上であっても、ばねに好適なベイナイト組織を有する。つまり、本発明のばねが板ばねである場合、板厚１．５ｍｍ以上であってもベイナイト組織を有し、ビッカース硬さが４００Ｈｖ以上である。更に、板厚２ｍｍ以上の本発明のばねもまた、ベイナイト組織を有し、ビッカース硬さが４００Ｈｖ以上である。本発明のばねにおいては、板厚の上限は特に限定しないが、３．０ｍｍ以下であるのが好ましく、２．５ｍｍ以下であるのがより好ましく、２．２ｍｍ以下であるのが更に好ましい。なお、本発明のばねは板ばねに限らず線ばねであっても良いが、本発明のばねが線ばねである場合には、上記した板厚を直径と言い換えれば良い。
The spring of the present invention has a bainite structure suitable for a spring even if the plate thickness is 1.5 mm or more. That is, when the spring of this invention is a leaf | plate spring, even if it is plate | board thickness 1.5mm or more, it has a bainite structure and Vickers hardness is 400Hv or more. Furthermore, the spring of the present invention having a plate thickness of 2 mm or more also has a bainite structure and a Vickers hardness of 400 Hv or more. In the spring of the present invention, the upper limit of the plate thickness is not particularly limited, but is preferably 3.0 mm or less, more preferably 2.5 mm or less, and even more preferably 2.2 mm or less. The spring of the present invention is not limited to a leaf spring but may be a wire spring. However, when the spring of the present invention is a wire spring, the above-described plate thickness may be referred to as a diameter.
本発明のばねは各種の用途に応じた形状とすることができる。その成形方法としては、プレス成形やマルチフォーミング等の既知の方法を採用すれば良い。更に本発明のばねには、めっき層や各種の被膜を形成しても良いし、或いはその他の表面処理を施しても良い。本発明のばねの用途としては、例えば既述したホースクランプに加えて、皿ばねやトレランスリング等も好適である。
The spring of the present invention can be shaped according to various uses. As the forming method, a known method such as press forming or multi-forming may be employed. Furthermore, the spring of the present invention may be formed with a plating layer or various coatings, or may be subjected to other surface treatments. As an application of the spring of the present invention, for example, a disc spring or a tolerance ring is also suitable in addition to the above-described hose clamp.
以下、具体例を挙げ、本発明のばね材料及びばねを説明する。
Hereinafter, the spring material and the spring of the present invention will be described with specific examples.
（ばね材料）
（ばね材料Ｎｏ．１）
ばね材料Ｎｏ．１は、Ｃ：０．４６％（以下、特に明記しない限り質量％とする）、Ｓｉ：０．２％、Ｍｎ：０．７５％、Ｐ：０．０１％、Ｎｉ：０．０１２％、Ｃｒ：０．０２％、不純物としてＡｌ：０．００２％、Ｓ：０．００２％、Ｃａ：２３質量ｐｐｍを含み、残部がＦｅであるものを用いた。
ばね材料の化学組成の分析はＪＩＳ Ｇ ０３２１に基づいて行った。これは以下のばね材料においても同様である。
なお、後述するように、ばね材料Ｎｏ．１並びに以下のばね材料Ｎｏ．２～Ｎｏ．４及びばね材料Ｎｏ．７は本発明のばね材料に相当し、製造時に脱酸剤としてＳｉとＣａとの合金を用いたものである。
一方、ばね材料Ｎｏ．５及びＮｏ．６は本発明のばね材料には相当せず、製造時に脱酸剤としてＡｌを用いたものである。ばね材料Ｎｏ．１の組成を、以下のばね材料Ｎｏ．２～Ｎｏ．７の組成も含めて、ばね材料の項末尾の表１に示す。 (Spring material)
(Spring material No. 1)
Spring material No. 1 is C: 0.46% (hereinafter referred to as mass% unless otherwise specified), Si: 0.2%, Mn: 0.75%, P: 0.01%, Ni: 0.012%, A material containing Cr: 0.02%, impurities: Al: 0.002%, S: 0.002%, Ca: 23 mass ppm, and the balance being Fe is used.
The chemical composition of the spring material was analyzed based on JIS G 0321. The same applies to the following spring materials.
As will be described later, the spring material No. 1 and the following spring material No. 2 to No. 4 and spring material no. 7 corresponds to the spring material of the present invention, and an alloy of Si and Ca is used as a deoxidizer at the time of manufacture.
On the other hand, the spring material No. 5 and no. No. 6 does not correspond to the spring material of the present invention, and uses Al as a deoxidizing agent at the time of manufacture. Spring material No. 1 with the following spring material No. 2 to No. 7 including the composition of No. 7 is shown in Table 1 at the end of the term of the spring material.
（ばね材料Ｎｏ．１）
ばね材料Ｎｏ．１は、Ｃ：０．４６％（以下、特に明記しない限り質量％とする）、Ｓｉ：０．２％、Ｍｎ：０．７５％、Ｐ：０．０１％、Ｎｉ：０．０１２％、Ｃｒ：０．０２％、不純物としてＡｌ：０．００２％、Ｓ：０．００２％、Ｃａ：２３質量ｐｐｍを含み、残部がＦｅであるものを用いた。
ばね材料の化学組成の分析はＪＩＳ Ｇ ０３２１に基づいて行った。これは以下のばね材料においても同様である。
なお、後述するように、ばね材料Ｎｏ．１並びに以下のばね材料Ｎｏ．２～Ｎｏ．４及びばね材料Ｎｏ．７は本発明のばね材料に相当し、製造時に脱酸剤としてＳｉとＣａとの合金を用いたものである。
一方、ばね材料Ｎｏ．５及びＮｏ．６は本発明のばね材料には相当せず、製造時に脱酸剤としてＡｌを用いたものである。ばね材料Ｎｏ．１の組成を、以下のばね材料Ｎｏ．２～Ｎｏ．７の組成も含めて、ばね材料の項末尾の表１に示す。 (Spring material)
(Spring material No. 1)
Spring material No. 1 is C: 0.46% (hereinafter referred to as mass% unless otherwise specified), Si: 0.2%, Mn: 0.75%, P: 0.01%, Ni: 0.012%, A material containing Cr: 0.02%, impurities: Al: 0.002%, S: 0.002%, Ca: 23 mass ppm, and the balance being Fe is used.
The chemical composition of the spring material was analyzed based on JIS G 0321. The same applies to the following spring materials.
As will be described later, the spring material No. 1 and the following spring material No. 2 to No. 4 and spring material no. 7 corresponds to the spring material of the present invention, and an alloy of Si and Ca is used as a deoxidizer at the time of manufacture.
On the other hand, the spring material No. 5 and no. No. 6 does not correspond to the spring material of the present invention, and uses Al as a deoxidizing agent at the time of manufacture. Spring material No. 1 with the following spring material No. 2 to No. 7 including the composition of No. 7 is shown in Table 1 at the end of the term of the spring material.
（ばね材料Ｎｏ．２）
Ｃ：０．５５％、Ｓｉ：０．２％、Ｍｎ：０．６５％、Ｐ：０．０１３％、Ｎｉ：０．０１２％、Ｃｒ：０．０１５％、不純物としてＡｌ：０．００３％、Ｓ：０．０１１％、Ｃａ：２０質量ｐｐｍを含み、残部がＦｅであるものを用いた。 (Spring material No. 2)
C: 0.55%, Si: 0.2%, Mn: 0.65%, P: 0.013%, Ni: 0.012%, Cr: 0.015%, Al as impurities: 0.003% , S: 0.011%, Ca: 20 ppm by mass, with the balance being Fe.
Ｃ：０．５５％、Ｓｉ：０．２％、Ｍｎ：０．６５％、Ｐ：０．０１３％、Ｎｉ：０．０１２％、Ｃｒ：０．０１５％、不純物としてＡｌ：０．００３％、Ｓ：０．０１１％、Ｃａ：２０質量ｐｐｍを含み、残部がＦｅであるものを用いた。 (Spring material No. 2)
C: 0.55%, Si: 0.2%, Mn: 0.65%, P: 0.013%, Ni: 0.012%, Cr: 0.015%, Al as impurities: 0.003% , S: 0.011%, Ca: 20 ppm by mass, with the balance being Fe.
（ばね材料Ｎｏ．３）
Ｃ：０．６３％、Ｓｉ：０．２４％、Ｍｎ：０．６９％、Ｐ：０．０１４％、Ｎｉ：０．０１２％、Ｃｒ：０．０４％、不純物としてＡｌ：０．００３％、Ｓ：０．００６％、Ｃａ：２５質量ｐｐｍを含み、残部がＦｅであるものを用いた。 (Spring material No. 3)
C: 0.63%, Si: 0.24%, Mn: 0.69%, P: 0.014%, Ni: 0.012%, Cr: 0.04%, Al as impurities: 0.003% , S: 0.006%, Ca: 25 ppm by mass, with the balance being Fe.
Ｃ：０．６３％、Ｓｉ：０．２４％、Ｍｎ：０．６９％、Ｐ：０．０１４％、Ｎｉ：０．０１２％、Ｃｒ：０．０４％、不純物としてＡｌ：０．００３％、Ｓ：０．００６％、Ｃａ：２５質量ｐｐｍを含み、残部がＦｅであるものを用いた。 (Spring material No. 3)
C: 0.63%, Si: 0.24%, Mn: 0.69%, P: 0.014%, Ni: 0.012%, Cr: 0.04%, Al as impurities: 0.003% , S: 0.006%, Ca: 25 ppm by mass, with the balance being Fe.
（ばね材料Ｎｏ．４）
Ｃ：０．８２％、Ｓｉ：０．１９％、Ｍｎ：０．４％、Ｐ：０．０２％、Ｎｉ：０．０１％、Ｃｒ：０．０１４％、不純物としてＡｌ：０．００３％、Ｓ：０．００４％、Ｃａ：１９質量ｐｐｍを含み、残部がＦｅであるものを用いた。 (Spring material No. 4)
C: 0.82%, Si: 0.19%, Mn: 0.4%, P: 0.02%, Ni: 0.01%, Cr: 0.014%, Al: 0.003% as impurities , S: 0.004%, Ca: 19 ppm by mass, with the balance being Fe.
Ｃ：０．８２％、Ｓｉ：０．１９％、Ｍｎ：０．４％、Ｐ：０．０２％、Ｎｉ：０．０１％、Ｃｒ：０．０１４％、不純物としてＡｌ：０．００３％、Ｓ：０．００４％、Ｃａ：１９質量ｐｐｍを含み、残部がＦｅであるものを用いた。 (Spring material No. 4)
C: 0.82%, Si: 0.19%, Mn: 0.4%, P: 0.02%, Ni: 0.01%, Cr: 0.014%, Al: 0.003% as impurities , S: 0.004%, Ca: 19 ppm by mass, with the balance being Fe.
（ばね材料Ｎｏ．５）
Ｃ：０．６１％、Ｓｉ：０．２４％、Ｍｎ：０．６４％、Ｐ：０．０１３％、Ｎｉ：０．０１％、Ｃｒ：０．０４％、不純物としてＡｌ：０．０２％、Ｓ：０．００５％、Ｃａ：２３質量ｐｐｍを含み、残部がＦｅであるものを用いた。 (Spring material No. 5)
C: 0.61%, Si: 0.24%, Mn: 0.64%, P: 0.013%, Ni: 0.01%, Cr: 0.04%, Al as an impurity: 0.02% , S: 0.005%, Ca: 23 mass ppm was used, and the balance was Fe.
Ｃ：０．６１％、Ｓｉ：０．２４％、Ｍｎ：０．６４％、Ｐ：０．０１３％、Ｎｉ：０．０１％、Ｃｒ：０．０４％、不純物としてＡｌ：０．０２％、Ｓ：０．００５％、Ｃａ：２３質量ｐｐｍを含み、残部がＦｅであるものを用いた。 (Spring material No. 5)
C: 0.61%, Si: 0.24%, Mn: 0.64%, P: 0.013%, Ni: 0.01%, Cr: 0.04%, Al as an impurity: 0.02% , S: 0.005%, Ca: 23 mass ppm was used, and the balance was Fe.
（ばね材料Ｎｏ．６）
Ｃ：０．８６％、Ｓｉ：０．２％、Ｍｎ：０．４３％、Ｐ：０．０１３％、Ｎｉ：０．０１２％、Ｃｒ：０．０１５％、不純物としてＡｌ：０．０２％、Ｓ：０．０１１％、Ｃａ：２３質量ｐｐｍを含み、残部がＦｅであるものを用いた。 (Spring material No. 6)
C: 0.86%, Si: 0.2%, Mn: 0.43%, P: 0.013%, Ni: 0.012%, Cr: 0.015%, Al as an impurity: 0.02% , S: 0.011%, Ca: 23 mass ppm was used, and the balance was Fe.
Ｃ：０．８６％、Ｓｉ：０．２％、Ｍｎ：０．４３％、Ｐ：０．０１３％、Ｎｉ：０．０１２％、Ｃｒ：０．０１５％、不純物としてＡｌ：０．０２％、Ｓ：０．０１１％、Ｃａ：２３質量ｐｐｍを含み、残部がＦｅであるものを用いた。 (Spring material No. 6)
C: 0.86%, Si: 0.2%, Mn: 0.43%, P: 0.013%, Ni: 0.012%, Cr: 0.015%, Al as an impurity: 0.02% , S: 0.011%, Ca: 23 mass ppm was used, and the balance was Fe.
（ばね材料Ｎｏ．７）
Ｃ：０．８５％、Ｓｉ：０．２％、Ｍｎ：０．４２％、Ｐ：０．０１３％、Ｎｉ：０．０１２％、Ｃｒ：０．０１５％、不純物としてＡｌ：０．００３％、Ｓ：０．０１１％、Ｃａ：１８質量ｐｐｍを含み、残部がＦｅであるものを用いた。 (Spring material No. 7)
C: 0.85%, Si: 0.2%, Mn: 0.42%, P: 0.013%, Ni: 0.012%, Cr: 0.015%, Al as impurities: 0.003% , S: 0.011%, Ca: 18 ppm by mass, with the balance being Fe.
Ｃ：０．８５％、Ｓｉ：０．２％、Ｍｎ：０．４２％、Ｐ：０．０１３％、Ｎｉ：０．０１２％、Ｃｒ：０．０１５％、不純物としてＡｌ：０．００３％、Ｓ：０．０１１％、Ｃａ：１８質量ｐｐｍを含み、残部がＦｅであるものを用いた。 (Spring material No. 7)
C: 0.85%, Si: 0.2%, Mn: 0.42%, P: 0.013%, Ni: 0.012%, Cr: 0.015%, Al as impurities: 0.003% , S: 0.011%, Ca: 18 ppm by mass, with the balance being Fe.
（評価試験）
（ばね材料評価試験１ ばね材料の板厚）
上記した各ばね材料は、熱間圧延、冷間圧延及び焼鈍処理されたものであり、特に冷間圧延においては多段圧延機で圧延されたものである。多段圧延機としては、１６ロールの６段センヂミア圧延機を用いた。なお、多段圧延機はこれに限定されず、２０段センヂミア圧延機等に代表される、高い板厚精度で圧延できる各種の圧延機を使用できる。 (Evaluation test)
(Springmaterial evaluation test 1 Spring material plate thickness)
Each of the spring materials described above is subjected to hot rolling, cold rolling and annealing treatment, and in particular, in cold rolling, it is rolled with a multi-stage rolling mill. As the multi-stage rolling mill, a 16-roll 6-stage Sendia mill was used. In addition, a multi-high rolling mill is not limited to this, The various rolling mills which can be rolled with high sheet thickness precision represented by the 20-stage Sendemia rolling mill etc. can be used.
（ばね材料評価試験１ ばね材料の板厚）
上記した各ばね材料は、熱間圧延、冷間圧延及び焼鈍処理されたものであり、特に冷間圧延においては多段圧延機で圧延されたものである。多段圧延機としては、１６ロールの６段センヂミア圧延機を用いた。なお、多段圧延機はこれに限定されず、２０段センヂミア圧延機等に代表される、高い板厚精度で圧延できる各種の圧延機を使用できる。 (Evaluation test)
(Spring
Each of the spring materials described above is subjected to hot rolling, cold rolling and annealing treatment, and in particular, in cold rolling, it is rolled with a multi-stage rolling mill. As the multi-stage rolling mill, a 16-roll 6-stage Sendia mill was used. In addition, a multi-high rolling mill is not limited to this, The various rolling mills which can be rolled with high sheet thickness precision represented by the 20-stage Sendemia rolling mill etc. can be used.
各ばね材料として、上記した冷間圧延により板厚１ｍｍを目標値として製造したものと板厚２ｍｍを目標値として製造したものをそれぞれ１００個ずつ準備し、各ばね材料の板厚を実測した。
その結果、ばね材料Ｎｏ．１～ばね材料Ｎｏ．４及びばね材料Ｎｏ．７の板厚は、板厚１ｍｍを目標値として製造したものについては全て０．９９ｍｍ～１．０１ｍｍの範囲に入り、板厚２ｍｍを目標値として製造したものについては全て板厚２．０１５ｍｍ～１．９８５ｍｍの範囲に入った。
このため、本発明のばね材料であるばね材料Ｎｏ．１～ばね材料Ｎｏ．４及びばね材料Ｎｏ．７に関し、板厚０．１ｍｍ以上１ｍｍ以下を目標値として製造したものについては公差±０．０１の範囲に入り、板厚１ｍｍを超え２ｍｍ以下を目標値として製造したものについては公差±０．０１５の範囲に入ることがわかる。つまり、本発明のばね材料は板厚の精度に優れる。 As each spring material, 100 pieces each prepared by cold rolling as described above with a plate thickness of 1 mm as a target value and 100 mm with a plate thickness of 2 mm as a target value were prepared, and the plate thickness of each spring material was measured.
As a result, the spring material No. 1 to spring material No. 4 and spring material no. The thicknesses of 7 are all in the range of 0.99 mm to 1.01 mm for those manufactured with a target thickness of 1 mm, and all of those manufactured with a target thickness of 2 mm are 2.015 mm to 2.015 mm. It entered the range of 1.985 mm.
For this reason, the spring material No. which is the spring material of the present invention. 1 to spring material No. 4 and spring material no. 7 with a thickness of 0.1 mm or more and 1 mm or less as a target value, the tolerance is within ± 0.01, and for those manufactured with a thickness of more than 1 mm and 2 mm or less as a target value, tolerance ± 0. It can be seen that it falls within the range of 015. That is, the spring material of the present invention is excellent in plate thickness accuracy.
その結果、ばね材料Ｎｏ．１～ばね材料Ｎｏ．４及びばね材料Ｎｏ．７の板厚は、板厚１ｍｍを目標値として製造したものについては全て０．９９ｍｍ～１．０１ｍｍの範囲に入り、板厚２ｍｍを目標値として製造したものについては全て板厚２．０１５ｍｍ～１．９８５ｍｍの範囲に入った。
このため、本発明のばね材料であるばね材料Ｎｏ．１～ばね材料Ｎｏ．４及びばね材料Ｎｏ．７に関し、板厚０．１ｍｍ以上１ｍｍ以下を目標値として製造したものについては公差±０．０１の範囲に入り、板厚１ｍｍを超え２ｍｍ以下を目標値として製造したものについては公差±０．０１５の範囲に入ることがわかる。つまり、本発明のばね材料は板厚の精度に優れる。 As each spring material, 100 pieces each prepared by cold rolling as described above with a plate thickness of 1 mm as a target value and 100 mm with a plate thickness of 2 mm as a target value were prepared, and the plate thickness of each spring material was measured.
As a result, the spring material No. 1 to spring material No. 4 and spring material no. The thicknesses of 7 are all in the range of 0.99 mm to 1.01 mm for those manufactured with a target thickness of 1 mm, and all of those manufactured with a target thickness of 2 mm are 2.015 mm to 2.015 mm. It entered the range of 1.985 mm.
For this reason, the spring material No. which is the spring material of the present invention. 1 to spring material No. 4 and spring material no. 7 with a thickness of 0.1 mm or more and 1 mm or less as a target value, the tolerance is within ± 0.01, and for those manufactured with a thickness of more than 1 mm and 2 mm or less as a target value, tolerance ± 0. It can be seen that it falls within the range of 015. That is, the spring material of the present invention is excellent in plate thickness accuracy.
（ばね）
（ばねＮｏ．１）
板厚２ｍｍのばね材料Ｎｏ．１及び板厚１ｍｍのばね材料Ｎｏ．１にオーステンパ処理を行い、ばねＮｏ．１を製造した。 (Spring)
(Spring No. 1)
Spring material No. 2 mm thick 1 and a spring material No. 1 having a plate thickness of 1 mm. 1 is subjected to austempering treatment, and spring no. 1 was produced.
（ばねＮｏ．１）
板厚２ｍｍのばね材料Ｎｏ．１及び板厚１ｍｍのばね材料Ｎｏ．１にオーステンパ処理を行い、ばねＮｏ．１を製造した。 (Spring)
(Spring No. 1)
Spring material No. 2 mm thick 1 and a spring material No. 1 having a plate thickness of 1 mm. 1 is subjected to austempering treatment, and spring no. 1 was produced.
具体的には、各板厚のばね材料Ｎｏ．１につき、５０ｍｍ角のテストピースを準備した。そして各テストピースについて、オーステナイト化温度８６０℃で２０分間加熱した後に溶融塩中にて冷却時間１秒以内でテンパー温度３５０℃にまで降温し、そのまま２０分間保持するオーステンパ処理を行った。
Specifically, spring material No. One test piece of 50 mm square was prepared. Each test piece was heated at an austenitizing temperature of 860 ° C. for 20 minutes, then cooled to a temper temperature of 350 ° C. within 1 second in a molten salt, and subjected to austempering for 20 minutes.
（ばねＮｏ．２）
ばねＮｏ．１と同様に、板厚２ｍｍのばね材料Ｎｏ．２及び板厚１ｍｍのばね材料Ｎｏ．２につき各々５０ｍｍ角のテストピースを準備し、各テストピースについてオーステナイト化温度８５０℃で２０分間加熱した後に溶融塩中にてテンパー温度３５０℃で２０分間保持するオーステンパ処理を行うことでばねＮｏ．２を製造した。 (Spring No. 2)
Spring No. As in the case of the spring material No. 1 having a plate thickness of 2 mm. 2 and 1 mm thick spring material No. 50 mm square test pieces were prepared for each No. 2, and each test piece was heated at an austenitizing temperature of 850 ° C. for 20 minutes and then subjected to austempering treatment in a molten salt at a temper temperature of 350 ° C. for 20 minutes. 2 was produced.
ばねＮｏ．１と同様に、板厚２ｍｍのばね材料Ｎｏ．２及び板厚１ｍｍのばね材料Ｎｏ．２につき各々５０ｍｍ角のテストピースを準備し、各テストピースについてオーステナイト化温度８５０℃で２０分間加熱した後に溶融塩中にてテンパー温度３５０℃で２０分間保持するオーステンパ処理を行うことでばねＮｏ．２を製造した。 (Spring No. 2)
Spring No. As in the case of the spring material No. 1 having a plate thickness of 2 mm. 2 and 1 mm thick spring material No. 50 mm square test pieces were prepared for each No. 2, and each test piece was heated at an austenitizing temperature of 850 ° C. for 20 minutes and then subjected to austempering treatment in a molten salt at a temper temperature of 350 ° C. for 20 minutes. 2 was produced.
（ばねＮｏ．３）
ばねＮｏ．１と同様に、板厚２ｍｍのばね材料Ｎｏ．３及び板厚１ｍｍのばね材料Ｎｏ．３につき各々５０ｍｍ角のテストピースを準備し、各テストピースについてオーステナイト化温度８４０℃で２０分間加熱した後に溶融塩中にてテンパー温度３５０℃で２０分間保持するオーステンパ処理を行うことでばねＮｏ．３を製造した。 (Spring No. 3)
Spring No. As in the case of the spring material No. 1 having a plate thickness of 2 mm. 3 and 1 mm thick spring material No. 50 mm square test pieces were prepared for each No. 3, and each test piece was heated at an austenitizing temperature of 840 ° C. for 20 minutes and then subjected to austempering treatment in a molten salt at a temper temperature of 350 ° C. for 20 minutes. 3 was produced.
ばねＮｏ．１と同様に、板厚２ｍｍのばね材料Ｎｏ．３及び板厚１ｍｍのばね材料Ｎｏ．３につき各々５０ｍｍ角のテストピースを準備し、各テストピースについてオーステナイト化温度８４０℃で２０分間加熱した後に溶融塩中にてテンパー温度３５０℃で２０分間保持するオーステンパ処理を行うことでばねＮｏ．３を製造した。 (Spring No. 3)
Spring No. As in the case of the spring material No. 1 having a plate thickness of 2 mm. 3 and 1 mm thick spring material No. 50 mm square test pieces were prepared for each No. 3, and each test piece was heated at an austenitizing temperature of 840 ° C. for 20 minutes and then subjected to austempering treatment in a molten salt at a temper temperature of 350 ° C. for 20 minutes. 3 was produced.
（ばねＮｏ．４）
ばねＮｏ．１と同様に、板厚２ｍｍのばね材料Ｎｏ．４及び板厚１ｍｍのばね材料Ｎｏ．４につき各々５０ｍｍ角のテストピースを準備し、各テストピースについてオーステナイト化温度８３０℃で２０分間加熱した後に溶融塩中にてテンパー温度３５０℃で２０分間保持するオーステンパ処理を行うことでばねＮｏ．４を製造した。 (Spring No. 4)
Spring No. Similar to the spring material No. 1 having a plate thickness of 2 mm, as in FIG. 4 and 1 mm thick spring material No. 50 mm square test pieces were prepared for each No. 4, and each test piece was heated at an austenitizing temperature of 830 ° C. for 20 minutes and then subjected to austempering treatment in a molten salt at a temper temperature of 350 ° C. for 20 minutes. 4 was produced.
ばねＮｏ．１と同様に、板厚２ｍｍのばね材料Ｎｏ．４及び板厚１ｍｍのばね材料Ｎｏ．４につき各々５０ｍｍ角のテストピースを準備し、各テストピースについてオーステナイト化温度８３０℃で２０分間加熱した後に溶融塩中にてテンパー温度３５０℃で２０分間保持するオーステンパ処理を行うことでばねＮｏ．４を製造した。 (Spring No. 4)
Spring No. Similar to the spring material No. 1 having a plate thickness of 2 mm, as in FIG. 4 and 1 mm thick spring material No. 50 mm square test pieces were prepared for each No. 4, and each test piece was heated at an austenitizing temperature of 830 ° C. for 20 minutes and then subjected to austempering treatment in a molten salt at a temper temperature of 350 ° C. for 20 minutes. 4 was produced.
（ばねＮｏ．５）
ばねＮｏ．１と同様に、板厚２ｍｍのばね材料Ｎｏ．５及び板厚１ｍｍのばね材料Ｎｏ．５につき各々５０ｍｍ角のテストピースを準備し、各テストピースについてオーステナイト化温度８４０℃で２０分間加熱した後に溶融塩中にてテンパー温度３５０℃で２０分間保持するオーステンパ処理を行うことでばねＮｏ．５を製造した。 (Spring No. 5)
Spring No. As in the case of the spring material No. 1 having a plate thickness of 2 mm. 5 and spring material No. 1 having a plate thickness of 1 mm. 50 mm square test pieces were prepared for each of No. 5 and each test piece was heated at an austenitizing temperature of 840 ° C. for 20 minutes and then subjected to austempering treatment in a molten salt at a temper temperature of 350 ° C. for 20 minutes. 5 was produced.
ばねＮｏ．１と同様に、板厚２ｍｍのばね材料Ｎｏ．５及び板厚１ｍｍのばね材料Ｎｏ．５につき各々５０ｍｍ角のテストピースを準備し、各テストピースについてオーステナイト化温度８４０℃で２０分間加熱した後に溶融塩中にてテンパー温度３５０℃で２０分間保持するオーステンパ処理を行うことでばねＮｏ．５を製造した。 (Spring No. 5)
Spring No. As in the case of the spring material No. 1 having a plate thickness of 2 mm. 5 and spring material No. 1 having a plate thickness of 1 mm. 50 mm square test pieces were prepared for each of No. 5 and each test piece was heated at an austenitizing temperature of 840 ° C. for 20 minutes and then subjected to austempering treatment in a molten salt at a temper temperature of 350 ° C. for 20 minutes. 5 was produced.
（ばねＮｏ．６）
ばねＮｏ．１と同様に、板厚２ｍｍのばね材料Ｎｏ．６及び板厚１ｍｍのばね材料Ｎｏ．６につき各々５０ｍｍ角のテストピースを準備し、各テストピースについてオーステナイト化温度８３０℃で２０分間加熱した後に溶融塩中にてテンパー温度３５０℃で２０分間保持するオーステンパ処理を行うことでばねＮｏ．６を製造した。 (Spring No. 6)
Spring No. As in the case of the spring material No. 1 having a plate thickness of 2 mm. 6 and spring material No. 1 having a plate thickness of 1 mm. A test piece of 50 mm square was prepared for each No. 6, and each test piece was heated at an austenitizing temperature of 830 ° C. for 20 minutes and then subjected to austempering treatment in a molten salt at a temper temperature of 350 ° C. for 20 minutes. 6 was produced.
ばねＮｏ．１と同様に、板厚２ｍｍのばね材料Ｎｏ．６及び板厚１ｍｍのばね材料Ｎｏ．６につき各々５０ｍｍ角のテストピースを準備し、各テストピースについてオーステナイト化温度８３０℃で２０分間加熱した後に溶融塩中にてテンパー温度３５０℃で２０分間保持するオーステンパ処理を行うことでばねＮｏ．６を製造した。 (Spring No. 6)
Spring No. As in the case of the spring material No. 1 having a plate thickness of 2 mm. 6 and spring material No. 1 having a plate thickness of 1 mm. A test piece of 50 mm square was prepared for each No. 6, and each test piece was heated at an austenitizing temperature of 830 ° C. for 20 minutes and then subjected to austempering treatment in a molten salt at a temper temperature of 350 ° C. for 20 minutes. 6 was produced.
（ばねＮｏ．７）
ばねＮｏ．１～ばねＮｏ．６と同様に、板厚２ｍｍのばね材料Ｎｏ．７及び板厚１ｍｍのばね材料Ｎｏ．７につき５０ｍｍ角のテストピースを準備し、各テストピースについて８５０℃で２０分間保持後、油中で１８０℃／秒の冷却速度で冷却を行う焼入れを行い、その後３８０℃で３０分間焼戻しすることでばねＮｏ．７を製造した。 (Spring No. 7)
Spring No. 1 to Spring No. Similar to 6, the spring material No. 2 having a plate thickness of 2 mm is used. 7 and spring material No. 1 having a plate thickness of 1 mm. Prepare test pieces of 50 mm square per 7 and hold each test piece at 850 ° C. for 20 minutes, then quench in oil at a cooling rate of 180 ° C./second, and then temper at 380 ° C. for 30 minutes. Spring No. 7 was produced.
ばねＮｏ．１～ばねＮｏ．６と同様に、板厚２ｍｍのばね材料Ｎｏ．７及び板厚１ｍｍのばね材料Ｎｏ．７につき５０ｍｍ角のテストピースを準備し、各テストピースについて８５０℃で２０分間保持後、油中で１８０℃／秒の冷却速度で冷却を行う焼入れを行い、その後３８０℃で３０分間焼戻しすることでばねＮｏ．７を製造した。 (Spring No. 7)
Spring No. 1 to Spring No. Similar to 6, the spring material No. 2 having a plate thickness of 2 mm is used. 7 and spring material No. 1 having a plate thickness of 1 mm. Prepare test pieces of 50 mm square per 7 and hold each test piece at 850 ° C. for 20 minutes, then quench in oil at a cooling rate of 180 ° C./second, and then temper at 380 ° C. for 30 minutes. Spring No. 7 was produced.
ばねＮｏ．１～ばねＮｏ．７につき、ばね材料の種類及び熱処理の条件を以下の表２に示す
Spring No. 1 to Spring No. Table 2 shows the types of spring materials and heat treatment conditions for 7
（評価試験）
（ばね材料評価試験２ オーステナイト結晶粒度番号の測定）
ばねＮｏ．１～ばねＮｏ．７につき、オーステナイト結晶粒度番号を測定した。測定方法としてはＪＩＳ Ｇ ０５５１に規定される方法を用いた。なお、ばね材料のオーステナイト結晶粒度番号は、ばねのオーステナイト結晶粒度番号で代替可能である。オーステナイト結晶粒度番号の測定結果を上記表１に示す。なお、代表的な本発明のばね材料の断面の電子顕微鏡像を図１に示す。図１に示すばね材料は、ＪＩＳ Ｇ ０５５１ 付属書の徐冷法によってオーステナイト結晶粒の結晶粒界を出現させたものである。具体的には、ばね材料を９００℃で１０分間加熱した後に７５０℃まで徐冷し、その後空冷したものである。図１において線状に白く見える部分が結晶粒界であり、当該結晶粒界で区画された結晶粒の大きさをＪＩＳ Ｇ ０５５１に規定される方法により測定し、算出した結晶粒径は３２．０μｍ程度であり、オーステナイト結晶粒度番号は７．０番であった。 (Evaluation test)
(SpringMaterial Evaluation Test 2 Measurement of austenite grain size number)
Spring No. 1 to Spring No. For 7, the austenite grain size number was measured. As a measuring method, a method defined in JIS G 0551 was used. The austenite grain size number of the spring material can be replaced with the austenite grain size number of the spring. The measurement results of the austenite grain size number are shown in Table 1 above. In addition, the electron microscope image of the cross section of the typical spring material of this invention is shown in FIG. The spring material shown in FIG. 1 is one in which a grain boundary of austenite crystal grains appears by the slow cooling method of JIS G 0551 appendix. Specifically, the spring material is heated at 900 ° C. for 10 minutes, gradually cooled to 750 ° C., and then air-cooled. In FIG. 1, the portion that appears linearly white is a crystal grain boundary, the size of the crystal grain partitioned by the crystal grain boundary is measured by the method defined in JIS G 0551, and the calculated crystal grain size is 32. The austenite grain size number was about 7.0 μm.
（ばね材料評価試験２ オーステナイト結晶粒度番号の測定）
ばねＮｏ．１～ばねＮｏ．７につき、オーステナイト結晶粒度番号を測定した。測定方法としてはＪＩＳ Ｇ ０５５１に規定される方法を用いた。なお、ばね材料のオーステナイト結晶粒度番号は、ばねのオーステナイト結晶粒度番号で代替可能である。オーステナイト結晶粒度番号の測定結果を上記表１に示す。なお、代表的な本発明のばね材料の断面の電子顕微鏡像を図１に示す。図１に示すばね材料は、ＪＩＳ Ｇ ０５５１ 付属書の徐冷法によってオーステナイト結晶粒の結晶粒界を出現させたものである。具体的には、ばね材料を９００℃で１０分間加熱した後に７５０℃まで徐冷し、その後空冷したものである。図１において線状に白く見える部分が結晶粒界であり、当該結晶粒界で区画された結晶粒の大きさをＪＩＳ Ｇ ０５５１に規定される方法により測定し、算出した結晶粒径は３２．０μｍ程度であり、オーステナイト結晶粒度番号は７．０番であった。 (Evaluation test)
(Spring
Spring No. 1 to Spring No. For 7, the austenite grain size number was measured. As a measuring method, a method defined in JIS G 0551 was used. The austenite grain size number of the spring material can be replaced with the austenite grain size number of the spring. The measurement results of the austenite grain size number are shown in Table 1 above. In addition, the electron microscope image of the cross section of the typical spring material of this invention is shown in FIG. The spring material shown in FIG. 1 is one in which a grain boundary of austenite crystal grains appears by the slow cooling method of JIS G 0551 appendix. Specifically, the spring material is heated at 900 ° C. for 10 minutes, gradually cooled to 750 ° C., and then air-cooled. In FIG. 1, the portion that appears linearly white is a crystal grain boundary, the size of the crystal grain partitioned by the crystal grain boundary is measured by the method defined in JIS G 0551, and the calculated crystal grain size is 32. The austenite grain size number was about 7.0 μm.
表１に示すように、ばね材料Ｎｏ．１～ばね材料Ｎｏ．４及びばね材料Ｎｏ．７については、オーステナイト結晶粒が非常に大きく、オーステナイト結晶粒度番号は８番であった。表１に示すように、これらのばね材料の元素組成は本発明のばね材料の元素組成の範囲内である。したがって、ばね材料Ｎｏ．１～ばね材料Ｎｏ．４及びばね材料Ｎｏ．７は本発明のばね材料に相当すると言える。
As shown in Table 1, the spring material No. 1 to spring material No. 4 and spring material no. For No. 7, the austenite grain size was very large and the austenite grain size number was No. 8. As shown in Table 1, the elemental composition of these spring materials is within the range of the elemental composition of the spring material of the present invention. Therefore, the spring material No. 1 to spring material No. 4 and spring material no. 7 can be said to correspond to the spring material of the present invention.
一方、ばね材料Ｎｏ．５及びばね材料Ｎｏ．６については、オーステナイト結晶粒が小さく、オーステナイト結晶粒度番号は１２番又は１２．５番と、何れも１０番以上であった。また、表１に示すように、これらのばね材料の元素組成は本発明のばね材料の元素組成の範囲外であり、特にＡｌ含有量が多い。したがって、ばね材料Ｎｏ．５及びばね材料Ｎｏ．６は本発明のばね材料には相当しないと言える。換言すると、ばね材料Ｎｏ．５及びばね材料Ｎｏ．６は従来のばね材料と言える。
On the other hand, spring material No. 5 and spring material no. For No. 6, the austenite crystal grains were small, and the austenite grain size number was No. 12 or No. 12.5, both of which were No. 10 or more. Further, as shown in Table 1, the elemental composition of these spring materials is outside the range of the elemental composition of the spring material of the present invention, and the Al content is particularly large. Therefore, the spring material No. 5 and spring material no. It can be said that 6 does not correspond to the spring material of the present invention. In other words, the spring material No. 5 and spring material no. 6 can be said to be a conventional spring material.
また、この結果から、ばね材料Ｎｏ．１～Ｎｏ．４及びばね材料Ｎｏ．７のオーステナイト結晶粒は大きいが、ばね材料Ｎｏ．５及びばね材料Ｎｏ．６のオーステナイト結晶粒は微細であることがわかる。
Also, from this result, the spring material No. 1-No. 4 and spring material no. Although the austenite crystal grains of No. 7 are large, the spring material No. 5 and spring material no. It can be seen that the austenite crystal grains of 6 are fine.
（評価試験）
（ばね評価試験１ ばねの硬さ測定）
板厚１ｍｍのばねＮｏ．１～Ｎｏ．７及び板厚２ｍｍのばねＮｏ．１～Ｎｏ．７につき、ＪＩＳ Ｚ ２２４４、ＩＳＯ６５０７－１、ＩＳＯ６５０７－４に基づいてビッカース硬さを測定した。測定位置は、上記５０ｍｍ角のテストピースを上面視した時に中央に位置するＢ点と、同じく上面視した時にテストピースの端面から中央部側に５ｍｍ入った位置のＡ点と、の２点とした。 (Evaluation test)
(Spring evaluation test 1 Spring hardness measurement)
Spring No. 1 mm thick 1-No. 7 and a spring No. 2 having a plate thickness of 2 mm. 1-No. For No. 7, the Vickers hardness was measured based on JIS Z 2244, ISO 6507-1, and ISO 6507-4. The measurement position has two points: a point B located in the center when the 50 mm square test piece is viewed from the top, and a point A located 5 mm from the end face of the test piece to the center when viewed from the top. did.
（ばね評価試験１ ばねの硬さ測定）
板厚１ｍｍのばねＮｏ．１～Ｎｏ．７及び板厚２ｍｍのばねＮｏ．１～Ｎｏ．７につき、ＪＩＳ Ｚ ２２４４、ＩＳＯ６５０７－１、ＩＳＯ６５０７－４に基づいてビッカース硬さを測定した。測定位置は、上記５０ｍｍ角のテストピースを上面視した時に中央に位置するＢ点と、同じく上面視した時にテストピースの端面から中央部側に５ｍｍ入った位置のＡ点と、の２点とした。 (Evaluation test)
(
Spring No. 1 mm thick 1-No. 7 and a spring No. 2 having a plate thickness of 2 mm. 1-No. For No. 7, the Vickers hardness was measured based on JIS Z 2244, ISO 6507-1, and ISO 6507-4. The measurement position has two points: a point B located in the center when the 50 mm square test piece is viewed from the top, and a point A located 5 mm from the end face of the test piece to the center when viewed from the top. did.
ばねＮｏ．１、ばねＮｏ．２、ばねＮｏ．４、ばねＮｏ．６及びばねＮｏ．７については、板厚１ｍｍ及び板厚２ｍｍの各ばねのビッカース硬さを、上記Ａ点における板厚方向の中央位置、及び、上記Ｂ点における板厚方向の中央位置の２点でそれぞれ一度ずつ測定した。つまり、Ａ点を通る位置で各テストピースを切断し、その断面における板厚方向の中央位置のビッカース硬さを各々測定した。また、Ｂ点を通る位置で各テストピースを切断し、その断面における板厚方向の中央位置のビッカース硬さを各々測定した。
ばねＮｏ．３及びばねＮｏ．５については、測定位置Ａ点、Ｂ点の各々につき、板厚方向における複数の位置のビッカース硬さを測定した。詳しくは、上記と同様に各テストピースを切断し、一方の表面からの板厚方向の距離が０．０２ｍｍ、０．０５ｍｍ、０．１ｍｍ、０．１５ｍｍ、０．２ｍｍ、０．３ｍｍ、０．５ｍｍ、０．６ｍｍ、１ｍｍ、１．４ｍｍ、１．５ｍｍ、１．７ｍｍ、１．８ｍｍ、１．８５ｍｍ、１．９ｍｍ、１．９５ｍｍ及び１．９８ｍｍとなる各点のビッカース硬さを各々測定した。
ばねの硬さ測定の測定結果を後述する他の機械的特性とともに表３に示す。
更に、ばねＮｏ．３及びばねＮｏ．５については、板厚１ｍｍのテストピース、板厚２ｍｍのテストピースの各々につき、測定位置Ａ点と測定位置Ｂ点とに場合分けして、上記一方の表面からの板厚方向の距離とビッカース硬さとの関係を評価した。各テストピースにおける一方の表面からの板厚方向の距離とビッカース硬さとの関係を表すグラフを、図２～図５に示す。なお、図２は板厚２ｍｍのばねＮｏ．３についてのグラフであり、図３は板厚２ｍｍのばねＮｏ．５についてのグラフであり、図４は板厚１ｍｍのばねＮｏ．３についてのグラフであり、図５は板厚１ｍｍのばねＮｏ．５についてのグラフである。 Spring No. 1, spring no. 2. Spring No. 4. Spring No. 6 and spring no. 7, the Vickers hardness of each spring having a plate thickness of 1 mm and a plate thickness of 2 mm is measured once at each of the two points of the center position in the plate thickness direction at point A and the center position in the plate thickness direction at point B. It was measured. That is, each test piece was cut at a position passing through point A, and the Vickers hardness at the center position in the thickness direction in the cross section was measured. Moreover, each test piece was cut | disconnected in the position which passes B point, and the Vickers hardness of the center position of the thickness direction in the cross section was measured, respectively.
Spring No. 3 and spring no. For 5, the Vickers hardness at a plurality of positions in the plate thickness direction was measured for each of the measurement positions A and B. Specifically, each test piece is cut in the same manner as described above, and the distance in the thickness direction from one surface is 0.02 mm, 0.05 mm, 0.1 mm, 0.15 mm, 0.2 mm, 0.3 mm, 0 Vickers hardness at each point of 0.5 mm, 0.6 mm, 1 mm, 1.4 mm, 1.5 mm, 1.7 mm, 1.8 mm, 1.85 mm, 1.9 mm, 1.95 mm and 1.98 mm It was measured.
Table 3 shows the measurement results of the spring hardness measurement together with other mechanical characteristics described later.
Furthermore, the spring No. 3 and spring no. 5 for each of a test piece with a plate thickness of 1 mm and a test piece with a plate thickness of 2 mm, divided into a measurement position A point and a measurement position B point, and the distance in the plate thickness direction from the one surface and the Vickers The relationship with hardness was evaluated. Graphs showing the relationship between the distance in the thickness direction from one surface of each test piece and the Vickers hardness are shown in FIGS. 2 shows a spring No. 2 having a plate thickness of 2 mm. 3 is a graph for the spring No. 2 having a plate thickness of 2 mm. 5 is a graph for the spring No. 1 having a plate thickness of 1 mm. 3 is a graph for the spring No. 1 having a plate thickness of 1 mm. 5 is a graph for 5.
ばねＮｏ．３及びばねＮｏ．５については、測定位置Ａ点、Ｂ点の各々につき、板厚方向における複数の位置のビッカース硬さを測定した。詳しくは、上記と同様に各テストピースを切断し、一方の表面からの板厚方向の距離が０．０２ｍｍ、０．０５ｍｍ、０．１ｍｍ、０．１５ｍｍ、０．２ｍｍ、０．３ｍｍ、０．５ｍｍ、０．６ｍｍ、１ｍｍ、１．４ｍｍ、１．５ｍｍ、１．７ｍｍ、１．８ｍｍ、１．８５ｍｍ、１．９ｍｍ、１．９５ｍｍ及び１．９８ｍｍとなる各点のビッカース硬さを各々測定した。
ばねの硬さ測定の測定結果を後述する他の機械的特性とともに表３に示す。
更に、ばねＮｏ．３及びばねＮｏ．５については、板厚１ｍｍのテストピース、板厚２ｍｍのテストピースの各々につき、測定位置Ａ点と測定位置Ｂ点とに場合分けして、上記一方の表面からの板厚方向の距離とビッカース硬さとの関係を評価した。各テストピースにおける一方の表面からの板厚方向の距離とビッカース硬さとの関係を表すグラフを、図２～図５に示す。なお、図２は板厚２ｍｍのばねＮｏ．３についてのグラフであり、図３は板厚２ｍｍのばねＮｏ．５についてのグラフであり、図４は板厚１ｍｍのばねＮｏ．３についてのグラフであり、図５は板厚１ｍｍのばねＮｏ．５についてのグラフである。 Spring No. 1, spring no. 2. Spring No. 4. Spring No. 6 and spring no. 7, the Vickers hardness of each spring having a plate thickness of 1 mm and a plate thickness of 2 mm is measured once at each of the two points of the center position in the plate thickness direction at point A and the center position in the plate thickness direction at point B. It was measured. That is, each test piece was cut at a position passing through point A, and the Vickers hardness at the center position in the thickness direction in the cross section was measured. Moreover, each test piece was cut | disconnected in the position which passes B point, and the Vickers hardness of the center position of the thickness direction in the cross section was measured, respectively.
Spring No. 3 and spring no. For 5, the Vickers hardness at a plurality of positions in the plate thickness direction was measured for each of the measurement positions A and B. Specifically, each test piece is cut in the same manner as described above, and the distance in the thickness direction from one surface is 0.02 mm, 0.05 mm, 0.1 mm, 0.15 mm, 0.2 mm, 0.3 mm, 0 Vickers hardness at each point of 0.5 mm, 0.6 mm, 1 mm, 1.4 mm, 1.5 mm, 1.7 mm, 1.8 mm, 1.85 mm, 1.9 mm, 1.95 mm and 1.98 mm It was measured.
Table 3 shows the measurement results of the spring hardness measurement together with other mechanical characteristics described later.
Furthermore, the spring No. 3 and spring no. 5 for each of a test piece with a plate thickness of 1 mm and a test piece with a plate thickness of 2 mm, divided into a measurement position A point and a measurement position B point, and the distance in the plate thickness direction from the one surface and the Vickers The relationship with hardness was evaluated. Graphs showing the relationship between the distance in the thickness direction from one surface of each test piece and the Vickers hardness are shown in FIGS. 2 shows a spring No. 2 having a plate thickness of 2 mm. 3 is a graph for the spring No. 2 having a plate thickness of 2 mm. 5 is a graph for the spring No. 1 having a plate thickness of 1 mm. 3 is a graph for the spring No. 1 having a plate thickness of 1 mm. 5 is a graph for 5.
表３に示すように、板厚２ｍｍのばねＮｏ．５及びばねＮｏ．６は端部であるＡ点のビッカース硬さに対して中央部であるＢ点のビッカース硬さが非常に小さい。つまり、板厚２ｍｍのばねＮｏ．５及びばねＮｏ．６においては、ばねの中央部が好適にベイナイト変態していないと考えられる。これは、上記したようにばね材料Ｎｏ．５及びばね材料Ｎｏ．６のオーステナイト結晶粒が微細であることに由来すると考えられる。
As shown in Table 3, spring No. 2 mm thick. 5 and spring no. No. 6 has a very small Vickers hardness at the B point, which is the center, compared to the Vickers hardness at the A point, which is the end. That is, the spring No. 2 having a plate thickness of 2 mm. 5 and spring no. In No. 6, it is considered that the central portion of the spring is not suitably transformed into bainite. As described above, this is because the spring material No. 5 and spring material no. This is considered to be derived from the fact that the 6 austenite crystal grains are fine.
これに対して、ばねＮｏ．１～Ｎｏ．４では板厚及び測定位置を問わず、ビッカース硬さが４００Ｈｖ以上である。つまり、本発明のばね材料を用いたばねＮｏ．１～Ｎｏ．４は何れも好適にベイナイト変態していると考えられる。これは、上記したようにばね材料Ｎｏ．１～Ｎｏ．４のオーステナイト結晶粒が大きいことに由来すると考えられる。
On the other hand, spring No. 1-No. In 4, the Vickers hardness is 400 Hv or more regardless of the plate thickness and the measurement position. That is, the spring No. using the spring material of the present invention. 1-No. All of 4 are considered to be suitably transformed into bainite. As described above, this is because the spring material No. 1-No. This is considered to be derived from the fact that the austenite crystal grains of No. 4 are large.
つまり、オーステナイト結晶粒度番号１０番未満の本発明のばね材料を用いると、オーステンパ処理を好適に行うことができ、硬さに優れるばねを製造できると言える。なお、本発明のばね材料におけるオーステナイト結晶粒は、大きい方が良い。したがって、本発明のばね材料のオーステナイト結晶粒度番号は、小さい方が良く、具体的には、オーステナイト結晶粒度番号９番以下であるのが好ましく、９番未満であるのがより好ましく、８番以下であるのが更に好ましい。
That is, when the spring material of the present invention having an austenite grain size number of less than 10 is used, it can be said that an austempering treatment can be suitably performed and a spring having excellent hardness can be manufactured. The larger austenite crystal grains in the spring material of the present invention are better. Therefore, the austenite grain size number of the spring material of the present invention should be small, specifically, preferably austenite grain size number 9 or less, more preferably less than 9 and more preferably 8 or less. More preferably.
なお、図４及び図５に示すように、板厚１ｍｍのばね材料を用いたばねにおいては、Ａ点及びＢ点を含むばねの板幅方向の全域でビッカース硬さが４００Ｈｖ以上であり、かつ、図中横軸で示されるばねの板厚方向の全域でもビッカース硬さが４００Ｈｖ以上である。これに対して、図２及び図３に示すように、板厚２ｍｍのばね材料を用いたばねにおいては、本発明のばね材料Ｎｏ．３を用いたばねＮｏ．３では板幅方向及び板厚方向の全域でビッカース硬さが４００Ｈｖ以上であるのに比べて、従来のばね材料Ｎｏ．５を用いたばねＮｏ．５では板幅方向及び板厚方向の中央部においてビッカース硬さが４００Ｈｖに満たない。
As shown in FIGS. 4 and 5, in the spring using a spring material having a plate thickness of 1 mm, the Vickers hardness is 400 Hv or more in the entire region in the plate width direction of the spring including the points A and B, and The Vickers hardness is 400 Hv or more even in the entire region in the plate thickness direction of the spring indicated by the horizontal axis in the figure. On the other hand, as shown in FIGS. 2 and 3, in the spring using the spring material having a plate thickness of 2 mm, the spring material No. 1 of the present invention is used. Spring No. 3 using 3 has a Vickers hardness of 400 Hv or more in the entire region in the plate width direction and the plate thickness direction, compared with the conventional spring material No. Spring No. 5 using In No. 5, the Vickers hardness is less than 400 Hv at the center in the plate width direction and the plate thickness direction.
つまり、オーステナイト結晶粒度番号が１０番以上であるばね材料を用いると、オーステンパ処理を好適に行うことができず、硬さに優れるばねを製造できると言い難い。
That is, if a spring material having an austenite grain size number of 10 or more is used, it is difficult to say that an austempering treatment cannot be suitably performed and a spring having excellent hardness can be manufactured.
（ばね評価試験２ ばねの組織観察）
ばねＮｏ．１～Ｎｏ．６につき、断面の電子顕微鏡像を撮像して、その組織が如何なるものであるか観察した。その結果、ばねＮｏ．１～Ｎｏ．６の組織はベイナイト組織であることが確認された。板厚２ｍｍのばねＮｏ．３のＢ点の表面から板厚方向に１ｍｍ離れた位置における電子顕微鏡像を図６に示す。また、板厚２ｍｍのばねＮｏ．５のＢ点の表面から板厚方向に１ｍｍ離れた位置での電子顕微鏡像を図７に示す。ベイナイト組織は、図６及び図７に示すように、略針状の構造体を有する。ここで言う針状とは、長針状、短針状を問わず、更に、棒状、リボン状、繊維状等の長細い形状全般を含む概念である。 (Spring evaluation test 2 Spring structure observation)
Spring No. 1-No. For No. 6, an electron microscope image of the cross section was taken and the structure was observed. As a result, the spring No. 1-No. It was confirmed that the structure of 6 was a bainite structure. Spring No. 2 mm thick FIG. 6 shows an electron microscopic image at aposition 1 mm away from the surface of point B in the thickness direction. In addition, a spring No. 2 having a plate thickness of 2 mm is used. FIG. 7 shows an electron microscope image at a position 1 mm away from the surface of point B in the thickness direction. The bainite structure has a substantially needle-like structure as shown in FIGS. The needle shape here is a concept including all long and thin shapes such as a rod shape, a ribbon shape, and a fiber shape, regardless of a long needle shape or a short needle shape.
ばねＮｏ．１～Ｎｏ．６につき、断面の電子顕微鏡像を撮像して、その組織が如何なるものであるか観察した。その結果、ばねＮｏ．１～Ｎｏ．６の組織はベイナイト組織であることが確認された。板厚２ｍｍのばねＮｏ．３のＢ点の表面から板厚方向に１ｍｍ離れた位置における電子顕微鏡像を図６に示す。また、板厚２ｍｍのばねＮｏ．５のＢ点の表面から板厚方向に１ｍｍ離れた位置での電子顕微鏡像を図７に示す。ベイナイト組織は、図６及び図７に示すように、略針状の構造体を有する。ここで言う針状とは、長針状、短針状を問わず、更に、棒状、リボン状、繊維状等の長細い形状全般を含む概念である。 (
Spring No. 1-No. For No. 6, an electron microscope image of the cross section was taken and the structure was observed. As a result, the spring No. 1-No. It was confirmed that the structure of 6 was a bainite structure. Spring No. 2 mm thick FIG. 6 shows an electron microscopic image at a
ベイナイトは、フェライト相とセメンタイト相とが混在してなるとされ、本発明においては上記の針状の構造体を有するものをベイナイトとみなす。より具体的には、（１）炭素鋼の電子顕微鏡像において確認される最大長さ１μｍ以上の針状の構造体を有し、（２）当該針状の構造体に外接する長方形の長辺の長さと、当該長方形の短辺の長さとの関係において、長辺の長さが短辺の長さの３倍以上であるものを、本発明におけるベイナイトと規定する。また、「ベイナイト組織を有する」とは、顕微鏡像に１００μｍ角の任意の正方形の領域をとり、当該領域中に上記に特定された針状の構造体が１０以上確認される場合を、「ベイナイト組織を有する」とし、当該領域中に当該針状の構造体が確認されない場合、及び、確認された当該針状の構造体が９以下である場合を「ベイナイト組織を有さない」と規定する。
ばねＮｏ．１～Ｎｏ．６は何れもベイナイト組織を有している。 A bainite is said to be a mixture of a ferrite phase and a cementite phase, and in the present invention, those having the above-mentioned acicular structure are regarded as bainite. More specifically, (1) a needle-like structure having a maximum length of 1 μm or more confirmed in an electron microscope image of carbon steel, and (2) a rectangular long side circumscribing the needle-like structure And the length of the short side of the rectangle is defined as bainite in the present invention in which the length of the long side is at least three times the length of the short side. Further, “having a bainite structure” refers to a case where an arbitrary square region of 100 μm square is taken in a microscopic image and 10 or more of the needle-like structures specified above are confirmed in the region. `` Having a structure '', and the case where the acicular structure is not confirmed in the region and the confirmed acicular structure is 9 or less is defined as “having no bainite structure” .
Spring No. 1-No. 6 has a bainite structure.
ばねＮｏ．１～Ｎｏ．６は何れもベイナイト組織を有している。 A bainite is said to be a mixture of a ferrite phase and a cementite phase, and in the present invention, those having the above-mentioned acicular structure are regarded as bainite. More specifically, (1) a needle-like structure having a maximum length of 1 μm or more confirmed in an electron microscope image of carbon steel, and (2) a rectangular long side circumscribing the needle-like structure And the length of the short side of the rectangle is defined as bainite in the present invention in which the length of the long side is at least three times the length of the short side. Further, “having a bainite structure” refers to a case where an arbitrary square region of 100 μm square is taken in a microscopic image and 10 or more of the needle-like structures specified above are confirmed in the region. `` Having a structure '', and the case where the acicular structure is not confirmed in the region and the confirmed acicular structure is 9 or less is defined as “having no bainite structure” .
Spring No. 1-No. 6 has a bainite structure.
ばねＮｏ．１～Ｎｏ．７はその材料であるばね材料Ｎｏ．１～Ｎｏ．７と同じ元素組成であり、ばねＮｏ．１～Ｎｏ．４については「質量％で、Ｃ：０．４％以上０．９％以下、Ｓｉ：０．１％以上０．３５％以下、Ｍｎ：０％を超え１％以下、Ｐ：０％を超え０．０３％以下、Ｎｉ：０％を超え０．２５％以下、Ｃｒ：０％を超え０．３％以下を含有し、残部がＦｅ及び不純物からなり、前記不純物のうちＡｌ：０．００５％以下である」という本発明のばねの元素組成に適合する。また、上記したように、ばねＮｏ．１～Ｎｏ．４はベイナイト組織を有し、ビッカース硬さが４００Ｈｖ以上である。したがって、ばねＮｏ．１～Ｎｏ．４は本発明のばねであると言える。
Spring No. 1-No. 7 is a spring material No. 7 as the material. 1-No. 7 with the same elemental composition as the spring no. 1-No. 4 is “mass%, C: 0.4% or more and 0.9% or less, Si: 0.1% or more and 0.35% or less, Mn: more than 0% and less than 1%, P: more than 0% 0.03% or less, Ni: more than 0% and not more than 0.25%, Cr: more than 0% and not more than 0.3%, with the balance being Fe and impurities, of which Al: 0.005 It is suitable for the elemental composition of the spring of the present invention. As described above, the spring No. 1-No. 4 has a bainite structure and a Vickers hardness of 400 Hv or more. Therefore, the spring No. 1-No. 4 can be said to be a spring of the present invention.
また、ばねＮｏ．５及びばねＮｏ．６については、その元素組成が本発明のばねで規定する元素組成と異なり、ビッカース硬さもまた本発明のばねで規定する範囲外である。このため、ばねＮｏ．５及びばねＮｏ．６は本発明のばねでないと言える。ばねＮｏ．５及びばねＮｏ．６は従来のばね材料を用いた従来品のばねと言うこともできる。更に、ばねＮｏ．７については、元素組成及びビッカース硬さにおいて本発明のばねと同程度であるが、ベイナイトを有さないために、本発明のばねでないと言える。更に、ばねＮｏ．７が、後述するばねの引張強さ、０．２％耐力、伸び及び疲労限度においても、本発明のばね
Ｎｏ．１～Ｎｏ．４を大きく下回る。このことによっても、ばねＮｏ．７が本発明のばねと大きく異なることが裏付けられる。 In addition, spring No. 5 and spring no. For element 6, the elemental composition differs from the elemental composition defined by the spring of the present invention, and the Vickers hardness is also outside the range defined by the spring of the present invention. For this reason, the spring No. 5 and spring no. It can be said that 6 is not the spring of the present invention. Spring No. 5 and spring no. 6 can also be said to be a conventional spring using a conventional spring material. Furthermore, the spring No. 7 is similar to the spring of the present invention in elemental composition and Vickers hardness, but is not a spring of the present invention because it does not have bainite. Furthermore, the spring No. 7 is the spring No. 7 of the present invention even in the tensile strength, 0.2% proof stress, elongation and fatigue limit of the spring described later. 1-No. 4 is significantly below. As a result, the spring No. It is confirmed that 7 differs greatly from the spring of the present invention.
Ｎｏ．１～Ｎｏ．４を大きく下回る。このことによっても、ばねＮｏ．７が本発明のばねと大きく異なることが裏付けられる。 In addition, spring No. 5 and spring no. For element 6, the elemental composition differs from the elemental composition defined by the spring of the present invention, and the Vickers hardness is also outside the range defined by the spring of the present invention. For this reason, the spring No. 5 and spring no. It can be said that 6 is not the spring of the present invention. Spring No. 5 and spring no. 6 can also be said to be a conventional spring using a conventional spring material. Furthermore, the spring No. 7 is similar to the spring of the present invention in elemental composition and Vickers hardness, but is not a spring of the present invention because it does not have bainite. Furthermore, the spring No. 7 is the spring No. 7 of the present invention even in the tensile strength, 0.2% proof stress, elongation and fatigue limit of the spring described later. 1-No. 4 is significantly below. As a result, the spring No. It is confirmed that 7 differs greatly from the spring of the present invention.
（ばね評価試験３ ばねのその他の機械的特性）
板厚１ｍｍかつ１０ｍｍ×１００ｍｍのばねＮｏ．１～Ｎｏ．７につき、ＪＩＳ Ｚ ２２７５に基づいてばねの機械的特性を測定した。具体的な測定項目は、ばねの引張強さ、０．２％耐力、伸び、及び、疲労限度である。疲労限度は板ばね曲げ疲労試験機を使用し、その他の試験条件は、ヤング率２０６．０００ＭＰａ、振り角５°、負荷応力４００～１３５０ＭＰａ、打ち切り回数１×１０７回であった。結果を上記の表３に示す。また、ばねＮｏ．３及びばねＮｏ．５については疲労限度を算出する際に用いたＳ－Ｎ線図を図８に示す。 (Spring evaluation test 3 Other mechanical properties of the spring)
Spring No. with a plate thickness of 1 mm and 10 mm × 100 mm. 1-No. 7, the mechanical properties of the spring were measured based on JIS Z 2275. Specific measurement items are the tensile strength, 0.2% proof stress, elongation, and fatigue limit of the spring. The fatigue limit was a leaf spring bending fatigue tester, and other test conditions were Young's modulus of 206.000 MPa, swing angle of 5 °, load stress of 400 to 1350 MPa, and number of censoring times of 1 × 10 7 times. The results are shown in Table 3 above. In addition, spring No. 3 and spring no. As for No. 5, the SN diagram used for calculating the fatigue limit is shown in FIG.
板厚１ｍｍかつ１０ｍｍ×１００ｍｍのばねＮｏ．１～Ｎｏ．７につき、ＪＩＳ Ｚ ２２７５に基づいてばねの機械的特性を測定した。具体的な測定項目は、ばねの引張強さ、０．２％耐力、伸び、及び、疲労限度である。疲労限度は板ばね曲げ疲労試験機を使用し、その他の試験条件は、ヤング率２０６．０００ＭＰａ、振り角５°、負荷応力４００～１３５０ＭＰａ、打ち切り回数１×１０７回であった。結果を上記の表３に示す。また、ばねＮｏ．３及びばねＮｏ．５については疲労限度を算出する際に用いたＳ－Ｎ線図を図８に示す。 (
Spring No. with a plate thickness of 1 mm and 10 mm × 100 mm. 1-No. 7, the mechanical properties of the spring were measured based on JIS Z 2275. Specific measurement items are the tensile strength, 0.2% proof stress, elongation, and fatigue limit of the spring. The fatigue limit was a leaf spring bending fatigue tester, and other test conditions were Young's modulus of 206.000 MPa, swing angle of 5 °, load stress of 400 to 1350 MPa, and number of censoring times of 1 × 10 7 times. The results are shown in Table 3 above. In addition, spring No. 3 and spring no. As for No. 5, the SN diagram used for calculating the fatigue limit is shown in FIG.
表３に示すように、本発明のばねＮｏ．１～Ｎｏ．４は、ばねの引張強さ、０．２％耐力、伸び、疲労限度の何れにおいても優れた機械的特性を有する。
As shown in Table 3, the spring no. 1-No. No. 4 has excellent mechanical properties in any of the tensile strength, 0.2% proof stress, elongation and fatigue limit of the spring.
なお、本発明のばね材料を焼入れ及び焼戻ししたばねＮｏ．７については、本発明のばね材料にオーステンパ処理を行ったばねＮｏ．１～Ｎｏ．４と同程度の硬さであったものの、その他の機械的特性についてはオーステンパ処理によって得られたばねＮｏ．１～Ｎｏ．６を大きく下回る結果であった。このことによっても、ばねＮｏ．７が本発明のばねと大きく異なることが裏付けられる。
In addition, the spring No. obtained by quenching and tempering the spring material of the present invention. No. 7, the spring No. 7 was obtained by subjecting the spring material of the present invention to austempering treatment. 1-No. Although the hardness was about the same as that of the spring No. 4, the other mechanical characteristics of the spring No. 4 obtained by the austempering treatment were used. 1-No. The result was much lower than 6. As a result, the spring No. It is confirmed that 7 differs greatly from the spring of the present invention.
さらに、表３に示すばねの機械的特性を考慮すると、本発明のばねは、引張強さが１４００Ｎ／ｍｍ２以上、０．２％耐力が１３００Ｎ／ｍｍ２以上、伸びが６％以上、１～１０７回まで繰り返し負荷を加えた時にみられる疲労限度が３９０ＭＰａ以上、の何れかを満足するのが良いと言える。また、これらの複数を満足するのがより好ましく、全てを満たすのが特に好ましいと言える。
図８のＳ－Ｎ線図に示されるように、本発明のばねＮｏ．３と、従来品のばねＮｏ．５との耐久性を比較すると、ばねＮｏ．３はばねＮｏ．５に比べて応力振幅が大きく、サイクル経過に伴う応力振幅の低下も少なく、更に疲労限度が大きい。つまり、本発明のばねＮｏ．３は従来品のばねＮｏ．５に比べて耐疲労特性に優れるといえる。 Furthermore, in view of the mechanical properties of the spring shown in Table 3, the spring of the present invention has a tensile strength of 1400 N / mm 2 or more, a 0.2% proof stress 1300 N / mm 2 or more, elongation of 6% or more, 1 It can be said that it is preferable that the fatigue limit observed when a load is repeatedly applied up to 10 7 times satisfies 390 MPa or more. Moreover, it is more preferable to satisfy these pluralities, and it is particularly preferable to satisfy all of them.
As shown in the SN diagram of FIG. 3 and the conventional spring No. 3 When comparing the durability with the spring No. 5, 3 is a spring no. Compared to 5, the stress amplitude is large, the decrease of the stress amplitude with the progress of the cycle is small, and the fatigue limit is large. That is, the spring No. of the present invention. 3 is a conventional spring No. 3. Compared to 5, it can be said to be excellent in fatigue resistance.
図８のＳ－Ｎ線図に示されるように、本発明のばねＮｏ．３と、従来品のばねＮｏ．５との耐久性を比較すると、ばねＮｏ．３はばねＮｏ．５に比べて応力振幅が大きく、サイクル経過に伴う応力振幅の低下も少なく、更に疲労限度が大きい。つまり、本発明のばねＮｏ．３は従来品のばねＮｏ．５に比べて耐疲労特性に優れるといえる。 Furthermore, in view of the mechanical properties of the spring shown in Table 3, the spring of the present invention has a tensile strength of 1400 N / mm 2 or more, a 0.2% proof stress 1300 N / mm 2 or more, elongation of 6% or more, 1 It can be said that it is preferable that the fatigue limit observed when a load is repeatedly applied up to 10 7 times satisfies 390 MPa or more. Moreover, it is more preferable to satisfy these pluralities, and it is particularly preferable to satisfy all of them.
As shown in the SN diagram of FIG. 3 and the conventional spring No. 3 When comparing the durability with the spring No. 5, 3 is a spring no. Compared to 5, the stress amplitude is large, the decrease of the stress amplitude with the progress of the cycle is small, and the fatigue limit is large. That is, the spring No. of the present invention. 3 is a conventional spring No. 3. Compared to 5, it can be said to be excellent in fatigue resistance.
（ばね評価試験４ ばねの破面観察）
電子顕微鏡により、疲労破壊したばねＮｏ．３及びばねＮｏ．５の破面を観察した。その結果、従来品のばねＮｏ．５の内部には高硬度介在物である粒状のＡｌ２Ｏ３が生成しており、当該介在物を起点としてばねの内部から破壊が生じていることが確認された。また、本発明のばねＮｏ．３には破壊の起点付近にこの種の介在物は存在せず、ばねの表面から破壊が生じていることが確認された。この結果から、脱酸剤として用いたＡｌを多く含む従来品のばねＮｏ．５に比べ、脱酸剤としてＡｌを用いなかった本発明のばねＮｏ．３は、破壊の起点となる介在物が少なく、その結果、耐疲労特性に優れると推測される。 (Spring evaluation test 4 Spring fracture surface observation)
Using an electron microscope, the spring No. 3 and spring no. A fracture surface of 5 was observed. As a result, the conventional spring No. It was confirmed that granular Al 2 O 3 , which is a high-hardness inclusion, was generated inside 5, and breakage occurred from the inside of the spring starting from the inclusion. In addition, the spring No. of the present invention. In No. 3, there was no inclusion of this kind near the starting point of the fracture, and it was confirmed that the fracture occurred from the surface of the spring. From this result, the conventional spring No. 1 containing a large amount of Al used as a deoxidizer was obtained. Compared to 5, the spring No. 5 of the present invention in which Al was not used as a deoxidizer. No. 3 has few inclusions as a starting point of fracture, and as a result, is presumed to have excellent fatigue resistance.
電子顕微鏡により、疲労破壊したばねＮｏ．３及びばねＮｏ．５の破面を観察した。その結果、従来品のばねＮｏ．５の内部には高硬度介在物である粒状のＡｌ２Ｏ３が生成しており、当該介在物を起点としてばねの内部から破壊が生じていることが確認された。また、本発明のばねＮｏ．３には破壊の起点付近にこの種の介在物は存在せず、ばねの表面から破壊が生じていることが確認された。この結果から、脱酸剤として用いたＡｌを多く含む従来品のばねＮｏ．５に比べ、脱酸剤としてＡｌを用いなかった本発明のばねＮｏ．３は、破壊の起点となる介在物が少なく、その結果、耐疲労特性に優れると推測される。 (Spring evaluation test 4 Spring fracture surface observation)
Using an electron microscope, the spring No. 3 and spring no. A fracture surface of 5 was observed. As a result, the conventional spring No. It was confirmed that granular Al 2 O 3 , which is a high-hardness inclusion, was generated inside 5, and breakage occurred from the inside of the spring starting from the inclusion. In addition, the spring No. of the present invention. In No. 3, there was no inclusion of this kind near the starting point of the fracture, and it was confirmed that the fracture occurred from the surface of the spring. From this result, the conventional spring No. 1 containing a large amount of Al used as a deoxidizer was obtained. Compared to 5, the spring No. 5 of the present invention in which Al was not used as a deoxidizer. No. 3 has few inclusions as a starting point of fracture, and as a result, is presumed to have excellent fatigue resistance.
（ばねの実施例）
以下、上記したばねＮｏ．１～Ｎｏ．４の何れかに所定形状を付与して製造し得る、実施例のホースクランプ、皿ばね、トレランスリングについて図示する。 (Example of spring)
Hereinafter, the spring No. described above is used. 1-No. 4 shows a hose clamp, a disc spring, and a tolerance ring of an embodiment that can be manufactured by giving a predetermined shape to any one of the four.
以下、上記したばねＮｏ．１～Ｎｏ．４の何れかに所定形状を付与して製造し得る、実施例のホースクランプ、皿ばね、トレランスリングについて図示する。 (Example of spring)
Hereinafter, the spring No. described above is used. 1-No. 4 shows a hose clamp, a disc spring, and a tolerance ring of an embodiment that can be manufactured by giving a predetermined shape to any one of the four.
図９に示す実施例のホースクランプ、図１０に示す実施例の皿ばね、及び、図１１に示す実施例のトレランスリングは、何れも、上記の本発明のばね材料の何れかをプレス成形しその後オーステンパ処理することで製造できる。
The hose clamp of the embodiment shown in FIG. 9, the disc spring of the embodiment shown in FIG. 10, and the tolerance ring of the embodiment shown in FIG. 11 are all formed by press-molding any of the spring materials of the present invention described above. Thereafter, it can be manufactured by austempering.
図９は実施例のホースクランプを模式的に表す斜視図であり、図１０は実施例の皿ばねを模式的に表す斜視図であり、図１１は実施例のトレランスリングを模式的に表す斜視図である。
FIG. 9 is a perspective view schematically showing the hose clamp of the embodiment, FIG. 10 is a perspective view schematically showing the disc spring of the embodiment, and FIG. 11 is a perspective view schematically showing the tolerance ring of the embodiment. FIG.
Claims (8)
- 質量％で、Ｃ：０．４％以上０．９％以下、Ｓｉ：０．１％以上０．３５％以下、Ｍｎ：０％を超え１％以下、Ｐ：０％を超え０．０３％以下、Ｎｉ：０％を超え０．２５％以下、Ｃｒ：０％を超え０．３％以下を含有し、残部がＦｅ及び不純物からなり、前記不純物のうちＡｌ：０．００５％以下であり、
オーステナイト結晶粒度番号が１０番未満である、ばね材料。 In mass%, C: 0.4% to 0.9%, Si: 0.1% to 0.35%, Mn: more than 0% and 1% or less, P: more than 0% and 0.03% Hereinafter, Ni: more than 0% and not more than 0.25%, Cr: more than 0% and not more than 0.3%, with the balance being Fe and impurities, and among the impurities, Al: not more than 0.005% ,
A spring material having an austenite grain size number of less than 10. - 前記不純物のうちＣａ：１０質量ｐｐｍ以上５０質量ｐｐｍ以下である、請求項１に記載のばね材料。 The spring material according to claim 1, wherein, of the impurities, Ca: 10 mass ppm or more and 50 mass ppm or less.
- 前記不純物のうちＡｌ：０．００３％以下である、請求項１又は請求項２に記載のばね材料。 The spring material according to claim 1 or 2, wherein Al: 0.003% or less of the impurities.
- 前記ばね材料は板状をなし、目標板厚１．０ｍｍを超え２．０ｍｍ以下の場合に板厚の実測値が目標板厚±０．０１５ｍｍであり、目標板厚０．１ｍｍ以上１．０ｍｍ以下の場合に板厚の実測値が目標板厚±０．０１ｍｍである、請求項１～請求項３の何れか一項に記載のばね材料。 The spring material has a plate shape, and when the target plate thickness exceeds 1.0 mm and is 2.0 mm or less, the measured value of the plate thickness is the target plate thickness ± 0.015 mm, and the target plate thickness is 0.1 mm or more and 1.0 mm. The spring material according to any one of claims 1 to 3, wherein the measured value of the plate thickness is a target plate thickness ± 0.01 mm in the following cases.
- 質量％で、Ｃ：０．４％以上０．９％以下、Ｓｉ：０．１％以上０．３５％以下、Ｍｎ：０％を超え１％以下、Ｐ：０％を超え０．０３％以下、Ｎｉ：０％を超え０．２５％以下、Ｃｒ：０％を超え０．３％以下を含有し、残部がＦｅ及び不純物からなり、前記不純物のうちＡｌ：０．００５％以下であり、
ベイナイト組織を有し、
ビッカース硬さが４００Ｈｖ以上である、ばね。 In mass%, C: 0.4% to 0.9%, Si: 0.1% to 0.35%, Mn: more than 0% and 1% or less, P: more than 0% and 0.03% Hereinafter, Ni: more than 0% and not more than 0.25%, Cr: more than 0% and not more than 0.3%, with the balance being Fe and impurities, and among the impurities, Al: not more than 0.005% ,
Has a bainite structure,
A spring having a Vickers hardness of 400 Hv or more. - ビッカース硬さが４５０Ｈｖ以上である、請求項５に記載のばね。 The spring according to claim 5, wherein the Vickers hardness is 450 Hv or more.
- 板厚１．５ｍｍ以上である、請求項５又は請求項６に記載のばね。 The spring according to claim 5 or 6, wherein the plate thickness is 1.5 mm or more.
- 皿ばね、トレランスリングおよびホースクランプからなる群から選ばれる１種である、請求項５～請求項７の何れか一項に記載のばね。 The spring according to any one of claims 5 to 7, which is one selected from the group consisting of a disc spring, a tolerance ring, and a hose clamp.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2016179708A JP6776073B2 (en) | 2016-09-14 | 2016-09-14 | Spring and spring material |
| JP2016-179708 | 2016-09-14 |
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| WO2018051599A1 true WO2018051599A1 (en) | 2018-03-22 |
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| PCT/JP2017/022834 WO2018051599A1 (en) | 2016-09-14 | 2017-06-21 | Spring and spring material |
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0448049A (en) * | 1990-06-14 | 1992-02-18 | Tougou Seisakusho:Kk | Leaf spring hose band and its manufacture |
| JP2001220650A (en) * | 1999-11-30 | 2001-08-14 | Sumitomo Electric Ind Ltd | Steel wire, spring and producing method therefor |
| JP2006097098A (en) * | 2004-09-30 | 2006-04-13 | Nisshin Steel Co Ltd | Heat-treated medium carbon steel strip superior in strength and workability |
| JP2006200039A (en) * | 2004-12-22 | 2006-08-03 | Kobe Steel Ltd | High carbon steel wire material having excellent wire drawability and manufacturing process thereof |
| JP2009013436A (en) * | 2007-06-29 | 2009-01-22 | Piolax Inc | Spring workpiece and manufacturing method therefor |
-
2016
- 2016-09-14 JP JP2016179708A patent/JP6776073B2/en active Active
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2017
- 2017-06-21 WO PCT/JP2017/022834 patent/WO2018051599A1/en active Application Filing
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0448049A (en) * | 1990-06-14 | 1992-02-18 | Tougou Seisakusho:Kk | Leaf spring hose band and its manufacture |
| JP2001220650A (en) * | 1999-11-30 | 2001-08-14 | Sumitomo Electric Ind Ltd | Steel wire, spring and producing method therefor |
| JP2006097098A (en) * | 2004-09-30 | 2006-04-13 | Nisshin Steel Co Ltd | Heat-treated medium carbon steel strip superior in strength and workability |
| JP2006200039A (en) * | 2004-12-22 | 2006-08-03 | Kobe Steel Ltd | High carbon steel wire material having excellent wire drawability and manufacturing process thereof |
| JP2009013436A (en) * | 2007-06-29 | 2009-01-22 | Piolax Inc | Spring workpiece and manufacturing method therefor |
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| JP6776073B2 (en) | 2020-10-28 |
| JP2018044208A (en) | 2018-03-22 |
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