JP2003050233A - Eddy-current flaw detection testing method and eddy- current flaw detection testing device - Google Patents

Eddy-current flaw detection testing method and eddy- current flaw detection testing device

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Publication number
JP2003050233A
JP2003050233A JP2001239902A JP2001239902A JP2003050233A JP 2003050233 A JP2003050233 A JP 2003050233A JP 2001239902 A JP2001239902 A JP 2001239902A JP 2001239902 A JP2001239902 A JP 2001239902A JP 2003050233 A JP2003050233 A JP 2003050233A
Authority
JP
Japan
Prior art keywords
detected
eddy current
change
test object
magnetic field
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.)
Pending
Application number
JP2001239902A
Other languages
Japanese (ja)
Inventor
Tatsuo Hiroshima
龍夫 廣島
Ichizo Uetake
一蔵 植竹
Satoru Nishio
哲 西尾
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Marktec Corp
Hokuto Denshi Kogyo KK
Original Assignee
Marktec Corp
Hokuto Denshi Kogyo KK
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Filing date
Publication date
Application filed by Marktec Corp, Hokuto Denshi Kogyo KK filed Critical Marktec Corp
Priority to JP2001239902A priority Critical patent/JP2003050233A/en
Publication of JP2003050233A publication Critical patent/JP2003050233A/en
Pending legal-status Critical Current

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  • Investigating Or Analyzing Materials By The Use Of Magnetic Means (AREA)

Abstract

PROBLEM TO BE SOLVED: To provide a low-cost eddy-current flaw detection testing device capable of making an analysis required for flaw detection using many parameters. SOLUTION: This eddy-current flaw detection testing device detects the change, generated by the presence of a discontinuous part around the surface, of an eddy current induced around the surface of a test object 22 formed of a conductor, by the AC magnetic field formed by an exciting coil 13, by the change of the magnetic field around the surface detected by a detecting coil 12, and detects the flaw of the test object 22 on the basis of the detected change of the eddy current. The device is provided with means 25, 11 for supplying an alternating current continuously changed in frequency, to the exciting coil 13, and means 17a, 18a, 21 for detecting the change of the magnetic field generated by the discontinuous part around the surface, of the eddy current induced around the surface of the test object 22 by the AC magnetic field formed by the exciting coil 13. The flaw detection of the test object 22 is carried out on the basis of the changes detected by the detecting means 17a, 18a, 21.

Description

【発明の詳細な説明】Detailed Description of the Invention

【０００１】[0001]

【発明の属する技術分野】本発明は、励磁コイルが形成
した交流磁界により導体からなる試験対象の表面付近に
誘起された渦電流の表面付近の不連続部により生じた変
化に基づき、試験対象の探傷を行う渦流探傷試験方法及
び渦流探傷試験装置に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is based on a change caused by a discontinuity near the surface of an eddy current induced near the surface of the test object made of a conductor by an alternating magnetic field formed by an exciting coil. The present invention relates to an eddy current flaw testing method and an eddy current flaw testing device for performing flaw detection.

【０００２】[0002]

【従来の技術】渦流探傷試験は、鉄鋼業等における資材
製造時の検査、自動車部品等の圧延、鍛造、絞り加工等
における成品段階での品質管理、品質保証の為の検査、
また、発電プラント、化学プラント等の保守検査、操業
モニター等広い範囲で行われている。渦流探傷試験は、
試験対象表面上に近接して置かれた励磁コイルに交流電
流を流すことにより交流磁界を発生させ、その交流磁界
により試験対象表面に誘起される渦電流が、試験対象表
面の割れ等によって変化することを利用するものであ
る。渦電流の変化を検出するには、励磁コイルを試験対
象表面上で略等速度で移動させ、割れ等が存在しない健
全部の信号と比較する。2. Description of the Related Art Eddy current flaw testing is an inspection for material manufacturing in the steel industry, quality control at the product stage in rolling, forging, drawing of automobile parts, etc. for quality assurance,
In addition, it is performed in a wide range such as maintenance inspections of power plants and chemical plants and operation monitors. Eddy current testing
An AC magnetic field is generated by passing an AC current through an exciting coil placed close to the test surface, and the eddy current induced on the test surface by the AC magnetic field changes due to cracks on the test surface. This is what you use. To detect the change in eddy current, the exciting coil is moved at a substantially constant speed on the surface to be tested and compared with the signal of a sound part where there is no crack or the like.

【０００３】試験対象表面に誘起される渦電流密度は、
磁界強度及び試験対象の材料（抵抗率、透磁率）に依存
する。試験対象表面に割れ等のきずがある場合、渦電流
の流路がきず部分と正常部分との境界に生じることか
ら、見かけの抵抗が変わる。また、渦電流により生じる
磁界の強さ及び方向の変化が、コイルと試験対象表面と
の系に関わる磁界を変化させる為、検出コイルに誘起さ
れる電圧が変化する。この電圧変化は振幅及び位相の変
化として検出できる為、このコイルの端子電圧の振幅及
び位相を測定し、その測定結果に基づき試験対象表面に
存在する割れ等のきずを検出する方法を渦流探傷試験法
と称している。一般的にきずに関わる情報は、位相と振
幅との２つの要因を有している為、理論的には他の放射
線探傷試験法や超音波探傷試験法に比べて、きずの定量
化及び雑音との弁別性が良いと言われている。The eddy current density induced on the surface under test is
Depends on the magnetic field strength and the material under test (resistivity, permeability). When there is a crack such as a crack on the surface of the test object, the apparent resistance changes because the flow path of the eddy current occurs at the boundary between the flaw part and the normal part. Further, the change in the strength and direction of the magnetic field generated by the eddy current changes the magnetic field related to the system of the coil and the surface to be tested, so that the voltage induced in the detection coil changes. Since this voltage change can be detected as a change in amplitude and phase, the method of measuring the amplitude and phase of the terminal voltage of this coil and detecting flaws such as cracks existing on the surface of the test object based on the measurement results is an eddy current flaw test. It is called the law. In general, information related to flaws has two factors, that is, phase and amplitude. Therefore, theoretically, quantification of flaws and noise can be performed as compared with other radiation flaw detection test methods and ultrasonic flaw detection test methods. It is said that the distinctiveness with

【０００４】図７は、従来の渦流探傷試験装置の要部構
成例を示すブロック図である。この渦流探傷試験装置
は、周波数Ｆの正弦波信号を発振する発振器１０と、発
振器１０が発振した正弦波信号を増幅する電力増幅器１
１と、電力増幅器１１が増幅して出力した周波数Ｆの交
流電流が流され、試験対象２２の表面付近を励磁する励
磁コイル１３と、この励磁により試験対象２２の表面付
近に生じた渦電流による交流磁界を検出して交流電圧を
出力する検出コイル１２と、検出コイル１２が出力した
交流電圧を増幅すると共に、試験対象２２の健全部分に
おける検出コイル１２の出力電圧に逆位相の電圧を加え
て、その増幅電圧を０付近に調節してヌル（Null）状態
にする演算器１４と、演算器１４が増幅した交流電圧が
それぞれ与えられる位相検波器１７，１８とを備えてい
る。FIG. 7 is a block diagram showing an example of the essential structure of a conventional eddy current flaw detector. This eddy current testing apparatus includes an oscillator 10 that oscillates a sine wave signal of frequency F, and a power amplifier 1 that amplifies the sine wave signal oscillated by the oscillator 10.
1 and the exciting coil 13 which excites the vicinity of the surface of the test object 22 by passing the alternating current of the frequency F amplified and output by the power amplifier 11, and the eddy current generated near the surface of the test object 22 by this excitation. A detection coil 12 that detects an AC magnetic field and outputs an AC voltage, and an AC voltage output by the detection coil 12 are amplified, and a voltage of opposite phase is added to the output voltage of the detection coil 12 in a healthy portion of the test object 22. An arithmetic unit 14 that adjusts the amplified voltage to a value near 0 to bring it into a null state and phase detectors 17 and 18 to which the AC voltage amplified by the arithmetic unit 14 is applied, respectively.

【０００５】この渦流探傷試験装置は、また、発振器１
０が発振した正弦波信号の位相を変位させ、位相検波器
１７，１８へそれぞれ与える移相器１５と、発振器１０
が発振した正弦波信号、及び移相器１５が位相を変位さ
せた正弦波信号に基づき、演算器１４からの指示信号に
より振幅及び位相を変えた電圧信号を、演算器１４が検
出コイル１２からの交流電圧に加算してヌル状態にする
為に、演算器１４へ与える平衡器１６と、位相検波器１
７，１８の各出力をアナログ／ディジタル変換するＡ／
Ｄ変換器１９，２０と、Ａ／Ｄ変換器１９，２０がそれ
ぞれ出力したディジタル信号に基づき、試験対象２２の
表面付近のきずの検出処理を行うディジタル信号処理装
置２１とを備えている。This eddy current flaw testing device is also used in the oscillator 1
0 shifts the phase of the sine wave signal oscillated and gives the phase detectors 17 and 18, respectively, a phase shifter 15 and an oscillator 10.
Is oscillated and the phase shifter 15 shifts the phase of the sine wave signal, the calculator 14 outputs a voltage signal whose amplitude and phase are changed by an instruction signal from the calculator 14 from the detection coil 12. Of the phase detector 1 and the balancer 16 provided to the calculator 14 in order to add to the AC voltage
A / for converting each output of 7 and 18 to analog / digital
The D converters 19 and 20 and the digital signal processing device 21 for detecting flaws near the surface of the test object 22 based on the digital signals output from the A / D converters 19 and 20, respectively.

【０００６】検出コイル１２の出力電圧をヌル状態にす
るとき、演算器１４は、検出コイル１２の出力電圧の増
幅電圧が０付近の所定電圧以内であるか否かを判定し、
所定電圧以内でなければ、平衡器１６が演算器１４へ与
える電圧信号の振幅及び位相を変えるように指示信号を
出力して、平衡器１６からの電圧信号を検出コイル１２
の出力電圧に加算した増幅電圧が所定電圧以内になる
迄、この動作を繰り返す。平衡器１６は、増幅電圧が所
定電圧以内になりヌル状態になったときは、演算器１４
へ与えるそのときの振幅及び位相をロックする。When the output voltage of the detection coil 12 is set to the null state, the arithmetic unit 14 determines whether the amplified voltage of the output voltage of the detection coil 12 is within a predetermined voltage near 0,
If the voltage is not within the predetermined voltage, the balancer 16 outputs an instruction signal to change the amplitude and phase of the voltage signal applied to the calculator 14, and the voltage signal from the balancer 16 is detected by the detection coil 12
This operation is repeated until the amplified voltage added to the output voltage of 1 is within a predetermined voltage. The balancer 16 operates when the amplified voltage is within a predetermined voltage and is in a null state.
The amplitude and phase at that time are locked.

【０００７】このような構成の渦流探傷試験装置では、
励磁コイル１３に電力増幅器１１から周波数Ｆの交流電
流が供給される。試験対象２２の表面付近には、励磁コ
イル１３により形成される交流磁界によって、周波数Ｆ
の渦電流が誘起される。演算器１４は、探傷試験の開始
時に、試験対象２２の健全部分において、検出コイル１
２の出力電圧の増幅電圧をヌル（Null）状態にしてお
き、ヌル状態にした後は、検出コイル１２の出力電圧の
増幅電圧に、平衡器１６からの電圧信号を加算して出力
する。In the eddy current flaw detector having such a structure,
An alternating current of frequency F is supplied from the power amplifier 11 to the exciting coil 13. In the vicinity of the surface of the test object 22, due to the alternating magnetic field formed by the exciting coil 13, the frequency F
Eddy currents are induced. At the start of the flaw detection test, the computing unit 14 detects the detection coil 1 in the sound part of the test target 22.
The amplified voltage of the output voltage of 2 is set to the null state, and after the null state is set, the voltage signal from the balancer 16 is added to the amplified voltage of the output voltage of the detection coil 12 and output.

【０００８】検出コイル１２は、周波数Ｆの渦電流によ
り形成された交流磁界を検出し、周波数Ｆの交流電圧を
出力する。この交流電圧は、演算器１４により増幅さ
れ、位相検波器１７，１８へそれぞれ与えられる。一
方、発振器１０が発振した正弦波信号は、励磁コイル１
３、試験対象２２及び検出コイル１２による位相の変位
分、移相器１５により位相が変位され、参照電圧として
位相検波器１７に与えられる。移相器１５は、また、位
相検波器１７に与えた正弦波信号より９０°位相を変位
させた正弦波信号を、参照電圧として位相検波器１８へ
与える。The detection coil 12 detects an AC magnetic field formed by an eddy current of frequency F and outputs an AC voltage of frequency F. This AC voltage is amplified by the calculator 14 and given to the phase detectors 17 and 18, respectively. On the other hand, the sine wave signal oscillated by the oscillator 10 is the excitation coil 1
3, the phase shifter 15 shifts the phase by the amount of phase shift caused by the test target 22 and the detection coil 12, and the phase shifter 15 supplies the reference voltage to the phase detector 17. The phase shifter 15 also gives a sine wave signal whose phase is shifted by 90 ° to the sine wave signal given to the phase detector 17 to the phase detector 18 as a reference voltage.

【０００９】位相検波器１７，１８がそれぞれ検波出力
した電圧は、Ａ／Ｄ変換器１９，２０でディジタル信号
にそれぞれ変換され、ディジタル信号処理装置２１は、
これらのディジタル信号に基づき、試験対象２２の表面
付近のきずの検出処理を行う。試験対象２２の表面付近
にきずが存在する場合には、検出コイル１２が出力する
交流電圧は、そのきずに特有なθｆだけ位相が変位して
いる。従って、図８（ａ）に示すように、位相検波器１
７が検波した位相が０°の成分Ｓ１と、位相検波器１８
が検波した位相が９０°の成分Ｓ２とから、そのきず信
号の大きさ（Ｓ１2 ＋Ｓ２2 ）1/2 、及びそのきず信号
の位相θｆ＝ｔａｎ-1（Ｓ２／Ｓ１）を求めることがで
きる。The voltages detected and output by the phase detectors 17 and 18 are converted into digital signals by the A / D converters 19 and 20, respectively, and the digital signal processing device 21
Based on these digital signals, the flaw detection process near the surface of the test object 22 is performed. When a flaw is present near the surface of the test object 22, the phase of the AC voltage output by the detection coil 12 is displaced by θf, which is peculiar to the flaw. Therefore, as shown in FIG. 8A, the phase detector 1
The component S1 having a phase of 0 ° detected by 7 and the phase detector 18
The magnitude (S1 2 + S2 2 ) 1/2 of the flaw signal and the phase θf = tan −1 (S2 / S1) of the flaw signal can be obtained from the component S2 whose phase is detected by 90 °. .

【００１０】きず信号は、励磁コイル１３に供給される
交流電流の周波数Ｆに応じて、一般的に図８（ｂ）に示
すような半円形のベクトル線図を描き、周波数Ｆが高い
場合、そのきずに特有な位相θｆは小さくなる。低域周
波数Ａでは、リフトオフの影響はインダクタンス成分に
大きく含まれ、中域周波数Ｂでは、リフトオフの影響は
小さく、低域周波数Ｃでは、リフトオフの影響は抵抗成
分に大きく含まれる。The flaw signal generally draws a semicircular vector diagram as shown in FIG. 8 (b) according to the frequency F of the alternating current supplied to the exciting coil 13. When the frequency F is high, The phase θf peculiar to the flaw becomes small. At low frequency A, the effect of lift-off is largely included in the inductance component, at middle frequency B, the effect of lift-off is small, and at low frequency C, the effect of lift-off is largely included in the resistance component.

【００１１】[0011]

【発明が解決しようとする課題】このような構成の渦流
探傷試験装置で渦流探傷試験を行った場合、試験対象２
２の表面付近に誘起される渦電流の密度は、試験対象２
２の材質変化、及びリフトオフ等励磁コイル１と試験対
象２２との空間的な関係によっても変化し、きずのみに
依存していない為、位相及び振幅の２つのパラメータだ
けでは、的確な判断ができないという問題がある。励磁
コイル１３に供給される電流が一定であっても、励磁コ
イル１３と試験対象２２との空間的な結合度が変化する
と、試験対象２２表面に与えられる磁界強度は変化する
し、試験対象２２の偏析等の材質の局部的な変化や表面
硬度の変化等、試験対象２２の抵抗率や透磁率の局部的
な変化を与える要因が存在すると、試験対象２２に誘起
される渦電流は局部的に変化する。When an eddy-current flaw detection test is conducted with the eddy-current flaw-detection test apparatus having such a configuration, the test object 2
The density of the eddy current induced near the surface of
2 changes due to the material change and the spatial relationship between the lift-off etc. exciting coil 1 and the test object 22 and does not depend only on flaws, so it is not possible to make an accurate judgment using only the two parameters of phase and amplitude. There is a problem. Even if the current supplied to the exciting coil 13 is constant, when the spatial coupling degree between the exciting coil 13 and the test object 22 changes, the magnetic field strength applied to the surface of the test object 22 changes, and the test object 22 If there is a factor that causes a local change in the resistivity or magnetic permeability of the test object 22, such as a local change in the material such as segregation of the material or a change in the surface hardness, the eddy current induced in the test object 22 will be localized. Changes to.

【００１２】従って、検出コイル１２の出力電圧を測定
することから、その出力電圧の変化がきずに起因するも
のか、励磁コイル１３及び検出コイル１２と試験対象２
２表面との距離の変化によるものか、試験対象２２表面
付近の局部的な材質変化によるものかを判断するのは極
めて困難であった。Therefore, since the output voltage of the detection coil 12 is measured, whether the change in the output voltage is caused by a flaw, the exciting coil 13, the detection coil 12 and the test object 2
It was extremely difficult to determine whether it was due to a change in the distance from the surface 2 or due to a local material change near the surface of the test object 22.

【００１３】このような問題を解決する為、多くの提案
がなされて来た。その１つは、多周波渦流探傷法と呼ば
れ、原子力発電設備の蒸気発生器細管の定期点検等に用
いられている。この方法は、１つの励磁コイルに複数の
周波数成分を有する電流を供給し、試験対象内に複数の
周波数成分を有する渦電流を誘起させる。検出コイルの
出力電圧も同様に複数の周波数成分を有する為、この出
力電圧をフィルタ等の手段により個々の周波数を有する
電圧に分け、各電圧の振幅及び位相の成分を収集するこ
とにより、同一のきずから得られる信号のパラメータが
増加し、より多くの情報を得ることができる。Many proposals have been made to solve such problems. One of them is called a multi-frequency eddy current flaw detection method and is used for periodic inspection of steam generator thin tubes of nuclear power generation facilities. This method supplies a current having a plurality of frequency components to one exciting coil, and induces an eddy current having a plurality of frequency components in a test object. Since the output voltage of the detection coil also has a plurality of frequency components, this output voltage is divided into voltages having individual frequencies by means of a filter or the like, and the amplitude and phase components of each voltage are collected to make the same. The parameter of the signal obtained from the flaw is increased, and more information can be obtained.

【００１４】例えば、Ｎｉ合金で製作されている蒸気発
生器細管は、通常、バッフル板と呼ばれる振動防止用板
に設けられた孔に挿通され固定されている。両端は壁板
に取り付けられており、材質が異なる壁板やバッフル板
が有る部分の管内面に有害なきずが存在していても、壁
板やバッフル板による信号が大きく検出され、有害なき
ずによる微細な信号は通常の方法では検出できなかっ
た。For example, a steam generator thin tube made of Ni alloy is usually inserted and fixed in a hole provided in a vibration prevention plate called a baffle plate. Both ends are attached to the wall plate, and even if there are harmful flaws on the inner surface of the pipe where there are wall plates and baffle plates made of different materials, the signal from the wall plate or baffle plate is detected significantly and the harmful flaws are not detected. The fine signal due to could not be detected by the usual method.

【００１５】現状では、２００ｋＨｚ及び４００ｋＨｚ
の２つの周波数を使用して探傷試験が行われており、管
内面のきずによる信号とバッフル板による信号とが弁別
されている。更に、例えばバッフル板ときずとの弁別
（２周波数で可能）、きずの分類、及びきずの深さの定
量評価を行う場合には、２周波数ではパラメータ数が不
足するので、４周波数が使用されている。このように、
多周波渦流探傷法では、より綿密な解析精度及びより多
くの弁別項目を対象にすると、使用する周波数を増やす
ことが必要となり、探傷試験装置の大型化及び価格の高
騰等が避けられないという問題があった。この為、通常
は４周波数迄が実用になっているのみである。Currently, 200 kHz and 400 kHz
The flaw detection test is performed by using two frequencies, and the signal due to the flaw on the inner surface of the pipe and the signal due to the baffle plate are discriminated. Furthermore, for example, when discriminating between a baffle plate and a flaw (possible with two frequencies), classifying a flaw, and quantitatively evaluating a flaw depth, four frequencies are used because the number of parameters is insufficient at two frequencies. ing. in this way,
In the multi-frequency eddy current flaw detection method, if more precise analysis accuracy and more discrimination items are targeted, it is necessary to increase the frequency to be used, and it is inevitable that the flaw detection test equipment becomes larger and the price rises. was there. For this reason, up to 4 frequencies are usually only practically used.

【００１６】また、他の１つの提案は、パルス渦流探傷
試験法と呼ばれており、励磁コイルに直流パルス電流を
供給すると、試験対象内に誘起される渦電流は理論的に
は無限の周波数列を有するので、検出コイルの出力電圧
は無限の周波数帯域の電圧に分解でき、無限の試験周波
数を使用して探傷試験を行うのと同等の結果を得ること
ができるというものである。しかし、励磁コイルは、接
続する電力増幅器のインダクタンス負荷として作用する
為、直流パルスを励磁コイルに供給した場合は波形が鈍
り、有限の周波数しか検出できないこと、広帯域の周波
数に対応するコイルの製造が難しいこと、及び渦電流の
密度を上げるのが困難である為、試験対象の深さ方向の
情報が、予想されるようには採取できないことを大きな
理由として、今日、実用レベルには達していない。Another proposal is called a pulse eddy current flaw test method. When a DC pulse current is supplied to the exciting coil, the eddy current induced in the test object theoretically has an infinite frequency. With the columns, the output voltage of the detection coil can be decomposed into a voltage in an infinite frequency band, and a result equivalent to that obtained by performing a flaw detection test using an infinite test frequency can be obtained. However, since the exciting coil acts as an inductance load of the power amplifier to be connected, when a DC pulse is supplied to the exciting coil, the waveform becomes dull and only a finite frequency can be detected. Due to the difficulty and the difficulty of increasing the eddy current density, the depth information of the test object cannot be collected as expected, which is why it has not reached the practical level today. .

【００１７】上述したように、渦流探傷試験では、きず
信号電圧の振幅及び位相の２つのパラメータを利用して
いるが、きずの大きさ、きずの種類及びきずが存在する
試験対象の深さ方向の位置を検出すること、並びにリフ
トオフの影響を除くこと等、通常、探傷に必要な解析を
行う為には、多数のパラメータを必要とし、単一周波数
の位相及び振幅の２つでは解析が不可能であり、その為
の方法として上述した方法では探傷試験装置が高価にな
る等の問題がある。本発明は、上述したような事情に鑑
みてなされたものであり、多数のパラメータを利用して
探傷に必要な解析を安価に行うことが可能な渦流探傷試
験方法、及び多数のパラメータを利用して探傷に必要な
解析を行うことが可能な安価な渦流探傷試験装置を提供
することを目的とする。As described above, in the eddy current flaw detection test, two parameters of the amplitude and phase of the flaw signal voltage are used. However, the size of the flaw, the type of flaw and the depth direction of the test object in which the flaw exists. In order to carry out the analysis required for flaw detection, such as detecting the position of and the effect of lift-off, many parameters are required, and the analysis is not possible with two phases of single frequency and amplitude. This is possible, and the method described above as a method therefor has a problem that the flaw detection test apparatus becomes expensive. The present invention has been made in view of the above-mentioned circumstances, and utilizes an eddy current flaw detection test method capable of inexpensively performing analysis necessary for flaw detection using a large number of parameters, and a large number of parameters. It is an object of the present invention to provide an inexpensive eddy current flaw testing device capable of performing an analysis required for flaw detection.

【００１８】[0018]

【課題を解決するための手段】第１発明に係る渦流探傷
試験方法は、励磁コイルが形成した交流磁界により、導
体からなる試験対象の表面付近に誘起された渦電流の前
記表面付近の不連続部の存在により生じた変化を、検出
コイルが検出した前記表面付近の磁界の変化により検出
し、検出した前記渦電流の変化に基づき、前記試験対象
の探傷を行う渦流探傷試験方法において、前記励磁コイ
ルは、周波数が連続的に変化する交流電流により前記交
流磁界を形成し、前記励磁コイルが形成した交流磁界に
より前記試験対象の表面付近に誘起された渦電流の前記
表面付近の不連続部により生じた磁界の変化を検出し、
検出した電気信号の変化に基づき前記試験対象の探傷を
行うことを特徴とする。The eddy current flaw testing method according to the first aspect of the present invention is a discontinuity in the vicinity of the surface of an eddy current induced near the surface of a test object made of a conductor by an alternating magnetic field formed by an exciting coil. A change caused by the presence of a portion is detected by a change in the magnetic field in the vicinity of the surface detected by the detection coil, and based on the change in the detected eddy current, in the eddy current flaw detection test method for performing flaw detection on the test object, the excitation The coil forms the AC magnetic field by an AC current whose frequency continuously changes, and by the discontinuity near the surface of the eddy current induced near the surface of the test object by the AC magnetic field formed by the exciting coil. Detects changes in the generated magnetic field,
It is characterized in that the flaw detection of the test object is performed based on the detected change of the electric signal.

【００１９】第２発明に係る渦流探傷試験方法は、前記
電気信号の変化は、前記交流電流の任意の周波数時に前
記試験対象の健全部で検出した前記検出コイルの出力
と、前記不連続部で検出した前記検出コイルの出力との
差であることを特徴とする。In the eddy current flaw detection test method according to the second aspect of the present invention, the change in the electric signal is detected by the output of the detection coil detected by the sound part of the test object at an arbitrary frequency of the alternating current and by the discontinuous part. It is characterized in that it is a difference from the detected output of the detection coil.

【００２０】第３発明に係る渦流探傷試験方法は、前記
健全部で検出すべき検出コイルの出力は、前記周波数の
変化の開始から終了迄の時間の１００分の１乃至１０分
の１の間隔毎に検出することを特徴とする。In the eddy current flaw detection test method according to the third aspect of the present invention, the output of the detection coil to be detected in the sound portion is at intervals of 1/100 to 1/10 of the time from the start to the end of the frequency change. It is characterized in that it is detected for each.

【００２１】第４発明に係る渦流探傷試験方法は、励磁
コイルが形成した交流磁界により、導体からなる試験対
象の表面付近に誘起された渦電流の前記表面付近の不連
続部の存在により生じた変化を、検出コイルが検出した
前記表面付近の磁界の変化により検出し、検出した前記
渦電流の変化に基づき、前記試験対象の探傷を行う渦流
探傷試験方法において、前記励磁コイルは、周波数が段
階的に変化する交流電流により前記交流磁界を形成し、
前記励磁コイルが形成した交流磁界により前記試験対象
の表面付近に誘起された渦電流の前記表面付近の不連続
部により生じた磁界の変化を検出し、検出した電気信号
の変化に基づき前記試験対象の探傷を行うことを特徴と
する。The eddy current flaw testing method according to the fourth aspect of the present invention is caused by the presence of a discontinuity near the surface of the eddy current induced near the surface of the test object made of a conductor by the alternating magnetic field formed by the exciting coil. A change is detected by a change in the magnetic field in the vicinity of the surface detected by the detection coil, and based on the change in the detected eddy current, in the eddy current flaw detection test method for performing flaw detection on the test object, the exciting coil has a stepped frequency. The alternating magnetic field is formed by a changing alternating current,
The change of the magnetic field caused by the discontinuity near the surface of the eddy current induced near the surface of the test object by the AC magnetic field formed by the exciting coil is detected, and the test object is detected based on the change of the detected electric signal. It is characterized by performing flaw detection.

【００２２】第５発明に係る渦流探傷試験方法は、前記
電気信号の変化は、前記交流電流の周波数が変化した都
度、前記試験対象の健全部で検出した前記検出コイルの
出力と、前記不連続部で検出した前記検出コイルの出力
との差であることを特徴とする。In the eddy current flaw detection test method according to the fifth aspect of the present invention, the change in the electrical signal is detected by the output of the detection coil detected by the sound part of the test object and the discontinuity each time the frequency of the alternating current changes. It is a difference from the output of the detection coil detected by the section.

【００２３】第６発明に係る渦流探傷試験装置は、励磁
コイルが形成した交流磁界により、導体からなる試験対
象の表面付近に誘起された渦電流の前記表面付近の不連
続部の存在により生じた変化を、検出コイルが検出した
前記表面付近の磁界の変化により検出し、検出した前記
渦電流の変化に基づき、前記試験対象の探傷を行う渦流
探傷試験装置において、前記励磁コイルに周波数が連続
的に変化する交流電流を供給する手段と、前記励磁コイ
ルが形成した交流磁界により前記試験対象の表面付近に
誘起された渦電流の前記表面付近の不連続部により生じ
た磁界の変化を検出する手段とを備え、該手段が検出し
た変化に基づき前記試験対象の探傷を行うべくなしてあ
ることを特徴とする。The eddy current flaw detector according to the sixth aspect of the present invention is caused by the presence of a discontinuity near the surface of the eddy current induced near the surface of the test object made of a conductor by the alternating magnetic field formed by the exciting coil. The change is detected by a change in the magnetic field near the surface detected by the detection coil, and based on the change in the detected eddy current, in the eddy current flaw detection test device that performs flaw detection on the test object, the excitation coil has a continuous frequency. And a means for detecting a change in magnetic field caused by a discontinuity near the surface of the eddy current induced near the surface of the test object by the AC magnetic field formed by the exciting coil. And detecting the test object based on the change detected by the means.

【００２４】第１発明に係る渦流探傷試験方法及び第６
発明に係る渦流探傷試験装置では、励磁コイルが形成し
た交流磁界により、導体からなる試験対象の表面付近に
誘起された渦電流の試験対象の表面付近の不連続部の存
在により生じた変化を、検出コイルが検出した試験対象
の表面付近の磁界の変化により検出し、検出した渦電流
の変化に基づき、試験対象の探傷を行う。供給する手段
が、励磁コイルに周波数が連続的に変化する交流電流を
供給し、検出する手段が、励磁コイルが形成した交流磁
界により試験対象の表面付近に誘起された渦電流の表面
付近の不連続部により生じた磁界の変化を検出し、検出
する手段が検出した変化に基づき試験対象の探傷を行
う。これにより、多数のパラメータを利用して探傷に必
要な解析を安価に行うことが可能な渦流探傷試験方法及
びその安価な渦流探傷試験装置を実現することができ
る。Eddy Current Testing Method According to First Aspect and Sixth Aspect
In the eddy current flaw detection test apparatus according to the invention, by the alternating magnetic field formed by the exciting coil, the change caused by the presence of the discontinuity near the surface of the test object of the eddy current induced near the surface of the test object made of a conductor, The detection coil detects the change in the magnetic field near the surface of the test object and detects the test object based on the detected change in the eddy current. The means for supplying supplies an alternating current whose frequency changes continuously to the exciting coil, and the means for detecting detects an error in the vicinity of the surface of the eddy current induced near the surface of the test object by the alternating magnetic field formed by the exciting coil. The change in the magnetic field generated by the continuous portion is detected, and the test object is subjected to flaw detection based on the change detected by the detecting means. As a result, it is possible to realize an eddy-current flaw detection test method and an inexpensive eddy-current flaw detection test apparatus that can perform analysis necessary for flaw detection at low cost using a large number of parameters.

【００２５】第７発明に係る渦流探傷試験装置は、前記
変化は、前記交流電流の任意の周波数時に前記試験対象
の健全部で検出した前記検出コイルの出力と、前記不連
続部で検出した前記検出コイルの出力との差であること
を特徴とする。In the eddy current flaw detector according to the seventh aspect of the present invention, the change is detected by the output of the detection coil detected by the sound part of the test object at an arbitrary frequency of the alternating current and the change detected by the discontinuous part. It is characterized in that it is the difference from the output of the detection coil.

【００２６】第２発明に係る渦流探傷試験方法及び第７
発明に係る渦流探傷試験装置では、渦電流の磁界の変化
は、周波数が連続的に変化する交流電流の任意の周波数
時に、試験対象の健全部で検出した検出コイルの出力
と、試験対象の表面付近の不連続部で検出した検出コイ
ルの出力との差であるので、ヌル（Null）状態にしなが
ら、多数のパラメータを利用して探傷に必要な解析を安
価に行うことが可能な渦流探傷試験方法及びその安価な
渦流探傷試験装置を実現することができる。Eddy Current Testing Method According to Second Aspect and Seventh Aspect
In the eddy current flaw detection test apparatus according to the invention, the change in the magnetic field of the eddy current is caused by the output of the detection coil detected by the sound part of the test object and the surface of the test object at any frequency of the alternating current whose frequency changes continuously. Since it is the difference from the output of the detection coil detected at the discontinuity in the vicinity, it is possible to perform the analysis required for flaw detection at low cost by using many parameters while maintaining the null state. The method and its inexpensive eddy current flaw detector can be realized.

【００２７】第８発明に係る渦流探傷試験装置は、前記
健全部で検出すべき検出コイルの出力は、前記周波数の
変化の開始から終了迄の時間の１００分の１乃至１０分
の１の間隔毎に検出することを特徴とする。In the eddy current flaw detector according to the eighth aspect of the present invention, the output of the detection coil to be detected by the sound section is at intervals of 1/100 to 1/10 of the time from the start to the end of the frequency change. It is characterized in that it is detected for each.

【００２８】第３発明に係る渦流探傷試験方法及び第８
発明に係る渦流探傷試験装置では、試験対象の健全部で
検出すべき検出コイルの出力は、周波数が連続的に変化
する交流電流の周波数の変化の開始から終了迄の時間の
１００分の１乃至１０分の１の間隔毎に検出するので、
ヌル（Null）電圧が大幅に変化しない周波数範囲毎にヌ
ル状態にすることができ、多数のパラメータを利用して
探傷に必要な解析を安価に行うことが可能な渦流探傷試
験方法及びその安価な渦流探傷試験装置を実現すること
ができる。Eddy Current Testing Method According to Third Invention and Eighth Embodiment
In the eddy current flaw detection test apparatus according to the invention, the output of the detection coil to be detected in the sound portion of the test object is 1 / 100th to 100th of the time from the start to the end of the frequency change of the alternating current whose frequency changes continuously. Since it is detected at intervals of 1/10,
An eddy current flaw test method and its inexpensive method that can be set to a null state for each frequency range in which the null voltage does not change significantly and that can perform analysis necessary for flaw detection at low cost by using a large number of parameters. An eddy current flaw testing device can be realized.

【００２９】第９発明に係る渦流探傷試験装置は、励磁
コイルが形成した交流磁界により、導体からなる試験対
象の表面付近に誘起された渦電流の前記表面付近の不連
続部の存在により生じた変化を、検出コイルが検出した
前記表面付近の磁界の変化により検出し、検出した前記
渦電流の変化に基づき、前記試験対象の探傷を行う渦流
探傷試験装置において、前記励磁コイルに周波数が段階
的に変化する交流電流を供給する手段と、前記励磁コイ
ルが形成した交流磁界により前記試験対象の表面付近に
誘起された渦電流の前記表面付近の不連続部により生じ
た磁界の変化を検出する手段とを備え、該手段が検出し
た変化に基づき前記試験対象の探傷を行うべくなしてあ
ることを特徴とする。The eddy current flaw detector according to the ninth aspect of the invention is caused by the presence of a discontinuity near the surface of the eddy current induced near the surface of the test object made of a conductor by the AC magnetic field formed by the exciting coil. A change is detected by a change in the magnetic field in the vicinity of the surface detected by the detection coil, and based on the change in the detected eddy current, in the eddy-current flaw detection test device that performs flaw detection on the test object, the excitation coil has a stepwise frequency. And a means for detecting a change in magnetic field caused by a discontinuity near the surface of the eddy current induced near the surface of the test object by the AC magnetic field formed by the exciting coil. And detecting the test object based on the change detected by the means.

【００３０】第４発明に係る渦流探傷試験方法及び第９
発明に係る渦流探傷試験装置では、励磁コイルが形成し
た交流磁界により、導体からなる試験対象の表面付近に
誘起された渦電流の試験対象の表面付近の不連続部の存
在により生じた変化を、検出コイルが検出した試験対象
の表面付近の磁界の変化により検出し、検出した渦電流
の変化に基づき、試験対象の探傷を行う。供給する手段
が、励磁コイルに周波数が段階的に変化する交流電流を
供給し、検出する手段が、励磁コイルが形成した交流磁
界により試験対象の表面付近に誘起された渦電流の試験
対象の表面付近の不連続部により生じた磁界の変化を検
出し、検出する手段が検出した変化に基づき試験対象の
探傷を行う。これにより、多数のパラメータを利用して
探傷に必要な解析を安価に行うことが可能な渦流探傷試
験方法及びその安価な渦流探傷試験装置を実現すること
ができる。Eddy current flaw testing method according to the fourth invention and ninth aspect
In the eddy current flaw detection test apparatus according to the invention, by the alternating magnetic field formed by the exciting coil, the change caused by the presence of the discontinuity near the surface of the test object of the eddy current induced near the surface of the test object made of a conductor, The detection coil detects the change in the magnetic field near the surface of the test object and detects the test object based on the detected change in the eddy current. The means for supplying supplies an alternating current whose frequency changes stepwise to the exciting coil, and the means for detecting detects the surface of the eddy current induced near the surface of the object under test by the alternating magnetic field formed by the exciting coil. A change in the magnetic field caused by a discontinuous portion in the vicinity is detected, and flaw detection is performed on the test object based on the change detected by the detecting means. As a result, it is possible to realize an eddy-current flaw detection test method and an inexpensive eddy-current flaw detection test apparatus that can perform analysis necessary for flaw detection at low cost using a large number of parameters.

【００３１】第１０発明に係る渦流探傷試験装置は、前
記変化は、前記交流電流の周波数が変化した都度、前記
試験対象の健全部で検出した前記検出コイルの出力と、
前記不連続部で検出した前記検出コイルの出力との差で
あることを特徴とする。In the eddy current flaw detection test apparatus according to the tenth aspect of the invention, the change is the output of the detection coil detected in the sound part of the test object each time the frequency of the alternating current changes,
It is characterized in that it is a difference from the output of the detection coil detected at the discontinuous portion.

【００３２】第５発明に係る渦流探傷試験方法及び第１
０発明に係る渦流探傷試験装置では、渦電流の磁界の変
化は、周波数が段階的に変化する交流電流の周波数が変
化した都度、試験対象の健全部で検出した検出コイルの
出力と、試験対象の表面付近の不連続部で検出した検出
コイルの出力との差であるので、常にヌル状態にするこ
とができ、多数のパラメータを利用して探傷に必要な解
析を安価に行うことが可能な渦流探傷試験方法及びその
安価な渦流探傷試験装置を実現することができる。Eddy Current Testing Method According to Fifth Invention and First Aspect
In the eddy current flaw detector according to the present invention, the change of the magnetic field of the eddy current is detected by the output of the detection coil detected by the sound part of the test object and the test object each time the frequency of the alternating current changes stepwise. Since it is the difference from the output of the detection coil detected in the discontinuity near the surface of the, it can always be in the null state, and the analysis required for flaw detection can be performed inexpensively by using many parameters. An eddy current flaw testing method and an inexpensive eddy current flaw testing device can be realized.

【００３３】[0033]

【発明の実施の形態】以下に、本発明を、その実施の形
態を示す図面を参照しながら説明する。 実施の形態１．図１は、本発明に係る渦流探傷試験方法
及び渦流探傷試験装置の実施の形態１の要部構成を示す
ブロック図である。この渦流探傷試験装置は、図２
（ａ）に示すように、予め設定されたスイープ時間（例
えば３００秒間）の間に、予め設定された範囲（例えば
５０ｋＨｚ〜５００ｋＨｚ、周波数比で１から１０）で
周波数をスイープ（sweep ）させながら（所定の範囲で
周波数を連続的に上昇又は下降させながら）、正弦波信
号を発振するスイープ発振器２５（供給する手段）と、
スイープ発振器２５が発振した正弦波信号を増幅する電
力増幅器１１（供給する手段）と、電力増幅器１１が増
幅して出力した交流電流が流され、試験対象２２の表面
付近を励磁する励磁コイル１３と、この励磁により試験
対象２２の表面付近に生じた渦電流による交流磁界を検
出して交流電圧を出力する検出コイル１２とを備えてい
る。BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below with reference to the drawings showing the embodiments thereof. Embodiment 1. FIG. 1 is a block diagram showing a main part configuration of a first embodiment of an eddy current flaw testing method and an eddy current flaw testing device according to the present invention. This eddy current testing device is shown in FIG.
As shown in (a), while sweeping the frequency within a preset range (eg, 50 kHz to 500 kHz, frequency ratio of 1 to 10) during a preset sweep time (eg, 300 seconds). A sweep oscillator 25 (supplying means) that oscillates a sine wave signal (while continuously increasing or decreasing the frequency within a predetermined range);
A power amplifier 11 (a means for supplying) that amplifies the sine wave signal oscillated by the sweep oscillator 25, and an exciting coil 13 that excites the vicinity of the surface of the test object 22 through which the alternating current amplified and output by the power amplifier 11 flows. The detection coil 12 detects an AC magnetic field due to an eddy current generated near the surface of the test object 22 by this excitation and outputs an AC voltage.

【００３４】この渦流探傷試験装置は、また、試験対象
２２の健全部分における検出コイル１２の出力電圧に逆
位相の電圧を加算することにより、その出力電圧を０付
近の所定電圧以内に調節してヌル（Null）状態にする演
算を実行するヌル回路２７と、ヌル回路２７が出力した
交流電圧をそれぞれ与えられ、与えられた交流電圧をそ
れぞれ増幅する増幅器２３，２４と、増幅器２３，２４
がそれぞれ出力した交流電圧をそれぞれ位相検波する位
相検波器１７ａ，１８ａ（検出する手段）と、スイープ
発振器２５が発振した正弦波信号の位相を変位させ、位
相検波器１７ａ，１８ａへそれぞれ与える移相器１５ａ
と、位相検波器１７ａ，１８ａの各出力をそれぞれアナ
ログ／ディジタル変換するＡ／Ｄ変換器１９，２０と、
Ａ／Ｄ変換器１９，２０がそれぞれ出力したディジタル
信号に基づき、試験対象２２の表面付近のきずの検出処
理を行うディジタル信号処理装置２１（検出する手段）
とを備えている。This eddy current flaw detector also adjusts the output voltage within a predetermined voltage near 0 by adding the voltage of the opposite phase to the output voltage of the detection coil 12 in the sound portion of the test object 22. A null circuit 27 that executes a calculation to make a null state, amplifiers 23 and 24 that are given the AC voltage output from the null circuit 27 and that amplify the given AC voltage, and amplifiers 23 and 24, respectively.
And phase detectors 17a and 18a (detecting means) for phase-detecting the AC voltages respectively output by the respective units, and a phase shifter for displacing the phase of the sine wave signal oscillated by the sweep oscillator 25 and giving the phase detectors 17a and 18a, respectively. Bowl 15a
And A / D converters 19 and 20 for analog / digital converting the respective outputs of the phase detectors 17a and 18a,
A digital signal processing device 21 (detection means) for detecting flaws near the surface of the test object 22 based on the digital signals output from the A / D converters 19 and 20, respectively.
It has and.

【００３５】移相器１５ａは、ヌル回路２７からの指示
信号に基づき、スイープ発振器２５からの正弦波信号の
振幅及び位相を変えた電圧信号をヌル回路２７へ与え
る。ヌル回路２７は、移相器１５ａから与えられた電圧
信号を、検出コイル１２からの交流電圧に加算する。ヌ
ル回路２７は、その加算後の交流電圧が０付近の所定電
圧以内であるか否かを判定し、所定電圧以内でなけれ
ば、移相器１５ａがヌル回路２７へ与える電圧信号の振
幅及び位相を変えるように指示信号を出力する。ヌル回
路２７は、移相器１５ａからの電圧信号を検出コイル１
２の出力電圧に加算した電圧が所定電圧以内になり、ヌ
ル状態になる迄この動作を繰り返す。The phase shifter 15a supplies to the null circuit 27 a voltage signal in which the amplitude and the phase of the sine wave signal from the sweep oscillator 25 are changed based on the instruction signal from the null circuit 27. The null circuit 27 adds the voltage signal given from the phase shifter 15 a to the AC voltage from the detection coil 12. The null circuit 27 determines whether or not the AC voltage after the addition is within a predetermined voltage near 0, and if it is not within the predetermined voltage, the amplitude and phase of the voltage signal provided to the null circuit 27 by the phase shifter 15 a. An instruction signal is output to change the. The null circuit 27 detects the voltage signal from the phase shifter 15a in the detection coil 1
This operation is repeated until the voltage added to the output voltage of 2 falls within the predetermined voltage and becomes the null state.

【００３６】移相器１５ａは、ヌル状態になったとき
は、そのときの振幅及び位相をロックし、以後はロック
した振幅及び位相の電圧信号をヌル回路２７へ与える。
移相器１５ａ、スイープ発振器２５及びヌル回路２７
は、ヌル時間発生器２８からの指示信号を受けたとき、
上述したヌル状態にする為の動作を実行する。When in the null state, the phase shifter 15a locks the amplitude and phase at that time, and thereafter supplies the voltage signal of the locked amplitude and phase to the null circuit 27.
Phase shifter 15a, sweep oscillator 25, and null circuit 27
When receiving an instruction signal from the null time generator 28,
The operation for setting the null state is executed.

【００３７】以下に、このような構成の渦流探傷試験装
置の動作を説明する。この渦流探傷試験装置では、スイ
ープ発振器２５が、図２（ａ）に示すように、予め設定
されたスイープ時間の間（例えば３００秒間）に、予め
設定された範囲（例えば５０ｋＨｚ〜５００ｋＨｚ）で
周波数をスイープさせながら、正弦波信号を発振する。
電力増幅器１１は、スイープ発振器２５が発振した正弦
波信号を増幅し、その増幅した交流電流を励磁コイル１
３に供給する。励磁コイル１３及び検出コイル１２は、
試験対象２２表面上を略等速度で移動し、試験対象２２
の表面付近には、励磁コイル１３により形成される交流
磁界によって渦電流が誘起される。The operation of the eddy current flaw testing device having such a structure will be described below. In this eddy current flaw detector test apparatus, as shown in FIG. 2A, the sweep oscillator 25 has a frequency within a preset range (for example, 50 kHz to 500 kHz) during a preset sweep time (for example, 300 seconds). Generate a sine wave signal while sweeping.
The power amplifier 11 amplifies the sine wave signal oscillated by the sweep oscillator 25 and outputs the amplified alternating current to the exciting coil 1.
Supply to 3. The excitation coil 13 and the detection coil 12 are
The test target 22 moves on the surface of the test target 22 at a substantially constant speed,
An eddy current is induced in the vicinity of the surface by the alternating magnetic field formed by the exciting coil 13.

【００３８】検出コイル１２は、渦電流により形成され
た交流磁界を検出して交流電圧を出力する。この交流電
圧は、ヌル回路２７で補正された後、増幅器２３，２４
により増幅され、位相検波器１７ａ，１８ａへそれぞれ
与えられる。一方、スイープ発振器２５が発振した正弦
波信号は、励磁コイル１３、試験対象２２及び検出コイ
ル１２による位相の変位分、移相器１５により位相が変
位され、図３（ａ）の模式的な波形図で示すような（検
出コイル１２の出力電圧も同様）参照電圧として位相検
波器１７ａに与えられる。移相器１５は、また、位相検
波器１７ａに与えた正弦波信号より９０°位相を変位さ
せた正弦波信号を、図３（ｂ）の模式的な波形図で示す
ような参照電圧として位相検波器１８ａへ与える。The detection coil 12 detects an AC magnetic field formed by the eddy current and outputs an AC voltage. This AC voltage is corrected by the null circuit 27, and then the amplifiers 23, 24.
Are amplified by and are given to the phase detectors 17a and 18a, respectively. On the other hand, the sine wave signal oscillated by the sweep oscillator 25 has its phase displaced by the phase shifter 15 by the phase displacement by the exciting coil 13, the test object 22, and the detection coil 12, and the schematic waveform of FIG. As shown in the figure (the output voltage of the detection coil 12 is also the same), it is applied to the phase detector 17a as a reference voltage. The phase shifter 15 also uses a sine wave signal obtained by shifting the phase of the sine wave signal given to the phase detector 17a by 90 ° as a reference voltage as shown in the schematic waveform diagram of FIG. 3B. It is given to the detector 18a.

【００３９】位相検波器１７ａ，１８ａがそれぞれ検波
出力した電圧は、Ａ／Ｄ変換器１９，２０でディジタル
信号にそれぞれ変換され、ディジタル信号処理装置２１
は、これらのディジタル信号に基づき、試験対象２２の
表面付近のきずの検出処理を行う。試験対象２２の表面
付近にきずが存在する場合には、検出コイル１２が出力
する交流電圧は、そのきずに特有なθｆだけ位相が変位
している。従って、ディジタル信号処理装置２１は、図
８（ａ）に示すように、位相検波器１７が検波した位相
が０°の成分Ｓ１と、位相検波器１８が検波した位相が
９０°の成分Ｓ２とから、そのきず信号の大きさ（Ｓ１
2 ＋Ｓ２2 ）1/2 、及びそのきず信号の位相θｆ＝ｔａ
ｎ-1（Ｓ２／Ｓ１）を求めることができる。The voltages detected and output by the phase detectors 17a and 18a are converted into digital signals by the A / D converters 19 and 20, respectively, and the digital signal processing device 21
Performs detection processing for flaws near the surface of the test object 22 based on these digital signals. When a flaw is present near the surface of the test object 22, the phase of the AC voltage output by the detection coil 12 is displaced by θf, which is peculiar to the flaw. Therefore, as shown in FIG. 8A, the digital signal processing device 21 has a component S1 having a phase of 0 ° detected by the phase detector 17 and a component S2 having a phase of 90 ° detected by the phase detector 18. The magnitude of the flaw signal (S1
2 + S2 2 ) 1/2 , and the phase of the flaw signal θf = ta
n −1 (S2 / S1) can be obtained.

【００４０】ディジタル信号処理装置２１は、上述した
検出処理により求めたきず信号を、図３（ｃ）に示すよ
うに、タイミング信号（破線）と共に記録又は出力す
る。また、ディジタル信号処理装置２１は、連続的に変
化する周波数毎に振幅及び位相の情報が得られる為、無
限に近い数のパラメータを得ることができ、演算処理と
周波数列の選択により、上述したきずの大きさ、種類、
きずが存在する試験対象の深さ方向の位置、及びリフト
オフの影響等を解析することが可能となる。The digital signal processing device 21 records or outputs the flaw signal obtained by the above-described detection processing together with the timing signal (broken line) as shown in FIG. 3 (c). Further, since the digital signal processing device 21 can obtain amplitude and phase information for each frequency that continuously changes, it is possible to obtain an infinite number of parameters. Size, type,
It is possible to analyze the position in the depth direction of the test object in which flaws exist and the effect of lift-off.

【００４１】ヌル時間発生器２８は、上述した探傷動作
の開始時及び設定されたスイープ時間の１／１００乃至
１／１０の時間間隔の都度、又は探傷動作の開始時の
み、ヌル状態にする為の指示信号を出力する。移相器１
５ａ及びヌル回路２７は、ヌル時間発生器２８からの指
示信号を受けたときは、上述したヌル状態にする為の動
作を実行する。ヌル状態にする為の所要時間は、スイー
プ発振器２５が発振した正弦波信号の３周期分程度であ
る。The null time generator 28 sets the null state at the start of the above-described flaw detection operation and at each time interval of 1/100 to 1/10 of the set sweep time, or only at the start of the flaw detection operation. The instruction signal of is output. Phase shifter 1
When receiving the instruction signal from the null time generator 28, the 5a and the null circuit 27 execute the above-described operation for setting the null state. The time required to enter the null state is about three cycles of the sine wave signal oscillated by the sweep oscillator 25.

【００４２】ところで、きずの存在によるヌル状態の崩
れは変化が速く（例えば、コイルの寸法１ｍｍ、きずの
幅０．１ｍｍ、センサの速度６ｍ／分の場合、約１０ミ
リ秒間の変化となる）、その変化よりもヌルの時定数を
遅く設定しておけば良い。例えば、鋼板上を６ｍ／分で
センサが移動しているとき、周波数を１ｋＨｚから１０
ｋＨｚ迄スイープさせ、そのスイープ開始を鋼板の探傷
部分１００ｍｍ毎に行うとすれば、その１００ｍｍをセ
ンサが通過する時間は１秒となる。１秒間に周波数を１
ｋＨｚから１０ｋＨｚ迄スイープさせることは容易であ
る。ヌル状態にする為の動作を、周波数の各スイープ開
始時から０．１秒毎に行うとすれば、鋼板の１０ｍｍ毎
にヌル状態にしながら周波数をスイープさせる探傷が可
能となる。By the way, the collapse of the null state due to the presence of a flaw changes rapidly (for example, when the coil size is 1 mm, the flaw width is 0.1 mm, and the sensor speed is 6 m / min, the change is about 10 milliseconds). , The null time constant should be set later than the change. For example, when the sensor is moving at 6 m / min on the steel plate, the frequency is changed from 1 kHz to 10
If the sweep is performed up to kHz and the sweep is started for every 100 mm of the flaw detection portion of the steel plate, the time required for the sensor to pass 100 mm is 1 second. 1 frequency per second
It is easy to sweep from kHz to 10 kHz. If the operation for making the null state is performed every 0.1 seconds from the start of each frequency sweep, it is possible to perform flaw detection by sweeping the frequency while making the steel sheet in the null state every 10 mm.

【００４３】つまり、周波数のスイープ時間（スイープ
開始から終了迄の時間）をヌル状態にする為に必要な演
算時間に比べて充分長くし、また、ヌル状態にする時間
間隔を周波数のスイープ時間の１／１００乃至１／１０
の時間間隔に選ぶことにより、ヌル電圧が大幅に変化し
ない周波数変化範囲（スイープ範囲の１／１００乃至１
／１０）で逐次ヌル状態にするようにする。これによ
り、周波数をスイープさせる範囲全体に渡って、常時ヌ
ル状態にしながら探傷試験を実施することができ、きず
部分できず信号のみを信号処理回路に取り入れることで
き、従来の単周波渦流探傷試験と同等の探傷が可能とな
る。また、後述するように、探傷動作の開始時のみにヌ
ル状態にすることにしても、探傷は可能である。That is, the frequency sweep time (the time from the start to the end of the sweep) is made sufficiently longer than the calculation time required to make the null state, and the time interval for making the null state is the frequency sweep time. 1/100 to 1/10
By selecting the time interval of, the frequency change range (1/100 to 1 of the sweep range) where the null voltage does not change significantly
/ 10), the null state is sequentially set. As a result, it is possible to carry out the flaw detection test while keeping it in the null state all the time over the entire range of sweeping the frequency. Equivalent flaw detection is possible. Further, as will be described later, flaw detection is possible even if the null state is set only at the start of flaw detection operation.

【００４４】図２（ｂ）は、周波数を５０ｋＨｚから５
００ｋＨｚ迄３００秒間でスイープさせた場合の、鋼板
に加工された深さ０．３ｍｍ、長さ１５ｍｍのきず信号
の増幅器２３，２４の出力信号を示した波形図である。
ヌル状態にするのは、探傷動作の開始時のみである。人
工きず信号は、略同一の出力値であるが、図２（ｃ）に
抽出して示すノイズ信号が周波数によって異なってい
る。おおよそ、周波数が高くなるに従い、ノイズが増加
しているのは、開始時にヌル状態にしたコイルの出力電
圧に対して、周波数が上昇するに従い、コイルの不平衡
電圧が増加したことによると思われる。In FIG. 2B, the frequency is changed from 50 kHz to 5
It is a waveform diagram which showed the output signal of the amplifiers 23 and 24 of the flaw signal of 0.3 mm in depth and 15 mm in length processed into the steel plate, when it was made to sweep to 00 kHz for 300 seconds.
The null state is set only when the flaw detection operation is started. The artificial flaw signals have substantially the same output value, but the noise signal extracted and shown in FIG. 2C differs depending on the frequency. It is considered that the noise increases with increasing frequency because the unbalanced voltage of the coil increases as the frequency increases with respect to the output voltage of the coil in the null state at the start. .

【００４５】尚、本実施の形態では、周波数をスイープ
させる（周波数を連続的に上昇又は下降させる）回数は
１回にしてあるが、連続的に周波数を繰り返しスイープ
させて探傷することも当然可能である。また、連続的に
周波数を繰り返し上昇及び下降させて探傷することも可
能である。In this embodiment, the frequency is swept (the frequency is continuously increased or decreased) once, but it is naturally possible to continuously repeat the frequency sweep to detect flaws. Is. It is also possible to detect the flaw by repeatedly increasing and decreasing the frequency.

【００４６】実施の形態２．図４は、本発明に係る渦流
探傷試験方法及び渦流探傷試験装置の実施の形態２の要
部構成を示すブロック図である。この渦流探傷試験装置
は、基準時間発生器２６が出力するタイミング信号に従
って、図５（ａ）に示すように、設定された周波数変化
時間（例えば６００秒間）の間に、設定された範囲（例
えば２０ｋＨｚ〜２００ｋＨｚ、周波数比で１から１
０）で周波数を段階的に（例えば１０ステップで）増加
させながら、正弦波信号を発振するスイープ発振器２５
（供給する手段）と、スイープ発振器２５が発振した正
弦波信号を増幅する電力増幅器１１（供給する手段）
と、電力増幅器１１が増幅して出力した交流電流が流さ
れ、試験対象２２の表面付近を励磁する励磁コイル１３
と、この励磁により試験対象２２の表面付近に生じた渦
電流による交流磁界を検出して交流電圧を出力する検出
コイル１２とを備えている。Embodiment 2. FIG. 4 is a block diagram showing a main configuration of an eddy current flaw testing method and an eddy current flaw testing device according to a second embodiment of the present invention. According to the timing signal output from the reference time generator 26, this eddy current flaw detection test equipment, as shown in FIG. 5 (a), has a set range (for example, 600 seconds) during a set frequency change time (for example, 600 seconds). 20 kHz to 200 kHz, frequency ratio 1 to 1
Sweep oscillator 25 that oscillates a sine wave signal while increasing the frequency stepwise (for example, in 10 steps) in 0).
(Supplying means) and the power amplifier 11 (supplying means) for amplifying the sine wave signal oscillated by the sweep oscillator 25.
Then, the exciting coil 13 that excites the vicinity of the surface of the test object 22 by passing the alternating current amplified and output by the power amplifier 11
And a detection coil 12 that detects an AC magnetic field due to an eddy current generated near the surface of the test object 22 by this excitation and outputs an AC voltage.

【００４７】この渦流探傷試験装置は、また、試験対象
２２の健全部分における検出コイル１２の出力電圧に逆
位相の電圧を加算することにより、その出力電圧を０付
近の所定電圧以内に調節してヌル（Null）状態にする為
の演算を実行するヌル回路２７ａと、ヌル回路２７ａが
出力した交流電圧をそれぞれ与えられ、与えられた交流
電圧をそれぞれ増幅する増幅器２３，２４と、増幅器２
３，２４がそれぞれ出力した交流電圧をそれぞれ位相検
波する位相検波器１７ａ，１８ａ（検出する手段）と、
スイープ発振器２５が発振した正弦波信号の位相を変位
させ、位相検波器１７ａ，１８ａへそれぞれ与える移相
器１５ａと、位相検波器１７ａ，１８ａの各出力をそれ
ぞれアナログ／ディジタル変換するＡ／Ｄ変換器１９，
２０と、Ａ／Ｄ変換器１９，２０がそれぞれ出力したデ
ィジタル信号に基づき、試験対象２２の表面付近のきず
の検出処理を行うディジタル信号処理装置２１（検出す
る手段）とを備えている。This eddy current flaw detector also adjusts the output voltage within a predetermined voltage near 0 by adding the voltage of the opposite phase to the output voltage of the detection coil 12 in the sound portion of the test object 22. A null circuit 27a that executes a calculation for making a null state, amplifiers 23 and 24 that are respectively given the AC voltage output from the null circuit 27a, and amplify the given AC voltage, and the amplifier 2
Phase detectors 17a and 18a (detecting means) for phase-detecting the AC voltages respectively output from 3 and 24,
A / D conversion that displaces the phase of the sine wave signal oscillated by the sweep oscillator 25 and applies the phase shifter 15a to the phase detectors 17a and 18a, and the respective outputs of the phase detectors 17a and 18a, respectively. Vessel 19,
20 and a digital signal processing device 21 (detection means) for detecting flaws near the surface of the test object 22 based on the digital signals output from the A / D converters 19 and 20, respectively.

【００４８】移相器１５ａは、ヌル回路２７ａからの指
示信号に基づき、スイープ発振器２５からの正弦波信号
の振幅及び位相を変えた電圧信号をヌル回路２７ａへ与
える。ヌル回路２７ａは、移相器１５ａから与えられた
電圧信号を、検出コイル１２からの交流電圧に加算す
る。ヌル回路２７ａは、その加算後の交流電圧が０付近
の所定電圧以内であるか否かを判定し、所定電圧以内で
なければ、移相器１５ａがヌル回路２７ａへ与える電圧
信号の振幅及び位相を変えるように指示信号を出力す
る。The phase shifter 15a provides the null circuit 27a with a voltage signal in which the amplitude and phase of the sine wave signal from the sweep oscillator 25 are changed based on the instruction signal from the null circuit 27a. The null circuit 27a adds the voltage signal given from the phase shifter 15a to the AC voltage from the detection coil 12. The null circuit 27a determines whether or not the AC voltage after the addition is within a predetermined voltage near 0, and if it is not within the predetermined voltage, the amplitude and phase of the voltage signal provided by the phase shifter 15a to the null circuit 27a. An instruction signal is output to change the.

【００４９】ヌル回路２７ａは、移相器１５ａからの電
圧信号を検出コイル１２の出力電圧に加算した電圧が所
定電圧以内になり、ヌル状態になる迄この動作を繰り返
す。移相器１５ａは、ヌル状態になったときは、そのと
きの振幅及び位相をロックし、以後はロックした振幅及
び位相の電圧信号をヌル回路２７ａへ与える。移相器１
５ａ及びヌル回路２７ａは、基準時間発生器２６からの
スイープ発振器２５が受けるのと同じタイミング信号を
受けたとき、上述したヌル状態にする為の動作を実行す
る。従って、スイープ発振器２５が発振周波数を上昇さ
せる都度、ヌル状態にし、このヌル状態にする為の所要
時間は、例えば、その発振周波数が固定されている時間
の１／４以内と定めておく。これにより、ヌル状態にす
る為の所要時間が無制限に大きくならず、実施の形態１
で説明した渦流探傷試験装置よりも高速に渦流探傷を実
施することが可能となる。The null circuit 27a repeats this operation until the voltage obtained by adding the voltage signal from the phase shifter 15a to the output voltage of the detection coil 12 becomes within the predetermined voltage and becomes the null state. When in the null state, the phase shifter 15a locks the amplitude and phase at that time, and thereafter supplies the voltage signal of the locked amplitude and phase to the null circuit 27a. Phase shifter 1
5a and the null circuit 27a execute the above-mentioned operation for setting the null state when receiving the same timing signal as that received by the sweep oscillator 25 from the reference time generator 26. Therefore, each time the sweep oscillator 25 raises the oscillation frequency, it is set to the null state, and the time required for making this null state is set to, for example, within 1/4 of the time when the oscillation frequency is fixed. As a result, the time required to enter the null state does not increase indefinitely, and the first embodiment
It becomes possible to carry out eddy current flaw detection at a higher speed than the eddy current flaw detection test device described in.

【００５０】以下に、このような構成の渦流探傷試験装
置の動作を説明する。この渦流探傷試験装置では、基準
時間発生器２６が出力するタイミング信号により、スイ
ープ発振器２５が、図５（ａ）に示すように、設定され
た周波数変化時間の間（例えば６００秒間）に、設定さ
れた範囲（例えば２０ｋＨｚ〜２００ｋＨｚ）で周波数
を段階的に（例えば１０ステップ）上昇させながら、正
弦波信号を発振する。電力増幅器１１は、スイープ発振
器２５が発振した正弦波信号を増幅し、その増幅した交
流電流を励磁コイル１３に供給する。励磁コイル１３及
び検出コイル１２は、試験対象２２表面上を略等速度で
移動し、試験対象２２の表面付近には、励磁コイル１３
により形成される交流磁界によって渦電流が誘起され
る。The operation of the eddy current flaw testing device having such a configuration will be described below. In this eddy current flaw detector, the sweep oscillator 25 is set by the timing signal output from the reference time generator 26 during the set frequency change time (for example, 600 seconds) as shown in FIG. 5A. The sine wave signal is oscillated while increasing the frequency stepwise (for example, 10 steps) in the range (for example, 20 kHz to 200 kHz). The power amplifier 11 amplifies the sine wave signal oscillated by the sweep oscillator 25 and supplies the amplified alternating current to the exciting coil 13. The excitation coil 13 and the detection coil 12 move on the surface of the test target 22 at a substantially constant speed, and the excitation coil 13 is located near the surface of the test target 22.
An eddy current is induced by the alternating magnetic field formed by

【００５１】この渦電流は、励磁コイル１３に供給され
た交流電流の周波数、試験対象２２の材質変化、リフト
オフ等励磁コイル１３と試験対象２２との空間的な関
係、及び試験対象２２表面付近の割れ等のきずによって
変化する。This eddy current is the frequency of the alternating current supplied to the exciting coil 13, the material change of the test object 22, the spatial relationship between the exciting coil 13 such as lift-off coil 13 and the test object 22, and the vicinity of the surface of the test object 22. It changes depending on flaws such as cracks.

【００５２】検出コイル１２は、渦電流により形成され
た交流磁界を検出して交流電圧を出力する。この交流電
圧は、ヌル回路２７ａで補正された後、増幅器２３，２
４により増幅され、位相検波器１７ａ，１８ａへそれぞ
れ与えられる。一方、図６（ａ）の模式的な波形図で示
すような基準時間発生器２６が出力するタイミング信号
に対して、スイープ発振器２５が発振した正弦波信号
は、励磁コイル１３、試験対象２２及び検出コイル１２
による位相の変位分、移相器１５により位相が変位さ
れ、図６（ｂ）の模式的な波形図で示すような（検出コ
イル１２の出力電圧も同様）参照電圧として位相検波器
１７ａに与えられる。移相器１５は、また、位相検波器
１７ａに与えた正弦波信号より９０°位相を変位させた
正弦波信号を、図６（ｃ）の模式的な波形図で示すよう
な参照電圧として位相検波器１８ａへ与える。The detection coil 12 detects an AC magnetic field formed by the eddy current and outputs an AC voltage. This AC voltage is corrected by the null circuit 27a, and then the amplifiers 23, 2
It is amplified by 4 and given to the phase detectors 17a and 18a, respectively. On the other hand, the sine wave signal oscillated by the sweep oscillator 25 with respect to the timing signal output from the reference time generator 26 as shown in the schematic waveform diagram of FIG. Detection coil 12
The phase shifter 15 shifts the phase by an amount corresponding to the phase shift, and is given to the phase detector 17a as a reference voltage as shown in the schematic waveform diagram of FIG. 6B (the output voltage of the detection coil 12 is also the same). To be The phase shifter 15 also uses a sine wave signal whose phase is displaced by 90 ° from the sine wave signal given to the phase detector 17a as a reference voltage as shown in the schematic waveform diagram of FIG. 6C. It is given to the detector 18a.

【００５３】位相検波器１７ａ，１８ａがそれぞれ検波
出力した電圧は、Ａ／Ｄ変換器１９，２０でディジタル
信号にそれぞれ変換され、ディジタル信号処理装置２１
は、図６（ｄ）の模式的な波形図で示すような基準時間
発生器２６が出力する取り込み信号により、これらのデ
ィジタル信号を取り込み、試験対象２２の表面付近のき
ずの検出処理を行う。試験対象２２の表面付近にきずが
存在する場合には、検出コイル１２が出力する交流電圧
は、そのきずに特有なθｆだけ位相が変位している。従
って、ディジタル信号処理装置２１は、図８（ａ）に示
すように、位相検波器１７が検波した位相が０°の成分
Ｓ１と、位相検波器１８が検波した位相が９０°の成分
Ｓ２とから、そのきず信号の大きさ（Ｓ１2 ＋Ｓ２2 ）
1/2 、及びそのきず信号の位相θｆ＝ｔａｎ-1（Ｓ２／
Ｓ１）を求めることができる。The voltages detected and output by the phase detectors 17a and 18a are converted into digital signals by the A / D converters 19 and 20, respectively, and the digital signal processing device 21
6 captures these digital signals by a capture signal output from the reference time generator 26 as shown in the schematic waveform diagram of FIG. 6D, and performs a flaw detection process near the surface of the test object 22. When a flaw is present near the surface of the test object 22, the phase of the AC voltage output by the detection coil 12 is displaced by θf, which is peculiar to the flaw. Therefore, as shown in FIG. 8A, the digital signal processing device 21 has a component S1 having a phase of 0 ° detected by the phase detector 17 and a component S2 having a phase of 90 ° detected by the phase detector 18. Therefore, the size of the flaw signal (S1 2 + S2 2 )
1/2 , and the phase of the flaw signal θf = tan −1 (S2 /
S1) can be obtained.

【００５４】また、ディジタル信号処理装置２１は、段
階的に変化する周波数毎に振幅及び位相の情報が得られ
る為、無限に近い数のパラメータを得ることができ、演
算処理と周波数列の選択により、上述したきずの大き
さ、種類、きずが存在する試験対象の深さ方向の位置、
及びリフトオフの影響等を解析することが可能となる。Further, since the digital signal processing device 21 can obtain amplitude and phase information for each frequency that changes in a stepwise manner, it is possible to obtain an infinite number of parameters, and by arithmetic processing and frequency sequence selection. , The size and type of the flaws described above, the position in the depth direction of the test object in which the flaws exist,
It is also possible to analyze the effects of lift-off and the like.

【００５５】図５（ｂ）は、周波数を１０ステップで段
階的に２０ｋＨｚから２００ｋＨｚ迄、６００秒間で上
昇させた場合の、鋼板に加工された深さ０．３ｍｍ、長
さ１５ｍｍのきず信号の増幅器２３，２４の出力信号を
示した波形図である。ステップ毎にヌル状態にしている
ので、人工きず信号は、略同一の出力値であると共に、
ノイズ信号も、周波数が上昇するに従って増加するよう
な傾向は見られない。尚、本実施の形態２では、段階的
に周波数を上昇させ、その回数を１回にしてあるが、段
階的に周波数を下降させて探傷することも可能であり、
また、段階的に周波数を繰り返し上昇又は下降させて探
傷することも可能である。また、段階的に周波数を繰り
返し上昇及び下降させて探傷することも可能である。ま
た、上述した実施の形態１，２では、検出コイルを使用
しているが、検出コイルに代えて、磁気センサを使用す
ることも可能である。FIG. 5B shows a flaw signal of a depth of 0.3 mm and a length of 15 mm formed on a steel plate when the frequency is increased stepwise from 20 kHz to 200 kHz in 10 steps in 600 seconds. It is a wave form diagram which showed the output signal of amplifier 23 and 24. Since it is in the null state for each step, the artificial flaw signal has almost the same output value,
The noise signal does not tend to increase as the frequency increases. In the second embodiment, the frequency is increased stepwise and the number of times is once. However, it is also possible to decrease the frequency stepwise for flaw detection.
It is also possible to detect the flaw by repeatedly increasing or decreasing the frequency stepwise. It is also possible to detect the flaw by repeatedly increasing and decreasing the frequency stepwise. Further, although the detection coil is used in the first and second embodiments described above, a magnetic sensor may be used instead of the detection coil.

【００５６】[0056]

【発明の効果】第１，４発明に係る渦流探傷試験方法及
び第６，９発明に係る渦流探傷試験装置によれば、多数
のパラメータを利用して探傷に必要な解析を安価に行う
ことが可能な渦流探傷試験方法及びその安価な渦流探傷
試験装置を実現することができる。また、従来の渦流探
傷試験では、最適な試験周波数を選択するのに、周波数
を幾度も幾度も変えながらデータを採り、最も所望のき
ずをＳ／Ｎ比良く検出できる周波数を選定しており、探
傷条件の決定に、通常半日程度を要している。それに対
して、本渦流探傷試験方法及び本渦流探傷試験装置で
は、僅か数分で図５に示すような結果を得ることがで
き、例えば試験周波数１８０ｋＨｚが最適であるという
判断が即座に可能となる。According to the eddy-current flaw detection test method according to the first and fourth inventions and the eddy-current flaw detection test apparatus according to the sixth and ninth inventions, it is possible to inexpensively perform the analysis required for flaw detection by using a large number of parameters. It is possible to realize a possible eddy current flaw testing method and an inexpensive eddy current flaw testing device. Further, in the conventional eddy current flaw detection test, in order to select the optimum test frequency, data is taken while changing the frequency many times, and the frequency that can detect the most desired flaw with a good S / N ratio is selected. It usually takes about half a day to determine the flaw detection conditions. On the other hand, with the present eddy current flaw testing method and the present eddy current flaw testing device, the result as shown in FIG. 5 can be obtained in only a few minutes, and for example, it is immediately possible to determine that the test frequency of 180 kHz is optimal. .

【００５７】また、割れ状のきず、孔状のきず及び突起
状のきず等をそれぞれ最適の周波数で探傷したい場合、
従来は、２，３日かけて３つのきずが検出される周波数
条件を探す実験を行っていたが、本渦流探傷試験方法及
び本渦流探傷試験装置では、数分の試験で可能となり、
大幅に工数を節約することができる。また、３種類のき
ずを同時に検出できる為、従来は２度又は３度条件を変
えて行っていた探傷試験を１度で済ますことができ、多
くの種類のきずを探傷する必要がある機械部品等の渦流
探傷試験には極めて大きな高価を得ることができる。Further, when it is desired to detect cracks, holes, protrusions, etc. at optimum frequencies,
Conventionally, an experiment was conducted to search for a frequency condition where three flaws were detected over a few days, but with this eddy current flaw testing method and this eddy current flaw testing device, a test can be performed in a few minutes,
Man-hours can be saved significantly. In addition, since 3 types of flaws can be detected simultaneously, it is possible to perform a flaw detection test that was conventionally performed by changing the condition of 2 or 3 degrees once, and it is necessary to detect many types of flaws. An extremely large cost can be obtained for the eddy current flaw detection test such as.

【００５８】第２発明に係る渦流探傷試験方法及び第７
発明に係る渦流探傷試験装置によれば、ヌル（Null）状
態にしながら、多数のパラメータを利用して探傷に必要
な解析を安価に行うことが可能な渦流探傷試験方法及び
その安価な渦流探傷試験装置を実現することができる。Eddy Current Testing Method According to Second Aspect and Seventh Aspect
ADVANTAGEOUS EFFECTS OF INVENTION According to the eddy current flaw testing device according to the invention, an eddy current flaw testing method and an inexpensive eddy current flaw testing method capable of inexpensively performing analysis necessary for flaw flaw detection using a large number of parameters while maintaining a null state The device can be realized.

【００５９】第３発明に係る渦流探傷試験方法及び第８
発明に係る渦流探傷試験装置によれば、ヌル（Null）電
圧が大幅に変化しない周波数範囲毎にヌル状態にするこ
とができ、多数のパラメータを利用して探傷に必要な解
析を安価に行うことが可能な渦流探傷試験方法及びその
安価な渦流探傷試験装置を実現することができる。Eddy Current Testing Method According to Third Invention and Eighth Embodiment
According to the eddy current flaw detector test apparatus of the present invention, the null state can be set for each frequency range in which the null voltage does not change significantly, and the analysis required for flaw detection can be performed inexpensively using a large number of parameters. It is possible to realize an eddy current flaw testing method capable of achieving the above and an inexpensive eddy current flaw testing device.

【００６０】第５発明に係る渦流探傷試験方法及び第１
０発明に係る渦流探傷試験装置によれば、常にヌル状態
にすることができ、多数のパラメータを利用して探傷に
必要な解析を安価に行うことが可能な渦流探傷試験方法
及びその安価な渦流探傷試験装置を実現することができ
る。Eddy Current Testing Method According to Fifth Aspect and First Aspect
According to the eddy current flaw detection test apparatus of the present invention, an eddy current flaw detection test method and an inexpensive eddy current flaw detection method that can always be in a null state and can perform an analysis required for flaw detection inexpensively by using a large number of parameters. A flaw detection test device can be realized.

【図面の簡単な説明】[Brief description of drawings]

【図１】本発明に係る渦流探傷試験方法及び渦流探傷試
験装置の実施の形態の要部構成を示すブロック図であ
る。FIG. 1 is a block diagram showing a main part configuration of an embodiment of an eddy current flaw testing method and an eddy current flaw testing device according to the present invention.

【図２】本発明に係る渦流探傷試験装置の動作を示す波
形図である。FIG. 2 is a waveform diagram showing an operation of the eddy current flaw testing device according to the present invention.

【図３】本発明に係る渦流探傷試験装置の動作を示す波
形図である。FIG. 3 is a waveform diagram showing the operation of the eddy current flaw testing device according to the present invention.

【図４】本発明に係る渦流探傷試験方法及び渦流探傷試
験装置の実施の形態の要部構成を示すブロック図であ
る。FIG. 4 is a block diagram showing a main part configuration of an embodiment of an eddy current flaw testing method and an eddy current flaw testing device according to the present invention.

【図５】本発明に係る渦流探傷試験装置の動作を示す波
形図である。FIG. 5 is a waveform diagram showing an operation of the eddy current flaw testing device according to the present invention.

【図６】本発明に係る渦流探傷試験装置の動作を示す波
形図である。FIG. 6 is a waveform diagram showing an operation of the eddy current flaw testing device according to the present invention.

【図７】従来の渦流探傷試験装置の要部構成例を示すブ
ロック図である。FIG. 7 is a block diagram showing a configuration example of a main part of a conventional eddy current flaw testing device.

【図８】渦流探傷試験装置の信号処理方法を示す説明図
である。FIG. 8 is an explanatory diagram showing a signal processing method of the eddy current flaw detector.

【符号の説明】[Explanation of symbols]

１１ 電力増幅器（供給する手段） １２ 検出コイル １３ 励磁コイル １５ａ 移相器 １７ａ，１８ａ 位相検波器（検出する手段） １９，２０ Ａ／Ｄ変換器 ２１ ディジタル信号処理装置（検出する手段） ２２ 試験対象 ２３，２４ 増幅器 ２５ スイープ発振器（供給する手段） ２６ 基準時間発生器 ２７，２７ａ ヌル回路 ２８ ヌル時間発生器 11 Power amplifier (supply means) 12 detection coil 13 Excitation coil 15a Phase shifter 17a, 18a Phase detector (detection means) 19,20 A / D converter 21 Digital Signal Processing Device (Detecting Means) 22 test target 23, 24 amplifier 25 Sweep oscillator (supply means) 26 Reference time generator 27, 27a Null circuit 28 Null time generator

─────────────────────────────────────────────────────
─────────────────────────────────────────────────── ───

【手続補正書】[Procedure amendment]

【提出日】平成１３年９月１０日（２００１．９．１
０）[Submission date] September 10, 2001 (2001.9.1)
0)

【手続補正１】[Procedure Amendment 1]

【補正対象書類名】明細書[Document name to be amended] Statement

【補正対象項目名】００１０[Correction target item name] 0010

【補正方法】変更[Correction method] Change

【補正内容】[Correction content]

【００１０】きず信号は、励磁コイル１３に供給される
交流電流の周波数Ｆに応じて、一般的に図８（ｂ）に示
すような半円形のベクトル線図を描き、周波数Ｆが高い
場合、そのきずに特有な位相θｆは小さくなる。低域周
波数Ａでは、リフトオフの影響はインダクタンス成分に
大きく含まれ、中域周波数Ｂでは、リフトオフの影響は
小さく、高域周波数Ｃでは、リフトオフの影響は抵抗成
分に大きく含まれる。The flaw signal generally draws a semicircular vector diagram as shown in FIG. 8 (b) according to the frequency F of the alternating current supplied to the exciting coil 13. When the frequency F is high, The phase θf peculiar to the flaw becomes small. At low frequency A, the effect of lift-off is largely included in the inductance component, at medium frequency B, the effect of lift-off is small, and at high frequency C, the effect of lift-off is largely included in the resistance component.

【手続補正２】[Procedure Amendment 2]

【補正対象書類名】明細書[Document name to be amended] Statement

【補正対象項目名】００３３[Correction target item name] 0033

【補正方法】変更[Correction method] Change

【補正内容】[Correction content]

【００３３】[0033]

【発明の実施の形態】以下に、本発明を、その実施の形
態を示す図面を参照しながら説明する。 実施の形態１．図１は、本発明に係る渦流探傷試験方法
及び渦流探傷試験装置の実施の形態１の要部構成を示す
ブロック図である。この渦流探傷試験装置は、図２
（ａ）に示すように、予め設定されたスイープ時間（例
えば３００秒間）の間に、予め設定された範囲（例えば
５０ｋＨｚ〜５００ｋＨｚ、周波数比で１から１０）で
周波数をスイープ（sweep ）させながら（所定の範囲で
周波数を連続的に上昇又は下降させながら）、正弦波信
号を発振するスイープ発振器２５（供給する手段）と、
スイープ発振器２５が発振した正弦波信号を増幅する電
力増幅器１１（供給する手段）と、電力増幅器１１が増
幅して出力した交流電流が流され、試験対象２２（試験
体）の表面付近を励磁する励磁コイル１３と、この励磁
により試験対象２２の表面付近に生じた渦電流による交
流磁界を検出して交流電圧を出力する検出コイル１２と
を備えている。BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below with reference to the drawings showing the embodiments thereof. Embodiment 1. FIG. 1 is a block diagram showing a main part configuration of a first embodiment of an eddy current flaw testing method and an eddy current flaw testing device according to the present invention. This eddy current testing device is shown in FIG.
As shown in (a), while sweeping the frequency within a preset range (eg, 50 kHz to 500 kHz, frequency ratio of 1 to 10) during a preset sweep time (eg, 300 seconds). A sweep oscillator 25 (supplying means) that oscillates a sine wave signal (while continuously increasing or decreasing the frequency within a predetermined range);
The power amplifier 11 (means for supplying) that amplifies the sine wave signal oscillated by the sweep oscillator 25, and the alternating current amplified and output by the power amplifier 11 are supplied to the test target 22 (test
An excitation coil 13 that excites the vicinity of the surface of the body) and a detection coil 12 that detects an AC magnetic field due to an eddy current generated near the surface of the test object 22 by this excitation and outputs an AC voltage.

【手続補正３】[Procedure 3]

【補正対象書類名】明細書[Document name to be amended] Statement

【補正対象項目名】００４３[Correction target item name] 0043

【補正方法】変更[Correction method] Change

【補正内容】[Correction content]

【００４３】つまり、周波数のスイープ時間（スイープ
開始から終了迄の時間）をヌル状態にする為に必要な演
算時間に比べて充分長くし、また、ヌル状態にする時間
間隔を周波数のスイープ時間の１／１００乃至１／１０
の時間間隔に選ぶことにより、ヌル電圧が大幅に変化し
ない周波数変化範囲（スイープ範囲の１／１００乃至１
／１０）で逐次ヌル状態にするようにする。これによ
り、周波数をスイープさせる範囲全体に渡って、常時ヌ
ル状態にしながら探傷試験を実施することができ、きず
部分できず信号のみを信号処理回路に取り入れることが
でき、従来の単周波渦流探傷試験と同等の探傷が可能と
なる。また、後述するように、探傷動作の開始時のみに
ヌル状態にすることにしても、探傷は可能である。That is, the frequency sweep time (the time from the start to the end of the sweep) is made sufficiently longer than the calculation time required to make the null state, and the time interval for making the null state is the frequency sweep time. 1/100 to 1/10
By selecting the time interval of, the frequency change range (1/100 to 1 of the sweep range) where the null voltage does not change significantly
/ 10), the null state is sequentially set. Thus, over the entire range for sweeping the frequency, while always null state can be carried out flaw detection test can <br/> be incorporated only to the signal processing circuit signal can not be scratched part, conventional single It enables flaw detection equivalent to the frequency eddy current flaw testing. Further, as will be described later, flaw detection is possible even if the null state is set only at the start of flaw detection operation.

【手続補正４】[Procedure amendment 4]

【補正対象書類名】明細書[Document name to be amended] Statement

【補正対象項目名】００５７[Name of item to be corrected] 0057

【補正方法】変更[Correction method] Change

【補正内容】[Correction content]

【００５７】また、割れ状のきず、孔状のきず及び突起
状のきず等をそれぞれ最適の周波数で探傷したい場合、
従来は、２，３日かけて３つのきずが検出される周波数
条件を探す実験を行っていたが、本渦流探傷試験方法及
び本渦流探傷試験装置では、数分の試験で可能となり、
大幅に工数を節約することができる。また、３種類のき
ずを同時に検出できる為、従来は２度又は３度条件を変
えて行っていた探傷試験を１度で済ますことができ、多
くの種類のきずを探傷する必要がある機械部品等の渦流
探傷試験には極めて大きな効果を得ることができる。Further, when it is desired to detect cracks, holes, protrusions, etc. at optimum frequencies,
Conventionally, an experiment was conducted to search for a frequency condition where three flaws were detected over a few days, but with this eddy current flaw testing method and this eddy current flaw testing device, a test can be performed in a few minutes,
Man-hours can be saved significantly. In addition, since 3 types of flaws can be detected simultaneously, it is possible to perform a flaw detection test that was conventionally performed by changing the condition of 2 or 3 degrees once, and it is necessary to detect many types of flaws. It is possible to obtain an extremely large effect in an eddy current flaw detection test such as.

【手続補正５】[Procedure Amendment 5]

【補正対象書類名】明細書[Document name to be amended] Statement

【補正対象項目名】符号の説明[Correction target item name] Explanation of code

【補正方法】変更[Correction method] Change

【補正内容】[Correction content]

【符号の説明】 １１ 電力増幅器（供給する手段） １２ 検出コイル １３ 励磁コイル １５ａ 移相器 １７ａ，１８ａ 位相検波器（検出する手段） １９，２０ Ａ／Ｄ変換器 ２１ ディジタル信号処理装置（検出する手段） ２２ 試験対象（試験体） ２３，２４ 増幅器 ２５ スイープ発振器（供給する手段） ２６ 基準時間発生器 ２７，２７ａ ヌル回路 ２８ ヌル時間発生器[Explanation of reference numerals] 11 power amplifier (supply means) 12 detection coil 13 excitation coil 15a phase shifters 17a and 18a phase detector (detection means) 19, 20 A / D converter 21 digital signal processing device (detection) Means) 22 Test object (test body) 23, 24 Amplifier 25 Sweep oscillator (supply means) 26 Reference time generator 27, 27a Null circuit 28 Null time generator

【手続補正６】[Procedure correction 6]

【補正対象書類名】図面[Document name to be corrected] Drawing

【補正対象項目名】図８[Correction target item name] Figure 8

【補正方法】変更[Correction method] Change

【補正内容】[Correction content]

【図８】 [Figure 8]

フロントページの続き (72)発明者 植竹 一蔵 茨城県牛久市上柏田４−34−４ (72)発明者 西尾 哲 兵庫県西宮市塩瀬町名塩538 北斗電子工 業株式会社内 Ｆターム(参考） 2G053 AA11 AB21 BA02 BA12 BB11 BC02 BC14 CA03 CA18 CB16 CB17 Continued front page    (72) Inventor Ichizo Uetake             4-34-4 Kamishashida, Ushiku, Ibaraki Prefecture (72) Inventor Satoshi Nishio             Hokuto Electronics Co., Ltd.             Business F term (reference) 2G053 AA11 AB21 BA02 BA12 BB11                       BC02 BC14 CA03 CA18 CB16                       CB17

Claims (10)

【特許請求の範囲】[Claims] 【請求項１】 励磁コイルが形成した交流磁界により、
導体からなる試験対象の表面付近に誘起された渦電流の
前記表面付近の不連続部の存在により生じた変化を、検
出コイルが検出した前記表面付近の磁界の変化により検
出し、検出した前記渦電流の変化に基づき、前記試験対
象の探傷を行う渦流探傷試験方法において、 前記励磁コイルは、周波数が連続的に変化する交流電流
により前記交流磁界を形成し、前記励磁コイルが形成し
た交流磁界により前記試験対象の表面付近に誘起された
渦電流の前記表面付近の不連続部により生じた磁界の変
化を検出し、検出した電気信号の変化に基づき前記試験
対象の探傷を行うことを特徴とする渦流探傷試験方法。1. An alternating magnetic field formed by an exciting coil,
The change in the eddy current induced near the surface of the test object made of a conductor caused by the presence of the discontinuity near the surface is detected by the change in the magnetic field near the surface detected by the detection coil, and the detected vortex is detected. In the eddy current flaw test method for performing flaw detection on the test object based on a change in current, the exciting coil forms the alternating magnetic field by an alternating current whose frequency continuously changes, and by the alternating magnetic field formed by the exciting coil. It is characterized in that a change in the magnetic field caused by a discontinuity near the surface of the eddy current induced near the surface of the test object is detected, and flaw detection of the test object is performed based on the detected change in the electrical signal. Eddy current testing method. 【請求項２】 前記電気信号の変化は、前記交流電流の
任意の周波数時に前記試験対象の健全部で検出した前記
検出コイルの出力と、前記不連続部で検出した前記検出
コイルの出力との差である請求項１記載の渦流探傷試験
方法。2. The change in the electric signal is caused by an output of the detection coil detected by a sound part of the test object at an arbitrary frequency of the alternating current and an output of the detection coil detected by the discontinuous part. The eddy current flaw detection test method according to claim 1, which is a difference. 【請求項３】 前記健全部で検出すべき検出コイルの出
力は、前記周波数の変化の開始から終了迄の時間の１０
０分の１乃至１０分の１の間隔毎に検出する請求項２記
載の渦流探傷試験方法。3. The output of the detection coil to be detected by the sound section is 10 times the time from the start to the end of the frequency change.
The eddy current flaw detection test method according to claim 2, wherein the detection is performed at intervals of 1/0 to 1/10. 【請求項４】 励磁コイルが形成した交流磁界により、
導体からなる試験対象の表面付近に誘起された渦電流の
前記表面付近の不連続部の存在により生じた変化を、検
出コイルが検出した前記表面付近の磁界の変化により検
出し、検出した前記渦電流の変化に基づき、前記試験対
象の探傷を行う渦流探傷試験方法において、 前記励磁コイルは、周波数が段階的に変化する交流電流
により前記交流磁界を形成し、前記励磁コイルが形成し
た交流磁界により前記試験対象の表面付近に誘起された
渦電流の前記表面付近の不連続部により生じた磁界の変
化を検出し、検出した電気信号の変化に基づき前記試験
対象の探傷を行うことを特徴とする渦流探傷試験方法。4. The alternating magnetic field formed by the exciting coil,
The change in the eddy current induced near the surface of the test object made of a conductor caused by the presence of the discontinuity near the surface is detected by the change in the magnetic field near the surface detected by the detection coil, and the detected vortex is detected. In the eddy current flaw detection test method for performing flaw detection on the test object based on a change in current, the exciting coil forms the alternating magnetic field by an alternating current whose frequency changes stepwise, and by the alternating magnetic field formed by the exciting coil. It is characterized in that a change in the magnetic field caused by a discontinuity near the surface of the eddy current induced near the surface of the test object is detected, and flaw detection of the test object is performed based on the detected change in the electrical signal. Eddy current testing method. 【請求項５】 前記電気信号の変化は、前記交流電流の
周波数が変化した都度、前記試験対象の健全部で検出し
た前記検出コイルの出力と、前記不連続部で検出した前
記検出コイルの出力との差である請求項４記載の渦流探
傷試験方法。5. The output of the detection coil detected by the sound part of the test object and the output of the detection coil detected by the discontinuous part are changed every time the frequency of the alternating current changes. The eddy current flaw detection test method according to claim 4, which is a difference from the above. 【請求項６】 励磁コイルが形成した交流磁界により、
導体からなる試験対象の表面付近に誘起された渦電流の
前記表面付近の不連続部の存在により生じた変化を、検
出コイルが検出した前記表面付近の磁界の変化により検
出し、検出した前記渦電流の変化に基づき、前記試験対
象の探傷を行う渦流探傷試験装置において、 前記励磁コイルに周波数が連続的に変化する交流電流を
供給する手段と、前記励磁コイルが形成した交流磁界に
より前記試験対象の表面付近に誘起された渦電流の前記
表面付近の不連続部により生じた磁界の変化を検出する
手段とを備え、該手段が検出した変化に基づき前記試験
対象の探傷を行うべくなしてあることを特徴とする渦流
探傷試験装置。6. The alternating magnetic field formed by the exciting coil,
The change in the eddy current induced near the surface of the test object made of a conductor caused by the presence of the discontinuity near the surface is detected by the change in the magnetic field near the surface detected by the detection coil, and the detected vortex is detected. In the eddy current flaw detection test apparatus for performing flaw detection on the test object based on a change in current, a means for supplying an alternating current whose frequency continuously changes to the excitation coil, and the test object by an alternating magnetic field formed by the excitation coil. A means for detecting a change in magnetic field caused by a discontinuity near the surface of the eddy current induced near the surface of the test object, and to detect the test object based on the change detected by the means. An eddy current flaw testing device characterized in that 【請求項７】 前記変化は、前記交流電流の任意の周波
数時に前記試験対象の健全部で検出した前記検出コイル
の出力と、前記不連続部で検出した前記検出コイルの出
力との差である請求項６記載の渦流探傷試験装置。7. The change is a difference between an output of the detection coil detected at a sound portion of the test object and an output of the detection coil detected at the discontinuous portion at an arbitrary frequency of the alternating current. The eddy current flaw detection test apparatus according to claim 6. 【請求項８】 前記健全部で検出すべき検出コイルの出
力は、前記周波数の変化の開始から終了迄の時間の１０
０分の１乃至１０分の１の間隔毎に検出する請求項７記
載の渦流探傷試験装置。8. The output of the detection coil to be detected by the sound section is 10 times from the start to the end of the frequency change.
The eddy-current flaw detection test apparatus according to claim 7, wherein the eddy current flaw detection test apparatus detects at intervals of 0th to 1 / 10th. 【請求項９】 励磁コイルが形成した交流磁界により、
導体からなる試験対象の表面付近に誘起された渦電流の
前記表面付近の不連続部の存在により生じた変化を、検
出コイルが検出した前記表面付近の磁界の変化により検
出し、検出した前記渦電流の変化に基づき、前記試験対
象の探傷を行う渦流探傷試験装置において、 前記励磁コイルに周波数が段階的に変化する交流電流を
供給する手段と、前記励磁コイルが形成した交流磁界に
より前記試験対象の表面付近に誘起された渦電流の前記
表面付近の不連続部により生じた磁界の変化を検出する
手段とを備え、該手段が検出した変化に基づき前記試験
対象の探傷を行うべくなしてあることを特徴とする渦流
探傷試験装置。9. An alternating magnetic field formed by the exciting coil,
The change in the eddy current induced near the surface of the test object made of a conductor caused by the presence of the discontinuity near the surface is detected by the change in the magnetic field near the surface detected by the detection coil, and the detected vortex is detected. In the eddy current flaw detection test apparatus for performing flaw detection on the test object based on a change in current, a means for supplying an alternating current whose frequency changes stepwise to the exciting coil, and the alternating magnetic field formed by the exciting coil, the test object A means for detecting a change in magnetic field caused by a discontinuity near the surface of the eddy current induced near the surface of the test object, and to detect the test object based on the change detected by the means. An eddy current flaw testing device characterized in that 【請求項１０】 前記変化は、前記交流電流の周波数が
変化した都度、前記試験対象の健全部で検出した前記検
出コイルの出力と、前記不連続部で検出した前記検出コ
イルの出力との差である請求項９記載の渦流探傷試験装
置。10. The change is a difference between an output of the detection coil detected in a sound part of the test object and an output of the detection coil detected in the discontinuous part each time the frequency of the alternating current changes. The eddy current flaw testing device according to claim 9.
JP2001239902A 2001-08-07 2001-08-07 Eddy-current flaw detection testing method and eddy- current flaw detection testing device Pending JP2003050233A (en)

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Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2011085502A (en) * 2009-10-16 2011-04-28 Shinshu Univ Magnetic field detection sensor of metal component, and method for determining quality of the metal component
CN107422029A (en) * 2017-04-28 2017-12-01 陕西科技大学 A kind of apparatus and method of accurate detection metal plate defect
CN108872373A (en) * 2018-07-27 2018-11-23 爱德森（厦门）电子有限公司 One kind is based on vortex frequency sweep imaging chromatography detection method
WO2020075339A1 (en) * 2018-10-10 2020-04-16 新東工業株式会社 Method for nondestructive assessment of steel
CN112630294A (en) * 2020-12-07 2021-04-09 清华大学 Chirp signal-based rotation chromatography defect detection method and device

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS60152950A (en) * 1983-12-16 1985-08-12 エロクトロメツク　デイビジヨン　マリテイム　アイエヌシー． Eddy current nondestructive testing method and device thereof
JPS639182B2 (en) * 1979-07-10 1988-02-26 Hara Denshi Sokki
JPH0763730A (en) * 1993-08-25 1995-03-10 Mitsubishi Materials Corp Eddy current flaw detector
JPH09178710A (en) * 1995-12-22 1997-07-11 Mitsubishi Heavy Ind Ltd Flaw detecting element for eddy current flaw detection device
JPH102883A (en) * 1996-06-18 1998-01-06 Mitsubishi Heavy Ind Ltd Eddy current flaw detection apparatus
JPH1038853A (en) * 1996-07-22 1998-02-13 Toshiba Corp Material strength evaluation method of metal material and method and device for diffusion layer thickness evaluation
JP2000028583A (en) * 1998-07-08 2000-01-28 Nippon Telegr & Teleph Corp <Ntt> Break detecting device and method for reinforcement inside concrete pole
JP2000346830A (en) * 1999-06-09 2000-12-15 Sumitomo Metal Ind Ltd Eddy current flaw-detecting method and its device

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS639182B2 (en) * 1979-07-10 1988-02-26 Hara Denshi Sokki
JPS60152950A (en) * 1983-12-16 1985-08-12 エロクトロメツク　デイビジヨン　マリテイム　アイエヌシー． Eddy current nondestructive testing method and device thereof
JPH0763730A (en) * 1993-08-25 1995-03-10 Mitsubishi Materials Corp Eddy current flaw detector
JPH09178710A (en) * 1995-12-22 1997-07-11 Mitsubishi Heavy Ind Ltd Flaw detecting element for eddy current flaw detection device
JPH102883A (en) * 1996-06-18 1998-01-06 Mitsubishi Heavy Ind Ltd Eddy current flaw detection apparatus
JPH1038853A (en) * 1996-07-22 1998-02-13 Toshiba Corp Material strength evaluation method of metal material and method and device for diffusion layer thickness evaluation
JP2000028583A (en) * 1998-07-08 2000-01-28 Nippon Telegr & Teleph Corp <Ntt> Break detecting device and method for reinforcement inside concrete pole
JP2000346830A (en) * 1999-06-09 2000-12-15 Sumitomo Metal Ind Ltd Eddy current flaw-detecting method and its device

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2011085502A (en) * 2009-10-16 2011-04-28 Shinshu Univ Magnetic field detection sensor of metal component, and method for determining quality of the metal component
CN107422029A (en) * 2017-04-28 2017-12-01 陕西科技大学 A kind of apparatus and method of accurate detection metal plate defect
CN107422029B (en) * 2017-04-28 2020-11-03 陕西科技大学 Device and method for accurately detecting defects of metal plate
CN108872373A (en) * 2018-07-27 2018-11-23 爱德森（厦门）电子有限公司 One kind is based on vortex frequency sweep imaging chromatography detection method
CN108872373B (en) * 2018-07-27 2020-07-17 爱德森（厦门）电子有限公司 Tomography detection method based on eddy current frequency sweep imaging
WO2020075339A1 (en) * 2018-10-10 2020-04-16 新東工業株式会社 Method for nondestructive assessment of steel
JP2020060454A (en) * 2018-10-10 2020-04-16 新東工業株式会社 Nondestructive inspection method of steel material
CN112119302A (en) * 2018-10-10 2020-12-22 新东工业株式会社 Nondestructive inspection method for steel material
CN112630294A (en) * 2020-12-07 2021-04-09 清华大学 Chirp signal-based rotation chromatography defect detection method and device
CN112630294B (en) * 2020-12-07 2022-11-29 清华大学 Chirp signal-based rotation chromatography defect detection method and device

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