JP3114983B2 - Crawler pin and method of manufacturing the same - Google Patents
Crawler pin and method of manufacturing the sameInfo
- Publication number
- JP3114983B2 JP3114983B2 JP02158675A JP15867590A JP3114983B2 JP 3114983 B2 JP3114983 B2 JP 3114983B2 JP 02158675 A JP02158675 A JP 02158675A JP 15867590 A JP15867590 A JP 15867590A JP 3114983 B2 JP3114983 B2 JP 3114983B2
- Authority
- JP
- Japan
- Prior art keywords
- pin
- crawler
- hardness
- martensite
- represented
- 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
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/25—Process efficiency
Description
【０００１】[0001]
本発明は、装軌車両等に用いる履帯用ピンおよびその
製造方法に関する。The present invention relates to a crawler belt pin used for a tracked vehicle and the like, and a method for manufacturing the same.
【０００２】[0002]
従来は、つぎに述べる（イ）、（ロ）、（ハ）の方法
等で履帯用ピンを製造しており、それぞれ、以下の問題
を有していた。 （イ） 中炭素低合金鋼（たとえばS50C、S53C、S48C
B、SAE15B35など）を素材として、これを炉中加熱焼入
れ焼もどしして、中心部付近に柔かい延性部を作り、残
りを硬化する。その後、熱処理で生じた脱炭層除去のた
め表面を研摩する。 −問題点− 履帯用ピンの端面が硬化し、焼割れ発生の危険が生
じ、製造を困難にしている。 有効硬化層深さは、適正な鋼種選定により設定して
いるが、同一鋼種内の焼入性のバラツキにより変動す
る。焼入性が高いほうに変動する場合、中心部まで硬化
し、表面に引張り残留応力が付与される危険が生じる。 熱処理により付与された表面の圧縮残留応力が、そ
の後の研摩加工により、減少あるいは消失する危険が生
じる。 （ロ） 中炭素低合金鋼を素材とし、t/Rが0.30未満の
範囲を高周波焼入れし、その後、焼もどしする方法。た
だし、t/Rは、半径Ｒに対する80％マルテンサイト硬さ
以上の有効硬化層深さをｔの比である。 −問題点− （イ）に比べ、静的曲げ強度、疲労強度が劣化す
る。 （ハ） 肌焼鋼（たとえばSCM415、SCM420など）を素材
とし、これを浸炭焼入れしたあと、焼もどしを行なう方
法。 −問題点− （イ）、（ロ）に比べて耐摩耗性は優れているが、
静的曲げ強度、疲労強度が劣化する。Conventionally, crawler track pins have been manufactured by the following methods (a), (b), and (c), and have the following problems. (B) Medium carbon low alloy steel (for example, S50C, S53C, S48C
B, SAE15B35, etc.) and heat quenching and tempering in a furnace to create a soft ductile part near the center and harden the rest. Thereafter, the surface is polished to remove the decarburized layer generated by the heat treatment. -Problems- The end faces of the crawler belt pins are hardened, and there is a risk of occurrence of burning cracks, which makes manufacture difficult. The effective hardened layer depth is set by selecting an appropriate steel type, but fluctuates due to variations in hardenability within the same steel type. If the hardenability changes to a higher one, there is a danger that the hardening will take place to the center and a tensile residual stress will be applied to the surface. There is a danger that the compressive residual stress on the surface imparted by the heat treatment will be reduced or eliminated by subsequent polishing. (B) A method in which medium carbon low alloy steel is used as the material, induction hardening is performed in the range of t / R less than 0.30, and then tempering. Here, t / R is the ratio of the effective hardened layer depth equal to or more than 80% martensite hardness to the radius R. -Problems-Static bending strength and fatigue strength are deteriorated as compared with (a). (C) A method in which case hardened steel (for example, SCM415, SCM420, etc.) is used as a material, carburized and quenched, and then tempered. -Problems- Abrasion resistance is better than (A) and (B),
Static bending strength and fatigue strength deteriorate.
【０００３】[0003]
本発明が解決しようとする課題は、上記の問題点であ
り、本発明の目的は、焼割れが発生せず、かつ静的曲げ
強度、疲労強度を劣化させない履帯用ピンと、その製造
方法を提供することにある。The problem to be solved by the present invention is the above-mentioned problem, and an object of the present invention is to provide a crawler track pin which does not cause sintering cracks and does not deteriorate static bending strength and fatigue strength, and a method for manufacturing the same. Is to do.
【０００４】[0004]
上記課題を解決するための本発明はつぎの通りであ
る。 （１） 素材が中炭素低合金鋼であり、半径をＲ、80％
マルテンサイト硬さ以上の有効硬化層深さをｔで表した
場合、表面から比（t/R）が0.35〜0.50までの範囲のみ
が80％マルテンサイト硬さ以上であり、中心部が未変態
組織であり、表面あらさが10μｍ以下の黒皮肌を有する
ことを特徴とする履帯用ピン。 （２） 中炭素低合金鋼を素材する履帯用ピンを10μｍ
以下の表面あらさに加工し、 しかる後、半径をＲ、80％マルテンサイト硬さ以上の有
効硬化層深さをｔで表した場合、表面から比（t/R）が
0.35〜0.50までの範囲のみが80％マルテンサイト硬さ以
上になるように高周波誘導加熱および冷却を施して高周
波焼入れし、 その後焼もどしを行なう、 ことを特徴とする履帯用ピンの製造方法。The present invention for solving the above problems is as follows. (1) The material is medium carbon low alloy steel, radius is R, 80%
When the effective hardened layer depth equal to or greater than the martensite hardness is represented by t, only the ratio (t / R) from the surface to the range of 0.35 to 0.50 is 80% martensite hardness or higher, and the center is untransformed. A crawler pin having a texture and a dark skin having a surface roughness of 10 μm or less. (2) Track pins made of medium carbon low alloy steel are 10 μm thick.
When the surface is processed to the following surface roughness and the radius is represented by R and the effective hardened layer depth of 80% martensite hardness or more is represented by t, the ratio (t / R) from the surface is
A method of manufacturing a crawler pin, comprising: performing induction hardening by induction heating and cooling so that only the range of 0.35 to 0.50 becomes 80% or more of martensite hardness, and then performing tempering;
【０００５】 一般的に、焼きの入った深さとして50％マルテンサイ
ト組織が、基準とされているが、実用的にはかたさが低
すぎる場合が多く、焼きの入った深さをさらに高いマル
テンサイト量によって表す場合があり、本発明では80％
マルテンサイトとした。また、鋼の焼き入れ硬さはＣ量
により決まり、また、マルテンサイト量によっても異な
るので、80％マルテンサイトの硬さはＣ量に応じて決め
られる。なお、Ｃ量は中炭素（低合金）鋼の場合、0.3
〜0.5重量％である。[0005] In general, a 50% martensite structure is used as a reference for a baked depth. However, in practice, the hardness is often too low. May be represented by the amount of site, 80% in the present invention
Martensite. Further, since the quenching hardness of steel is determined by the amount of C and also depends on the amount of martensite, the hardness of 80% martensite is determined in accordance with the amount of C. The C content is 0.3% for medium carbon (low alloy) steel.
~ 0.5% by weight.
【０００６】 上記履帯用ピンおよびその製造方法には、つぎの作
用、効果がある。 t/Rは、焼入性が十分である場合、冷却強さにより
調整せず、高周波誘導加熱により調整するため、極めて
バラツキが小さく安定している。 したがって、静的曲げ強度、疲労強度のバラツキが小
さい。 熱処理による脱炭層の発生がなく、熱処理後の研摩
加工が不要となるため、熱処理で生じた高い圧縮残留応
力が保持される。 この圧縮残留応力によって、さらに疲労強度が向上す
る。 t/Rが0.35〜0.50であり、かつ表面あらさが10μｍ
以下の黒皮肌を有するため、炉中加熱焼入れ焼もどし品
と同等以上の静的曲げ強度、疲労強度を有する。 履帯用ピンの表面からt/Rが0.35〜0.50までの範囲
のみをAC3点以上の適正な温度範囲内に加熱し、他はAC3
点以下であるため、高周波加熱原単位を低く押さえるこ
とができる。 中心部は未変態組織であるため、履帯用ピンの端面
に焼割れは発生しない。The crawler belt pin and the method for manufacturing the same have the following actions and effects. When the hardenability is sufficient, the t / R is not adjusted by the cooling strength but adjusted by high-frequency induction heating, so that the variation is very small and stable. Therefore, variations in static bending strength and fatigue strength are small. Since no decarburized layer is generated by the heat treatment and polishing after the heat treatment is not required, a high compressive residual stress generated by the heat treatment is maintained. This compressive residual stress further improves the fatigue strength. t / R is 0.35-0.50 and surface roughness is 10μm
Since it has the following dark skin, it has a static flexural strength and fatigue strength equal to or higher than that of a product heated and quenched and tempered in a furnace. Heat only the range of t / R from 0.35 to 0.50 from the surface of the crawler pin within the appropriate temperature range of 3 points or more AC, and AC 3
Since it is below the point, the high-frequency heating unit can be kept low. Since the central portion has an untransformed structure, no cracking occurs on the end surface of the crawler belt pin.
【０００７】[0007]
以下、本発明を、実施例により、さらに詳細に説明す
る。 中炭素低合金の履帯用ピン素材として、中炭素ボロン
鋼（S48CB）から成る、直径38mm、長さ218mmのピン素材
を選定した。その化学成分は、0.45〜0.51C、0.47〜0.2
7Si、0.73Mn、0.025P、0.010S、0.05Ni、0.09Cu、0.16C
r、0.0023B、残りFeである。 まず、履帯用ピン素材の外周表面を、切削、研摩によ
り、10μｍ以下の表面あらさに加工した。10μｍ以下と
したのは、それを越えると、履帯用ピンに荷重が繰り返
しかかるときの疲労耐久性が低下するからである。ま
た、熱処理前研摩としたのは、熱処理によってできる表
面残留圧縮応力の硬化層が削りとられるのを紡糸するた
めである。Hereinafter, the present invention will be described in more detail with reference to Examples. A pin material with a diameter of 38 mm and a length of 218 mm made of medium carbon boron steel (S48CB) was selected as the medium-carbon low alloy track pin material. Its chemical components are 0.45-0.51C, 0.47-0.2
7Si, 0.73Mn, 0.025P, 0.010S, 0.05Ni, 0.09Cu, 0.16C
r, 0.0023B, remaining Fe. First, the outer peripheral surface of the crawler pin material was machined to a surface roughness of 10 μm or less by cutting and polishing. The reason why the thickness is set to 10 μm or less is that if the thickness exceeds 10 μm, the fatigue durability when a load is repeatedly applied to the crawler belt pin decreases. The polishing before the heat treatment is performed in order to spin the hardened layer of the surface residual compressive stress generated by the heat treatment.
【０００８】 つぎに、表面あらさが10μｍ以下に加工された履帯用
ピンを、履帯用ピンの表面からt/Rが0.35〜0.50までの
範囲のみにAC3点以上の温度範囲に高周波誘導加熱、お
よび、冷却を施して、履帯用ピンの表面からt/Rが0.35
〜0.50までの範囲を、80％マルテンサイト硬さ以上に焼
入れする。中心部は未変態組織である。Next, the crawler pin whose surface roughness is processed to 10 μm or less is subjected to high-frequency induction heating to a temperature range of AC 3 points or more only from the surface of the crawler pin to t / R of 0.35 to 0.50, And after cooling, t / R is 0.35 from the surface of crawler pin
Quench the range up to 0.50 to 80% martensite hardness or higher. The center is an untransformed structure.
【０００９】 高周波誘導加熱は、3KHz以下の適正な周波数、たとえ
ば1KHzの周波数を選定し、高周波誘導コイル通過後、冷
却までの時間を適正に選定することにより、表面の加熱
を防止しながら熱を浸透させて行なう。 t/Rの下限値、上限値の根拠は次の通りである。疲労
強度劣化を防止するためには、t/Rを大きくし、かつ表
面に圧縮残留応力を付与することが有効であるが、t/R
が0.35以上で、かつ表面あらさが10μｍ以下の黒皮肌を
有することにより、従来の炉中加熱焼入れ焼もどし品と
同等以上の静的曲げ強度、疲労強度が保持されることが
試験により判明したので、下限を0.35とした。また、t/
Rの上限値は、t/Rが小さい方が、高周波誘導加熱の加熱
原単位が小さくなり、経済メリットがあるため、高周波
焼入れの工程能力を勘案して、0.50とした。t/Rは、冷
却強さにより調整せず、高周波誘導加熱により調整する
ため、極めてバラツキが小さく安定している。したがっ
て、静的曲げ強度、疲労強度のバラツキも小さい。ま
た、中心部は未変態組織であるため、履帯用ピンの端面
に焼割れは発生しない。In the high-frequency induction heating, a proper frequency of 3 KHz or less, for example, a frequency of 1 KHz is selected, and after passing through the high-frequency induction coil, a time until cooling is properly selected, so that heat is prevented while heating the surface. Perform by infiltrating. The grounds for the lower and upper limits of t / R are as follows. In order to prevent fatigue strength deterioration, it is effective to increase t / R and apply compressive residual stress to the surface.
The test revealed that by having a black skin with a surface roughness of 0.35 or more and a surface roughness of 10 μm or less, the static bending strength and fatigue strength equivalent to or higher than those of the conventional furnace-hardened and tempered product were maintained. Therefore, the lower limit was set to 0.35. Also, t /
The upper limit of R is set to 0.50 in consideration of the process capability of induction quenching, because the smaller the value of t / R, the smaller the heat intensity of high-frequency induction heating and the economical advantage. Since t / R is not adjusted by the cooling strength but adjusted by high-frequency induction heating, the dispersion is very small and stable. Therefore, variations in static bending strength and fatigue strength are small. In addition, since the central portion has an untransformed structure, no burning crack occurs on the end surface of the crawler belt pin.
【００１０】 上記の高周波焼入れにより、履帯用ピンの外周部は硬
く耐摩耗性に優れ、かつ静的曲げ強度に優れた履帯用ピ
ンが得られる。また、表面には圧縮残留応力が残るの
で、優れた疲労強度が得られる。表１は本発明品と従来
品の残留応力を示しており、表２は曲げ特性を示してお
り、また、図１はピン断面の硬さ分布を示しており、図
２は疲労強度特性を示している。ただし、これらの値
は、次に述べる焼もどしを施した後の値である。[0010] By the above-described induction hardening, a crawler belt pin is obtained in which the outer peripheral portion of the crawler belt pin is hard and has excellent wear resistance and excellent static bending strength. Further, since residual compressive stress remains on the surface, excellent fatigue strength can be obtained. Table 1 shows the residual stress of the present invention product and the conventional product, Table 2 shows the bending characteristics, FIG. 1 shows the hardness distribution of the pin cross section, and FIG. 2 shows the fatigue strength characteristics. Is shown. However, these values are values after tempering described below.
【００１１】[0011]
【表１】 [Table 1]
【００１２】[0012]
【表２】 [Table 2]
【００１３】 焼入れ後、低温焼もどしを行なう。焼もどしは炉中に
て180℃で２時間保持した。低温焼もどしとしたのは、
焼もどしによる表面硬度の低下を最小限にするためであ
る。After quenching, low-temperature tempering is performed. Tempering was maintained at 180 ° C. for 2 hours in a furnace. What was tempered at low temperature
This is to minimize the decrease in surface hardness due to tempering.
【００１４】[0014]
高周波誘導のため、端面の焼割れが発生しない。 t/Rを0.35〜0.50としたため、表２、図１、図２から
わかるように、従来品と同程度かそれ以上の静的曲げ強
度、硬さ特性、疲労強度が得られ、バラツキが小さく安
定した品質が得られる。 熱処理前に表面あらさを10μｍ以下に加工し熱処理後
の切削、研摩を除去したので、表面硬化部と表面の残留
圧縮部（表１参照）を削りとらないでそのまま黒皮肌と
して残すことができ、耐摩耗性、疲労強度を従来と同程
度かそれ以上にすることができる。Due to the high frequency induction, the end face does not crack. Since t / R is set to 0.35 to 0.50, as can be seen from Table 2, FIGS. 1 and 2, static bending strength, hardness characteristics and fatigue strength equivalent to or higher than those of the conventional product are obtained, and the variation is small. Stable quality is obtained. Before heat treatment, the surface roughness was processed to 10 μm or less, and cutting and polishing after heat treatment were removed, so that the hardened part and the residual compressed part (see Table 1) on the surface could be left as black skin without being scraped off. , Abrasion resistance and fatigue strength can be made equal to or more than the conventional one.
【図１】 本発明の履帯用ピンの断面硬さ分布図である。FIG. 1 is a cross-sectional hardness distribution diagram of a crawler belt pin of the present invention.
【図２】 本発明の履帯用ピンの疲労特性図である。FIG. 2 is a fatigue characteristic diagram of the crawler belt pin of the present invention.
Ｒ……半径 ｔ……有効硬化深さ R: radius t: effective curing depth
───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特公 昭62−37691（ＪＰ，Ｂ２) (58)調査した分野(Int.Cl.7，ＤＢ名) C22C 38/00 - 38/60 C21D 1/10 C21D 9/00 - 9/44 C21D 9/50 ────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-B-62-37691 (JP, B2) (58) Fields investigated (Int. Cl. 7 , DB name) C22C 38/00-38/60 C21D 1 / 10 C21D 9/00-9/44 C21D 9/50
Claims (2)
80％マルテンサイト硬さ以上の有効硬化層深さをｔで表
した場合、表面から比（t/R）が0.35〜0.50までの範囲
のみが80％マルテンサイト硬さ以上であり、中心部が未
変態組織であり、表面あらさが10μｍ以下の黒皮肌を有
することを特徴とする履帯用ピン。1. The material is a medium carbon low alloy steel having a radius of R,
When the effective hardened layer depth of 80% martensite hardness or more is represented by t, only the ratio (t / R) from the surface to the range of 0.35 to 0.50 is 80% martensite hardness or more, and the center is A crawler pin having an untransformed structure and having black skin having a surface roughness of 10 μm or less.
10μｍ以下の表面あらさに加工し、 しかる後、半径をＲ、80％マルテンサイト硬さ以上の有
効硬化層深さをｔで表した場合、表面から比（t/R）が
0.35〜0.50までの範囲のみが80％マルテンサイト硬さ以
上になるように高周波誘導加熱および冷却を施して高周
波焼入れし、 その後焼もどしを行なう、 ことを特徴とする履帯用ピンの製造方法。2. A track pin made of medium carbon low alloy steel.
When the surface is processed to a surface roughness of 10 μm or less, and then the radius is represented by R and the effective hardened layer depth of 80% martensite hardness or more is represented by t, the ratio (t / R) from the surface is
A method for manufacturing crawler pin, characterized in that induction hardening is performed by induction heating and cooling so that only the range from 0.35 to 0.50 is 80% or more of martensite hardness, and then tempering is performed.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP02158675A JP3114983B2 (en) | 1990-06-19 | 1990-06-19 | Crawler pin and method of manufacturing the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP02158675A JP3114983B2 (en) | 1990-06-19 | 1990-06-19 | Crawler pin and method of manufacturing the same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0452247A JPH0452247A (en) | 1992-02-20 |
| JP3114983B2 true JP3114983B2 (en) | 2000-12-04 |
Family
ID=15676913
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP02158675A Expired - Lifetime JP3114983B2 (en) | 1990-06-19 | 1990-06-19 | Crawler pin and method of manufacturing the same |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3114983B2 (en) |
Cited By (1)
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| JP5424298B2 (en) * | 2008-09-08 | 2014-02-26 | トピー工業株式会社 | Heat treatment method for cylindrical parts |
| JP5371084B2 (en) * | 2007-11-12 | 2013-12-18 | トピー工業株式会社 | Heat treatment method for cylindrical parts |
| CN103773937B (en) * | 2007-11-12 | 2015-10-28 | 都美工业株式会社 | The heat treating method of columnar component |
| US10053168B2 (en) * | 2015-11-24 | 2018-08-21 | Caterpillar Inc. | Track pin with improved hardness profile and method of producing the same |
-
1990
- 1990-06-19 JP JP02158675A patent/JP3114983B2/en not_active Expired - Lifetime
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0713194U (en) * | 1993-08-03 | 1995-03-07 | 株式会社大阪前田製菓 | Transparent food such as jelly |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0452247A (en) | 1992-02-20 |
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