JPH036351A - High fatigue strength spring steel and its manufacture - Google Patents
High fatigue strength spring steel and its manufactureInfo
- Publication number
- JPH036351A JPH036351A JP13976489A JP13976489A JPH036351A JP H036351 A JPH036351 A JP H036351A JP 13976489 A JP13976489 A JP 13976489A JP 13976489 A JP13976489 A JP 13976489A JP H036351 A JPH036351 A JP H036351A
- Authority
- JP
- Japan
- Prior art keywords
- steel
- fatigue strength
- spring steel
- high fatigue
- strength spring
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 229910000639 Spring steel Inorganic materials 0.000 title claims abstract description 19
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 11
- 229910000831 Steel Inorganic materials 0.000 claims abstract description 51
- 239000010959 steel Substances 0.000 claims abstract description 51
- 229910052750 molybdenum Inorganic materials 0.000 claims abstract description 11
- 238000010791 quenching Methods 0.000 claims abstract description 11
- 230000000171 quenching effect Effects 0.000 claims abstract description 10
- 238000005096 rolling process Methods 0.000 claims abstract description 10
- 229910052804 chromium Inorganic materials 0.000 claims abstract description 9
- 229910052748 manganese Inorganic materials 0.000 claims abstract description 9
- 229910052710 silicon Inorganic materials 0.000 claims abstract description 9
- 239000012535 impurity Substances 0.000 claims abstract description 7
- 229910052742 iron Inorganic materials 0.000 claims abstract description 7
- 238000005496 tempering Methods 0.000 claims abstract description 4
- 229910052758 niobium Inorganic materials 0.000 claims abstract description 3
- 229910052720 vanadium Inorganic materials 0.000 claims abstract 3
- 229910052799 carbon Inorganic materials 0.000 abstract description 3
- 238000005098 hot rolling Methods 0.000 abstract 1
- 229910001566 austenite Inorganic materials 0.000 description 11
- 230000000694 effects Effects 0.000 description 10
- 239000013078 crystal Substances 0.000 description 7
- 238000000034 method Methods 0.000 description 6
- 229910001562 pearlite Inorganic materials 0.000 description 5
- 230000009466 transformation Effects 0.000 description 5
- 230000000052 comparative effect Effects 0.000 description 4
- 238000010438 heat treatment Methods 0.000 description 4
- 210000005252 bulbus oculi Anatomy 0.000 description 3
- 238000005261 decarburization Methods 0.000 description 3
- 230000001771 impaired effect Effects 0.000 description 3
- 229910000734 martensite Inorganic materials 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 229920006395 saturated elastomer Polymers 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 239000002344 surface layer Substances 0.000 description 2
- 239000000725 suspension Substances 0.000 description 2
- 238000009864 tensile test Methods 0.000 description 2
- 101100043866 Caenorhabditis elegans sup-10 gene Proteins 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000009661 fatigue test Methods 0.000 description 1
- 238000005242 forging Methods 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 150000001247 metal acetylides Chemical class 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 238000005480 shot peening Methods 0.000 description 1
- 238000010583 slow cooling Methods 0.000 description 1
- 239000002436 steel type Substances 0.000 description 1
- 229910000859 α-Fe Inorganic materials 0.000 description 1
Abstract
Description
【発明の詳細な説明】
［産業上の利用分野］
本発明は自動車などの懸架装置に用いられる重ね板ばね
に適した高疲労強度のばね用鋼およびその製造方法に関
する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a high fatigue strength spring steel suitable for laminated leaf springs used in suspension systems for automobiles and the like, and a method for manufacturing the same.
［従来の技術］
近年、自動車軽量化の一環として懸架用板ばねの軽量化
が強く求められるようになってきた。板ばねの場合、同
一断面形状とすると、ばねの中央部が最も応力的に厳し
くなることから、中央部の厚さを最大とし、端部はと厚
さを薄くしたＬＴＬ（ロングテーパリーフ）ばねを製造
し、しかも板ばねの枚数を減少させて、軽量化を図ると
いう試みが積極的に進められてきた。[Prior Art] In recent years, as part of efforts to reduce the weight of automobiles, there has been a strong demand for lighter suspension leaf springs. In the case of leaf springs, if the cross-sectional shape is the same, the stress will be the most severe in the center of the spring, so LTL (Long Taper Leaf) springs have the maximum thickness in the center and thinner edges. Attempts have been actively made to reduce the weight of the springs by manufacturing them and reducing the number of leaf springs.
しかしながら、枚数の減少、適用範囲の拡大が進められ
るに従って、使用する板厚の範囲が広がり、従来から使
用されていた５ＵＰ９Ａ、５ＵＰ１０では焼入性の点で
要求を満足することができなくなっている。However, as the number of plates is reduced and the range of application is expanded, the range of plate thicknesses used is expanded, and the conventionally used 5UP9A and 5UP10 are no longer able to satisfy the requirements in terms of hardenability. .
［発明が解決しようとする課題］
然るに、従来の板ばねの製造方法では、ばね板の圧延加
工や目玉成形などの加工は、それぞれ別々に熱間で行な
われた後、−旦除冷されて再び焼入のために鋼をオース
テナイト化し、油等で急冷したのちに焼もどしをしてい
る。このため、鋼内部では圧延加工により結晶粒を微細
化したにも拘わらず、除冷などにより粗大化してしまい
、表面部では脱炭のおそれが出ており、鋼自体の強度が
減少し、かつエネルギー消費の増大を招いている。[Problems to be Solved by the Invention] However, in the conventional manufacturing method of leaf springs, processes such as rolling and eye-forming of the spring leaf are performed separately in a hot state, and then the spring leaf is first cooled down. The steel is turned into austenite for quenching again, rapidly cooled with oil, and then tempered. For this reason, even though the grains inside the steel have been made finer by rolling, they become coarser due to slow cooling, etc., and there is a risk of decarburization on the surface, reducing the strength of the steel itself. This results in an increase in energy consumption.
そこで、Ａ３点以上の高温でテーパ圧延後、フェライト
＋パーライト変態前で、加工の影響が消えないうちに焼
入を施し、その後焼もどしを行うという加工熱処理（以
下オースフォーミングという。Therefore, after taper rolling at a high temperature of A3 point or higher, quenching is performed before the ferrite + pearlite transformation occurs, before the effects of processing disappear, and then tempering is performed (hereinafter referred to as ausforming).
）を行うことにより、材料そのものの疲労強度を向上さ
せようとする試みが行なわれるようになってきた。), attempts have been made to improve the fatigue strength of the material itself.
しかしながら、従来の５ＵＰ９Ａや５ＵＰＩＯ等のばね
用鋼を使用してオースフォーミングを行っ一
てもオーステナイト領域が狭いため、ばね用鋼を加熱し
オーステナイト化状態で圧延、端部加工等の加工後に直
ちに焼入を施しても、焼入前にフェライト・パーライト
変態を開始することとなり、完全均一のマルテンサイト
組織が得られず、がっ表面硬さの低下のおそれがあった
。However, even if ausforming is performed using conventional spring steels such as 5UP9A and 5UPIO, the austenite region is narrow, so the spring steel is heated and rolled in an austenitized state, and immediately sintered after processing such as edge processing. Even if hardening is applied, the ferrite-pearlite transformation will start before quenching, and a completely uniform martensitic structure will not be obtained, leading to a risk of a decrease in surface hardness.
そこで、本発明は前記の従来鋼や従来技術の欠点を解決
すべくなされたもので、オーステナイト化状態でテーパ
圧延および目玉成形等の熱間加工ができ、直ちに焼入類
もどしをすることにより、所望の組織と靭性が得られる
オースフォーミングに好適なばね用鋼で、しかも高強度
で耐久性に優れたばね用鋼およびその製造方法を提供す
ることを目０勺とする。Therefore, the present invention was made to solve the above-mentioned drawbacks of the conventional steel and the conventional technology, and it is possible to perform hot working such as taper rolling and eyeball forming in the austenitized state, and immediately restore the quenched state. It is an object of the present invention to provide a spring steel suitable for ausforming that can obtain a desired structure and toughness, has high strength and excellent durability, and a method for producing the same.
［課題を解決するための手段］
本発明者は従来のばね用鋼について、オースフォーミン
グを可能にし疲労強度を向上するため、鋭意研究を重ね
た。その結果、オーステナイト領域を拡大し、適切なオ
ースフォーミングを可能にするなめには、ＭｏおよびＢ
の添加が有効であるこ４
と、さらにＶを添加することにより疲労強度が著しく改
善されることを知見し本発明を完成した。[Means for Solving the Problems] The present inventor has conducted extensive research on conventional spring steels in order to enable ausforming and improve fatigue strength. As a result, in order to expand the austenite region and enable proper ausforming, Mo and B
The present invention was completed based on the findings that the addition of V is effective and that fatigue strength is significantly improved by further adding V.
また、オースフォーミングの条件についても研究を重ね
、所望の疲労強度が得られる条件を見出だした。We also conducted extensive research on the conditions for ausforming, and found conditions that would allow us to obtain the desired fatigue strength.
本発明の高疲労強度はね用鋼は第１発明として、重量比
でＣ；０．４０〜０．６５％、Ｓｉ；０．１５〜０．３
５％、Ｍｎ；０．７０〜１５０％、Ｃｒ；０．５０〜１
．１０％、Ｍｏｎ０．１０〜０．４０％、■；０゜１０
〜０．３０％を含有し、残部がＦｅならびに不純物元素
からなることを要旨とする。また、第２発明は第１発明
の焼入性をさらに改善するため、さらにＢ ；Ｏ、ｏ
Ｏ５〜０．０１００％添加し、第３発明は第２発明の靭
性をさらに改善するなめＮｂ；０．０５〜０．３０％を
添加したことを要旨とするものである。The high fatigue strength spring steel of the present invention has a weight ratio of C: 0.40 to 0.65% and Si: 0.15 to 0.3.
5%, Mn; 0.70-150%, Cr; 0.50-1
．． 10%, Mon0.10~0.40%, ■;0°10
~0.30%, with the remainder consisting of Fe and impurity elements. In addition, in order to further improve the hardenability of the first invention, the second invention further improves the hardenability of the first invention.
The gist of the third invention is that 0.05 to 0.30% of Nb is added to further improve the toughness of the second invention.
さらに、本発明方法は高疲労強度ばね用鋼の製造方法で
あって、第１発明鋼および第２発明鋼を８００〜９５０
℃の温度でオーステナイト化した後圧延加工し、５００
℃の温度に降下する前に焼入しその後焼もどしを施すこ
とを要旨とする。Furthermore, the method of the present invention is a method for producing high fatigue strength spring steel, and the method comprises manufacturing a first invention steel and a second invention steel of 800 to 950%.
After being austenitized at a temperature of 500°C, it is rolled and
The main idea is to quench the material before the temperature drops to ℃ and then temper it.
［作用］
本発明鋼は従来のばね用鋼にＭｏを０．１０〜０４０％
添加することにより、結晶粒が微細化されるととも、に
、オーステナイト領域が拡大し、焼入性が改善される。[Function] The steel of the present invention is a conventional spring steel with Mo content of 0.10 to 040%.
By adding Ni, the crystal grains become finer, the austenite region expands, and the hardenability is improved.
そのため本発明の温度域に加熱することによって、オー
ステナイトの状態で圧延加工および目玉成形等の熱間加
工が可能であって、フェライト・パーライト変態が開始
する前に焼入することができる。その結果、衝撃値が改
善されるとともに、疲労強度が飛躍的に向上する。Therefore, by heating to the temperature range of the present invention, hot working such as rolling and eyeball forming can be performed in the austenite state, and quenching can be performed before ferrite-pearlite transformation starts. As a result, the impact value is improved and the fatigue strength is dramatically improved.
また、ＭｏおよびＢの添加により本発明方法のオースフ
ォーミング加工が可能であり、圧延加工により微細化さ
れた金属組織がその後の焼入焼もどしによって常温まで
持ち来されるので、板ばねとしての強度や靭性および耐
久性が増大する。さらに、Ｂの添加により焼入性がさら
に改善され、■の添加により結晶粒が微細化し強度およ
び靭性が改善される。In addition, the addition of Mo and B enables ausforming processing using the method of the present invention, and the metal structure refined through rolling is brought to room temperature through subsequent quenching and tempering, which increases the strength of the leaf spring. increased toughness and durability. Furthermore, the addition of B further improves the hardenability, and the addition of (2) refines the crystal grains and improves strength and toughness.
次に本発明の高疲労強度ばね用鋼の化学成分の組成範囲
限定の理由について説明する。Next, the reason for limiting the composition range of the chemical components of the high fatigue strength spring steel of the present invention will be explained.
Ｃ；ｏ 、４０〜０．６５％
Ｃは熱処理後にばねとして強度を確保するために必要な
元素であり、高強度ばね鋼として十分な強度を確保する
ために０，４０％以上添加する必要がある。しかし、０
．６５％を超えて含有されると、靭性が阻害されるので
、上限を０．６５％とした。C; o, 40-0.65% C is an element necessary to ensure strength as a spring after heat treatment, and it is necessary to add 0.40% or more to ensure sufficient strength as a high-strength spring steel. be. However, 0
．． If the content exceeds 65%, toughness will be impaired, so the upper limit was set at 0.65%.
Ｓｉ；０．１５〜０．３５％
Ｓｉは製鋼時の脱酸剤として必要な元素であり、０．１
５％未満では十分な脱酸を行い、欠陥のない鋼を得るこ
とが困難であるので、下限を０．１５％とした。しかし
、０．３５％を超えて添加されると、靭性が阻害される
ので、上限を０．３５％とした。Si: 0.15-0.35% Si is an element necessary as a deoxidizer during steel manufacturing, and 0.1%
If it is less than 5%, it is difficult to perform sufficient deoxidation and obtain defect-free steel, so the lower limit was set at 0.15%. However, if added in excess of 0.35%, toughness will be impaired, so the upper limit was set at 0.35%.
Ｍｎ；０．７０〜１５０％
Ｍｎはばね鋼の焼入性を確保するために必要な元素であ
り、ばねの中心まで充分に焼が入るためには、少なくと
も０．７０％以上添加する必要がある。しかし、１５０
％を超えて添加されると靭性が劣化するので、上限を１
５０％とした。Mn: 0.70-150% Mn is an element necessary to ensure the hardenability of spring steel, and in order to harden sufficiently to the center of the spring, it is necessary to add at least 0.70% or more. be. However, 150
If added in excess of 1%, the toughness will deteriorate, so the upper limit is set at 1%.
It was set at 50%.
Ｃｒ；０．５０〜１．１０％
ＣｒはＭｎと同様に焼入性を向上させ、かつ脱炭防止に
効果のある元素である。これらの効果を得るためには０
，５０％以上添加する必要があり、その下限を０．５０
％とした。しかし、１．１０％を超えて含有させると、
熱処理後に残留オーステナイトが増加し、また靭性が阻
害されるので上限を１．１０％とした。Cr; 0.50 to 1.10% Cr is an element that improves hardenability like Mn and is effective in preventing decarburization. To obtain these effects, 0
, it is necessary to add 50% or more, and the lower limit is 0.50%.
%. However, if the content exceeds 1.10%,
After heat treatment, retained austenite increases and toughness is impaired, so the upper limit was set at 1.10%.
Ｍｏ；０．１０〜０．４０％
Ｍｏはオーステナイト領域を拡大し焼入性を向上させる
元素である。前記効果を得るためには少なくとも０．１
０％以上の添加が必要である。しかし、０．４０％を超
えて添加されると、オーステナイト領域拡大の効果が飽
和するばかりでなく、経済的でないので、その上限を０
．４０％とした。Mo; 0.10 to 0.40% Mo is an element that expands the austenite region and improves hardenability. In order to obtain the above effect, at least 0.1
It is necessary to add 0% or more. However, if it is added in excess of 0.40%, not only will the effect of expanding the austenite region become saturated, but it will also be uneconomical, so the upper limit should be set at 0.
．． It was set at 40%.
Ｖ、０．１０〜０．３０％、Ｎｂ、０．０５〜０．３０
％
■およびＮｂは鋼中において炭化物を形成し、オーステ
ナイト結晶粒を微細化し、耐久性を向上する。前記効果
を得るためには少なくともＶは０゜１０％以上、Ｎｂは
０．０５％以上を添加する必要がある。しかし、■およ
びＮｂは０．３０％を超えて添加されると、結晶粒微細
化の効果は飽和するとともに、Ｃと結び付いて熱処理に
悪影響を及ぼすので、上限を共に０．３０％とした。V, 0.10-0.30%, Nb, 0.05-0.30
% (1) and Nb form carbides in steel, refine austenite grains, and improve durability. In order to obtain the above effect, it is necessary to add at least 0.10% or more of V and 0.05% or more of Nb. However, if (2) and Nb are added in an amount exceeding 0.30%, the grain refinement effect is saturated and they combine with C to adversely affect heat treatment, so the upper limit for both was set at 0.30%.
Ｂ、０．０００５〜０．０１００％
Ｂはばね鋼の焼入性を向上する元素であり、この効果を
得るためには少なくとも０．０００５％以上添加する必
要がある。しかし、０．０１００％を超えて含有される
と、ボロン化物が析出し熱間脆性が現れるので、上限を
０．０１００％とした。B, 0.0005-0.0100% B is an element that improves the hardenability of spring steel, and in order to obtain this effect, it is necessary to add at least 0.0005% or more. However, if the content exceeds 0.0100%, boronides precipitate and hot brittleness appears, so the upper limit was set at 0.0100%.
また、本発明方法において、オーステナイト化温度を８
００〜９５０℃としたのは、８００℃未満では熱間加工
後の焼入温度が５００℃未満になり、オーステナイト状
態での焼入が不可能となるからであり、９５０℃を超え
ると脱炭が生しオーステナイト結晶粒が粗大化するから
である。In addition, in the method of the present invention, the austenitizing temperature is set to 8
The reason why the range is 00 to 950°C is that if it is less than 800°C, the quenching temperature after hot working will be less than 500°C, making it impossible to harden the austenitic state.If it exceeds 950°C, decarburization will occur. This is because the austenite crystal grains become coarse.
［実施例］
次に本発明鋼の特徴を従来鋼、比較鋼と比べて実施例で
もって明らかにする。[Example] Next, the characteristics of the steel of the present invention will be clarified by comparing it with conventional steel and comparative steel through examples.
第１表はこれら供試鋼の化学成分を示すものである。第
１表において、Ａ〜Ｄ鋼は第１発明鋼、Ｅ〜Ｆ鋼は第２
発明鋼で、Ｇ〜Ｈ鋼は第３発明鋼である。また、■鋼は
Ｍｏ含有量の少なかった比較鋼、Ｊ鋼は５ＵＰ９Ａに相
当する従来鋼、ｌぐ鋼はＳＵＰ １０に相当する従来鋼
である。Table 1 shows the chemical composition of these test steels. In Table 1, A to D steels are the first invention steels, and E to F steels are the second invention steels.
Among the invention steels, G to H steels are the third invention steels. In addition, steel (■) is a comparison steel with a low Mo content, steel J (steel J) is a conventional steel equivalent to 5UP9A, and steel (l) is a conventional steel equivalent to SUP 10.
（以下余白）
これら供試鋼について、引張試験、伸びおよび絞りを測
定するため、供試鋼を１０ｍ＋ｎ直径に鍛伸した後、平
行部が５ｍ＋ｎ直径の試験片に加工し、焼入類もどしに
よりＨＲＣ５１となるように調整し、引張速度０．５ｍ
ｍ１分の速度で引張試験を行った。(Left below) In order to perform tensile tests, elongation, and reduction of area of these test steels, the test steels were forged to a diameter of 10m+n, then processed into test pieces with a parallel part of 5m+n diameter, and then quenched and Adjust to HRC51, tensile speed 0.5m
The tensile test was conducted at a speed of m1 min.
また併せて伸びおよび絞りについても測定し第２表に示
した。In addition, elongation and reduction of area were also measured and shown in Table 2.
第２表の結果より、引張強さについては本発明鋼は従来
鋼と何等遜色ない値が得られた。また、伸びおよび絞り
については本発明鋼は従来鋼よりも優れた値を示しな。From the results shown in Table 2, the tensile strength of the steel of the present invention was comparable to that of the conventional steel. Furthermore, regarding elongation and reduction of area, the steel of the present invention exhibits better values than the conventional steel.
次に、供試鋼を２０で６ｍ直径に鍛伸した後、ＪＩＳＢ
号試験片を作成し、焼入類もどし処理をしＩ−ＩＲＣ５
１に調整してから、常温でシャルピー衝撃値を測定した
。得られた結果は第２表に示した。Next, after forging the test steel to a diameter of 6 m at 20, JISB
I-IRC5
After adjusting to 1, the Charpy impact value was measured at room temperature. The results obtained are shown in Table 2.
第２表の衝撃値の結果より明らかなように、比較鋼の衝
撃値が３ 、６ ｋｇｆｍ／ ０ｍ２であり、従来鋼の
衝撃値が１ 、０〜３ 、２ ｋｇｆｍ／ ０ｍ２であ
るのに対し、本発明鋼は３ 、９〜５ 、１ ｋｇｆｔ
ｎ／ ０ｍ２であって、本発明鋼の靭性が向上している
ことが確認された。As is clear from the impact value results in Table 2, the impact value of the comparative steel is 3,6 kgfm/0m2, whereas the impact value of conventional steel is 1,0~3,2 kgfm/0m2. , the steel of the present invention has a weight of 3,9~5,1 kgft
n/0 m2, and it was confirmed that the toughness of the steel of the present invention was improved.
次に、供試鋼について実体ばね疲労試験を行った。厚さ
１５ｍｍ、幅７０ｍｍの板を用い、板厚が７〜１３＋ｎ
ｍ、板幅７０ｍｍになるように圧延し、長さ１００ ｍ
ｍのＬＴＬばねとした。処理条件としてオーステナイト
化温度８８０℃、焼入温度７００℃でオースフォーミン
グ処理を施して試作し、ショットピーニングを施した後
、平均応力６５ ｋｇｆ ／ ＋ａｍ２、振幅応力５０
ｋｇｆ／ｍｍ２で各鋼種３枚づつ試・験を行った。また
、結晶粒度についても測定し、併せて第２表に示した。Next, a physical spring fatigue test was conducted on the sample steel. Using a plate with a thickness of 15 mm and a width of 70 mm, the plate thickness is 7 to 13 + n
m, rolled to a plate width of 70 mm, length 100 m
An LTL spring of m was used. A prototype was produced by performing ausforming treatment at an austenitizing temperature of 880°C and a quenching temperature of 700°C as processing conditions, and after shot peening, the average stress was 65 kgf/+am2, and the amplitude stress was 50.
Three sheets of each steel type were tested at kgf/mm2. In addition, the crystal grain size was also measured and shown in Table 2.
第２表の結果より、比較鋼および従来鋼は板ばねの表層
部でフェライト・パーライト変態を起こし、不完全焼入
組織となり、疲労強度は比較鋼で１５万回、従来鋼で７
〜１０万回弱であり、結晶粒度も粗い。From the results in Table 2, the comparative steel and conventional steel undergo ferrite-pearlite transformation in the surface layer of the leaf spring, resulting in an incompletely quenched structure, and the comparative steel has a fatigue strength of 150,000 cycles and the conventional steel has a fatigue strength of 7.
~100,000 times or less, and the crystal grain size is coarse.
これに対して、本発明鋼はいずれも板ばねの表層部も中
心部も完全なマルテンサイト組織を示し、５０万回まで
未折損で、結晶粒度も１１前後と優れており、本発明の
効果が確認された。On the other hand, the steel of the present invention exhibits a perfect martensitic structure in both the surface layer and the center of the leaf spring, remains unbroken up to 500,000 cycles, and has an excellent crystal grain size of around 11, which shows the effects of the present invention. was confirmed.
［発明の効果］
本発明の高疲労強度ばね用鋼は以上説明したように、従
来のばね用鋼にＭｏおよびＢを添加することにより、結
晶粒を微細化するとともに、オーステナイト禦域を拡大
し、焼入性を改善することにより、オーステナイトの状
態で圧延加工および目玉形成等の熱間加工が可能であっ
て、フェライト・パーライト変態が開始する前に焼入す
ることができるので、強度および靭性が数構されるとと
もに、疲労寿命が飛躍的に向上するという優れた効果が
ある。その結果強度の向上外が板厚の減少を可能とし、
重ね板ばねの軽量化を達成できる。[Effects of the Invention] As explained above, the high fatigue strength spring steel of the present invention refines the crystal grains and expands the austenite area by adding Mo and B to the conventional spring steel. By improving hardenability, it is possible to perform hot working such as rolling and eyeball formation in the austenitic state, and quenching can be performed before the ferrite-pearlite transformation begins, resulting in improved strength and toughness. This has the excellent effect of dramatically improving fatigue life. As a result, it is possible to reduce the plate thickness while improving the strength.
It is possible to reduce the weight of stacked leaf springs.
Claims (1)
１５〜０．３５％、Ｍｎ；０．７０〜１．５０％、Ｃｒ
；０．５０〜１．１０％、Ｍｏ；０．１０〜０．４０％
、Ｖ；０．１０〜０．３０％を含有し、残部がＦｅなら
びに不純物元素からなることを特徴とする高疲労強度ば
ね用鋼。 （２）重量比でＣ；０．４０〜０．６５％、Ｓｉ；０．
１５〜０．３５％、Ｍｎ；０．７０〜１．５０％、Ｃｒ
；０．５０〜１．１０％、Ｍｏ；０．１０〜０．４０％
、Ｖ；０．１０〜０．３０％、Ｂ；０．０００５〜０．
０１００％を含有し、残部がＦｅならびに不純物元素か
らなることを特徴とする高疲労強度ばね用鋼。 （３）重量比でＣ；０．４０〜０．６５％、Ｓｉ；０．
１５〜０．３５％、Ｍｎ；０．７０〜１．５０％、Ｃｒ
；０．５０〜１．１０％、Ｍｏ；０．１０〜０．４０％
、Ｖ；０．１０〜０．３０％、Ｂ；０．０００５〜０．
０１００％、Ｎｂ；０．０５〜０．３０％を含有し、残
部がＦｅならびに不純物元素からなることを特徴とする
高疲労強度ばね用鋼。（４）重量比でＣ；０．４０〜０
．６５％、Ｓｉ；０．１５〜０．３５％、Ｍｎ；０．７
０〜１．５０％、Ｃｒ；０．５０〜１．１０％、Ｍｏ；
０．１０〜０．４０％、Ｖ；０．１０〜０．３０％を含
有し、残部がＦｅならびに不純物元素からなる鋼を、８
００〜９５０℃の温度でオーステナイト化した後圧延加
工し、５００℃の温度に降下する前に焼入し、その後焼
もどしを施すことを特徴とする高疲労強度ばね用鋼の製
造方法。 （５）重量比でＣ；０．４０〜０．６５％、Ｓｉ；０．
１５〜０．３５％、Ｍｎ；０．７０〜１．５０％、Ｃｒ
；０．５０〜１．１０％、Ｍｏ；０．１０〜０．４０％
、Ｖ；０．１０〜０．３０％、Ｂ；０．０００５〜０．
０１００％を含有し、残部がＦｅならびに不純物元素か
らなる鋼を、８００〜９５０℃の温度でオーステナイト
化した後圧延加工し、５００℃の温度に降下する前に焼
入し、その後焼もどしを施すことを特徴とする高疲労強
度ばね用鋼の製造方[Claims] (1) Weight ratio: C: 0.40 to 0.65%, Si: 0.
15-0.35%, Mn; 0.70-1.50%, Cr
;0.50~1.10%, Mo;0.10~0.40%
, V; 0.10 to 0.30%, with the remainder consisting of Fe and impurity elements. (2) Weight ratio of C: 0.40 to 0.65%, Si: 0.
15-0.35%, Mn; 0.70-1.50%, Cr
;0.50~1.10%, Mo;0.10~0.40%
, V; 0.10-0.30%, B; 0.0005-0.
A high fatigue strength spring steel characterized by containing 100% of Fe and the remainder consisting of Fe and impurity elements. (3) Weight ratio of C: 0.40 to 0.65%, Si: 0.
15-0.35%, Mn; 0.70-1.50%, Cr
;0.50~1.10%, Mo;0.10~0.40%
, V; 0.10-0.30%, B; 0.0005-0.
A high fatigue strength spring steel characterized by containing 0.0100%, Nb: 0.05 to 0.30%, and the remainder consisting of Fe and impurity elements. (4) C by weight ratio: 0.40-0
．． 65%, Si; 0.15-0.35%, Mn; 0.7
0-1.50%, Cr; 0.50-1.10%, Mo;
0.10 to 0.40%, V; 0.10 to 0.30%, and the balance is Fe and impurity elements.
A method for producing a high fatigue strength spring steel, which comprises austenitizing at a temperature of 00 to 950°C, followed by rolling, quenching before dropping to a temperature of 500°C, and then tempering. (5) Weight ratio of C: 0.40 to 0.65%, Si: 0.
15-0.35%, Mn; 0.70-1.50%, Cr
;0.50~1.10%, Mo;0.10~0.40%
, V; 0.10-0.30%, B; 0.0005-0.
A steel containing 100% Fe and the remainder consisting of Fe and impurity elements is austenitized at a temperature of 800 to 950°C, then rolled, quenched before dropping to a temperature of 500°C, and then tempered. A method for producing high fatigue strength spring steel characterized by
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13976489A JPH036351A (en) | 1989-05-31 | 1989-05-31 | High fatigue strength spring steel and its manufacture |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13976489A JPH036351A (en) | 1989-05-31 | 1989-05-31 | High fatigue strength spring steel and its manufacture |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH036351A true JPH036351A (en) | 1991-01-11 |
Family
ID=15252850
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP13976489A Pending JPH036351A (en) | 1989-05-31 | 1989-05-31 | High fatigue strength spring steel and its manufacture |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH036351A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH062074A (en) * | 1992-06-19 | 1994-01-11 | Sumitomo Metal Ind Ltd | Spring steel excellent in hardenability |
| KR20010060753A (en) * | 1999-12-28 | 2001-07-07 | 이구택 | Method for manufacturing low alloy type spring having high strength |
| KR100833051B1 (en) * | 2006-12-20 | 2008-05-27 | 주식회사 포스코 | Steel wire rod for high strength spring, method for producing the same |
| CN104947005A (en) * | 2015-06-08 | 2015-09-30 | 舞阳钢铁有限责任公司 | Large-thickness and high-performance hydroforming 14Cr1MoR steel plate and production method thereof |
-
1989
- 1989-05-31 JP JP13976489A patent/JPH036351A/en active Pending
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH062074A (en) * | 1992-06-19 | 1994-01-11 | Sumitomo Metal Ind Ltd | Spring steel excellent in hardenability |
| KR20010060753A (en) * | 1999-12-28 | 2001-07-07 | 이구택 | Method for manufacturing low alloy type spring having high strength |
| KR100833051B1 (en) * | 2006-12-20 | 2008-05-27 | 주식회사 포스코 | Steel wire rod for high strength spring, method for producing the same |
| CN104947005A (en) * | 2015-06-08 | 2015-09-30 | 舞阳钢铁有限责任公司 | Large-thickness and high-performance hydroforming 14Cr1MoR steel plate and production method thereof |
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