JPS6347336A - Production of high-strength spring steel - Google Patents
Production of high-strength spring steelInfo
- Publication number
- JPS6347336A JPS6347336A JP19150986A JP19150986A JPS6347336A JP S6347336 A JPS6347336 A JP S6347336A JP 19150986 A JP19150986 A JP 19150986A JP 19150986 A JP19150986 A JP 19150986A JP S6347336 A JPS6347336 A JP S6347336A
- Authority
- JP
- Japan
- Prior art keywords
- steel
- rolling
- ferrite
- austenite
- strength
- 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 description 14
- 238000004519 manufacturing process Methods 0.000 title claims description 8
- 238000001816 cooling Methods 0.000 claims abstract description 24
- 229910000859 α-Fe Inorganic materials 0.000 claims abstract description 20
- 238000005096 rolling process Methods 0.000 claims abstract description 16
- 229910000831 Steel Inorganic materials 0.000 claims abstract description 13
- 229910001566 austenite Inorganic materials 0.000 claims abstract description 13
- 239000010959 steel Substances 0.000 claims abstract description 13
- 238000001953 recrystallisation Methods 0.000 claims abstract description 6
- 238000000034 method Methods 0.000 claims abstract description 5
- 239000000463 material Substances 0.000 claims description 19
- 229910000734 martensite Inorganic materials 0.000 claims description 10
- 239000012535 impurity Substances 0.000 claims description 2
- 229910001562 pearlite Inorganic materials 0.000 claims description 2
- 238000010791 quenching Methods 0.000 abstract description 7
- 238000005496 tempering Methods 0.000 abstract description 6
- 230000000171 quenching effect Effects 0.000 abstract description 5
- 239000000523 sample Substances 0.000 description 9
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 3
- 229910052799 carbon Inorganic materials 0.000 description 3
- 238000010438 heat treatment Methods 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 229910001563 bainite Inorganic materials 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- 238000005336 cracking Methods 0.000 description 2
- 238000009792 diffusion process Methods 0.000 description 2
- 238000005098 hot rolling Methods 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 229910000885 Dual-phase steel Inorganic materials 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 238000005261 decarburization Methods 0.000 description 1
- 230000009977 dual effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 238000010583 slow cooling Methods 0.000 description 1
- 238000009864 tensile test Methods 0.000 description 1
Landscapes
- Heat Treatment Of Steel (AREA)
- Heat Treatment Of Articles (AREA)
Abstract
Description
【発明の詳細な説明】
［産業上の利用分野］
末完ＩＪ１は、高強度ばね鋼の製造方法に関する。特に
、たとえば、重ね板ばね、コイルばね、トーションバー
等に使用するに好適な高強度ばね鋼の製造方法に係る。DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] Seikan IJ1 relates to a method for manufacturing high-strength spring steel. In particular, the present invention relates to a method of manufacturing high-strength spring steel suitable for use in, for example, stacked leaf springs, coil springs, torsion bars, and the like.
［従来技術］
ばね鋼には機械的性質として高い捩り耐力と高い疲労限
が求められている。[Prior Art] Spring steel is required to have high torsional strength and high fatigue limit as mechanical properties.
かかる特性を有する鋼として従来５ＵＰ７ （化学成分
Ｃ：０．６％、Ｓｔ：２．０％、Ｍｎ：０．８５、Ｐ：
（１０３５％以下、Ｓ：０．０３５％以下）が知られて
いる。Conventional steel with such characteristics is 5UP7 (chemical composition C: 0.6%, St: 2.0%, Mn: 0.85, P:
(1035% or less, S: 0.035% or less) is known.
すなわち、５ＵＰ７においては高炭素を基本成分とし、
耐力を高める目的でＳｉを２％程度含有せしめている。In other words, in 5UP7, high carbon is the basic component,
Approximately 2% Si is contained in order to increase yield strength.
この鋼は所望の強度（約１８０ｋｇ ｆ ／ ｍｍ’）
と延靭性を得るために油焼入れ（焼き割れ防止のため油
焼入を行なう）の後焼戻しの熱処理が施されている。This steel has the desired strength (approximately 180 kg f/mm')
After oil quenching (oil quenching is performed to prevent quench cracking) to obtain ductility and toughness, a heat treatment of tempering is performed.
しかし、焼入、焼戻の熱処理を行なうことは工程数及び
費用等がかかる。However, performing heat treatments such as quenching and tempering requires a large number of steps and costs.
そこで、ばね鋼を非調質化して、所望の強度と延靭性を
得ようとする試みがなされている。Therefore, attempts have been made to non-thermalize spring steel to obtain desired strength and ductility.
かかる試みとしては次のものがある。Such attempts include:
かかる試みとしては、従来材のマルテンサイト型組の組
織に対して■マルテンサイト中ベイナイト（特開昭６ｌ
−３０６５３）、■フェライト＋マルテンサイト（特開
昭６ｌ−３０６５０）の二相組織鋼にする技術である。As an attempt to do this, the structure of the martensite-type structure of the conventional material was changed to ■ Martensite-medium bainite (Japanese Patent Application Laid-open No.
-30653), (2) A technology to produce steel with a dual phase structure of ferrite + martensite (Japanese Patent Application Laid-Open No. 61-30650).
［発明が解決しようとする問題点］
上記の製造方法では、例えば■では強制空冷程度の冷却
速度で一部をベイナイト組織にし、そのために従来材よ
り高めの炭素当量に組成を調整している。また、■では
直接急冷することにより目的の強度が得られるように低
炭素マルテンサイトとフェライトの二相鋼にし、かつ圧
延を二相域まで行ない、焼入れすることを特徴としてい
る。[Problems to be Solved by the Invention] In the above manufacturing method, for example, in (2), a part of the material is made into a bainite structure at a cooling rate comparable to forced air cooling, and the composition is therefore adjusted to have a higher carbon equivalent than conventional materials. In addition, (2) is characterized in that it is made into a dual-phase steel of low carbon martensite and ferrite so that the desired strength can be obtained by direct quenching, and that it is rolled to the dual-phase region and then quenched.
しかし、本発明は、急冷することにより、■のような特
別の元素を添加せず、かつ■の場合と異なり圧延をオー
ステナイト域で終了し、その後の急冷と、冷却停止温度
を制御し、巻取るまでのコンベア上でもしくは集束した
状態で焼戻すことにより、目的の強度とばね特性を付４
することを目的としている０本方法によれば、組織は極
めて等方的なフェライトがマルテンサイト中に均一分散
した組織となり、すぐれたばね特性を示すことを見出し
たものである。However, in the present invention, by performing rapid cooling, special elements such as (2) are not added, and unlike in (2), rolling is finished in the austenite region, and the subsequent rapid cooling and cooling stop temperature are controlled, and the rolling By tempering on the conveyor or in a focused state until the material is removed, the desired strength and spring characteristics are imparted.
It has been discovered that, according to the method aimed at achieving this, the structure becomes a structure in which extremely isotropic ferrite is uniformly dispersed in martensite, and exhibits excellent spring characteristics.
［問題点を解決するための手段］
本発明は、重量％でＣ：０．２〜０．４゜Ｓｉ：１．０
〜３．０、Ｍｎ：≦１．５を含み残部はＦｅ及び不可避
的不純物から成る鋼の圧延をオーステナイトの再結晶域
で終了した後、温度を制御して該圧延材をフェライト十
オーステナイトの二相域にした後、５０℃／ｓｅｃ以上
の冷却速度で１００℃〜１６０℃の温度範囲まで急冷し
、その後該圧延材を恒温保持しフェライト＋マルテンサ
イト組織とすることを特徴とする。[Means for solving the problems] The present invention provides C: 0.2 to 0.4°Si: 1.0 in weight%
~3.0, Mn: ≦1.5 and the remainder consists of Fe and unavoidable impurities. After finishing the rolling of the steel in the austenite recrystallization region, the temperature is controlled to transform the rolled material into ferrite and austenite. After being brought into the phase range, the rolled material is rapidly cooled to a temperature range of 100°C to 160°C at a cooling rate of 50°C/sec or more, and then the rolled material is kept at a constant temperature to form a ferrite + martensitic structure.
以下に本発明において成分元素及び圧延後の熱処理条件
を限定した理由を示す。The reasons for limiting the component elements and post-rolling heat treatment conditions in the present invention will be shown below.
ＣはＳｉ：ｌ−０〜３．０％を含むフェライト＋マルテ
ンサイト鋼において、０．２％より少ない場合、圧延後
の強度が不十分となる。一方、Ｃを０．４％より多く含
む場合は強度は十分であるが焼割れが生じる場合がある
。When C is less than 0.2% in ferritic + martensitic steel containing Si:l-0 to 3.0%, the strength after rolling becomes insufficient. On the other hand, if it contains more than 0.4% of C, the strength is sufficient, but quench cracking may occur.
Ｓｔについては、ばねの特性上１．０％以上必要である
が、３％を越えると脱炭が生じるという問題がある。Regarding St, 1.0% or more is required due to the characteristics of the spring, but if it exceeds 3%, there is a problem that decarburization occurs.
Ｍｎは以下にのべる冷却を行う時にＭｓ点およびＭｆ点
を高くする必要がある事から限定されたもので、Ｍｓ点
を低くする元素であるＭｎはＭｓ点を高くするために１
．５％以下とする必要がある。なお、０．３５Ｃ−２，
０５ｉ−１，５Ｍｎとした場合にはＭｓ点は約３５０℃
である。Mn is limited because it is necessary to raise the Ms point and Mf point when performing the cooling described below, and Mn, which is an element that lowers the Ms point, is used in order to raise the Ms point.
．． It needs to be 5% or less. In addition, 0.35C-2,
In the case of 05i-1,5Mn, the Ms point is approximately 350℃
It is.
圧延をオーステナイトの再結晶域で終了するのはばねの
耐捩り耐力を高くするためである。圧延を過度に行なう
と圧延により素材に異方性が生じ、線軸方向のみ強度が
増加してばねの耐捩り応力性は増加しない事による。つ
まり、ばねは一般に捩り応力がかかった状態で動作する
ものであるため異方性化による線軸方向のみの高強度化
は好ましくないからである。The purpose of finishing the rolling in the austenite recrystallization region is to increase the torsional strength of the spring. If rolling is performed excessively, anisotropy will occur in the material due to rolling, and the strength will only increase in the axial direction, but the torsional stress resistance of the spring will not increase. In other words, since springs generally operate under torsional stress, it is not desirable to increase the strength only in the axial direction by making them anisotropic.
なお、オーステナイトの再結晶域で圧延を終了した後は
２相域までは徐冷してもよい。Note that after the rolling is completed in the austenite recrystallization region, slow cooling may be performed until the two-phase region is reached.
また、圧延材がフェライト十オーステナイトの２相とな
るまで圧延後の温度を制御するのはＳｉを初析フェライ
ト中へ十分均一に拡散させるためである。拡散が不十分
な場合は拡散が十分な場合に比べ強度が約１５ ｋｇｆ
／ｍｍ２低下することになる。Further, the temperature after rolling is controlled until the rolled material becomes two phases of ferrite decaustenite in order to sufficiently uniformly diffuse Si into the pro-eutectoid ferrite. When diffusion is insufficient, the strength is approximately 15 kgf compared to when diffusion is sufficient.
/mm2.
圧延材をフェライト十オーステナイトの二相域にした後
１００℃〜１６０℃の温度範囲まで急冷するのは、速い
冷却速度（例えば水冷却）により冷却を行ない、冷却停
止温度を１００℃〜１６０℃とした場合には第２表に示
すように十分な延性が確保できることを見出したことに
よる。すなわち、室温まで完全冷却した場合（第２表■
の場合）には延性が極めて低くなる。Rapidly cooling the rolled material to a temperature range of 100°C to 160°C after converting it into a two-phase region of ferrite deaustenite is performed by cooling at a fast cooling rate (e.g. water cooling) and setting the cooling stop temperature to 100°C to 160°C. This is due to the discovery that sufficient ductility can be ensured as shown in Table 2 when In other words, when completely cooled to room temperature (Table 2 ■
), the ductility is extremely low.
冷却時の冷却速度は５０℃／ｓｅｃ以上の速さが必要で
ある。The cooling rate during cooling must be 50° C./sec or more.
急冷後は冷却停止温度で恒温保持し、フェライト＋マル
テンサイト組織とする。After rapid cooling, the temperature is maintained constant at the cooling stop temperature to form a ferrite + martensitic structure.
なお、圧延後徐冷したフェライト＋パーライト組織を有
するばね鋼を２相域に再加熱した場合にも本発明は適用
できる。Note that the present invention can also be applied to a case where a spring steel having a ferrite + pearlite structure that has been slowly cooled after rolling is reheated to a two-phase region.
［発明の実施例］ 第１表に示す化学成分のばね鋼を溶製した。[Embodiments of the invention] Spring steel having the chemical composition shown in Table 1 was produced.
第１表
Ｍｓ点：３６４℃
このばね鋼につき熱間圧延を行なった。熱間圧延はオー
ステナイト再結晶域で終了した。Table 1 Ms point: 364°C This spring steel was hot rolled. Hot rolling ended in the austenite recrystallization zone.
熱間圧延終了後、１〜ｂ
で温度制御して圧延材をフェライト十オーステナイトの
２相城とした。After the hot rolling was completed, the temperature was controlled in steps 1 to b to make the rolled material a two-phase castle of ferrite and ten austenite.
フェライト十オーステナイトの２相域とした圧延材のう
ちの１つを８５５℃から常温まで水冷して供試材■を得
た。また、８５５℃から１５０℃まで水冷し、水冷後３
００℃に０．５時間恒温保持してフェライト＋マルテン
サイト組織として供試材■を得、８５５℃から１６０℃
まで水冷し、水冷後その温度に０．５時間恒温保持して
フェライト＋マルテンサイト組織として供試材■を得た
。供試材■は比較例であり、供試材■及び■は本発明の
実施例である。One of the rolled materials made into a two-phase region of ferrite decaustenite was water-cooled from 855° C. to room temperature to obtain sample material (2). In addition, water cooling was performed from 855°C to 150°C, and after water cooling,
The sample material ■ was obtained as a ferrite + martensitic structure by maintaining the temperature at 00°C for 0.5 hours, and the temperature was increased from 855°C to 160°C.
After cooling with water, the sample was kept constant at that temperature for 0.5 hours to obtain sample material (2) as a ferrite + martensitic structure. Sample material (1) is a comparative example, and sample materials (2) and (2) are examples of the present invention.
以上のようにして作成した供試材につき以下の機械的性
質を試験した。The following mechanical properties were tested for the sample materials prepared as described above.
（延性）
引張試験を行ない、その破断絞りにより延性を評価した
。(Ductility) A tensile test was conducted, and the ductility was evaluated based on the rupture area.
その結果を第２表に示す。The results are shown in Table 2.
第２表
第２表に示すように本発明の実施例に係る供試材（供試
材■及び■）は４５〜５６％の破断絞りを示し十分に延
性があることがわかる。それに対し、比較例（供試材■
）は８％と低い破断絞りを示している。Table 2 As shown in Table 2, the test materials according to the examples of the present invention (test materials ① and ①) exhibited a reduction in area at break of 45 to 56%, indicating that they were sufficiently ductile. On the other hand, comparative example (sample material ■
) shows a low rupture area of 8%.
また、引張強さも本発明の実施例は１８０ｋｇｆ ／
ｍ ｒｎ’以上を示している。Furthermore, the tensile strength of the embodiment of the present invention is 180 kgf/
m rn' or more is shown.
（耐へたり性）
耐へたり性については第３表に示すコイルを製造し、こ
のコイルにつき、
試験条件 セツティング １０８ ｋｇｆ／履ｍ２試
験応力 １００ ｋｇｆ／＊ｍ２で、締付けて７２
時間保持し、７２時間後の残留せん断歪を測定すること
により評価した。(Settling resistance) Regarding the setting resistance, coils shown in Table 3 were manufactured, and the coils were tested under the following conditions: Setting 108 kgf/m2 Test stress: 100 kgf/*m2, tightening to 72 kgf/*m2
The evaluation was made by holding the sample for a period of time and measuring the residual shear strain after 72 hours.
第３表 その結果を第４表に示す。Table 3 The results are shown in Table 4.
第４表
第４表に示すように従来例である５ＵＰ７ばね鋼材と比
較して本発明銅鋼は残留せん断歪が少ない事から十分な
耐へたり性を有していることが分る。Table 4 As shown in Table 4, compared to the conventional 5UP7 spring steel, the copper steel of the present invention has less residual shear strain, indicating that it has sufficient fatigue resistance.
［発明の効果］
本発明の高強度ばね鋼の製造方法によれば、従来からあ
るフェライトマルテンサイト組織のばね鋼と同等以上の
機械的性質を有するばね鋼を焼入れ、焼戻しを省略して
低コストで製造する方法が提供できる。[Effects of the Invention] According to the method for manufacturing high-strength spring steel of the present invention, a spring steel having mechanical properties equivalent to or higher than conventional spring steel with a ferritic martensitic structure is quenched and tempering is omitted, resulting in a low cost. We can provide a manufacturing method.
手続補正書 ご 昭和６２年 ５月、１４日 ４＋１ＪProcedural amendment Go May 14th, 1986 4+1J
Claims (2)
．０．Ｍｎ：≦１．５を含み残部はＦｅ及び不可避的不
純物から成る鋼の圧廷をオーステナイトの再結晶域で終
了した後、温度を制御して該圧延材をフェライト＋オー
ステナイトの二相域にした後５０℃／ｓｅｃ以上の冷却
速度で１００℃〜１６０℃の温度範囲まで急冷し、その
後該圧延材を恒温保持しフェライト＋マルテンサイト組
織とすることを特徴とする高強度ばね鋼の製造方法。(1) C: 0.2-0.4, Si: 1.0-3 in weight%
．． 0. After rolling the steel containing Mn:≦1.5 and the remainder consisting of Fe and unavoidable impurities in an austenite recrystallization region, the temperature was controlled to make the rolled material into a two-phase region of ferrite + austenite. A method for producing high-strength spring steel, which comprises rapidly cooling the rolled material to a temperature range of 100°C to 160°C at a cooling rate of 50°C/sec or more, and then maintaining the rolled material at a constant temperature to form a ferrite + martensitic structure.
た後再加熱しフェライト＋オーステナイト二相組織にし
た特許請求の範囲第１項記載の高強度ばね鋼の製造方法
。(2) The method for manufacturing a high-strength spring steel according to claim 1, wherein after rolling, the steel is gradually cooled to form a ferrite + pearlite structure, and then reheated to form a ferrite + austenite two-phase structure.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19150986A JPS6347336A (en) | 1986-08-14 | 1986-08-14 | Production of high-strength spring steel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19150986A JPS6347336A (en) | 1986-08-14 | 1986-08-14 | Production of high-strength spring steel |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS6347336A true JPS6347336A (en) | 1988-02-29 |
Family
ID=16275836
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP19150986A Pending JPS6347336A (en) | 1986-08-14 | 1986-08-14 | Production of high-strength spring steel |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6347336A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0974676A3 (en) * | 1998-07-20 | 2003-06-04 | Firma Muhr und Bender | Process for thermo-mechanically treating steel for torsion spring elements |
-
1986
- 1986-08-14 JP JP19150986A patent/JPS6347336A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0974676A3 (en) * | 1998-07-20 | 2003-06-04 | Firma Muhr und Bender | Process for thermo-mechanically treating steel for torsion spring elements |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP4018905B2 (en) | Hot rolled wire rod and bar for machine structure and manufacturing method thereof | |
| JP2012041587A (en) | Wire for machine part excellent in high strength and hydrogen embrittlement resistance characteristic, steel wire, and the machine part and method for manufacturing the same | |
| JPH0257637A (en) | Manufacture of spring with high fatigue strength and steel wire for spring for use therein | |
| US4702778A (en) | Method for softening rolled medium carbon machine structural steels | |
| JPS5921370B2 (en) | Manufacturing method for highly ductile and high tensile strength wire with excellent stress corrosion cracking resistance | |
| JPS62199718A (en) | Direct softening method for rolling material of steel for machine structural use | |
| JPH05105957A (en) | Production of heat resistant high strength bolt | |
| JPH1161272A (en) | Manufacture of high carbon cold-rolled steel plate excellent in formability | |
| WO2019186257A1 (en) | A high ductile bainitic steel and a method of manufacturing thereof | |
| CN114929922B (en) | Wire rod and part for cold forging each having excellent delayed fracture resistance characteristics and method for manufacturing the same | |
| JPH036981B2 (en) | ||
| JP2000336460A (en) | Hot rolled wire rod and steel bar for machine structure and manufacture of the same | |
| JPS6347336A (en) | Production of high-strength spring steel | |
| JPS62253724A (en) | Production of wire rod for cold forging having granular cementite structure | |
| JPH0219175B2 (en) | ||
| JPH0576522B2 (en) | ||
| KR102494554B1 (en) | Steel for tool and manufacturing method for the same | |
| JPH04329824A (en) | Production of martensitic stainless steel for cold forging | |
| JP2919642B2 (en) | Manufacturing method of high carbon steel for tempering with excellent toughness and fatigue resistance | |
| JPH01195242A (en) | Manufacture of high tension steel plate having superior toughness at low temperature with uniformity in thickness direction | |
| JPH02175817A (en) | Manufacture of hot-rolled high-tensile steel plate having dual-phase structure and excellent in workability | |
| JPS62280326A (en) | Non-heattreated steel material for bolt excellent in toughness | |
| JPS63303036A (en) | High-strength steel wire | |
| JPH04131323A (en) | Production of heat treatment saving type high tensile steel wire having excellent fatigue resistance and wear resistance | |
| JPH0445227A (en) | Production of steel product with low yield ratio |