JP2000256746A - Method for heat treating hollow steel rod - Google Patents
Method for heat treating hollow steel rodInfo
- Publication number
- JP2000256746A JP2000256746A JP11060388A JP6038899A JP2000256746A JP 2000256746 A JP2000256746 A JP 2000256746A JP 11060388 A JP11060388 A JP 11060388A JP 6038899 A JP6038899 A JP 6038899A JP 2000256746 A JP2000256746 A JP 2000256746A
- Authority
- JP
- Japan
- Prior art keywords
- steel rod
- tempering
- hollow steel
- carburizing
- executed
- 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.)
- Withdrawn
Links
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- Earth Drilling (AREA)
- Heat Treatment Of Articles (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、削岩機用中空鋼ロ
ッドの熱処理方法に関する。The present invention relates to a method for heat treating hollow steel rods for rock drills.
【０００２】[0002]
【従来の技術】岩盤や地盤に穿孔する際に用いられる削
岩機用中空鋼ロッドは、中心軸に沿って貫通する水孔を
有し、円形または多角形の断面形状を有する鋼棒で、そ
の一端には掘削用ビットを装着するためのビット取付け
部を有し、軸部の他端には該中空鋼ロッドを削岩機に装
着するためのシャンク部を備える。ビット取付け部は、
通常、掘削用ビットを螺着するためのねじ部と、該ねじ
部から軸部への移行部分であるフィレット部とよりな
る。2. Description of the Related Art A hollow steel rod for a rock drill used when drilling in rock or ground is a steel rod having a water hole penetrating along a central axis and having a circular or polygonal cross-sectional shape. One end has a bit mounting portion for mounting a drill bit, and the other end of the shaft portion has a shank portion for mounting the hollow steel rod to a rock drill. The bit mounting part is
Usually, it is composed of a screw portion for screwing a drill bit and a fillet portion which is a transition portion from the screw portion to the shaft portion.
【０００３】ねじ部に掘削用ビットを装着し、シャンク
部によって削岩機に取り付けられた中空鋼ロッドは、削
岩機から繰り返し加えられる衝撃的推力（パーカッショ
ンと呼ぶ）を掘削用ビットに伝え、掘削用ビット刃に当
接した岩盤、地盤等を掘削し、穿孔する。このとき、シ
ャンク部端から水孔に水を圧入し、掘削用ビットに設け
た噴出口から前記圧入した水を噴出する。この水によっ
て、破砕された岩片は穿孔された孔から搬送・除去さ
れ、穿孔の能率を向上する。[0003] A hollow steel rod attached to a rock drill by means of a shank and having a drill bit attached to a screw portion transmits a shocking thrust (called percussion) repeatedly applied from the rock drill to the drill bit. Excavate and drill holes in rock, ground, etc. abutting the drill bit. At this time, water is injected into the water hole from the end of the shank, and the injected water is ejected from the ejection port provided in the drill bit. With this water, the crushed rock fragments are transported and removed from the drilled hole, thereby improving the efficiency of the drilling.
【０００４】ところで、中空鋼ロッドは、その使用時
に、軸方向の大きな繰り返し衝撃力を受けるとともに、
繰り返し曲げモーメントを受ける。この曲げモーメント
により、特に、掘削用ビット取付け側ねじ部において、
不完全ねじ形状を呈するねじ切り上がり部、ないしフィ
レット部には大きな曲げ応力が生じる。また、ねじ部お
よびフィレット部は、掘削用ビット台金との間に大きな
摩擦力を生じる。軸部は、削岩機により加えられるパー
カッション、軸部の湾曲による曲げ応力、破砕された岩
片による摩耗などの攻撃を受ける。また、シャンク部
は、削岩機により加えられるパーカッションを受けると
ともに、削岩機側の接合部品との間に大きな摩擦力を生
じる。[0004] By the way, the hollow steel rod receives a large repeated impact force in the axial direction during its use,
Subject to repeated bending moment. Due to this bending moment, in particular, in the thread portion on the side where the drill bit is attached,
A large bending stress is generated in the thread cut-up portion or fillet portion having an incomplete thread shape. Further, the screw portion and the fillet portion generate a large frictional force between the screw portion and the fillet portion. The shaft is subject to attacks such as percussion applied by a rock drill, bending stress due to the curvature of the shaft, and wear due to crushed rock fragments. In addition, the shank portion receives a percussion applied by the rock drill, and generates a large frictional force between the shank and the joint component on the rock drill side.
【０００５】上記のように、中空鋼ロッドの各部分に
は、パーカッションに耐える強度、耐摩耗性、耐疲労性
が要求される。これらの特性を満たすものとして、近
時、炭素含有率が０．３質量％以下と比較的低い鋼を用
い、浸炭焼入れを施した中空鋼ロッドが用いられて、大
きな効果を上げている。しかしながら、前記のように大
きな曲げ応力を生じるねじ切り上がり部及びフィレット
部の強度については必ずしも満足すべきものではなく、
一層の強度向上、特に疲労強度の向上が望まれている。[0005] As described above, each part of the hollow steel rod is required to have strength to withstand percussion, wear resistance, and fatigue resistance. As a material satisfying these characteristics, a steel having a relatively low carbon content of 0.3% by mass or less and a hollow steel rod which has been subjected to carburizing and quenching have recently been used, and a great effect has been achieved. However, the strength of the thread cut-up portion and the fillet portion that generate a large bending stress as described above is not always satisfactory,
Further improvement in strength, particularly improvement in fatigue strength, is desired.
【０００６】[0006]
【発明が解決しようとする課題】本発明が解決しようと
する課題は、掘削用ビット取付け側ねじ部およびフィレ
ット部の疲労強度を向上することによって、長寿命を有
する経済的な削岩機用中空鋼ロッドを与える熱処理方法
を提供することにある。SUMMARY OF THE INVENTION An object of the present invention is to improve the fatigue strength of a thread portion and a fillet portion on the side where a drill bit is attached, thereby providing an economical hollow rock drill having a long life. It is to provide a heat treatment method for providing a steel rod.
【０００７】[0007]
【課題を解決するための手段】上記の課題を解決するた
め、本発明の中空鋼ロッドの熱処理方法は、一端にビッ
ト取付け部を有し、他端にシャンク部を有する中空鋼ロ
ッド材を浸炭焼入れ焼戻ししたのち、ビット取付け部に
対して高周波焼入れを施し、その後、更に１５０〜２５
０℃で焼戻しを施すことを特徴とする。In order to solve the above-mentioned problems, a method for heat-treating a hollow steel rod according to the present invention comprises carburizing a hollow steel rod material having a bit attachment portion at one end and a shank portion at the other end. After quenching and tempering, induction hardening is performed on the bit attachment portion, and then 150 to 25
It is characterized by tempering at 0 ° C.
【０００８】[0008]
【発明の実施の形態】本発明の中空鋼ロッド１の熱処理
方法において、対象とする中空鋼ロッド材について説明
する。中空鋼ロッド材は、炭素含有量０．３％以下の肌
焼き用鋼とする。前記肌焼き用鋼は、強度、焼入れ性、
耐食性等を向上するため、適量のＳｉ、Ｍｎ、Ｎｉ、Ｃ
ｒ、Ｍｏ、Ｖ、Ｎｂ、Ｔａ等の合金元素を含有すること
が好ましい。BEST MODE FOR CARRYING OUT THE INVENTION In the heat treatment method for a hollow steel rod 1 according to the present invention, a target hollow steel rod material will be described. The hollow steel rod material is a case hardening steel having a carbon content of 0.3% or less. The case hardening steel has strength, hardenability,
To improve corrosion resistance etc., appropriate amount of Si, Mn, Ni, C
It is preferable to contain alloy elements such as r, Mo, V, Nb, and Ta.
【０００９】通常の中空鋼ロッドの製造方法に従って、
中空鋼から機械加工により、その一端には掘削用ビット
を取り付けるためのビット取付け部３を設け、軸部２の
他端にはシャンク部６を設けて中空鋼ロッド材とする。
ビット取付け部３は、例えば、掘削用ビットを螺着する
ためのねじ部４と、該ねじ部４から軸部２への移行部分
であるフィレット部５とよりなる。また、シャンク部６
は、削岩機に装着するか、または、中間ロッドに接続す
るためにの部分で、例えば、ねじ部を備えており、カッ
プリングスリーブによって削岩機本体あるいは中間ロッ
ドに接続される。According to the usual method of manufacturing a hollow steel rod,
A hollow steel rod is formed by machining a hollow steel rod material at one end by providing a bit mounting portion 3 for mounting a drill bit, and at the other end of the shaft portion 2 by providing a shank portion 6.
The bit attaching part 3 includes, for example, a screw part 4 for screwing a drill bit and a fillet part 5 which is a transition part from the screw part 4 to the shaft part 2. In addition, shank part 6
Is a part for mounting on a rock drill or connecting to an intermediate rod, for example, having a threaded portion and connected to the rock drill body or the intermediate rod by a coupling sleeve.
【００１０】次に、本発明の中空鋼ロッドの熱処理方法
について説明する。まず、前記中空鋼ロッド材に全長に
亙って浸炭処理を施した後焼入れし、１５０〜２５０℃
で焼戻しを施す。浸炭処理および焼入れは通常の条件、
例えばガス浸炭・焼入れを行えばよい。この熱処理によ
って、中空鋼ロッド１の表層部分には高い硬度と耐摩耗
性が付与され、また、内部には強靭性が付与される。Next, a method for heat treating a hollow steel rod according to the present invention will be described. First, the hollow steel rod material is carburized over its entire length and then quenched at 150 to 250 ° C.
Tempering with. Carburizing and quenching are normal conditions,
For example, gas carburizing and quenching may be performed. By this heat treatment, high hardness and wear resistance are imparted to the surface layer portion of the hollow steel rod 1 and toughness is imparted inside.
【００１１】ついで、ビット取付け部３の疲労強度を向
上するために、前記浸炭焼入れ焼戻しした中空鋼ロッド
のビット取付け部３に高周波焼入れおよび焼戻しの熱処
理を施す。高周波焼入れに当たっては、少なくとも、前
記加熱部の浸炭層にオーステナイト層が生成するまで加
熱するが、あまり高温・長時間にわたって加熱すると、
結晶粒が粗大化し、また、中空鋼ロッド軸部２まで加熱
されて、その熱影響により軸部２の強度が低下するの
で、過剰の加熱を避けなければならない。適当な加熱条
件は、中空鋼ロッド１の材質、寸法、浸炭状態等によっ
て適宜選択する必要がある。Next, in order to improve the fatigue strength of the bit mounting portion 3, the bit mounting portion 3 of the carburized, quenched and tempered hollow steel rod is subjected to induction hardening and tempering heat treatment. In the case of induction hardening, at least heating until the austenite layer is formed in the carburized layer of the heating section, but when heated for a very high temperature and for a long time,
Since the crystal grains are coarsened and heated to the hollow steel rod shaft 2, the heat influences the strength of the shaft 2, so that excessive heating must be avoided. Appropriate heating conditions need to be appropriately selected depending on the material, dimensions, carburized state, etc. of the hollow steel rod 1.
【００１２】前記高周波焼入れした中空鋼ロッド１を１
５０〜２５０℃で焼戻しする。該焼戻しは、前記高周波
焼入れした中空鋼ロッド１の全体に対して施してもよ
く、また、高周波焼入れ部分に対してのみ行ってもよ
い。The induction hardened hollow steel rod 1 is
Tempering at 50-250 ° C. The tempering may be performed on the entire induction hardened hollow steel rod 1 or may be performed only on the induction hardened portion.
【００１３】本発明の熱処理を施すことによって、全長
にわたって、内部が強靭であり、表層部は高硬度で耐摩
耗性に富む硬化層を備え、かつ、疲労強度に優れたビッ
ト取付け部３を有する中空鋼ロッド１が得られるのであ
る。By performing the heat treatment of the present invention, the inner portion is tough over the entire length, the surface layer portion is provided with a hardened layer having high hardness and abrasion resistance, and has the bit mounting portion 3 excellent in fatigue strength. The hollow steel rod 1 is obtained.
【００１４】[0014]
【実施例】Ｃ：０．２５質量％、Ｎｉ：２．６５質量
％、Ｃｒ：１．２５質量％、Ｍｏ：０．２５質量％を含
む肌焼き用鋼により、呼び寸法２８ＨＨ〜３５ＨＨ（外
径２８〜３５ｍｍ六角断面）で長さ３〜６ｍの中空鋼ロ
ッド材を製造した。その形状を図１に、また、主要部寸
法を表１に示す。EXAMPLE Nominal dimensions of 28HH to 35HH (outer) were obtained from case hardening steel containing 0.25% by mass of C, 2.65% by mass of Ni, 1.25% by mass of Cr and 0.25% by mass of Mo. A hollow steel rod material having a diameter of 28 to 35 mm (hexagonal section) and a length of 3 to 6 m was produced. The shape is shown in FIG. 1, and the main part dimensions are shown in Table 1.
【００１５】[0015]
【表１】 [Table 1]
【００１６】前記中空鋼ロッド材に９４０℃×１７０〜
２００ｍｉｎのガス浸炭を施し、８５０℃からガス冷却
により焼入れを行った。ついで、１８０℃×１ｈｒの焼
戻しを行って浸炭焼入れ・焼もどし処理材を得た。該浸
炭焼入れ・焼もどし材の一部は、比較例として、本発明
の実施例と同様に、後述の試験に供した。The hollow steel rod material has a temperature of 940.degree.
The gas was carburized for 200 min and quenched by gas cooling from 850 ° C. Then, tempering at 180 ° C. × 1 hr was performed to obtain a carburized quenched and tempered material. A part of the carburized and quenched and tempered material was subjected to a test described later as a comparative example, similarly to the example of the present invention.
【００１７】前記浸炭焼入れ・焼もどし材のビット取付
け部に対して、高周波焼入れを行い、ついで、１８０℃
で１ｈｒの焼戻しを行って供試体を得た。高周波焼入れ
は下記の条件で実施した。 周波数：２００ｋＨｚ 加熱方法：回転焼入れ 冷却方法：水スプレー 加熱温度：８５０℃ 回転速度：２００ｒｐｍInduction hardening was performed on the bit mounting portion of the carburized and tempered material,
For 1 hour to obtain a specimen. Induction hardening was performed under the following conditions. Frequency: 200kHz Heating method: Rotary quenching Cooling method: Water spray Heating temperature: 850 ° C Rotation speed: 200 rpm
【００１８】実施例１供試体のビット取付け部のねじ
山、ねじ谷およびフィレット部各縦断面について、試験
荷重３００ｇとしてビッカース硬さ計を用いて断面硬さ
分布を測定した。比較例のフィレット部についても同様
に断面硬さ分布を測定した。その結果を図２に示す。図
２に示すように、本発明の実施例においては、浸炭焼入
れ・焼もどしのままである比較例に比べて表層部の硬さ
が高く、また、表面硬化深さも大きい。Example 1 A longitudinal hardness distribution of a screw thread, a thread root, and a fillet portion of a bit mounting portion of a specimen was measured using a Vickers hardness tester with a test load of 300 g. The cross-sectional hardness distribution was similarly measured for the fillet portion of the comparative example. The result is shown in FIG. As shown in FIG. 2, in the embodiment of the present invention, the hardness of the surface layer is higher and the surface hardening depth is larger than in the comparative example in which the case is carburized and tempered.
【００１９】供試体の中心軸を含む平面内で１５０ｋｇ
ｆ−ｍの曲げモーメント（軸部表面応力として９６ｋｇ
ｆ／ｃｍ2）を加え、中心軸の周りに回転速度２００ｒ
ｐｍで回転し、破断するまでの回転数（破断回転数）を
測定した。試験は供試体３本づつについて行い破断回転
数の平均値を疲れ寿命として表２に示す。表２によれ
ば、破断は、いずれもビット取付け部のねじ部で発生
し、同一呼び寸法に対して、実施例はいずれも比較例よ
りも疲労寿命が長いことが判る。150 kg in a plane including the central axis of the specimen
fm bending moment (96 kg as shaft surface stress)
f / cm 2 ) and a rotation speed of 200 r around the central axis.
The sample was rotated at pm, and the number of rotations before breaking (the number of rotations at break) was measured. The test was performed on three test pieces at a time, and the average value of the number of rotations at break is shown in Table 2 as the fatigue life. According to Table 2, it can be seen that the fractures occurred at the threaded portion of the bit attachment portion, and the fatigue life was longer in each of the examples than in the comparative example for the same nominal dimensions.
【００２０】[0020]
【表２】 [Table 2]
【００２１】実地テストとして、クローラードリルに供
試体を装着し、ベンチカット法によって岩盤を掘削し、
供試体が折損するまでの岩盤掘削長さを測定した。試験
は供試体３本づつについて行い平均値を求め、実地テス
ト寿命として表２に示す。表２によれば、破断は、いず
れもビット取付け部のねじ部で発生し、同一呼び寸法に
対して実施例はいずれも比較例よりも実地テスト寿命が
長いことが判る。As a field test, a test piece was mounted on a crawler drill, and rock was excavated by a bench cut method.
The length of rock excavation until the specimen broke was measured. The test was performed on three test pieces at a time, and the average value was obtained. According to Table 2, it can be seen that the breaks all occur at the threaded portion of the bit mounting portion, and that the examples have longer field test lives than the comparative examples for the same nominal dimensions.
【００２２】[0022]
【発明の効果】以上に説明したように、本発明によれ
ば、表層部硬さが高く、芯部は強靭性に富み、かつ、掘
削用ビット取付け側ねじ部およびフィレット部の疲労強
度の優れた中空鋼ロッドを提供することができる。これ
によって岩盤掘削の能率が向上する経済効果は究めて大
きいといえる。As described above, according to the present invention, the hardness of the surface layer is high, the core is rich in toughness, and the thread strength and the fillet of the drilling bit mounting side are excellent in fatigue strength. A hollow steel rod can be provided. Thus, the economic effect of improving the efficiency of rock excavation is extremely large.
【図１】実施例における中空鋼ロッド材の形状を示す説
明図である。FIG. 1 is an explanatory view showing the shape of a hollow steel rod material in an embodiment.
【図２】実施例の断面硬さ分布を示す、深さ−硬さ関係
線図である。FIG. 2 is a depth-hardness relationship diagram showing a cross-sectional hardness distribution of an example.
【符号の説明】 １ 中空鋼ロッド ２ 軸部 ３ ビット取付け部 ４ ねじ部 ５ フィレット部 ６ シャンク部[Description of Signs] 1 Hollow steel rod 2 Shaft 3 Bit mounting 4 Screw 5 Fillet 6 Shank
Claims (1)
ャンク部を有する中空鋼ロッド材を浸炭焼入れ焼戻しし
たのち、ビット取付け部に対して高周波焼入れを施し、
その後、更に１５０〜２５０℃で焼戻しを施すことを特
徴とする中空鋼ロッドの熱処理方法。1. A method of carburizing, quenching and tempering a hollow steel rod material having a bit mounting portion at one end and a shank portion at the other end, and then subjecting the bit mounting portion to induction hardening,
Thereafter, tempering is further performed at 150 to 250 [deg.] C., a method for heat treating a hollow steel rod.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11060388A JP2000256746A (en) | 1999-03-08 | 1999-03-08 | Method for heat treating hollow steel rod |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11060388A JP2000256746A (en) | 1999-03-08 | 1999-03-08 | Method for heat treating hollow steel rod |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2000256746A true JP2000256746A (en) | 2000-09-19 |
Family
ID=13140724
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP11060388A Withdrawn JP2000256746A (en) | 1999-03-08 | 1999-03-08 | Method for heat treating hollow steel rod |
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| Country | Link |
|---|---|
| JP (1) | JP2000256746A (en) |
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| CN107190129A (en) * | 2017-06-09 | 2017-09-22 | 贵州高峰石油机械股份有限公司 | A kind of Technology for Heating Processing of the solid drill steel of structural alloy steel |
| CN110628994A (en) * | 2019-10-30 | 2019-12-31 | 澳普洛钻探工具(无锡)有限公司 | Production process of sealing drill rod |
| CN111876576A (en) * | 2020-08-10 | 2020-11-03 | 湖南人文科技学院 | Manufacturing and strengthening method of lower core connecting rod in compression molding machine |
| CN113334029A (en) * | 2021-06-04 | 2021-09-03 | 重庆艾肯机电设备有限公司 | Manufacturing method of high-strength drill rod |
| CN113462859A (en) * | 2021-06-24 | 2021-10-01 | 重庆欣天利智能重工有限公司 | Heat treatment process for nitrate of drill rod |
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1999
- 1999-03-08 JP JP11060388A patent/JP2000256746A/en not_active Withdrawn
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| CN100424195C (en) * | 2005-12-20 | 2008-10-08 | 渤海能克钻杆有限公司 | Heat treatment process of sulfur resistant drill pipe joint |
| CN103624482A (en) * | 2012-08-21 | 2014-03-12 | 湖北奥德车桥有限公司 | Method for forming whole axle housing of automobile drive axle |
| CN103624482B (en) * | 2012-08-21 | 2016-05-11 | 李迎春 | A kind of forming method of automobile drive axle integral housing |
| CN103128507A (en) * | 2013-03-04 | 2013-06-05 | 南京紫薇精密机械有限公司 | Method for processing elastic collet with hardness at three different levels |
| CN104120431A (en) * | 2014-07-29 | 2014-10-29 | 武穴市长江工具有限责任公司 | Carburizing and manufacturing technology for split down-the-hole drill bit |
| CN107190129A (en) * | 2017-06-09 | 2017-09-22 | 贵州高峰石油机械股份有限公司 | A kind of Technology for Heating Processing of the solid drill steel of structural alloy steel |
| CN110628994A (en) * | 2019-10-30 | 2019-12-31 | 澳普洛钻探工具(无锡)有限公司 | Production process of sealing drill rod |
| CN111876576A (en) * | 2020-08-10 | 2020-11-03 | 湖南人文科技学院 | Manufacturing and strengthening method of lower core connecting rod in compression molding machine |
| CN113334029A (en) * | 2021-06-04 | 2021-09-03 | 重庆艾肯机电设备有限公司 | Manufacturing method of high-strength drill rod |
| CN113462859A (en) * | 2021-06-24 | 2021-10-01 | 重庆欣天利智能重工有限公司 | Heat treatment process for nitrate of drill rod |
| CN113462859B (en) * | 2021-06-24 | 2022-06-17 | 重庆欣天利智能重工有限公司 | Heat treatment process for nitrate of drill rod |
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