JP2544738B2 - High strength spring material manufacturing equipment - Google Patents
High strength spring material manufacturing equipmentInfo
- Publication number
- JP2544738B2 JP2544738B2 JP62145352A JP14535287A JP2544738B2 JP 2544738 B2 JP2544738 B2 JP 2544738B2 JP 62145352 A JP62145352 A JP 62145352A JP 14535287 A JP14535287 A JP 14535287A JP 2544738 B2 JP2544738 B2 JP 2544738B2
- Authority
- JP
- Japan
- Prior art keywords
- steel wire
- cooling
- temperature
- cooling medium
- cooling bath
- 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 - Fee Related
Links
- 239000000463 material Substances 0.000 title claims description 25
- 238000004519 manufacturing process Methods 0.000 title claims description 7
- 229910000831 Steel Inorganic materials 0.000 claims description 47
- 239000010959 steel Substances 0.000 claims description 47
- 238000001816 cooling Methods 0.000 claims description 40
- 239000002826 coolant Substances 0.000 claims description 36
- 238000010438 heat treatment Methods 0.000 claims description 17
- 229910001566 austenite Inorganic materials 0.000 claims description 13
- 229910000975 Carbon steel Inorganic materials 0.000 claims description 4
- 239000010962 carbon steel Substances 0.000 claims description 4
- 239000007788 liquid Substances 0.000 claims description 4
- 238000000034 method Methods 0.000 claims description 4
- 229910000851 Alloy steel Inorganic materials 0.000 claims description 3
- 230000008569 process Effects 0.000 claims description 3
- 230000009466 transformation Effects 0.000 description 18
- 229910000734 martensite Inorganic materials 0.000 description 7
- 229910001563 bainite Inorganic materials 0.000 description 5
- 239000002131 composite material Substances 0.000 description 4
- 238000010586 diagram Methods 0.000 description 4
- 229910001562 pearlite Inorganic materials 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- 229910000639 Spring steel Inorganic materials 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 230000003247 decreasing effect Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000010410 layer Substances 0.000 description 2
- 239000002344 surface layer Substances 0.000 description 2
- 238000005491 wire drawing Methods 0.000 description 2
- 229910000859 α-Fe Inorganic materials 0.000 description 2
- FBPFZTCFMRRESA-JGWLITMVSA-N D-glucitol Chemical compound OC[C@H](O)[C@@H](O)[C@H](O)[C@H](O)CO FBPFZTCFMRRESA-JGWLITMVSA-N 0.000 description 1
- 229910001035 Soft ferrite Inorganic materials 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 238000005485 electric heating Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000006698 induction Effects 0.000 description 1
- 229910052943 magnesium sulfate Inorganic materials 0.000 description 1
- 235000019341 magnesium sulphate Nutrition 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 238000013021 overheating Methods 0.000 description 1
- 238000007781 pre-processing Methods 0.000 description 1
- 238000010791 quenching Methods 0.000 description 1
- 230000000171 quenching effect Effects 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 238000004904 shortening Methods 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 239000002436 steel type Substances 0.000 description 1
- 230000003746 surface roughness Effects 0.000 description 1
- 239000000725 suspension Substances 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
Landscapes
- Metal Extraction Processes (AREA)
- Heat Treatment Of Steel (AREA)
Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明は、例えば自動車の懸架用ばねや弁ばね等の線
状ばねの材料を高強度化させるために使われる高強度ば
ね材料の製造装置に関する。DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an apparatus for producing a high-strength spring material used to increase the strength of a material for a linear spring such as a suspension spring for an automobile or a valve spring. Regarding
高張力鋼線あるいは強靭性鋼線の製造方法として、特
公昭46−27138号公報（先行技術１）や特公昭57−19168
号公報（先行技術２）などに示されているようなオース
フォーミングを用いた製造方法が提案されている。As a method for producing a high-strength steel wire or a tough steel wire, Japanese Patent Publication No. 27138/1976 (prior art 1) and Japanese Patent Publication No. 57-19168
A manufacturing method using ausforming as disclosed in Japanese Unexamined Patent Application Publication (Prior Art 2) and the like has been proposed.
上記先行技術１は、加工性の問題から加工後の鋼線温
度をマルテンサイト生成温度（Ms点）以上とし、この時
60％以上の残留オーステナイトが残存するようにしてい
る。すなわち加工によって鋼線の変態速度が助長される
が、鋼線組織の40％以下であればオーステナイト以外の
変態生成物の混在を許容している。In the prior art 1 described above, the temperature of the steel wire after processing is set to the martensite formation temperature (Ms point) or higher due to the problem of workability.
At least 60% of retained austenite remains. That is, the transformation speed of the steel wire is promoted by working, but if 40% or less of the steel wire structure is allowed, the inclusion of transformation products other than austenite is allowed.
一方、先行技術２は先行技術１と類似の方法である
が、加工後に恒温変態処理を行なうことによって、微細
なフェライト・セメンタイト組織を得ることを特徴とし
ている。On the other hand, the prior art 2 is similar to the prior art 1, but is characterized by obtaining a fine ferrite-cementite structure by performing a constant temperature transformation treatment after processing.
しかしながら先行技術１のように、オーステナイト以
外の変態生成物（例えばベーナイトとかフェライト・パ
ーライトなど）とオーステナイトとが混在した状態から
焼入れが行なわれた鋼線は、オーステナイト以外の変態
生成物とオーステナイトの変態したマルテンサイトから
なる複合組織になってしまうため、高強度ばね鋼に必要
とされる強度・延性バランスは得られない。すなわち一
般に延性が低いものである。このため、高強度ばね鋼に
するには加工後きわめて短時間に焼入れを行なう必要が
ある。However, as in Prior Art 1, a steel wire that has been quenched from a state in which a transformation product other than austenite (for example, bainite or ferrite / pearlite) and austenite are mixed has a transformation product other than austenite and a transformation of austenite. Since it becomes a composite structure composed of martensite, the strength / ductility balance required for high strength spring steel cannot be obtained. That is, the ductility is generally low. Therefore, in order to obtain high strength spring steel, it is necessary to perform quenching in an extremely short time after working.
一方、先行技術２のような複合組織を得る方法では、
組織中に柔らかいフェライト層を含んでいるため抗張力
で最大（160Kgfmm2程度の強度しか得られず、高強度ば
ね材料の目標値である200Kgfmm2には到底及ばなかっ
た。On the other hand, in the method of obtaining the composite structure as in the prior art 2,
Since the structure contains a soft ferrite layer, the maximum tensile strength (160Kgfmm 2) was obtained, which was far below the target value of 200Kgfmm 2 for high strength spring materials.
従って本発明の目的とするところは、オースフォーミ
ングによる伸線加工を行なう場合に、高強度ばね材料に
必要とされるマルテンサイト単相を生成できるとともに
表面状態が改善され、強度と延性バランスに優れたばね
材料が得られるような製造装置を提供することにある。Therefore, the object of the present invention is to produce a martensite single phase required for a high-strength spring material when wire drawing by ausforming is performed, and the surface condition is improved, which is excellent in strength and ductility balance. Another object of the present invention is to provide a manufacturing apparatus capable of obtaining a spring material.
上記目的を果たすために本発明では、炭素鋼線あるい
は合金鋼線Ａをオーステナイト化温度まで加熱する加熱
手段１と、この加熱手段１から送り出される鋼線Ａの搬
送下流側に配置されかつ鋼線ＡのMs点以上の温度に保た
れた冷却媒体３が収容されていてこの冷却媒体３に鋼線
Ａを通すことにより鋼線Ａを過冷オーステナイト温度ま
で冷却する冷却浴２と、この冷却浴２の出口部近傍に設
けられていて冷却浴２内の冷却媒体３によってこの冷却
媒体３と同等の温度に保たれかつ鋼線Ａを通すことによ
り鋼線Ａを塑性加工によって減面させる引抜き加工具７
と、この加工具７の出口側近傍に設けられて加工後の鋼
線ＡをMs点以下の温度まで急冷する冷却手段８とを具備
した製造装置を提供する。To achieve the above object, in the present invention, a heating means 1 for heating a carbon steel wire or an alloy steel wire A to an austenitizing temperature, and a steel wire arranged downstream of the steel wire A fed from the heating means 1 A cooling bath 2 which contains a cooling medium 3 kept at a temperature of Ms point A or higher and cools the steel wire A to a supercooled austenite temperature by passing the steel wire A through the cooling medium 3. 2 is provided in the vicinity of the exit of the cooling bath 2 and is kept at a temperature equal to that of the cooling medium 3 by the cooling medium 3 in the cooling bath 2 and the steel wire A is passed through the drawing process to reduce the surface of the steel wire A by plastic working. Tool 7
And a cooling means 8 provided near the outlet side of the processing tool 7 for rapidly cooling the steel wire A after processing to a temperature below the Ms point.
加工具７としては例えばダイスが使われるが、要する
に鋼線を引抜く際に塑性加工によって減面させるもので
あればよいから、ロール圧延、その他の加工具が適用で
きる。また、冷却浴２に収容される冷却媒体３として
は、溶融鉛や各種の塩浴用ソルト，流動層などを使うこ
とができる。As the processing tool 7, for example, a die is used. In short, roll processing or other processing tools can be applied as long as it can reduce the surface by plastic working when the steel wire is pulled out. Further, as the cooling medium 3 contained in the cooling bath 2, molten lead, various salt bath salts, fluidized bed, or the like can be used.
上述した本発明装置を用いて高強度ばね材料を製造す
るには、炭素鋼線または合金鋼線を上記加熱手段によっ
てオーステナイト化温度まで加熱したのち、冷却浴中の
冷却媒体に鋼線を通すことにより過冷オーステナイト温
度まで冷却する。そしてこの鋼線を引抜き加工具に通す
ことによって減面させる。この加工時においては、加工
具が上記冷却媒体と同等の温度に保たれているから、鋼
線が加工具に触れても鋼線の温度は低下しない。このた
め過冷オーステナイト状態を保ったまま正しい等温変態
を生じさせることができる。そして加工後の鋼線は、加
工具の出口側近傍に設けられている冷却手段によってMs
点以下の温度まで急冷させられ、短時間に組織が凍結さ
れる。To manufacture a high-strength spring material using the apparatus of the present invention described above, after heating the carbon steel wire or alloy steel wire to the austenitizing temperature by the heating means, pass the steel wire through the cooling medium in the cooling bath. To cool to the supercooled austenite temperature. Then, the steel wire is reduced by passing it through a drawing tool. During this processing, the temperature of the processing tool is maintained at the same temperature as the cooling medium, so that the temperature of the steel wire does not decrease even when the steel wire touches the processing tool. Therefore, a correct isothermal transformation can be generated while maintaining the supercooled austenite state. And the steel wire after processing is Ms by the cooling means provided near the exit side of the processing tool.
The tissue is frozen to a temperature below the point and the tissue is frozen in a short time.
以下、本発明の一実施例につき第１図ないし第７図を
参照して説明する。An embodiment of the present invention will be described below with reference to FIGS. 1 to 7.
ばね材料となる炭素鋼線Ａは、図示しない巻取りロー
ルなどから連続的に供給される。加熱手段１は、上記鋼
線Ａをオーステナイト化温度まで加熱するものであり、
例えば通電加熱あるいは高周波誘導加熱等が好適である
が、通常の加熱炉であってもよい。The carbon steel wire A, which is a spring material, is continuously supplied from a winding roll (not shown) or the like. The heating means 1 heats the steel wire A to an austenitizing temperature,
For example, electric heating or high frequency induction heating is suitable, but a normal heating furnace may be used.
この加熱手段１から送り出される鋼線Ａの搬送下流側
に、冷却浴２が配置されている。冷却浴２の槽2aの中に
は冷却媒体３の一例として溶融鉛が収容される。この冷
却媒体３は鋼線ＡのMs点以上の温度に保たれている。冷
却浴２の槽2aには、鋼線Ａを通すための孔4,5が開設さ
れている。そしてこの槽2aは、図示しない駆動機構によ
って、第２図に示される第１の位置と、第３図に示され
る第２の位置とにわたって水平軸回りに揺動可能として
あり、しかもいずれの位置でも保持できるようになって
いる。さらにこの槽2aは、上記第１の位置の時には後述
する加工具７が冷却媒体３から露出し、第２の位置の時
に加工具７が冷却媒体３に漬かるような形状に作られて
いる。The cooling bath 2 is arranged on the downstream side of the transportation of the steel wire A sent from the heating means 1. Molten lead is contained in the bath 2a of the cooling bath 2 as an example of the cooling medium 3. The cooling medium 3 is kept at a temperature equal to or higher than the Ms point of the steel wire A. Holes 4 and 5 for passing the steel wire A are formed in the bath 2a of the cooling bath 2. The tank 2a can be swung about a horizontal axis between a first position shown in FIG. 2 and a second position shown in FIG. 3 by a drive mechanism (not shown), and at any position. But you can hold it. Further, the tank 2a is formed in such a shape that the processing tool 7 described later is exposed from the cooling medium 3 in the first position and the processing tool 7 is immersed in the cooling medium 3 in the second position.
冷却浴２の出口端、すなわち出口部近傍に伸線加工具
７が設けられている。この加工具７の一例はダイスであ
り、連続的に鋼線Ａを通すことにより、所定の減面率で
引抜きを行なうようになっている。この加工具７は、第
３図に示されるように冷却媒体３に漬かることで冷却媒
体３と同等の温度に予熱される。A wire drawing tool 7 is provided at the outlet end of the cooling bath 2, that is, near the outlet. An example of the processing tool 7 is a die, and the steel wire A is continuously passed through to perform drawing with a predetermined surface reduction rate. This processing tool 7 is preheated to a temperature equivalent to that of the cooling medium 3 by immersing it in the cooling medium 3 as shown in FIG.
更に加工具７の出口側近傍に冷却手段８が設けられて
いる。この冷却手段８は、加工具７から引出された鋼線
ＡをMs点以下の温度まで急冷するためのもので、鋼線Ａ
の表面に水等の冷却媒体を吹付けるためのノズル９を備
えている。なお、鋼線Ａの鋼種や外径等によっては水の
代りに空気あるいは油等の冷却媒体を用いることも可能
である。Further, cooling means 8 is provided near the outlet side of the processing tool 7. The cooling means 8 is for rapidly cooling the steel wire A drawn from the processing tool 7 to a temperature below the Ms point.
Is provided with a nozzle 9 for spraying a cooling medium such as water on the surface thereof. Depending on the steel type and outer diameter of the steel wire A, a cooling medium such as air or oil may be used instead of water.
上記構成の本実施例装置を用いて高強度ばね材料Ａ′
を製造するには、第４図中に実線で示されるような温度
履歴を経てオースドローを行なう。まず、引抜き開始時
には、予め先付け加工により縮径されている鋼線Ａの先
端部を冷却浴２を通し、引抜き方向にセットするととも
に引抜き用のチャックでつかむ。この時、冷却浴２は第
２図に示されるような第１の位置に保持され、従って加
工具７の全部または大部分が冷却媒体３から露出した状
態にある。鋼線Ａをチャックしたのち、加工具７が冷却
媒体３に漬かるように、槽2aを第３図に示される第２の
位置まで傾ける。こうすることにより、冷却媒体３の液
面は第１図中の２点鎖線Ｐ付近まで相対的に上昇し、加
工具７は冷却媒体３とほぼ同一の温度（400〜500℃のMs
点より高く、ノーズより低い温度）まで予熱される。予
熱終了と同時に、鋼線Ａを第１図中の矢印方向に引抜く
とともに、冷却手段８による水冷を開始する。A high-strength spring material A ′ is manufactured by using the apparatus of this embodiment having the above-mentioned structure
In order to manufacture, the ausdrawing is performed through the temperature history shown by the solid line in FIG. First, at the start of drawing, the tip of the steel wire A, which has been previously reduced in diameter by pre-processing, is passed through the cooling bath 2, set in the drawing direction, and grasped by the drawing chuck. At this time, the cooling bath 2 is held in the first position as shown in FIG. 2, so that all or most of the working tool 7 is exposed from the cooling medium 3. After chucking the steel wire A, the tank 2a is tilted to the second position shown in FIG. 3 so that the processing tool 7 is immersed in the cooling medium 3. By doing so, the liquid level of the cooling medium 3 relatively rises to the vicinity of the two-dot chain line P in FIG. 1, and the processing tool 7 has almost the same temperature as the cooling medium 3 (Ms of 400 to 500 ° C.).
Above the point and below the nose). Simultaneously with the end of preheating, the steel wire A is pulled out in the direction of the arrow in FIG. 1, and water cooling by the cooling means 8 is started.
鋼線Ａは、冷却浴２に導入される前に加熱手段１によ
ってオーステナイト化温度（例えば1050℃付近）まで加
熱されており、冷却浴２内において冷却媒体３に触れる
ことにより過冷オーステナイト温度（例えば450℃付
近）まで急冷される。加工具７から引抜かれた鋼線Ａ
は、直ちに冷却手段８によってMs点以下の温度まで急冷
される。こうして得られたばね材料Ａ′は、適当な温度
で所定時間焼戻しが行なわれたのち、例えば冷間でコイ
ルばね等に成形される。なお鋼線Ａの引抜き完了ととも
に冷却浴２は第２図に示される位置に戻される。このよ
うに、鋼線Ａの引抜き中においてのみ加工具７を冷却媒
体３に漬けて加工具７を加熱するため、加工具７の過熱
による寿命低下を軽減できる。また、引抜き開始と引抜
き終了時点では冷却媒体３の液面を下げることができる
ため、孔4,5から冷却媒体３が外部に漏れることを防止
できる。The steel wire A is heated to the austenitizing temperature (for example, around 1050 ° C.) by the heating means 1 before being introduced into the cooling bath 2, and is contacted with the cooling medium 3 in the cooling bath 2 so that the supercooled austenite temperature ( For example, it is rapidly cooled to around 450 ° C.). Steel wire A drawn from processing tool 7
Is immediately cooled to a temperature below the Ms point by the cooling means 8. The spring material A'obtained in this way is tempered at an appropriate temperature for a predetermined time, and then, for example, cold formed into a coil spring or the like. When the drawing of the steel wire A is completed, the cooling bath 2 is returned to the position shown in FIG. In this way, since the working tool 7 is immersed in the cooling medium 3 to heat the working tool 7 only during the drawing of the steel wire A, it is possible to reduce the life shortening due to overheating of the working tool 7. Further, since the liquid level of the cooling medium 3 can be lowered at the start of drawing and at the end of drawing, it is possible to prevent the cooling medium 3 from leaking to the outside from the holes 4 and 5.
第４図において、破線ａはダイスを冷却浴中に浸漬し
ない場合の温度履歴を示している。すなわちこの従来例
では、ダイスが予熱されないため実際上は鋼線を過冷オ
ーステナイト域で等温保持することが不可能であり、鋼
線表層部はダイスと接触した瞬間に冷却される。このた
めMs点を横切り、マルテンサイト変態を起こした状態で
引抜くことになるから、引抜き加工性は当然悪くなり、
材質的にも靭性の少ない材料になってしまう。In FIG. 4, the broken line a shows the temperature history when the die is not immersed in the cooling bath. That is, in this conventional example, since the die is not preheated, it is practically impossible to keep the steel wire isothermal in the supercooled austenite region, and the surface portion of the steel wire is cooled at the moment of contact with the die. For this reason, since it is necessary to cross the Ms point and draw in a state where martensitic transformation has occurred, the drawability deteriorates naturally,
In terms of material, it becomes a material with low toughness.
第４図に示された破線ｂは、ダイスを冷却浴の途中に
浸漬した場合である。従って鋼線がダイスを通過したの
ちも冷却媒体に触れ続けるため、ダイス加工による変態
促進効果に恒温処理が加わって更に変態が促進される。
このため複合組織を生じやすい。また、冷却浴の入口部
からダイスに至るまでの距離が不足し、材料を充分に過
冷させる余裕が少ないから、ダイスに導入する前にPs点
を横切り、変態を生じることがある。The broken line b shown in FIG. 4 represents the case where the die is immersed in the cooling bath. Therefore, since the steel wire continues to contact the cooling medium even after passing through the die, a constant temperature treatment is added to the transformation accelerating effect by the die processing, and the transformation is further promoted.
Therefore, a composite structure is likely to occur. In addition, since the distance from the inlet of the cooling bath to the die is insufficient and there is little room to sufficiently supercool the material, transformation may occur across the Ps point before introducing into the die.
これに対し本実施例装置によれば、冷却媒体３の出口
端に冷却媒体３と同等の温度まで予熱された加工具７を
設け、更には加工具７と近接した位置に冷却手段８を設
けることによって引抜き後に直ちに急冷できるようにし
たから、過冷オーステナイト温度域で正しい等温変態を
起こさせることができるとともに、引抜き後はきわめて
短時間で組織が凍結される。このため組織的には均一な
マルテンサイトが得られ、焼戻されたのちは複合組織を
含まない均一なソルバイトとなる。すなわち、オースド
ローが行なわれたばね材料Ａ′の組織中にベーナイトも
しくはパーライト変態が生じることが抑制され、ダイス
加工による微細なマルテンサイト単相を残存させた均一
な組織が得られる。On the other hand, according to the apparatus of this embodiment, the processing tool 7 preheated to a temperature equivalent to that of the cooling medium 3 is provided at the outlet end of the cooling medium 3, and the cooling means 8 is provided at a position close to the processing tool 7. As a result, rapid cooling can be performed immediately after drawing, so that a correct isothermal transformation can be caused in the supercooled austenite temperature range, and the structure is frozen in an extremely short time after drawing. Therefore, martensite that is structurally uniform is obtained, and after being tempered, it becomes a uniform sorbite that does not contain a composite structure. That is, the bainite or pearlite transformation is suppressed from occurring in the structure of the spring material A ′ that has been subjected to ausdrawing, and a uniform structure in which a fine martensite single phase remains by die processing is obtained.
なお、冷却浴２に導入された直後の鋼線Ａの温度は冷
却媒体３の温度よりも高く、次第に冷却媒体３の温度に
近付くといったヒートパターンを示す。従って、冷却浴
２の長さまたは引抜き速度を制御すれば、上述したよう
な過冷オートステナイト域での引抜きはもとより、第５
図に破線で示されるように引抜き速度を低下させること
によってベーナイト域での引抜きを行なったり、更に速
度を低下させてベーナイト変態を完了したフェライト・
パーライト域での引抜きを行なうことなどにより、冷却
媒体３の温度を一定に保ったまま所望の調質が可能であ
る。The temperature of the steel wire A immediately after being introduced into the cooling bath 2 is higher than the temperature of the cooling medium 3, and the heating pattern gradually approaches the temperature of the cooling medium 3. Therefore, if the length of the cooling bath 2 or the withdrawal speed is controlled, not only the withdrawal in the supercooled autostenite region as described above but also the fifth
As shown by the broken line in the figure, the drawing speed is decreased to perform drawing in the bainite region, and the ferrite speed is decreased to complete the bainite transformation.
Desired refining can be performed while keeping the temperature of the cooling medium 3 constant by performing drawing in the pearlite region.
第６図と第７図に、本実施例装置を使ってオースドロ
ーと熱処理が行なわれたばね用材料（SUP7とSUP12）の
硬さ分布を示す。この２つの例の場合、オーステナイト
化温度が1050℃，鉛浴450℃，材料送り速度は22.5mm/se
cである。同図から判るようにばね材料の最表層部は軟
化し、中心部はほぼ均一の硬さとなっている。このよう
に最表面に軟化させることにより、高硬度材料での切欠
感受性を低下させることができるため、耐疲労性が向上
する。また、ばね材料の表層部にダイス加工によって微
細化された加工層が得られ、表面粗さがRmaxで0.5μｍ
ときわめて良好であり、このことも長寿命化の一因とな
る。FIG. 6 and FIG. 7 show hardness distributions of spring materials (SUP7 and SUP12) subjected to ausdraw and heat treatment using the apparatus of this embodiment. In these two examples, the austenitizing temperature is 1050 ℃, the lead bath is 450 ℃, and the material feed rate is 22.5mm / se.
c. As can be seen from the figure, the outermost surface layer of the spring material is softened, and the center has a substantially uniform hardness. By softening the outermost surface in this way, the notch sensitivity in a high hardness material can be reduced, and the fatigue resistance is improved. In addition, the surface layer of the spring material can be processed into a fine processing layer by die processing, and the surface roughness is 0.5μm at Rmax.
Is extremely good, and this also contributes to a longer life.
本実施例で得られたばね材料（SUP7）の機械的性質は
以下の通りである。The mechanical properties of the spring material (SUP7) obtained in this example are as follows.
σＢ＝220Kgfmm2で伸び７〜８％，絞り42％，降伏
比0.91以上 σＢ＝200Kgfmm2で伸び８〜９％，絞り49％，降伏
比0.91以上 この２つの例のように、強度・延性バランスに優れた
高強度ばね材料を得ることができた。また、両振り曲げ
疲労強度は、従来の調質材での疲労限σwb＝±75Kgfmm2
に対し、同一硬さの本実施例品（本発明品）では、σwb
＝±80Kgfmm2と優れた値が得られた。なお、前述した先
行技術１（特公昭46−27138号公報）の0.8％Ｃ鋼では、
σＢ＝210Kgfmm2,伸び4.2％，絞り41.7％であるから、
本実施例品の方が伸びが良好で加工性がよい。また、先
行技術２（特公昭57−19168号公報）の0.88％Ｃ鋼では
σＢ＝156Kgfmm2,絞り43に対して、本実施例品の方が大
きな値のσＢが得られている。σ B = 220Kgfmm 2 elongation 7-8%, drawing 42%, yield ratio 0.91 or more σ B = 200Kgfmm 2 elongation 8-9%, drawing 49%, yield ratio 0.91 or more It was possible to obtain a high-strength spring material with excellent ductility balance. In addition, the double bending fatigue strength is the fatigue limit σwb = ± 75Kgfmm 2 of the conventional tempered material.
On the other hand, in the case of this example product (invention product) having the same hardness, σwb
= ± 80 Kgfmm 2, which is an excellent value. In addition, in the 0.8% C steel of the prior art 1 (Japanese Patent Publication No. 46-27138) described above,
σ B = 210 Kgfmm 2 , elongation 4.2%, diaphragm 41.7%,
The product of this example has better elongation and better workability. Further, in the 0.88% C steel of Prior Art 2 (Japanese Patent Publication No. 57-19168), σ B = 156 Kgfmm 2 and the diaphragm 43, the σ B of a larger value is obtained in the product of this embodiment.
本発明によれば、引抜き直後におけるベーナイトもし
くはパーライト変態が抑制され、等温変態による良質で
均一なマルテンサイト単相組織が得られるとともに、オ
ースドローによる良好な表面状態が得られ、耐久性の高
い高強度ばね材料を得る上できわめて大きな効果があ
る。According to the present invention, bainite or pearlite transformation immediately after drawing is suppressed, a good and uniform martensite single-phase structure is obtained by isothermal transformation, and a good surface state by ausdrawing is obtained, and high durability and high strength are obtained. It is extremely effective in obtaining a spring material.
第１図は本発明の一実施例装置を概念的に示す略断面
図、第２図は第１図中のII−II線に沿う冷却浴の断面
図、第３図は冷却浴が傾いた状態を示す断面図、第４図
は鋼線の温度履歴を示す恒温変態曲線図、第５図は引抜
き速度を制御した場合を示す恒温変態曲線図、第６図は
SUP7を用いた場合の表面からの距離と硬さを示す図、そ
して第７図はSUP12を用いた場合の表面からの距離と硬
さを示す図である。 Ａ……鋼線、１……加熱手段、２……冷却浴、３……冷
却媒体、７……加工具、８……冷却手段。FIG. 1 is a schematic sectional view conceptually showing an apparatus of one embodiment of the present invention, FIG. 2 is a sectional view of a cooling bath taken along line II-II in FIG. 1, and FIG. FIG. 4 is a sectional view showing the state, FIG. 4 is a constant temperature transformation curve diagram showing the temperature history of the steel wire, FIG. 5 is a constant temperature transformation curve diagram showing the case where the drawing speed is controlled, and FIG.
FIG. 7 is a diagram showing the distance from the surface and hardness when SUP7 was used, and FIG. 7 is a diagram showing the distance from the surface and hardness when SUP12 was used. A: Steel wire, 1 ... Heating means, 2 ... Cooling bath, 3 ... Cooling medium, 7 ... Processing tool, 8 ... Cooling means.
Claims (2)
ト化温度まで加熱する加熱手段と、この加熱手段から送
り出される上記鋼線の搬送下流側に配置されかつ鋼線の
Ms点以上の温度に保たれた冷却媒体が収容されていてこ
の冷却媒体に上記鋼線を通すことにより鋼線を過冷オー
ステナイト温度まで冷却する冷却浴と、この冷却浴の出
口部近傍に設けられていて冷却浴内の冷却媒体によって
この冷却媒体と同等の温度に保たれかつ上記鋼線を通す
ことにより鋼線を塑性加工によって減面させる引抜き加
工具と、この加工具の出口側近傍に設けられて加工後の
鋼線をMs点以下の温度まで急冷する冷却手段とを具備し
たことを特徴とする高強度ばね材料の製造装置。1. A heating means for heating a carbon steel wire or an alloy steel wire to an austenitizing temperature, and a heating means arranged downstream of the steel wire fed from the heating means.
A cooling bath that contains a cooling medium maintained at a temperature of Ms or higher, and cools the steel wire to a supercooled austenite temperature by passing the steel wire through the cooling medium, and the cooling bath is provided near the outlet of the cooling bath. A drawing tool that is kept at a temperature equivalent to this cooling medium by a cooling medium in a cooling bath and reduces the surface of the steel wire by plastic working by passing the steel wire, and in the vicinity of the exit side of this processing tool. An apparatus for manufacturing a high-strength spring material, comprising: a cooling means that is provided to rapidly cool the processed steel wire to a temperature not higher than the Ms point.
の位置と引抜き加工中における第２の位置とにわたって
揺動可能に設けられており、かつこの冷却浴は、上記第
１の位置にある時には上記加工具が露出するまで冷却媒
体の液面が下がりかつ第２の位置にある時には上記加工
具が冷却媒体中に漬かるまで液面が上がるような形状と
してあることを特徴とする特許請求の範囲第（１）項記
載の高強度ばね材料の製造装置。2. The cooling bath is the first before the drawing process.
And the second position during the drawing process, and when the cooling bath is in the first position, the liquid level of the cooling medium drops until the working tool is exposed. An apparatus for producing a high-strength spring material according to claim (1), characterized in that, when in the second position, the processing tool is shaped so that the liquid level rises until it is immersed in the cooling medium. .
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62145352A JP2544738B2 (en) | 1987-06-12 | 1987-06-12 | High strength spring material manufacturing equipment |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62145352A JP2544738B2 (en) | 1987-06-12 | 1987-06-12 | High strength spring material manufacturing equipment |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS63310916A JPS63310916A (en) | 1988-12-19 |
| JP2544738B2 true JP2544738B2 (en) | 1996-10-16 |
Family
ID=15383206
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62145352A Expired - Fee Related JP2544738B2 (en) | 1987-06-12 | 1987-06-12 | High strength spring material manufacturing equipment |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2544738B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115232954A (en) * | 2022-07-27 | 2022-10-25 | 江苏狼山钢绳股份有限公司 | Method for fully sorbitizing large-diameter disc circle |
-
1987
- 1987-06-12 JP JP62145352A patent/JP2544738B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPS63310916A (en) | 1988-12-19 |
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