JPH0610036A - Surface hardening heat treatment by induction heating - Google Patents
Surface hardening heat treatment by induction heatingInfo
- Publication number
- JPH0610036A JPH0610036A JP4169253A JP16925392A JPH0610036A JP H0610036 A JPH0610036 A JP H0610036A JP 4169253 A JP4169253 A JP 4169253A JP 16925392 A JP16925392 A JP 16925392A JP H0610036 A JPH0610036 A JP H0610036A
- Authority
- JP
- Japan
- Prior art keywords
- induction heating
- heat treatment
- heat
- treated
- surface hardening
- 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- Withdrawn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
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
Landscapes
- Heat Treatment Of Articles (AREA)
Abstract
Description
【0001】[0001]
【産業上の利用分野】本発明は誘導加熱によって複雑な
形状例えば凹部を有する鉄鋼機械部材の表面を確実に硬
化できるようにした誘導加熱表面硬化熱処理法に関する
ものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an induction heating surface hardening heat treatment method capable of reliably hardening the surface of a steel machine member having a complicated shape such as a recess by induction heating.
【0002】[0002]
【従来の技術】従来、複雑な形状を有する鉄鋼機械部材
を誘導加熱によって熱処理する表面硬化法においては、
均一な硬化層は得られにくくまた局部的に熱処理するこ
とが困難であった。2. Description of the Related Art Conventionally, in a surface hardening method for heat-treating a steel machine member having a complicated shape by induction heating,
It was difficult to obtain a uniform hardened layer and it was difficult to heat-treat locally.
【0003】[0003]
【発明が解決しようとする課題】誘導加熱法による熱処
理は、バッチ式電気炉等の熱処理に比べ処理時間が短
く、少ないスペースで行うことが可能であり、またイン
ライン化が容易等多くの点で有効な熱処理法である。し
かし、被熱処理品の形状が複雑例えば凹部を有する場
合、コイルと被熱処理材とのクリアランスを最適状態に
設定することが必ずしも可能であるとは限らず、通常は
凸部のオーバーヒートを防止できるクリアランスとする
ことが多い。しかし、この場合コイルとの距離が近い凸
部に熱が集中し、凹部には熱が伝わりずらく均一な硬化
層が得られないという問題点があった。本発明の目的
は、上記した従来技術の欠点をなくし、複雑な形状の鉄
鋼機械部材の表層部に均一な硬化層を形成させ、疲労特
性、耐摩耗及び耐衝撃性の向上を図ることができる表面
硬化熱処理法を提供することである。The heat treatment by the induction heating method is shorter than the heat treatment of a batch type electric furnace or the like, can be performed in a small space, and is easy to in-line. This is an effective heat treatment method. However, when the shape of the heat-treated product is complicated, for example, when the heat-treated product has a concave portion, it is not always possible to set the clearance between the coil and the material to be heat-treated to an optimum state. Often. However, in this case, there is a problem that heat is concentrated on the convex portion close to the coil, and the heat is difficult to be transmitted to the concave portion, and a uniform hardened layer cannot be obtained. The object of the present invention is to eliminate the above-mentioned drawbacks of the prior art, to form a uniform hardened layer on the surface layer portion of a steel machine member having a complicated shape, and to improve fatigue characteristics, wear resistance and impact resistance. It is to provide a surface hardening heat treatment method.
【0004】[0004]
【課題を解決するための手段】上記目的を達成するため
に、本発明の表面硬化熱処理法においては、従来の誘導
加熱法では熱処理が困難とされる複雑な形状を呈した鉄
鋼機械部材に高磁性粉末材を被覆させた後、誘導加熱を
行うことにより表面層全体の均一な硬化層の形成、ある
いは局部的な熱処理を可能にしようとするものである。In order to achieve the above object, in the surface hardening heat treatment method of the present invention, it is possible to improve the mechanical strength of a steel machine member having a complicated shape which is difficult to heat treat by the conventional induction heating method. By coating the magnetic powder material and then performing induction heating, it is possible to form a uniform hardened layer over the entire surface layer, or to enable localized heat treatment.
【0005】鉄鋼機械部材の凹部に高磁性材料である
鉄、軟鋼、ケイ素鋼、Fe−Co合金、Fe−Ni合金
等の一つまたはこれらの混合物からからなる粉末剤を夫
々水ガラスと混合させたものを塗布し、誘導加熱を行う
ことにより凹部に塗布した磁性粉末が夫々もっている抵
抗値と交番磁界により誘導され温度が上昇し、それによ
って凹部を熱処理する方法を開発した。また、上記の高
磁性材料粉末は、加熱冷却時に飛散してしまうため、な
んら不純物の存在しない通常の焼入れ硬化層が得られ
る。A powder agent made of one of a highly magnetic material such as iron, mild steel, silicon steel, Fe-Co alloy, Fe-Ni alloy or the like or a mixture thereof is mixed with water glass in the recess of the steel machine member. We developed a method of heat-treating recesses by applying the above materials and inducing heating to the magnetic powders applied to the recesses to increase the temperature induced by the respective resistance value and alternating magnetic field. Further, since the above-mentioned high magnetic material powder is scattered during heating and cooling, a normal quench-hardened layer without any impurities can be obtained.
【0006】[0006]
【作用】上記のようにして得られた硬化層は均一とな
り、表面層には熱応力と変態応力が生じ、内部に引張り
応力、表面に大きな圧縮残留応力が形成されるため、疲
労特性及び耐摩耗性が著しく向上する。また、被熱処理
材は、熱処理可能な鉄鋼材ならば低炭素鋼から高炭素鋼
までいかなる鉄鋼材に対しても有効であり、更に加熱出
力を制御することによって硬化層深さを自由に変えるこ
とができる。The hardened layer obtained as described above becomes uniform, thermal stress and transformation stress are generated in the surface layer, tensile stress is formed inside, and large compressive residual stress is formed on the surface. Abrasion property is significantly improved. In addition, the heat-treatable material is effective for any steel material from low carbon steel to high carbon steel as long as it can be heat-treated, and the hardened layer depth can be freely changed by controlling the heating output. You can
【0007】[0007]
【実施例】図1は本発明熱処理法を実施するための構成
の一実施例を示したものである。ほぼ中央部に凹部2を
有し、該凹部2に高磁性粉末剤3が塗布被覆された被処
理部材1は、両端がセンタピン4により保持され、図示
しない駆動機構によって回転されると共に図中下方に移
動され、この移動の過程で誘導加熱コイル5により誘導
加熱されて熱処理され、その後噴射冷却ジャケット6に
より吹き付けられる例えば水等の冷却剤によって冷却さ
れるすなわち焼入れされる。前記凹部2に高磁性粉末剤
3を塗布被覆したので、凹部2は確実に加熱処理される
ようになった。これは、通常凹部2は誘導加熱法による
焼入れが困難であるが、高磁性粉末剤3を塗布すること
により誘導加熱コイル5とのクリアランスを少なくする
と共に、磁気特性が優れているため交番磁界が凹部に集
中しやすくなるためである。また冷却時に前記噴射水冷
ジャケット6により噴射される冷却液によって前記磁性
粉末剤3が飛散してしまうため、不純物が存在しない熱
処理硬化層が得られるようになる。EXAMPLE FIG. 1 shows an example of a constitution for carrying out the heat treatment method of the present invention. A member 1 to be processed having a recess 2 at substantially the center thereof and the high magnetic powder agent 3 applied and coated on the recess 2 is held at both ends by center pins 4 and rotated by a drive mechanism (not shown). Is heated by induction heating coil 5 to be heat treated in the course of this movement, and then cooled or quenched by a coolant such as water sprayed by injection cooling jacket 6. Since the high magnetic powder agent 3 was applied and coated on the concave portion 2, the concave portion 2 was surely heat-treated. This is because it is usually difficult to quench the concave portion 2 by the induction heating method, but by applying the high magnetic powder agent 3 the clearance between the concave portion 2 and the induction heating coil 5 is reduced and the magnetic characteristics are excellent, so that an alternating magnetic field is generated. This is because it is easy to concentrate in the recess. Further, since the magnetic powder agent 3 is scattered by the cooling liquid jetted by the jet water cooling jacket 6 during cooling, a heat-treated hardened layer free of impurities can be obtained.
【0008】図2は本発明によって高磁性粉末剤3を被
覆して熱処理した被処理材1の凹部2の硬度と磁性粉末
剤3を被覆しないで熱処理した被処理材(以下無処理材
という)の凹部2の硬度を比較したものである。上記の
条件で焼き入れを行ったものと、同条件で被覆剤を用い
ずに焼き入れを行ったものとの切欠き部における硬度分
布比較を示したものである。なお被覆処理材1の材料を
JIS:SCM435構造用合金鋼、高磁性粉末剤3を
Fe−Ni合金の粉末と水ガラスを4:1の比率で混合
したものとし、また誘導加熱コイル5を100KHz、
30Kwで駆動し、被処理材1を200回/分の回転数
で回転させながら20m/秒で送り、硬化層の深さを2
mmとした。更に噴射水冷ジャケット6によって噴射さ
れる冷却剤を20℃の水とした。図から明らかな如く、
粉末剤3を被覆して熱処理したものが、表面から2mm
までは約Hv650の硬度を示しているのに対し、被覆
していない無処理材は硬化層がほとんど得られていない
ことが分かる。FIG. 2 shows the hardness of the concave portion 2 of the material 1 to be treated which is coated with the high magnetic powder 3 according to the present invention and the material which is heat treated without coating the magnetic powder 3 (hereinafter referred to as untreated material). The hardness of the recess 2 is compared. FIG. 3 shows a comparison of hardness distributions in the notch portion between the case where quenching was performed under the above conditions and the case where quenching was performed under the same conditions without using a coating agent. The coating material 1 was JIS: SCM435 structural alloy steel, the high magnetic powder 3 was a mixture of Fe-Ni alloy powder and water glass at a ratio of 4: 1, and the induction heating coil 5 was 100 KHz. ,
It is driven at 30 Kw, and the processed material 1 is sent at 20 m / sec while rotating at a rotation speed of 200 times / min, and the depth of the hardened layer is 2
mm. Furthermore, the coolant sprayed by the spray water cooling jacket 6 was 20 ° C. water. As you can see from the figure,
2 mm from the surface after being coated with powder 3 and heat treated
It can be seen that while a hardness of about Hv650 is exhibited up to the above, a hardened layer is hardly obtained in the untreated material which is not coated.
【0009】図3は打撃疲労試験を行うための概略構成
を示すもので、固定治具9により回転可能に支持され、
2個の支点8間に位置する被処理材1の凹部2近傍にハ
ンマ7より衝撃を与え、その応力と繰返し数により疲労
特性を評価するもので、被処理材1を1サイクル毎に1
80度回転させるようにした。図4は図3に示す打撃疲
労試験結果を示すグラフであり、前記ハンマ7の衝撃エ
ネルギを25、35、45Kgfcmと設定して試験し
た結果を示すものである。図から明らかな如く、粉末剤
3を被覆しないで熱処理した無処理材1に比べ被覆して
熱処理した被処理材1は、どの衝撃エネルギにおいても
高い値を示しているのが分かる。これは被覆処理した被
処理材1の凹部2において、均一な表面硬化層に圧縮残
留応力が形成されたことにより、耐衝撃疲労特性が著し
く向上したためである。また、被覆しないで熱処理した
無処理材1が低い値を示したのは、凹部2に硬化部と軟
化部ができ、その境界からクラックが発生したためと考
えられる。これより、本発明の表面硬化処理は、被覆し
ないで熱処理した無処理材1に比較し、約3倍の耐衝撃
疲労特性を有することが分かる。FIG. 3 shows a schematic structure for performing a hitting fatigue test, which is rotatably supported by a fixing jig 9.
Impact is applied from the hammer 7 to the vicinity of the recess 2 of the material 1 to be processed located between the two fulcrums 8, and fatigue characteristics are evaluated by the stress and the number of repetitions.
It was rotated by 80 degrees. FIG. 4 is a graph showing the results of the impact fatigue test shown in FIG. 3, and shows the results of the test when the impact energy of the hammer 7 is set to 25, 35 and 45 Kgfcm. As is apparent from the figure, the treated material 1 coated and heat-treated shows a higher value at any impact energy than the untreated material 1 heat-treated without coating the powder agent 3. This is because the compressive residual stress is formed in the uniform surface-hardened layer in the concave portion 2 of the material 1 to be coated, and thus the impact fatigue resistance is remarkably improved. Further, the low value of the untreated material 1 which was heat-treated without coating is considered to be because a hardened portion and a softened portion were formed in the concave portion 2 and a crack was generated from the boundary thereof. From this, it can be seen that the surface hardening treatment of the present invention has about three times the impact fatigue resistance as compared with the untreated material 1 which is heat-treated without coating.
【0010】図5は図1において被処理材1を回転させ
ないで凹部2のみを熱処理した場合の凹部2の半径方向
及び該半径方向と約45度の方向における硬度を比較した
ものである。なお、誘導加熱コイル5を25Kwで駆動
し、高磁性粉末剤3をFe−Co合金粉末とした。FIG. 5 compares the hardness in the radial direction of the recess 2 and the hardness in the direction of about 45 degrees with the recess 2 when only the recess 2 is heat-treated without rotating the workpiece 1 in FIG. The induction heating coil 5 was driven at 25 Kw, and the high magnetic powder material 3 was made of Fe—Co alloy powder.
【0011】図から明らかな如く、粉末剤3を塗布被覆
しないで熱処理した無処理材1はHv350〜400と
ほとんど有効な硬化層が得られなかったが、粉末剤3を
塗布被覆して熱処理した被処理材1は角部及び凹部2共
に一様な硬度Hv650〜680が形成されることが分
かる。As is apparent from the figure, the untreated material 1 which was heat-treated without coating the powder agent 3 could not obtain an effective hardened layer with Hv of 350 to 400, but the powder agent 3 was coated and heat-treated. It can be seen that the workpiece 1 has uniform hardness Hv650 to 680 at both the corners and the recesses 2.
【0012】図6は疲労強度試験結果を示すもので、被
覆しないで熱処理した無処理材1の疲労限度が32.5
Kg/mm2とかなり低い値を示しているのに対し、被覆
して熱処理した被処理材1では52.5Kg/mm2と無
処理材1に比べ約1.6倍も疲労強度が向上しているこ
とが分かる。本発明の被覆表面硬化熱処理は、局部的な
熱処理においても疲労強度を向上させることができると
いうことが分かる。FIG. 6 shows the result of fatigue strength test. The fatigue limit of the untreated material 1 which was heat-treated without coating was 32.5.
It shows a considerably low value of Kg / mm 2 , whereas the treated and heat-treated material 1 has a fatigue strength of 52.5 kg / mm 2 , which is about 1.6 times that of the untreated material 1. I understand that. It is understood that the coated surface hardening heat treatment of the present invention can improve the fatigue strength even in the local heat treatment.
【0013】図7は被処理材1を先端にピニオンを有す
る電動工具シャフトとし、高磁性粉末剤3を塗布被覆し
て熱処理したもの、粉末剤3を塗布被覆しないで熱処理
したもの及び全体調質品である現行品との耐衝撃疲労寿
命ついて比較したものである。すなわち該シャフトを電
動工具に組み込み、電動工具を、起動、30秒の無負荷
運転及び停止の1サイクルを繰返し行い、破壊に至まで
の寿命差を比較した結果である。なおシャフトの材料を
JIS:SCM435構造用合金鋼とし、誘導加熱コイ
ル5を100KHz、40Kwで駆動し、シャフトの送
り速度を25mm/秒とし、冷却剤には水を用いた。ま
た焼き入れ硬化層深さは2mmとし、粉末剤3はシャフ
トの歯底部及びベアリング溝部に夫々塗布した。この結
果、粉末剤3を被覆しないで熱処理したシャフトでは歯
底部に十分な硬化層が得られないため、歯部との間に生
ずる焼き境部分からクラックが発生し、いずれも約10
000回以下と現行品(全体調質)に比べ1/2とかな
り低い値となった。一方粉末剤3を被覆して熱処理した
シャフトの場合、約40000回以上の寿命で現行品の
約2倍の値を示した。なお被覆処理したシャフト及び現
行品の寿命形態はピッチ円付近の表面疲労によるチッピ
ングが主原因となったものであり、ピニオン寿命の通常
の寿命形態であった。以上のことから本発明の表面硬化
熱処理法は、耐衝撃疲労寿命でも優れた性能を示すこと
が分かる。FIG. 7 shows a material 1 to be treated as an electric tool shaft having a pinion at its tip, which is heat-treated by coating and coating the high magnetic powder agent 3, one which is heat-treated without coating the powder agent 3, and the entire tempering. This is a comparison of the impact fatigue life with the current product, which is a product. That is, it is a result of incorporating the shaft into an electric power tool, repeating the electric power tool for one cycle of starting, no-load operation for 30 seconds, and stopping, and comparing the life differences until destruction. The material for the shaft was JIS: SCM435 structural alloy steel, the induction heating coil 5 was driven at 100 KHz and 40 Kw, the shaft feed rate was 25 mm / sec, and water was used as the coolant. The depth of the quench-hardened layer was set to 2 mm, and the powder agent 3 was applied to the bottom of the shaft and the bearing groove. As a result, in the shaft heat-treated without coating the powder agent 3, a sufficient hardened layer cannot be obtained at the tooth bottom portion, so cracks are generated from the burning boundary portion formed between the tooth portion and the tooth portion, and both are about 10
The value was 000 times or less, which is a half of the current product (overall tempering), which is a considerably low value. On the other hand, in the case of the shaft which was coated with the powder agent 3 and heat-treated, the life was about 40,000 times or more, which was about twice the value of the current product. The life of the coated shaft and the current product was mainly due to chipping due to surface fatigue near the pitch circle, and was a normal life of pinion. From the above, it can be seen that the surface hardening heat treatment method of the present invention exhibits excellent performance even in impact fatigue life.
【0014】[0014]
【発明の効果】以上のように本発明によれば、複雑な形
状を有する鉄鋼機械部材であっても均一な硬化層を得る
ことができ、それにより著しい強度特性の向上を図るこ
とが可能である。As described above, according to the present invention, it is possible to obtain a uniform hardened layer even in a steel machine member having a complicated shape, and thereby it is possible to significantly improve the strength characteristics. is there.
【図1】 本発明熱処理法を行う構成の一実施例を示す
平面図。FIG. 1 is a plan view showing an embodiment of a structure for carrying out a heat treatment method of the present invention.
【図2】 硬度分布を示すグラフ。FIG. 2 is a graph showing hardness distribution.
【図3】 打撃疲労試験を行う構成の一例を示す側面
図。FIG. 3 is a side view showing an example of a configuration for performing a hitting fatigue test.
【図4】 打撃疲労試験結果を示すグラフ。FIG. 4 is a graph showing the results of impact fatigue test.
【図5】 硬度分布を示すグラフ。FIG. 5 is a graph showing hardness distribution.
【図6】 回転曲げ疲労試験結果を示すグラフ。FIG. 6 is a graph showing the results of a rotating bending fatigue test.
【図7】 電動工具シャフトの起動停止実機評価試験の
結果を示すグラフ。FIG. 7 is a graph showing the results of a start / stop evaluation test of an electric tool shaft.
1は被処理材、2は凹部、3は高磁性粉末剤、4はセン
タピン、5は誘導加熱コイル、6は噴射冷却ジャケット
である。Reference numeral 1 is a material to be treated, 2 is a concave portion, 3 is a high magnetic powder agent, 4 is a center pin, 5 is an induction heating coil, and 6 is an injection cooling jacket.
Claims (3)
状の鉄鋼機械部材を誘導加熱により熱処理して表面を硬
化させる誘導加熱表面硬化熱処理法であって、熱処理困
難な部分を高磁性材料粉末剤により被覆した後誘導加熱
を行うことを特徴とした誘導加熱表面硬化熱処理法。1. An induction heating surface hardening heat treatment method for hardening a surface of a steel mechanical member having a complicated shape requiring wear resistance and impact resistance by induction heating to harden the surface. An induction heating surface hardening heat treatment method characterized by performing induction heating after coating with a powdered material.
イ素鋼、Fe−Co合金、Fe−Ni合金のいずれか一
つまたはこれらの混合物により形成したことを特徴とす
る請求項1記載の誘導加熱表面硬化熱処理法。2. The high magnetic material powder agent is formed of any one of iron, mild steel, silicon steel, Fe—Co alloy, Fe—Ni alloy, or a mixture thereof. Induction heating surface hardening heat treatment method of.
等をバインダーとした混合物により形成したことを特徴
とする請求項2記載の誘導加熱表面硬化熱処理法。3. The induction heating surface hardening heat treatment method according to claim 2, wherein the highly magnetic powder agent is formed by a mixture using water glass, an organic agent or the like as a binder.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP4169253A JPH0610036A (en) | 1992-06-26 | 1992-06-26 | Surface hardening heat treatment by induction heating |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP4169253A JPH0610036A (en) | 1992-06-26 | 1992-06-26 | Surface hardening heat treatment by induction heating |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH0610036A true JPH0610036A (en) | 1994-01-18 |
Family
ID=15883087
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP4169253A Withdrawn JPH0610036A (en) | 1992-06-26 | 1992-06-26 | Surface hardening heat treatment by induction heating |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH0610036A (en) |
-
1992
- 1992-06-26 JP JP4169253A patent/JPH0610036A/en not_active Withdrawn
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A300 | Withdrawal of application because of no request for examination |
Free format text: JAPANESE INTERMEDIATE CODE: A300 Effective date: 19990831 |