JPH06194342A - Composite magnetic head - Google Patents
Composite magnetic headInfo
- Publication number
- JPH06194342A JPH06194342A JP35766392A JP35766392A JPH06194342A JP H06194342 A JPH06194342 A JP H06194342A JP 35766392 A JP35766392 A JP 35766392A JP 35766392 A JP35766392 A JP 35766392A JP H06194342 A JPH06194342 A JP H06194342A
- Authority
- JP
- Japan
- Prior art keywords
- magnetic
- head
- measured
- magnetic flux
- magnetic head
- 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.)
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- Investigating Or Analyzing Materials By The Use Of Magnetic Means (AREA)
Abstract
(57)【要約】
【目的】 本発明は、鋼材などの表面傷を検査する場
合、或いはその磁気的性質から材質等を非破壊的に検査
する場合、被測定物からの漏洩磁束を精度良く検出でき
る複合磁気ヘッドを提供することを目的とする。
【構成】 磁性体表面の局部領域の励磁、或いは、該
局部領域からの漏洩磁束の検出を行う励磁或いは検出ヘ
ッドの被測定物側に位置するヘッド先端部が形状可変な
磁性体で構成されていることを特徴とする複合磁気ヘッ
ド。さらに、形状可変な磁性体が磁性流体であることを
特徴とする複合磁気ヘッド。
(57) [Abstract] [Purpose] The present invention accurately measures leakage magnetic flux from an object to be measured when inspecting surface flaws of steel or the like or when nondestructively inspecting materials and the like due to its magnetic properties. It is an object to provide a detectable composite magnetic head. [Exemplary configuration] An excitation of a local area on the surface of a magnetic body, or an excitation for detecting a leakage magnetic flux from the local area, or a head end portion of a detection head located on the side of the object to be measured is formed of a magnetic body having a variable shape. A composite magnetic head characterized in that Further, a composite magnetic head characterized in that the deformable magnetic body is a magnetic fluid.
Description
【０００１】[0001]
【産業上の利用分野】本発明は被測定物の表面傷を検査
する場合、或いは被測定物の磁気的性質からその材質等
を非破壊的に検査する場合に使用する磁気ヘッドに関す
る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head used for inspecting a surface flaw of an object to be measured, or for nondestructively inspecting the material of the object to be measured due to its magnetic properties.
【０００２】[0002]
【従来の技術】鋼板等の品質に対する要求は、近年、ま
すます厳しくなっているため、製造工程に於ける表面傷
の探傷は、品質管理上、重要な工程の１つになってい
る。検出しなければならない傷の大きさも数１０μｍと
ますます小さくなっている。このような表面傷を検出す
る方法としては、漏洩磁束法、渦電流法、超音波法等が
あるが、小さな傷に対しては、漏洩磁束法が有効であ
る。2. Description of the Related Art Since the demand for quality of steel sheets and the like has become more and more stringent in recent years, surface flaw detection in the manufacturing process is one of the important processes in quality control. The size of the scratches that must be detected is tens of μm, which is becoming smaller and smaller. As a method of detecting such a surface flaw, there are a leakage magnetic flux method, an eddy current method, an ultrasonic method and the like, but the leakage flux method is effective for a small flaw.
【０００３】品質管理には、表面傷の他に材料の引張り
強度や硬度などの材質管理も重要な項目であり、材料の
磁気的性質が、結晶粒径や析出物などの組織、ひずみ等
に依存することを利用して、被測定物の材質を非破壊的
に検査することが試みられている。例えば、透磁率を測
定して鋼材の引っ張り強さを見積る方法、ひずみによる
透磁率の方位変化から残留ひずみの方向を見積る方法、
保磁力によって焼き入れ硬度を見積る方法等があるが、
最近、磁化の不連続性に起因するバルクハウゼンノイズ
を用いた方法が注目され、それを用いて軟鋼の疲労強度
（L.P. Karjalainenら、IEEE Trans. Mag. MAG16, 514
(1980)）や工具鋼の靭性を推定する方法（仲居ら、鉄と
鋼,75, 833(1989)）などが提唱されている。また、炭素
鋼のα−Ｆｅ粒径及び析出したセメンタイト粒径とバル
クハウゼンノイズの相関関係も理論的に考察されている
（H. Sakamotoら、IEEE Trans. Mag. MAG23, 2236(198
7)）。In addition to surface scratches, material quality control such as tensile strength and hardness is also an important item for quality control. The magnetic properties of a material affect the grain size, structure such as precipitates, strain, etc. Taking advantage of this dependency, it has been attempted to nondestructively inspect the material of the object to be measured. For example, a method of estimating the tensile strength of the steel material by measuring the magnetic permeability, a method of estimating the direction of the residual strain from the orientation change of the magnetic permeability due to strain,
There is a method to estimate quenching hardness by coercive force,
Recently, a method using Barkhausen noise caused by the discontinuity of magnetization has attracted attention, and using it, fatigue strength of mild steel (LP Karjalainen et al., IEEE Trans. Mag. MAG16, 514
(1980)) and a method for estimating the toughness of tool steel (Nakai et al., Iron and Steel, 75, 833 (1989)). Further, the correlation between the α-Fe grain size and the precipitated cementite grain size of carbon steel and Barkhausen noise has also been theoretically considered (H. Sakamoto et al., IEEE Trans. Mag. MAG23, 2236 (198).
7)).
【０００４】一般に被測定物を励磁する方法として、電
流貫通法、通電法、コイル法、及びヨーク法があるが、
これらの中で、ヨーク法は、実ラインで製造される鉄鋼
製品や既設構造物などの比較的大きな製品の一部分に当
てるだけで簡便にそれを励磁できる利点があるので、前
記した表面傷及び材質検査用の励磁用として使用されて
いる。被測定物の磁化の検出法に関しては、ヨーク法、
ホール素子法、磁気抵抗素子法などがある。ただし、後
者の２つは温度の影響を受けやすいため、影響を受けに
くいヨーク法が簡便である。しかし、温度の影響がない
場合には後者の２つの方法も用いられている。Generally, there are a current penetration method, an energization method, a coil method, and a yoke method as a method for exciting an object to be measured.
Among them, the yoke method has an advantage that it can be easily excited by simply applying it to a part of a relatively large product such as a steel product or an existing structure manufactured on an actual line. It is used for excitation for inspection. Regarding the method of detecting the magnetization of the DUT, the yoke method,
The Hall element method and the magnetoresistive element method are available. However, since the latter two are easily affected by temperature, the yoke method, which is not easily affected, is simple. However, the latter two methods are also used when there is no influence of temperature.
【０００５】ヨーク法による励磁ヘッドと検出ヘッドは
通常、被測定物に対して、図２に示すように配置され
る。励磁ヘッド及び検出ヘッドのコア２、３の材料とし
ては、珪素鋼、パーマロイ、ソフトフェライト等の軟質
磁性材料が用いられる。励磁コイル４に流す電流波形を
三角波、或いは正弦波にすることによって、それぞれの
波形に対応して励磁磁場が得られる。励磁ヘッドによっ
て発生した磁束７は図２に示したように被測定物６の中
を流れるが、表面傷があるとその部分の漏洩磁束が多く
なる。その結果、検出コイル５に誘起される電圧が変化
して傷の位置が分かる。傷がない場合でも被測定物内部
を通った磁束の一部が検出ヘッドを通るために、検出コ
イル５には、被測定物の磁化の変化に起因する電圧が誘
起される。The exciting head and the detecting head according to the yoke method are usually arranged on the object to be measured as shown in FIG. A soft magnetic material such as silicon steel, permalloy or soft ferrite is used as the material of the cores 2 and 3 of the exciting head and the detecting head. By making the waveform of the current flowing through the exciting coil 4 a triangular wave or a sine wave, an exciting magnetic field can be obtained corresponding to each waveform. The magnetic flux 7 generated by the exciting head flows through the DUT 6 as shown in FIG. 2, but if there is a surface flaw, the leakage magnetic flux at that portion increases. As a result, the voltage induced in the detection coil 5 changes and the position of the scratch can be seen. Even if there is no flaw, a part of the magnetic flux that has passed through the inside of the measured object passes through the detection head, so that a voltage caused by a change in the magnetization of the measured object is induced in the detection coil 5.
【０００６】この電圧を検出した後、信号処理すること
によって、バルクハウゼンノイズやＢ−Ｈループを求め
ることができ、これらの磁気的性質から被測定物の材質
を非破壊的に評価することができる。磁束の検出には、
図２の磁気ヘッドの他にホール素子や磁気抵抗素子も使
用される。Barkhausen noise and BH loop can be obtained by signal processing after detecting this voltage, and the material of the object to be measured can be evaluated nondestructively from these magnetic properties. it can. To detect magnetic flux,
In addition to the magnetic head shown in FIG. 2, Hall elements and magnetoresistive elements are also used.
【０００７】しかし、実際にヘッドを被測定物の表面を
走査させる場合には、ヘッド先端部と被測定物の接触を
避けるために、磁気ヘッドを所定のリフトオフ（ヘッド
と試料表面との距離）８を保った状態で被測定物６の表
面を走査させる必要がある。その場合には、励磁ヘッド
の励磁力が減少し、検出コイルに入り込む磁束も少なく
なってしまう。また、リフトオフがない状態でも被測定
物表面に凹凸がある場合には同様なことが生じる。従っ
て、このような状態では被測定物の磁束（磁化）の検出
精度が悪くなる。However, when actually scanning the surface of the object to be measured by the head, the magnetic head is lifted off by a predetermined distance (the distance between the head and the sample surface) in order to avoid contact between the tip of the head and the object to be measured. It is necessary to scan the surface of the DUT 6 while maintaining the value of 8. In that case, the exciting magnetic force of the exciting head decreases, and the magnetic flux entering the detection coil also decreases. Further, even if there is no lift-off, the same thing occurs when the surface of the object to be measured has irregularities. Therefore, in such a state, the accuracy of detecting the magnetic flux (magnetization) of the object to be measured deteriorates.
【０００８】[0008]
【発明が解決しようとする課題】従来の方法は、リフト
オフがある状態、或いは被測定物表面に凹凸がある状態
でヘッド方式によって被測定物の励磁と検出を行う場合
に、被測定物からの漏洩磁束を精度良く検出する方法を
提供していない。In the conventional method, when the object to be measured is excited and detected by the head system in the state where there is lift-off or the surface of the object to be measured has irregularities, It does not provide a method for accurately detecting the leakage magnetic flux.
【０００９】本発明は、ヘッド方式によって被測定物を
励磁し、その漏洩磁束を検出する場合、ヘッド先端部を
工夫することによって、リフトオフがある状態、或いは
被測定物表面に凹凸がある状態に於ても被測定物からの
漏洩磁束を精度良く検出できる複合磁気ヘッドを提供す
ることを目的とする。According to the present invention, when the object to be measured is excited by the head system and the leakage magnetic flux is detected, by devising the tip of the head, the lift-off or the surface of the object to be measured has unevenness. Even in this case, it is an object of the present invention to provide a composite magnetic head capable of accurately detecting a leakage magnetic flux from an object to be measured.
【００１０】[0010]
【課題を解決するための手段】本発明の要旨とするとこ
ろは、下記の通りである。 １．磁性体表面の局部領域の励磁、或いは、該局部領域
からの漏洩磁束の検出を行う磁気ヘッドに於て、励磁或
いは検出時に被測定物側に位置するヘッドの先端部が形
状可変な磁性体で構成されていることを特徴とする複合
磁気ヘッド。 ２．前項１に記載の形状可変な磁性体が磁性流体である
ことを特徴とする複合磁気ヘッド。ここで、形状可変な
磁性体に磁性流体を用いる場合には、磁性流体は液状で
あり、かつ、励磁中のヘッド先端部に吸引されるため、
ビニールパイプなどの細管を通して供給することによっ
て、前記複合磁気ヘッドを構成できる。また、形状可変
な磁性体として、軟質磁性体の微粒子を剛性が低いゴム
中に分散させたもの等のバルク体を用いる場合には、そ
れらをヘッド先端部に接着させることによって、前記複
合ヘッドを構成できる。The gist of the present invention is as follows. 1. In a magnetic head that excites a local area on the surface of a magnetic body or detects a leakage magnetic flux from the local area, the tip of the head located on the side of the DUT at the time of excitation or detection is a magnetic body whose shape is variable. A composite magnetic head characterized by being configured. 2. 2. A composite magnetic head, wherein the shape-variable magnetic body according to the above 1 is a magnetic fluid. Here, when a magnetic fluid is used for the shape-changeable magnetic body, the magnetic fluid is a liquid and is attracted to the head tip part during excitation,
The composite magnetic head can be constructed by supplying it through a thin tube such as a vinyl pipe. When a bulk body such as a magnetic body having a variable shape in which fine particles of a soft magnetic body are dispersed in rubber having low rigidity is used, the composite head is bonded by adhering them to the head end portion. Can be configured.
【００１１】[0011]
【作用】このようにして、リフトオフがある状態、或い
は被測定物表面に凹凸がある状態に於ても、被測定物か
らの漏洩磁束を精度良く検出できる。In this way, the leakage magnetic flux from the object to be measured can be accurately detected even when there is lift-off or the surface of the object to be measured has irregularities.
【００１２】[0012]
【実施例】以下、実施例に基づき本発明を添付の図面に
付いて詳細に説明する。DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the accompanying drawings based on embodiments.
【００１３】本発明による複合磁気ヘッドの概略図を図
１に示す。励磁ヘッドは、軟質磁性材料で作られたＵ型
コア２、それに巻かれている励磁用コイル４、さらに本
発明の特徴であるコアの先端部に位置する形状可変な磁
性体１で構成される。即ち、コア先端部と被測定物６と
の間にリフトオフ８がある場合でも、形状可変な磁性体
１がギャップを満たしている状態が維持されている。こ
の磁性体の役割は、（１）リフトオフによってできた空
間、或いは被測定物表面の凹凸による空間の透磁率を上
げて（磁気抵抗を下げて）、被測定物の励磁を容易にす
ること、（２）ヘッドが表面上を移動する場合、常に表
面の凹凸に応じて形状を変えることができるために、表
面状態の影響が低減できることである。A schematic diagram of a composite magnetic head according to the present invention is shown in FIG. The exciting head is composed of a U-shaped core 2 made of a soft magnetic material, an exciting coil 4 wound around the U-shaped core 2, and a variable-shape magnetic body 1 located at the tip of the core, which is a feature of the present invention. . That is, even if there is a lift-off 8 between the tip of the core and the DUT 6, the state in which the shape-changeable magnetic body 1 fills the gap is maintained. The role of this magnetic material is to (1) increase the magnetic permeability of the space created by lift-off or the space due to the irregularities on the surface of the object to be measured (reduce the magnetic resistance) to facilitate the excitation of the object to be measured, (2) When the head moves on the surface, the shape can be constantly changed according to the unevenness of the surface, so that the influence of the surface condition can be reduced.
【００１４】次に、図１に示したヨーク法を用いた場合
の検出ヘッドについて説明する。この検出ヘッドは、軟
質磁性材料で作られたＵ型コア、それに巻かれている検
出用コイル、さらに本発明の特徴であるコアの先端部に
位置する形状可変な磁性体で構成される。この磁性体の
役割は、前記した励磁ヘッドの場合と同様に、（１）リ
フトオフによってできた空間、或いは被測定物表面の凹
凸による空間の透磁率を上げて（磁気抵抗を下げて）、
被測定物からの磁束の漏洩を容易にして磁束の収磁効率
を上げること、（２）ヘッドが表面上を移動する場合、
常に表面の凹凸に応じて形状を変えることができるため
に、表面状態の影響が低減できることである。Next, a detection head using the yoke method shown in FIG. 1 will be described. The detection head is composed of a U-shaped core made of a soft magnetic material, a detection coil wound around the U-shaped core, and a variable-shape magnetic body located at the tip of the core, which is a feature of the present invention. The role of this magnetic substance is to increase the magnetic permeability (lower the magnetic resistance) of the space created by (1) the lift-off or the space due to the irregularities on the surface of the object to be measured, as in the case of the exciting head described above.
To facilitate the leakage of magnetic flux from the object to be measured and to improve the magnetic flux collection efficiency, (2) When the head moves on the surface,
Since the shape can be constantly changed according to the unevenness of the surface, the influence of the surface condition can be reduced.
【００１５】被測定物からの漏洩磁束の検出には、図１
に示したヨーク法の他に、ホール素子、磁気抵抗素子を
用いても検出可能である。本発明の特徴である形状可変
な磁性体をこれらの両素子の先端部につけることによっ
てもヨーク法の場合と同様に同じ効果を示す。しかし、
これらの素子は温度の影響を受け易いため、温度管理さ
れた室内などでの使用に限定される。To detect the magnetic flux leaking from the object to be measured, FIG.
In addition to the yoke method shown in (1), it can be detected using a Hall element or a magnetoresistive element. The same effect can be obtained as in the case of the yoke method by attaching the variable shape magnetic body, which is a feature of the present invention, to the tip portions of both of these elements. But,
Since these elements are easily affected by temperature, they are limited to use in a temperature-controlled room.
【００１６】形状可変な磁性体には、磁性流体を用い
る。磁性流体は、液状であるから形状が可変であり、か
つ、測定時には励磁コア或いは検出コアに吸引されるた
めにヘッドを被測定物表面上で移動させても磁性流体も
同じく移動する。また、使用中にその量が減少すれば、
ビニールパイプなどの細管を通して随時供給可能であ
る。さらに、磁性流体は約１０ｎｍのマグネタイト微粒
子の分散溶液であるため、個々の粒子が磁場ベクトルの
変化に追従しやすい。この他に、形状可変な磁性体とし
て、軟質磁性体の微粒子を剛性が低いゴム中に分散させ
たものも使用可能である。さらには、有機磁性体なども
使用可能である。A magnetic fluid is used for the magnetic material whose shape can be changed. Since the magnetic fluid is a liquid, its shape is variable, and since the magnetic fluid is attracted to the exciting core or the detecting core during measurement, the magnetic fluid also moves when the head is moved over the surface of the object to be measured. Also, if the amount decreases during use,
It can be supplied at any time through a thin pipe such as a vinyl pipe. Further, since the magnetic fluid is a dispersion solution of magnetite fine particles having a size of about 10 nm, individual particles can easily follow changes in the magnetic field vector. In addition to this, as the magnetic material having a variable shape, it is possible to use a magnetic material in which fine particles of a soft magnetic material are dispersed in rubber having low rigidity. Furthermore, an organic magnetic material or the like can also be used.
【００１７】以上詳述したように、本発明による励磁ヘ
ッドと検出ヘッドを用いることによって、リフトオフが
ある状態、或いは被測定物表面に凹凸がある状態に於て
も被測定物の励磁を容易にし、かつ、被測定物からの漏
洩磁束を精度良く検出することが可能になる。As described above in detail, by using the exciting head and the detecting head according to the present invention, it is possible to easily excite the object to be measured even when there is lift-off or when there is unevenness on the surface of the object to be measured. In addition, it becomes possible to accurately detect the leakage magnetic flux from the object to be measured.
【００１８】例 １ 形状可変な磁性体として磁性流体を用いた磁気ヘッドを
作製し、試料の励磁と磁束の検出を行った。磁性流体は
細管を通してヘッド先端部に供給した。尚、励磁用のコ
アには珪素鋼板、検出用のコアにはパーマロイを用い
た。測定用試料には表面に０．２ｍｍの凹凸を付けた板
厚２ｍｍの中炭素鋼を用いた。励磁は、周波数２．５Ｈ
ｚ、最大電流５００ｍＡの正弦波電流を励磁コイルに流
して行った。試料の磁化の変化は、検出コイルに誘起さ
れる電圧波形として測定した。ヘッドのリフトオフは
０．１ｍｍとした。 Example 1 A magnetic head using a magnetic fluid as a shape-changeable magnetic body was manufactured, and the sample was excited and the magnetic flux was detected. The magnetic fluid was supplied to the tip of the head through a thin tube. A silicon steel plate was used for the exciting core, and permalloy was used for the detecting core. As the measurement sample, a medium carbon steel having a plate thickness of 2 mm with a 0.2 mm uneven surface was used. Excitation is frequency 2.5H
A sine wave current having a maximum current of 500 mA was applied to the exciting coil. The change in the magnetization of the sample was measured as a voltage waveform induced in the detection coil. The lift-off of the head was 0.1 mm.
【００１９】比較として、磁性流体を使用しない場合に
ついて、同じ条件で測定を行った。漏洩磁束の検出量を
示すパラメータとして、電圧波形の最大値を用いて比較
した。尚、電圧の最大値は、磁性流体の有無にかかわら
ず電圧波形の同じ位置（時間軸上）であった。As a comparison, the measurement was performed under the same conditions when the magnetic fluid was not used. The maximum value of the voltage waveform was used as a parameter indicating the detected amount of the leakage magnetic flux for comparison. The maximum value of the voltage was the same position (on the time axis) of the voltage waveform regardless of the presence or absence of the magnetic fluid.
【００２０】結果を表１に示す。The results are shown in Table 1.
【００２１】[0021]
【表１】 [Table 1]
【００２２】以上の結果から、本発明の磁気ヘッドを用
いることによって、リフトオフがある状態、或いは被測
定物表面に凹凸がある状態に於ても被測定物の励磁を容
易にし、かつ、被測定物からの漏洩磁束を精度良く検出
することが可能になる。From the above results, by using the magnetic head of the present invention, it is possible to easily excite the object to be measured even when there is lift-off or the surface of the object to be measured is uneven, and the object to be measured can be easily excited. It is possible to accurately detect the magnetic flux leaking from the object.
【００２３】本発明を表面傷の検出及びバルクハウゼン
ノイズ測定に用いた鋼材の材質検査を行ったところ、検
出精度が向上した。When the material of the steel material used for the detection of surface scratches and the measurement of Barkhausen noise according to the present invention was inspected, the detection accuracy was improved.
【００２４】[0024]
【発明の効果】本発明による複合磁気ヘッドを用いるこ
とによって、被測定物の磁化を効率よく検出することが
可能になり、材料の表面傷の検出、或いは磁気的性質か
らその材質を非破壊的に評価する場合に、それらの精度
を向上させることができる。By using the composite magnetic head according to the present invention, it is possible to efficiently detect the magnetization of an object to be measured, detect surface scratches on the material, or nondestructively use the material due to its magnetic properties. In the case of evaluation, it is possible to improve their accuracy.
【図面の簡単な説明】[Brief description of drawings]
【図１】本発明による複合磁気ヘッドの概略図。FIG. 1 is a schematic view of a composite magnetic head according to the present invention.
【図２】従来の磁気ヘッド。FIG. 2 is a conventional magnetic head.
１ 形状可変な磁性体 ２ 励磁コア ３ 検出コア ４ 励磁コイル ５ 検出コイル ６ 被測定物 ７ 磁束の流れ ８ リフトオフ 1 Shape-changeable magnetic material 2 Excitation core 3 Detection core 4 Excitation coil 5 Detection coil 6 DUT 7 Magnetic flux flow 8 Lift-off
Claims (2)
は、該局部領域からの漏洩磁束の検出を行う磁気ヘッド
に於て、 励磁或いは検出時に被測定物側に位置するヘッドの先端
部が形状可変な磁性体で構成されていることを特徴とす
る複合磁気ヘッド。1. A magnetic head for exciting a local area on a surface of a magnetic body or for detecting a leakage magnetic flux from the local area, wherein the tip of the head located on the side of the object to be measured at the time of excitation or detection is shaped. A composite magnetic head comprising a variable magnetic body.
磁性流体であることを特徴とする複合磁気ヘッド。2. A composite magnetic head, wherein the shape-variable magnetic body according to claim 1 is a magnetic fluid.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP35766392A JPH06194342A (en) | 1992-12-24 | 1992-12-24 | Composite magnetic head |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP35766392A JPH06194342A (en) | 1992-12-24 | 1992-12-24 | Composite magnetic head |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH06194342A true JPH06194342A (en) | 1994-07-15 |
Family
ID=18455279
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP35766392A Pending JPH06194342A (en) | 1992-12-24 | 1992-12-24 | Composite magnetic head |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH06194342A (en) |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5565773A (en) * | 1993-11-05 | 1996-10-15 | Nippon Steel Corporation | Arrangement of excitation and detection heads for detecting the magnetic properties of an object |
| JP2002257788A (en) * | 2001-02-27 | 2002-09-11 | Takenaka Komuten Co Ltd | Diagnostic method of deterioration of steel product |
| JP2004151094A (en) * | 2002-10-15 | 2004-05-27 | General Electric Co <Ge> | Test probe |
| JP2005117892A (en) * | 2003-10-03 | 2005-04-28 | General Electric Co <Ge> | General purpose sensor probe with adjustable member |
| JP2007256274A (en) * | 2006-02-24 | 2007-10-04 | Jfe Steel Kk | Method and apparatus for detecting minute irregular surface defects |
| WO2008072508A1 (en) * | 2006-12-14 | 2008-06-19 | Osaka University | Nondestructive test instrument and nondestructive test method |
| CN103430017A (en) * | 2011-02-11 | 2013-12-04 | 西门子能量股份有限公司 | Fault detection for laminated core |
| JP2017015608A (en) * | 2015-07-02 | 2017-01-19 | アイシン高丘株式会社 | Method and apparatus for measuring hardness of steel sheet after hardening treatment |
| CN112326781A (en) * | 2021-01-04 | 2021-02-05 | 四川大学 | Bearing needle magnetic leakage detection device |
| WO2021181978A1 (en) * | 2020-03-11 | 2021-09-16 | 横河電機株式会社 | Device and method |
-
1992
- 1992-12-24 JP JP35766392A patent/JPH06194342A/en active Pending
Cited By (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5565773A (en) * | 1993-11-05 | 1996-10-15 | Nippon Steel Corporation | Arrangement of excitation and detection heads for detecting the magnetic properties of an object |
| JP2002257788A (en) * | 2001-02-27 | 2002-09-11 | Takenaka Komuten Co Ltd | Diagnostic method of deterioration of steel product |
| JP2004151094A (en) * | 2002-10-15 | 2004-05-27 | General Electric Co <Ge> | Test probe |
| JP2005117892A (en) * | 2003-10-03 | 2005-04-28 | General Electric Co <Ge> | General purpose sensor probe with adjustable member |
| JP2007256274A (en) * | 2006-02-24 | 2007-10-04 | Jfe Steel Kk | Method and apparatus for detecting minute irregular surface defects |
| WO2008072508A1 (en) * | 2006-12-14 | 2008-06-19 | Osaka University | Nondestructive test instrument and nondestructive test method |
| CN103430017A (en) * | 2011-02-11 | 2013-12-04 | 西门子能量股份有限公司 | Fault detection for laminated core |
| JP2014507659A (en) * | 2011-02-11 | 2014-03-27 | シーメンス エナジー インコーポレイテッド | Fault detection in laminated iron cores |
| KR101532555B1 (en) * | 2011-02-11 | 2015-07-01 | 지멘스 에너지, 인코포레이티드 | Fault detection for laminated core |
| JP2017015608A (en) * | 2015-07-02 | 2017-01-19 | アイシン高丘株式会社 | Method and apparatus for measuring hardness of steel sheet after hardening treatment |
| WO2021181978A1 (en) * | 2020-03-11 | 2021-09-16 | 横河電機株式会社 | Device and method |
| JPWO2021181978A1 (en) * | 2020-03-11 | 2021-09-16 | ||
| CN112326781A (en) * | 2021-01-04 | 2021-02-05 | 四川大学 | Bearing needle magnetic leakage detection device |
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