JPH09269316A - Eddy current flaw detection method and eddy current flaw detector - Google Patents
Eddy current flaw detection method and eddy current flaw detectorInfo
- Publication number
- JPH09269316A JPH09269316A JP9953896A JP9953896A JPH09269316A JP H09269316 A JPH09269316 A JP H09269316A JP 9953896 A JP9953896 A JP 9953896A JP 9953896 A JP9953896 A JP 9953896A JP H09269316 A JPH09269316 A JP H09269316A
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- Prior art keywords
- eddy current
- low
- flaw detection
- output
- current flaw
- Prior art date
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Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、部材表面域の亀裂
を発見するのに適した非破壊試験方法である渦流探傷方
法及びそれに用いる渦流探傷器に関する。特には、高マ
ンガン鋳鋼のような、表面に部分的強磁性相を含む非磁
性材料の探傷をも行うことのできる渦流探傷方法及び渦
流探傷器に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an eddy current flaw detection method which is a non-destructive test method suitable for finding cracks in the surface area of a member, and an eddy current flaw detector used therefor. In particular, the present invention relates to an eddy-current flaw detection method and an eddy-current flaw detector that can also perform flaw detection on a non-magnetic material containing a partially ferromagnetic phase on the surface, such as high-manganese cast steel.
【０００２】[0002]
【従来の技術】高速鉄道軌道の分岐器における亀裂検査
を例にとって従来技術を説明する。図５は、鉄道軌道の
分岐器の一例を示す図である。分岐器１０１は、鉄道レ
ールが分岐したり合流したりする部分に設けられる重要
部材である。大きいものでは（新幹線用＃１８分岐
器）、その長さ１７ｍ、重量３．３トンにもなる。この
分岐器は、高マンガン鋳鋼で作られているものが多い。
高マンガン鋳鋼は、亀裂の進展速度が遅くまた破壊靭性
が大であるため、強靭かつ高信頼性の求められる重要部
品用として好適だからである。2. Description of the Related Art The prior art will be described by taking crack inspection in a turnout of a high-speed railway track as an example. FIG. 5: is a figure which shows an example of the turnout device of a railroad track. The branching device 101 is an important member provided in a portion where the railroad rail branches or joins. The larger one (# 18 branch for Shinkansen) has a length of 17 m and a weight of 3.3 tons. Many of these switches are made of high-manganese cast steel.
This is because the high-manganese cast steel has a low crack growth rate and a large fracture toughness, and is therefore suitable for important parts that require toughness and high reliability.
【０００３】[0003]
【発明が解決しようとする課題】ところが、この高マン
ガン鋳鋼製の分岐器の検査（亀裂発見のための）におい
ては、他の材料で用いることのできる超音波探傷や渦流
探傷を用いることができなかった。前者は、高マンガン
鋳鋼中における超音波の減衰が著しいためである。後者
は、鋳肌に強磁性のフェライト相が残留しており、この
相は非磁性の本体と比べて透磁率が激変するため、残留
フェライト相で渦電流損失乱れが発生し、これが亀裂の
渦電流損失乱れ出力との判別が困難であったからであ
る。However, in the inspection (for crack detection) of the high manganese cast steel branch, it is possible to use ultrasonic flaw detection or eddy current flaw detection which can be used with other materials. There wasn't. The former is because the attenuation of ultrasonic waves in high-manganese cast steel is remarkable. In the latter, the ferromagnetic ferrite phase remains on the casting surface, and since the magnetic permeability of this phase changes drastically compared to the non-magnetic body, eddy current loss disturbance occurs in the residual ferrite phase, which causes crack eddy. This is because it was difficult to distinguish from the current loss disturbance output.
【０００４】そのため、分岐器の定期検査（周期半年〜
１年）においては、分岐器を解体・洗浄して浸透探傷に
よって亀裂の有無を調べている。そのため、分岐器の解
体に伴う路線の停止が生じる。また、分岐器が大型・大
重量品であるため、解体・洗浄にかかる工数も多大なも
のがある。Therefore, the periodical inspection of the branch device (cycle half year ~
In 1 year), the branch was disassembled and washed, and the presence or absence of cracks was examined by permeation flaw detection. Therefore, the line will be stopped due to the dismantling of the turnout. In addition, since the branch device is large and heavy, the number of man-hours required for dismantling and cleaning is enormous.
【０００５】本発明は、高マンガン鋳鋼のような、表面
に部分的強磁性相を含む非磁性材料の探傷をも行うこと
のできる渦流探傷方法及び渦流探傷器を提供することを
目的とする。An object of the present invention is to provide an eddy current flaw detection method and an eddy current flaw flaw detector which can also perform flaw detection on a non-magnetic material containing a partially ferromagnetic phase on the surface thereof, such as high manganese cast steel.
【０００６】[0006]
【課題を解決するための手段】上記課題を解決するた
め、本発明の渦流探傷方法は、 表面に部分的強磁性相
を含む非磁性材料を渦流探傷する方法であって； 低周
波励磁時及び高周波励磁時共に渦電流損失乱れの大なる
ものを強磁性相、 低周波励磁時には渦電流損失乱れが
小で、高周波励磁時には渦電流損失乱れが大なるものを
亀裂、 と判別することを特徴とする。In order to solve the above problems, the eddy current flaw detection method of the present invention is a method for eddy current flaw detection of a nonmagnetic material containing a partially ferromagnetic phase on the surface; One of the features is that the one with large eddy current loss disturbance during high-frequency excitation is a ferromagnetic phase, and the one with small eddy current loss disturbance during low-frequency excitation is the crack with a large eddy current loss disturbance during high-frequency excitation. To do.
【０００７】[0007]
【発明の実施の形態】本発明の一態様の渦流探傷方法に
おいては、高低二つの周波数で重複励磁し、渦電流損失
乱れ出力（一次出力）を上記高低二つの周波数の出力
（二次出力）に分離し、分離された高低二次出力を比較
することにより上記判別を行う。BEST MODE FOR CARRYING OUT THE INVENTION In the eddy current flaw detection method according to one aspect of the present invention, the eddy current loss turbulent output (primary output) is output by overlapping excitation at two high and low frequencies (secondary output). The above determination is performed by comparing the separated high and low secondary outputs with each other.
【０００８】すなわち、高低二つの周波数で重複励磁
し、部分的強磁性相（残留フェライト相）もしくは亀裂
の存在による一次出力を元の高低二つの周波数の出力に
分離し、両出力が共に大きいものを残留フェライト相の
存在によるもの、高周波数の出力が大きく低周波数の出
力が小さいものを亀裂の存在によるものと識別するので
ある。そして、亀裂の存在によるものだけを表示させ
る。That is, the primary output due to the presence of a partial ferromagnetic phase (residual ferrite phase) or cracks is separated into the original high and low frequency outputs, and both outputs are large. Is identified by the presence of residual ferrite phase, and the one with a large high frequency output and a small low frequency output is identified by the presence of cracks. And only those due to the presence of cracks are displayed.
【０００９】従来の渦流探傷法では、数ｋHz以上の比較
的高い周波数の交流磁場を金属表面に印加した際に該金
属表面に生じる渦電流が、割れなどの傷により乱される
ことを、電磁誘導の原理により検出するものである。と
ころがその乱れは、フェライト相などの強磁性体の混入
による透磁率のばらつきによっても生じる。そのため、
本件のようにそのばらつき（ノイズ）の大きい場合に
は、傷信号との区別が困難か、あるいはノイズの方が大
きくて探傷が不可能となる場合も多い。In the conventional eddy current flaw detection method, when an alternating magnetic field having a relatively high frequency of several kHz or more is applied to a metal surface, the eddy current generated on the metal surface is disturbed by a crack such as a crack. It is detected by the principle of induction. However, the disturbance is also caused by variations in magnetic permeability due to mixing of a ferromagnetic material such as a ferrite phase. for that reason,
When the variation (noise) is large as in the present case, it is often difficult to distinguish it from a flaw signal, or noise is larger and flaw detection is often impossible.
【００１０】一方、数百Hz以下の低い周波数の交流磁場
では、金属表面に生じる渦電流は極めて弱く、探傷信号
はほとんど得られない。しかしフェライト相の影響は高
い周波数の場合と同程度又はそれ以上に生じるので、こ
の両周波数の交流電流を同時に同一コイルに流して、そ
の磁場を生じさせる。そして、両者の周波数による誘導
渦電流を他の二次コイルで検出し、分離して、電気的に
引算すると、上述のように、高周波による傷信号は残る
が、フェライト相の影響は打ち消しあって軽減できる
か、うまく調整すると消滅することになる。On the other hand, in an alternating magnetic field with a low frequency of several hundred Hz or less, the eddy current generated on the metal surface is extremely weak, and almost no flaw detection signal can be obtained. However, since the influence of the ferrite phase occurs to the same extent as or higher than in the case of high frequency, alternating currents of both frequencies are simultaneously applied to the same coil to generate the magnetic field. When the induced eddy currents due to both frequencies are detected by another secondary coil, separated, and electrically subtracted, as described above, the scratch signal due to the high frequency remains, but the effect of the ferrite phase cancels out. It can be reduced by adjusting it, or it will disappear if adjusted properly.
【００１１】[0011]
【実施例】以下、本発明の実施例を説明する。図１は、
本発明の一実施例に係る渦流探傷器の全体構成を示す回
路図である。図２は、図１の渦流探傷器の渦流探傷セン
サ（検出コイル）の具体的構成を示す斜視図である。図
３は、図２の渦流探傷センサを用いて亀裂を検査する作
業の様子を示す図である。図４は、図１、２に示されて
いる本実施例の渦流探傷器を用いて分岐器の亀裂検査を
行っている様子を示す図である。Embodiments of the present invention will be described below. FIG.
It is a circuit diagram showing the whole eddy current flaw detector concerning one example of the present invention. FIG. 2 is a perspective view showing a specific configuration of the eddy current flaw detection sensor (detection coil) of the eddy current flaw detector in FIG. FIG. 3 is a diagram showing a state of an operation for inspecting a crack using the eddy current flaw detection sensor of FIG. FIG. 4 is a diagram showing a state in which crack inspection of a branching device is performed using the eddy current flaw detector of the present embodiment shown in FIGS.
【００１２】この図の実施例の渦流探傷器は、以下の構
成要素を有する。 検出コイル１３Ａ、１３Ｂの巻かれた磁芯を２本近
接させて並べ、その上に励磁コイル１１を巻くことによ
り構成された渦流探傷センサ。 この渦流探傷センサの２個の検出コイル１３Ａ、１
３Ｂを差動接続した、渦電流損失乱れ一次出力を検出す
る自己比較回路１２。 高周波発振器３及び低周波発振器５を含み、上記励
磁コイル１１に高周波・低周波重畳電流を流す励磁電流
用発振回路２。 上記渦電流損失乱れ一次出力を高周波成分と低周波
成分とに分離した後に比較加算して渦電流損失乱れ二次
出力を出力する判別回路１９。The eddy current flaw detector of the embodiment shown in this figure has the following components. An eddy current flaw detection sensor configured by arranging two wound magnetic cores of detection coils 13A and 13B in close proximity to each other and winding an exciting coil 11 on the magnetic cores. Two detection coils 13A, 1 of this eddy current flaw detection sensor
A self-comparison circuit 12 for detecting eddy current loss disturbance primary output, in which 3B is differentially connected. An exciting current oscillation circuit 2 including a high-frequency oscillator 3 and a low-frequency oscillator 5, and causing a high-frequency / low-frequency superimposed current to flow in the exciting coil 11. A discrimination circuit 19 for separating the eddy current loss disturbance primary output into a high frequency component and a low frequency component and then performing comparison and addition to output an eddy current loss disturbance secondary output.
【００１３】まず、図２を参照しつつ渦流探傷センサの
構造を説明する。わかり易くするため、渦流探傷センサ
の製造工程として説明する。最初に、フェライトコア製
の２本の磁芯４１Ａ、Ｂ（径２mm、長さ１０mm）を準備
する。この磁芯４１Ａ、Ｂのそれぞれの外周に検出コイ
ル１３Ａ、Ｂ（線径０．０７mm、ホルマル線、巻数２０
０）を巻く。次に、検出コイル１３Ａ、Ｂを巻いた２本
の磁芯４１Ａ、Ｂを横にたばねて（間に隙間３〜５m
m）、その外側に励磁コイル１１（線径０．１２mm、ホ
ルマル線、巻数１５０）を巻く。最後に、保護ケース４
３に納める。ケース４３には、棒状のホルダ４５がつい
ており、図４に示されているように、この棒を検査員が
手に持って検査作業を行う。First, the structure of the eddy current flaw detection sensor will be described with reference to FIG. For ease of understanding, the manufacturing process of the eddy current flaw detection sensor will be described. First, two magnetic cores 41A and 41B (diameter 2 mm, length 10 mm) made of ferrite core are prepared. The detection coils 13A and 13B (wire diameter 0.07 mm, formal wire, winding number 20) are provided on the outer circumferences of the magnetic cores 41A and B, respectively.
Roll 0). Next, the two magnetic cores 41A and 41B around which the detection coils 13A and 13B are wound are set as springs (with a gap of 3 to 5 m between them).
m), and the exciting coil 11 (wire diameter 0.12 mm, formal wire, number of turns 150) is wound on the outside. Finally, protective case 4
Pay in 3. The case 43 is provided with a rod-shaped holder 45, and as shown in FIG. 4, an inspector holds the rod in his / her hand to perform an inspection work.
【００１４】実際に亀裂の存在するものを検査する際に
は、図３に示されているように、亀裂５１あるいは残留
フェライト相の存在する近くにある検出コイル１３Ｂの
方では、被検査体（分岐器５０）中の渦電流が乱れ、検
出コイル１３Ｂの渦電流損失が小さくなって、両検出コ
イル１３Ａ、１３Ｂに生じる電圧バランスに乱れを生ず
る。これを渦流探傷センサ４０で検出する。When actually inspecting the presence of cracks, as shown in FIG. 3, the detection coil 13B near the crack 51 or the presence of the residual ferrite phase is the object to be inspected ( The eddy current in the branching device 50) is disturbed, the eddy current loss of the detection coil 13B is reduced, and the voltage balance generated in the detection coils 13A and 13B is disturbed. This is detected by the eddy current flaw detection sensor 40.
【００１５】次に、渦流探傷器全体の構成を図１を参照
しつつ説明する。励磁電流用発振回路２は、高周波発振
器３と低周波発振器５とを含む。高周波発振器３と低周
波発振器５の出力を、両発振器に接続されたポテンシオ
メータ７上で重畳させる。この重畳信号を、増幅器９で
増幅し、励磁コイル１１に印加する。Next, the overall structure of the eddy current flaw detector will be described with reference to FIG. The excitation current oscillation circuit 2 includes a high frequency oscillator 3 and a low frequency oscillator 5. The outputs of the high frequency oscillator 3 and the low frequency oscillator 5 are superimposed on the potentiometer 7 connected to both oscillators. The superimposed signal is amplified by the amplifier 9 and applied to the exciting coil 11.
【００１６】自己比較回路１２中においては、検出コイ
ル１３Ａと１３Ｂとが差動接続されて、ポテンシオメー
ターによる出力がほぼ０になるように調整している。し
たがって、検出コイル１３Ａと１３Ｂの渦電流損失出力
にアンバランスが生じたときに、両コイル１３Ａ、１３
Ｂの差分の出力が、検出コイル１３Ａ、１３Ｂの両端間
に接続されたポテンシオメーター１５上に表われる。こ
の出力は増幅器１７で増幅されて判別回路１９へ送られ
る。In the self-comparison circuit 12, the detection coils 13A and 13B are differentially connected so that the output from the potentiometer is adjusted to almost zero. Therefore, when an imbalance occurs in the eddy current loss output of the detection coils 13A and 13B, both coils 13A, 13B
The output of the difference of B appears on the potentiometer 15 connected across the detection coils 13A, 13B. This output is amplified by the amplifier 17 and sent to the discrimination circuit 19.
【００１７】判別回路１９は、並列接続されたハイパス
フィルター２１とローパスフィルター２３とを有する。
渦電流損失乱れ一次出力は、このフィルターを通り高周
波成分と低周波成分とに分離される。フィルター２１、
２３の先に直列接続されている検波器２５、２７は、そ
れぞれの振幅を検出するためのものであり、正及び負半
波整流している。検波器２５、２７を出た出力は、ポテ
ンシオメーター２９上にその差分が出力（二次出力）さ
れる。The discrimination circuit 19 has a high-pass filter 21 and a low-pass filter 23 connected in parallel.
The eddy current loss disturbed primary output passes through this filter and is separated into a high frequency component and a low frequency component. Filter 21,
The detectors 25 and 27 connected in series at the end of 23 are for detecting the respective amplitudes, and perform positive and negative half-wave rectification. The difference between the outputs from the detectors 25 and 27 is output (secondary output) on the potentiometer 29.
【００１８】ポテンシオメーター２９では、強磁性相に
よる高低二つの渦電流損失乱れ二次出力を、互いに打ち
消すように出力合成し、この際、無亀裂の標準サンプル
を用いて両高低出力のゲインを調節する。In the potentiometer 29, two high and low eddy current loss turbulent secondary outputs due to the ferromagnetic phase are combined so as to cancel each other out. At this time, the gains of both high and low outputs are obtained by using a crack-free standard sample. Adjust.
【００１９】判別回路１９の二次出力は、増幅器３１で
増幅された後、表示部３３（ブザー、メーター等）に表
示されるとともに、レコーダ３５に記録される。The secondary output of the discriminating circuit 19 is amplified by the amplifier 31, then displayed on the display unit 33 (buzzer, meter, etc.) and recorded on the recorder 35.
【００２０】本実施例の渦流探傷器の構造及び作用をま
とめて述べる。すなわち、この渦流探傷器は、１０ｋHz
以上の高周波を生じる発振器と、数百Hz以下の低周波を
生じる発振器とを有し、両周波を適当な振幅比で合成し
て励磁コイルに与える。そして、２個の検出コイルで渦
電流信号を検出し、両検出波を逆位相で合成する。この
とき、もし両検出コイルに生じる電圧が等しければ合成
した電圧は零であるが、もし両者いずれかの下に欠陥
（傷及びフェライト相のばらつき）があれば両コイルに
生じる誘導電圧の間に差を生じる。それを増幅した後、
高周波成分と低周波成分とに分離して、それぞれの変化
成分のみを増幅して減算する。フェライトの影響（ノイ
ズ）の低周波成分と高周波成分のそれとがちょうど打ち
消しされるように調整しても、高周波成分の傷信号成分
が残るので、傷信号のみを得ることができる。このよう
にして、フェライト相の影響のない又は少ない欠陥信号
を得ることができる。しかもこの方法によるとセンサの
走査速度には関係ないので、センサをゆっくり又は停止
して探傷することができるので、傷の位置を特定するこ
とができる。The structure and operation of the eddy current flaw detector of the present embodiment will be summarized. That is, this eddy current flaw detector has 10 kHz
It has an oscillator for generating the above high frequency and an oscillator for generating a low frequency of several hundred Hz or less, and both frequencies are combined with an appropriate amplitude ratio and given to the exciting coil. Then, the two detection coils detect the eddy current signal, and both detection waves are combined in opposite phases. At this time, if the voltages generated in both detection coils are equal, the combined voltage is zero, but if there is a defect (scratch or ferrite phase variation) under either of them, it will be between the induced voltages generated in both coils. Make a difference. After amplifying it
The high frequency component and the low frequency component are separated, and only the respective change components are amplified and subtracted. Even if adjustment is made so that the low-frequency component and the high-frequency component of the influence (noise) of ferrite are just cancelled, the flaw signal component of the high-frequency component remains, so that only the flaw signal can be obtained. In this way, it is possible to obtain a defect signal that is not affected by the ferrite phase or is less affected. In addition, according to this method, since the scanning speed of the sensor is irrelevant, the sensor can be slowly or stopped to perform flaw detection, so that the position of the flaw can be specified.
【００２１】ここで高周波と低周波の周波数の決定であ
るが、誘導される電圧は周波数に比例するので、試行錯
誤の末、低周波の電流を高周波の２倍以上に大きくし、
低周波数も誘導性を考えるとあまり下げない方がよいの
で約２００Hzとした。他方、高周波の周波数はある程度
傷検出感度をよくするため、約１０ｋHzとした。Here, the high frequency and the low frequency are determined. Since the induced voltage is proportional to the frequency, after trial and error, the low frequency current is increased to more than twice the high frequency.
Considering the inductive property, it is better not to lower the low frequency too much, so it was set to about 200 Hz. On the other hand, a high frequency is set to about 10 kHz in order to improve the scratch detection sensitivity to some extent.
【００２２】[0022]
【発明の効果】以上の説明から明らかなように、本発明
は、高マンガン鋳鋼のような表面に部分的強磁性相を含
む非磁性材料の探傷をも行うことのできる渦流探傷方法
及び渦流探傷器を提供できる。特に、本発明を鉄道の高
マンガン鋳鋼製分岐器に適用した場合、従来の分解・浸
透探傷法による場合と比べ、定期検査の工数が大幅に低
減できるのみならず、軌道の停止時間を短時間にできる
という大きな効果がある。As is apparent from the above description, the present invention provides an eddy current flaw detection method and an eddy current flaw flaw detection that can also perform flaw detection on a non-magnetic material containing a partially ferromagnetic phase on the surface, such as high manganese cast steel. Can be provided. In particular, when the present invention is applied to a high manganese cast steel turnout for railways, compared with the conventional disassembly / penetration flaw detection method, not only the number of man-hours for periodic inspection can be significantly reduced, but also the track stop time can be shortened. It has a great effect that
【図１】本発明の一実施例に係る渦流探傷器の全体構成
を示す回路図である。FIG. 1 is a circuit diagram showing an overall configuration of an eddy current flaw detector according to an embodiment of the present invention.
【図２】図１の渦流探傷器の渦流探傷センサ（検出コイ
ル）の具体的構成を示す斜視図である。FIG. 2 is a perspective view showing a specific configuration of an eddy current flaw detection sensor (detection coil) of the eddy current flaw detector in FIG.
【図３】図２の渦流探傷センサを用いて亀裂を検査する
作業の様子を示す図である。FIG. 3 is a diagram showing a state of an operation for inspecting a crack by using the eddy current flaw detection sensor of FIG.
【図４】図１、２に示されている本実施例の渦流探傷器
を用いて分岐器の亀裂検査を行っている様子を示す図で
ある。FIG. 4 is a diagram showing a state where a crack inspection of a branching device is performed using the eddy current flaw detector of the present embodiment shown in FIGS.
【図５】鉄道軌道の分岐器の一例を示す図である。FIG. 5 is a diagram showing an example of a railroad track branching device.
１ 渦流探傷器 ２ 発振回路 ３ 高周波発振器 ５ 低周波発
振器 ７、１５、２９ ポテンシオメーター ９、１７、３
１ 増幅器 １１ 励磁コイル １２ 自己比
較回路 １３ 検出コイル １９ 判別回
路 ２１ ハイパスフィルター ２３ ローパ
スフィルター ２５ 正検波器 ２７ 負検波器 ３３ 表示部 ３５ レコーダ1 Eddy current flaw detector 2 Oscillation circuit 3 High frequency oscillator 5 Low frequency oscillator 7, 15, 29 Potentiometer 9, 17, 3
1 Amplifier 11 Excitation Coil 12 Self-Comparison Circuit 13 Detection Coil 19 Discrimination Circuit 21 High Pass Filter 23 Low Pass Filter 25 Positive Detector 27 Negative Detector 33 Display 35 Recorder
Claims (4)
を渦流探傷する方法であって；低周波励磁時及び高周波
励磁時共に渦電流損失乱れの大なるものを強磁性相、 低周波励磁時には渦電流損失乱れが小で、高周波励磁時
には渦電流損失乱れが大なるものを亀裂、 と判別することを特徴とする渦流探傷方法。1. A method for eddy-current flaw detection of a non-magnetic material containing a partially ferromagnetic phase on the surface, wherein a large disturbance of eddy current loss occurs in both low frequency excitation and low frequency excitation. An eddy current flaw detection method characterized by determining that a eddy current loss disturbance is small during excitation and a large eddy current loss disturbance is detected during high frequency excitation as a crack.
損失乱れ出力（一次出力）を上記高低二つの周波数の出
力（二次出力）に分離し、分離された高低二次出力を比
較することにより上記判別を行う請求項１記載の渦流探
傷方法。2. An eddy current loss turbulent output (primary output) is separated into two high and low frequencies and the eddy current loss disturbance output (secondary output) is separated, and the separated high and low secondary outputs are compared. The eddy current flaw detection method according to claim 1, wherein the determination is performed by the above.
失乱れ二次出力を、互いに打ち消すように出力合成し、
この際、無亀裂の標準サンプルを用いて両高低出力のゲ
インを調節する請求項２記載の渦流探傷方法。3. The high and low eddy current loss disturbance secondary outputs due to the ferromagnetic phase are combined so as to cancel each other,
At this time, the eddy current flaw detection method according to claim 2, wherein both high and low output gains are adjusted using a crack-free standard sample.
せて並べ、その上に励磁コイルを巻くことにより構成さ
れた渦流探傷センサと、 この渦流探傷センサの２個の検出コイルを差動接続し
た、渦電流損失乱れ一次出力を検出する自己比較回路
と、 高周波及び低周波発振器を含み、上記励磁コイルに高周
波・低周波重畳電流を流す励磁電流用発振回路と、 上記渦電流損失乱れ一次出力を高周波成分と低周波成分
とに分離した後に比較加算して渦電流損失乱れ二次出力
を消去して残余乱れを亀裂と判別する回路と、 を含むことを特徴とする渦流探傷器。4. An eddy current flaw detection sensor constituted by arranging two magnetic cores wound with a detection coil in close proximity to each other and winding an excitation coil on the magnetic core, and two detection coils of the eddy current flaw detection sensor. Dynamically connected eddy current loss disturbance Self-comparison circuit for detecting primary output, high-frequency and low-frequency oscillator, exciting current oscillation circuit for flowing high-frequency / low-frequency superimposed current in the exciting coil, and eddy current loss disturbance An eddy current flaw detector comprising: a circuit for separating a primary output into a high-frequency component and a low-frequency component and then performing a comparison addition to eliminate an eddy current loss disturbance and a secondary output to determine a residual disturbance as a crack.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9953896A JPH09269316A (en) | 1996-03-29 | 1996-03-29 | Eddy current flaw detection method and eddy current flaw detector |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9953896A JPH09269316A (en) | 1996-03-29 | 1996-03-29 | Eddy current flaw detection method and eddy current flaw detector |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH09269316A true JPH09269316A (en) | 1997-10-14 |
Family
ID=14249982
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP9953896A Pending JPH09269316A (en) | 1996-03-29 | 1996-03-29 | Eddy current flaw detection method and eddy current flaw detector |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH09269316A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001255305A (en) * | 2000-03-08 | 2001-09-21 | Hatsuden Setsubi Gijutsu Kensa Kyokai | Method and apparatus for evaluating creep damage of ferromagnetic structure using ac magnetization |
| JP2008216091A (en) * | 2007-03-06 | 2008-09-18 | Railway Technical Res Inst | Device for detecting corrosion in railroad rail bottom |
| JP2010185832A (en) * | 2009-02-13 | 2010-08-26 | Tlv Co Ltd | Pulse eddy current flaw detector |
| JP2011095255A (en) * | 2009-10-30 | 2011-05-12 | Korea Electric Power Corp | Instrument and method for detecting corrosion of power transmission line |
| JP2014102197A (en) * | 2012-11-21 | 2014-06-05 | Meielec:Kk | Magnetic induction rail flow detection method, and magnetic induction rail flow detection device |
| CN108627570A (en) * | 2018-05-24 | 2018-10-09 | 北京工业大学 | Digital harmonic excitation source and implementation method |
-
1996
- 1996-03-29 JP JP9953896A patent/JPH09269316A/en active Pending
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001255305A (en) * | 2000-03-08 | 2001-09-21 | Hatsuden Setsubi Gijutsu Kensa Kyokai | Method and apparatus for evaluating creep damage of ferromagnetic structure using ac magnetization |
| JP2008216091A (en) * | 2007-03-06 | 2008-09-18 | Railway Technical Res Inst | Device for detecting corrosion in railroad rail bottom |
| JP2010185832A (en) * | 2009-02-13 | 2010-08-26 | Tlv Co Ltd | Pulse eddy current flaw detector |
| JP2011095255A (en) * | 2009-10-30 | 2011-05-12 | Korea Electric Power Corp | Instrument and method for detecting corrosion of power transmission line |
| JP2014102197A (en) * | 2012-11-21 | 2014-06-05 | Meielec:Kk | Magnetic induction rail flow detection method, and magnetic induction rail flow detection device |
| CN108627570A (en) * | 2018-05-24 | 2018-10-09 | 北京工业大学 | Digital harmonic excitation source and implementation method |
| CN108627570B (en) * | 2018-05-24 | 2022-05-17 | 北京工业大学 | Digital harmonic excitation source and implementation method |
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