JPH0686892B2 - Steel spring - Google Patents
Steel springInfo
- Publication number
- JPH0686892B2 JPH0686892B2 JP5988985A JP5988985A JPH0686892B2 JP H0686892 B2 JPH0686892 B2 JP H0686892B2 JP 5988985 A JP5988985 A JP 5988985A JP 5988985 A JP5988985 A JP 5988985A JP H0686892 B2 JPH0686892 B2 JP H0686892B2
- Authority
- JP
- Japan
- Prior art keywords
- hardness
- spring
- center
- tempering
- low
- 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.)
- Expired - Lifetime
Links
Classifications
-
- 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
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Springs (AREA)
- Heat Treatment Of Articles (AREA)
Description
【発明の詳細な説明】 ［産業上の利用分野］ 本発明は、例えばコイルばねや板ばねなどに使用される
鋼製ばねに関する。TECHNICAL FIELD The present invention relates to a steel spring used in, for example, a coil spring or a leaf spring.
［従来の技術］ 自動車用を始めとして、各種機器に使用されるばねの軽
量化と耐久性向上を図ることは、省エネルギー、省資源
などの見地から非常に重要な課題である。[Prior Art] It is a very important issue from the viewpoint of energy saving and resource saving to reduce the weight and improve the durability of springs used in various devices including those for automobiles.
鋼製ばねの軽量化と耐久性向上を図る場合、材料の強度
向上を図ることが一つの有力な手段となる。すなわち第
３図に示されるように、理論的には設計許容応力τを高
めることにより、軽量化を達成できることになる。In order to reduce the weight and improve the durability of steel springs, improving the strength of the material is one of the important means. That is, as shown in FIG. 3, theoretically, the weight can be reduced by increasing the design allowable stress τ.
しかしながら、強度向上を図るために材料の硬さを上げ
てゆくと、材料表面の微小傷等に対する切欠き感受性が
大きくなる。このため、第４図に示されるように硬度が
高過ぎるとかえって耐久性が低下することになり、ばね
の高強度化には限界がある。However, if the hardness of the material is increased in order to improve the strength, the notch susceptibility to minute scratches on the material surface increases. For this reason, as shown in FIG. 4, if the hardness is too high, the durability is rather reduced, and there is a limit to the increase in strength of the spring.
また、ばねは荷重付加状態で長期間使用すると塑性変形
（以下、へたりと呼ぶ）を生じる。このため耐へたり性
が要求されるが、その反面、使用中に折損しないように
するためには耐久性も要求される。耐へたり性を高める
場合、ばねを高硬度化することは有効であるが、硬度が
上がると前述したように切欠き感受性が高くなり、耐久
性が低下する。従って、これら相反する性質を克服する
ことが重要な課題である。Further, the spring undergoes plastic deformation (hereinafter referred to as “sag”) when used for a long period of time with a load applied. Therefore, sag resistance is required, but on the other hand, durability is also required to prevent breakage during use. In order to increase the sag resistance, it is effective to increase the hardness of the spring, but if the hardness increases, the notch sensitivity increases and the durability decreases as described above. Therefore, overcoming these conflicting properties is an important issue.
従来、一般に懸架用の鋼製ばねは、第５図に示されるよ
うに、ばねの横断面方向の硬さ分布がほぼ均一となるよ
うに焼入れおよび焼戻しの熱処理が施されている。ま
た、熱処理後はショットピーニングが行なわれ、ばね表
層部に圧縮残留応力を生じせしめて耐久性の向上が図ら
れている。Conventionally, steel springs for suspension have generally been subjected to heat treatment such as quenching and tempering so that the hardness distribution in the cross-sectional direction of the spring is substantially uniform, as shown in FIG. Further, shot peening is performed after the heat treatment to generate compressive residual stress in the surface layer of the spring to improve durability.
なお同第５図において、材料表面のごく限られた領域に
硬度の低下した箇所ａが見られるが、これは脱炭により
鋼材表面の炭素量が低下して不可避的に硬度が落ちた部
分である。周知の如く脱炭は耐久性の低下を引き起こす
有害な現象である。そのため市販のばね鋼の場合、脱炭
層の深さは材料表面から材料中心部までの距離の３％未
満（例えば２％前後まで）に制約されている ［発明が解決しようとする問題点］ 上述したように近時はばねの高応力化と高耐久性を図る
ために熱処理による硬さを高める傾向にあるが、硬さを
現状の最大HRC50前後よりも大きくすると、表面が硬過
ぎてショットピーニングが充分にかからなくなるととも
に、材料の切欠き感受性が大きくなるため、かえって耐
久性が低下したり耐久性のばらつきを引き起こす。耐久
性のばらつきは品質が不安定となる原因になる。In FIG. 5, a portion a where the hardness is reduced is seen in a very limited area of the material surface, but this is a portion where the hardness is unavoidably reduced due to a decrease in carbon content on the steel surface due to decarburization. is there. As is well known, decarburization is a harmful phenomenon that causes deterioration of durability. Therefore, in the case of commercially available spring steel, the depth of the decarburized layer is restricted to less than 3% (for example, up to about 2%) of the distance from the material surface to the material center [Problems to be solved by the invention] As mentioned above, the hardness tends to be increased by heat treatment in order to increase the stress and durability of the spring recently, but if the hardness is made higher than the current maximum of about H R C50, the surface is too hard. Since shot peening is not sufficiently applied and the notch sensitivity of the material is increased, the durability is rather deteriorated or the durability is varied. Variations in durability cause unstable quality.
［問題点を解決するための手段］ 本発明の鋼製ばねは、熱処理により硬度を高めたばね材
料内部と、このばね材料の表面側に設けられた低硬度部
分とを有する鋼製ばねであって、ばね材料の中心から材
料表面までの距離の３分の１の領域の硬さ（HRC）の平
均を中心部硬さＢと称し、この中心部硬さＢの98％の硬
さを示す位置から材料表面までの領域を低硬度部分と称
したとき、上記低硬度部分は実質的に脱炭を生じていな
い組織であってその硬さがHRC35〜53の範囲となるよう
に焼戻されており、しかも上記低硬度部分の表面硬さと
上記中心部硬さＢとの差はHRC硬さで２以上でかつ（Ｂ
−35）までの範囲であり、しかも上記低硬度部分の材料
表面からの深さは材料中心までの距離の３％以上でかつ
ばね材料の中心から材料表面までの距離の３分の１の領
域までとし、上記低硬度部分の材料表面にショットピー
ニングが施されていることを特徴とするものである。[Means for Solving Problems] A steel spring according to the present invention is a steel spring having an inside of a spring material whose hardness is increased by heat treatment and a low hardness portion provided on the surface side of the spring material. , the average hardness of the first region of the third of the distance from the center of the spring material to the material surface (H R C) referred to as a center hardness B and 98% of the hardness of the center hardness B When the region from the position shown to the material surface is called the low hardness portion, the low hardness portion is a structure in which substantially no decarburization has occurred and its hardness is in the range of H R C35 to 53. It is tempered, and the difference between the surface hardness of the low hardness portion and the hardness B of the central portion is 2 or more in H R C hardness and (B
-35), and the depth of the low hardness portion from the material surface is 3% or more of the distance to the material center and is one third of the distance from the center of the spring material to the material surface. In addition, shot peening is performed on the material surface of the low hardness portion.
上記鋼製ばねを得るには、ばね材料に焼入れの熱処理を
行なうことにより材料内部までほぼ均一に硬度を高めた
のち、ばね材料の主に表面側部分をたとえば高周波加熱
などにより焼戻し温度まで短時間急速加熱してから冷却
することによりパターン焼戻しを行なうことによって、
ばね材料の表面側部分の硬さを材料内部の硬さよりも低
くすることができる。In order to obtain the above-mentioned steel spring, the hardness of the spring material is increased almost uniformly to the inside of the material by subjecting the spring material to heat treatment, and then the surface side portion of the spring material is heated to a tempering temperature for a short time mainly by high frequency heating. By performing pattern tempering by rapidly heating and then cooling,
The hardness of the surface side portion of the spring material can be made lower than the hardness inside the material.
この明細書でいう“ほぼ均一に硬度を高め”とは、硬さ
のばらつきが中心硬さに対してHRC硬さで±１程度の範
囲に収まるように硬さを高めることを意味する。また、
“急速加熱”とは、通常の焼戻し加熱速度（１℃/sec以
下）のように熱伝導によって材料表層と材料中心部との
温度差が無くなるような緩慢な加熱ではなく、加熱部分
の結晶粒の粗大化を防ぎかつ炭化物の微細分散が得られ
るような加熱速度（具体的には20℃/sec以上）である。
この焼戻しによって得られる低硬度部分の組織は、見か
け上、材料内部とほとんど差異のない焼戻しソルバイト
となる。In this specification, "hardening the hardness almost uniformly" means increasing the hardness so that the variation of the hardness is within the range of about ± 1 in the H R C hardness with respect to the central hardness. . Also,
"Rapid heating" does not mean slow heating such as the normal tempering heating rate (1 ° C / sec or less) that eliminates the temperature difference between the material surface layer and the material central part due to heat conduction, but the crystal grains in the heated part Is a heating rate (specifically, 20 ° C./sec or more) that can prevent the coarsening of carbon and finely disperse the carbide.
The structure of the low hardness portion obtained by this tempering apparently becomes a tempering sorbite having almost no difference from the inside of the material.
［作用］ 上記鋼製ばねによれば、表面側部分の硬度が低下してい
るため切欠き感受性を低下させることができる。しかも
ショットピーニングがかかり易くなり、表層部に圧縮残
留応力を充分生じさせることができる。従ってばねの耐
久性が向上する。[Operation] According to the steel spring, since the hardness of the surface side portion is reduced, the notch sensitivity can be reduced. In addition, shot peening is easily applied, and compressive residual stress can be sufficiently generated in the surface layer portion. Therefore, the durability of the spring is improved.
また上記ばねによれば、冷間コイリングする際などに塑
性歪の最も大きくなる材料外周部の硬さが低く延性があ
るため、破断を生じさせずにコイリングすることができ
る。Further, according to the spring, since the hardness of the outer peripheral portion of the material that causes the greatest plastic strain during cold coiling is low and ductile, coiling can be performed without causing breakage.
本発明はコイルばねに限らず、例えば板ばねや弁ばね
等、要するに鋼を熱処理して得るばねであれば適用でき
る。The present invention is not limited to coil springs, and can be applied to any leaf springs, valve springs, and any other springs obtained by heat treating steel.
［実施例］ 車両懸架用コイルばねに適用する場合、ばね材料は一例
としてSUP7種（JIS.G4801）を用いる。線径は9mmであ
る。但し、他の鋼種を用いることも勿論可能である。[Example] When applied to a coil spring for vehicle suspension, SUP7 type (JIS.G4801) is used as the spring material as an example. The wire diameter is 9 mm. However, it is of course possible to use other steel types.
直棒状をなす上記ばね材料を900℃に加熱し、油焼入れ
を行なう。この焼入れにより、ばね材料はその内部まで
ほぼ均一な焼入れ硬さとなる。次に炉加熱による一次テ
ンパーを350℃×40分間、すなわち低温焼戻しを行な
う。The straight rod-shaped spring material is heated to 900 ° C. and oil-quenched. By this quenching, the spring material has a substantially uniform quenching hardness up to the inside. Next, the primary temper by furnace heating is subjected to 350 ° C. × 40 minutes, that is, low temperature tempering.
以上の熱処理を行なったのち、高周波加熱コイルを用い
て、ばね材料の主に表面側部分を焼戻し温度（この場
合、表面温度550℃）まで急速加熱後、徐冷する。これ
により主に表面側部分が短時間加熱されて焼戻され、パ
ターン焼戻しとなる。この焼戻しに要する時間は例えば
1.5秒間である。After the above heat treatment, a high-frequency heating coil is used to rapidly heat mainly the surface side portion of the spring material to a tempering temperature (in this case, a surface temperature of 550 ° C.) and then gradually cool. As a result, the surface side portion is mainly heated for a short time to be tempered, resulting in pattern tempering. The time required for this tempering is
1.5 seconds.
以上のパターン焼戻しが行なわれたばね材料は、第１図
に示されるように、ばね材料表面における硬さＡが、材
料内部平均硬さＢに比べて低くなる。As shown in FIG. 1, the spring material subjected to the above pattern tempering has a hardness A on the surface of the spring material lower than the average hardness B inside the material.
すなわち材料表面から材料中心部までの距離（材料半
径）をＲとした場合、材料直径の３分の１の領域の硬さ
の平均をとって中心部硬さとし、この中心部硬さの98％
の硬さを示す位置から材料表面までの距離、すなわち低
硬度部分の材料表面からの深さをＣとする。つまり、Ｃ
は硬さの低下域長さを示している。実際にばねとして用
いる場合、この低硬度部分の硬さはHRC硬さで35ないし5
3がよい。また材料表面の硬さＡと、材料内部の平均硬
さＢとの硬度差を、少なくともHRC硬さで２以上とす
る。低硬度部分の硬さの下限はHRC35であるから、上記
硬度差の上限は（B-35）である。That is, when the distance from the surface of the material to the center of the material (material radius) is R, the hardness of the center is calculated by averaging the hardness of the region of one-third of the material diameter, and 98% of this hardness
Let C be the distance from the position indicating the hardness to the material surface, that is, the depth of the low hardness portion from the material surface. That is, C
Indicates the length of the reduced hardness region. When actually used as a spring, the hardness of the low hardness portion 35 to at H R C hardness 5
3 is good. Further, the hardness difference between the hardness A of the material surface and the average hardness B inside the material is at least 2 in terms of H R C hardness. Since the lower limit of the hardness of the low hardness portion is H R C35, the upper limit of the hardness difference is (B-35).
また上記低硬度部分の深さＣが、材料表面から材料中心
部までの距離Ｒの３％以上となるように、パターン焼戻
しの加熱温度や時間などを鋼種、線径等との関係で設定
する。なお、この明細書では、前述のように材料中心か
ら材料表面までの距離の３分の１の領域の硬さの平均を
とって中心部硬さＢとしているため、低硬度部分の深さ
Ｃは、最大でも材料中心から材料表面までの距離の３分
の１である。Further, the heating temperature and time for pattern tempering are set in relation to the steel type, wire diameter, etc. so that the depth C of the low hardness portion becomes 3% or more of the distance R from the material surface to the material center portion. . In this specification, as described above, the hardness of the central portion is calculated by taking the average of the hardnesses of the one-third of the distance from the material center to the material surface. Is at most one third of the distance from the material center to the material surface.
線径9mmのばねでは、第２図に示されるように材料表面
の硬さが約HRC50、材料内部の硬さが約HRC57、そして硬
さの低下域長さＣは、材料表面から0.5mm以上である。For a spring with a wire diameter of 9 mm, the hardness of the material surface is about H R C50, the hardness inside the material is about H R C57, and the hardness decrease region length C is To 0.5 mm or more.
パターン焼戻し後、ばね素材に冷間コイリングまたは冷
却前に温間でコイリングを行ない、引き続き380℃×40
分間の二次テンパー、すなわち低温焼鈍を実施する。そ
の後、一般のばねと同様にショットピーニングを実施す
るとともに、セッチングを行なう。また、必要に応じて
防錆処理が施される。After pattern tempering, cold coiling the spring material or warm coiling before cooling, and continue at 380 ℃ × 40
Secondary tempering for 1 minute, that is, low temperature annealing is performed. After that, shot peening and setting are performed in the same manner as a general spring. In addition, anticorrosion treatment is performed if necessary.
上記方法によって得たコイルばねと、従来方法によるコ
イルばねの疲労強度試験を行ない比較したところ、応力
条件（τｍ±τａ）が65±55kgf/mm2においては、従来
品の寿命が８ないし15万回であったのに対し、本実施例
品は20ないし25万回であり、平均寿命が画期的に向上す
ることが確認された。しかも耐久性のばらつきも相対的
に小さくなった（ｎ＝５本）。ここで従来品とは、従来
の一般的な焼入れ、焼戻しの熱処理により、硬さをHRC5
2に調整したものである。When the fatigue strength test of the coil spring obtained by the above method and the coil spring by the conventional method is performed and compared, the life of the conventional product is 80 to 150,000 when the stress condition (τm ± τa) is 65 ± 55 kgf / mm 2 . The number of cycles was 200 to 250,000 times, whereas the average life was remarkably improved. Moreover, the variation in durability was relatively small (n = 5). Here, the conventional product has a hardness of H R C5 by the conventional general heat treatment of quenching and tempering.
It is adjusted to 2.
また、コイルばねの締付け試験によって耐へたり性の比
較を行なったところ、締付け応力τmax＝120kgf/mm2で
は、従来品は残留剪断歪γが平均５×10-4であったのに
対し、本実施例品では、平均2.5×10-4と約半分に減少
し、耐へたり性に関しても優れた性質を示した。In addition, when the sag resistance was compared by the tightening test of the coil springs, when the tightening stress τmax = 120 kgf / mm 2 , the conventional product had a residual shear strain γ of 5 × 10 -4 on average. The product of this example has an average of 2.5 × 10 −4, which is about half that of the product of the present example, and exhibits excellent sag resistance.
なお従来方法において、焼戻し温度を低くして低温焼戻
しを行ない、本実施例品の中心部硬さ（HRC57）と同程
度ににしたものは、上記条件で締付け試験を行なうとγ
＝２×10-4と良好な値を示す。しかし疲労試験に関して
は、折損に至るまでの回数が３ないし９万回と、HRC52
のものよりも寿命が短くなる。すなわち表面硬度が硬く
なり過ぎて切欠き感受性が高くなるからである。In still a conventional method, performs low-temperature tempering to lower the tempering temperature, heart hardness of the Example product with (H R C57) those in the same degree, when the tightened tested in the above condition γ
= 2 × 10 -4, which is a good value. But with respect to the fatigue test, and to that there is no 3 number of times leading up to the breakage 90,000 times, H R C52
Life is shorter than that of That is, the surface hardness becomes too hard and the notch sensitivity becomes high.
以上述べたように本実施例によれば、ばね材料表面の切
欠き感受性を低下させることができるばかりでなく、表
面硬度が下がるためショットピーニングがかかり易くな
り、表層部に圧縮の残留応力を充分生じせしめることが
できる。従って耐久性の向上に非常に有効となる。そし
て材料内部側は硬度が高いから、許容応力を高くとるこ
とができ、軽量化と耐へたり性の向上を図ることができ
る。As described above, according to the present embodiment, not only the notch sensitivity of the spring material surface can be lowered, but also the surface hardness is lowered, so that shot peening is likely to occur, and the compressive residual stress is sufficiently applied to the surface layer portion. It can be caused. Therefore, it is very effective in improving durability. Since the inner side of the material has a high hardness, the allowable stress can be made high, and the weight reduction and the sag resistance can be improved.
しかも製造面においては、冷間コイリング時に塑性歪の
最も大きくなる材料外周部の硬さが低く延性があるの
で、高硬度ばねでありながら冷間コイリングを行なう際
に破断を生じることがない。Moreover, in terms of manufacturing, since the hardness of the outer peripheral portion of the material that causes the greatest plastic strain during cold coiling is low and has ductility, it is a spring of high hardness and does not break during cold coiling.
なお前述したように、従来品においても焼入れ時の表面
層の脱炭によって、表面層の硬度が下がっていることが
ある（第５図のａ部参照）。しかしながら脱炭はコイル
ばねの場合、規格では線径10mmでも最大0.12mm以下であ
り、ごく限られた表面層のみに生じる。しかも脱炭は炭
素量が低下して耐久性に悪影響を与えるものである。こ
れに対して本発明の場合には、前述したように主に表面
側部分を短時間加熱することにより表面側の硬度を所望
の深さだけ低下させるのであり、硬さ低下域の長さＣを
大きくとれるとともに耐久性を向上できるなど、脱炭と
は本質的に相違するものである。As described above, the hardness of the surface layer of the conventional product may decrease due to decarburization of the surface layer during quenching (see part a in FIG. 5). However, in the case of a coil spring, decarburization is 0.12 mm or less at maximum even if the wire diameter is 10 mm, and it occurs only in a very limited surface layer. Moreover, decarburization reduces the amount of carbon and adversely affects durability. On the other hand, in the case of the present invention, as described above, the hardness of the surface side is reduced by a desired depth mainly by heating the surface side portion for a short time. It is essentially different from decarburization in that it can take a large amount and can improve durability.
［発明の効果］ 本発明によれば、ばねの高強度化によって軽量化が図れ
るとともに、切欠き感受性を下げることができかつショ
ットピーニングによる圧縮残留応力を充分に生じさせる
ことができるなど、ばねの軽量化と耐へたり性および耐
久性の向上を両立させることができ、しかも品質の安定
した鋼製ばねを提供でき、コイリング等の成形も容易で
あるなど、大きな効果を奏することができる。EFFECTS OF THE INVENTION According to the present invention, the strength of the spring is increased to reduce the weight, the notch sensitivity can be reduced, and the compressive residual stress due to shot peening can be sufficiently generated. It is possible to achieve both weight reduction and improvement in sag resistance and durability, to provide a steel spring of stable quality, and to easily form a coiling or the like, which is a great effect.
第１図はパターン焼戻しの行なわれたばね材料の硬さ分
布を示す図、第２図は硬さの低下域を示す図、第３図は
軽量化率と設計許容応力の関係を示す図、第４図は焼戻
し硬さと疲れ限度の関係を示す図、第５図は従来の熱処
理が施されたばね材料の硬さを示す図である。FIG. 1 is a diagram showing hardness distribution of a spring material subjected to pattern tempering, FIG. 2 is a diagram showing a region where hardness is reduced, and FIG. 3 is a diagram showing a relationship between a weight reduction rate and a design allowable stress. FIG. 4 is a diagram showing the relationship between tempering hardness and fatigue limit, and FIG. 5 is a diagram showing hardness of conventional spring material subjected to heat treatment.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 東野 豊之 神奈川県横浜市磯子区新磯子町１番地 株 式会社日発グループ中央研究所内 (72)発明者 綾田 倫彦 神奈川県横浜市磯子区新磯子町１番地 株 式会社日発グループ中央研究所内 (56)参考文献 特開 昭60−9827（ＪＰ，Ａ) 特開 昭53−19115（ＪＰ，Ａ) ばね技術研究会編「ばね」改訂２版（昭 和45年１月25日丸善発行) ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Toyoyuki Higashino, Inventor Toyoyuki Higashi, No. 1 Shinisogo-cho, Isogo-ku, Yokohama-shi, Kanagawa Inside the Central Research Laboratory, Nikka Group Co., Ltd. (72) Norihiko Ayada Shinisoko, Isogo-ku, Yokohama-shi, Kanagawa No. 1 in town Incorporated company Nikka Group Central Research Institute (56) Reference JP-A-60-9827 (JP, A) JP-A-53-19115 (JP, A) "Spring," 2nd edition, edited by Spring Technology Research Group (Published by Maruzen on January 25, 1945)
Claims (1)
と、このばね材料の表面側に設けられた低硬度部分とを
有する鋼製ばねであって、 ばね材料の中心から材料表面までの距離の３分の１の領
域の硬さ（HRC）の平均を中心部硬さＢと称し、この中
心部硬さＢの98％の硬さを示す位置から材料表面までの
領域を低硬度部分と称したとき、 上記低硬度部分は実質的に脱炭を生じていない組織であ
ってその硬さがHRC35〜53の範囲となるように焼戻され
ており、 しかも上記低硬度部分の表面硬さと上記中心部硬さＢと
の差はHRC硬さで２以上でかつ（B-35）までの範囲であ
り、 しかも上記低硬度部分の材料表面からの深さは材料中心
までの距離の３％以上でかつばね材料の中心から材料表
面までの距離の３分の１の領域までとし、 上記低硬度部分の材料表面にショットピーニングが施さ
れていることを特徴とする鋼製ばね。1. A steel spring having an inside of a spring material whose hardness is increased by heat treatment and a low hardness portion provided on the surface side of the spring material, wherein the distance from the center of the spring material to the surface of the material is 3 referred hardness of min 1 region the average (H R C) and the center hardness B, a region of low hardness portion from the position shown 98% of the hardness of the center hardness B until the material surface When referred to, the low hardness portion is a structure that has not been substantially decarburized and is tempered so that the hardness is in the range of H R C35 to 53, and the surface of the low hardness portion is the difference between the hardness and the center hardness B is in the range up to and at least 2 in H R C hardness (B-35), yet the depth of the material surface of the low hardness portion to the material center At least 3% of the distance and up to one-third of the distance from the center of the spring material to the material surface, Steel spring, characterized in that the shot peening is applied to the charge surface.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5988985A JPH0686892B2 (en) | 1985-03-25 | 1985-03-25 | Steel spring |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5988985A JPH0686892B2 (en) | 1985-03-25 | 1985-03-25 | Steel spring |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS61218843A JPS61218843A (en) | 1986-09-29 |
| JPH0686892B2 true JPH0686892B2 (en) | 1994-11-02 |
Family
ID=13126136
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5988985A Expired - Lifetime JPH0686892B2 (en) | 1985-03-25 | 1985-03-25 | Steel spring |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0686892B2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102009011118A1 (en) * | 2008-11-21 | 2010-05-27 | Muhr Und Bender Kg | Tempered spring steel, spring element and method for producing a spring element |
| JP2022097327A (en) * | 2020-12-19 | 2022-06-30 | デルタ工業株式会社 | Torsion bar and manufacturing method thereof |
-
1985
- 1985-03-25 JP JP5988985A patent/JPH0686892B2/en not_active Expired - Lifetime
Non-Patent Citations (1)
| Title |
|---|
| ばね技術研究会編「ばね」改訂２版（昭和４５年１月２５日丸善発行） |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS61218843A (en) | 1986-09-29 |
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