JPS63101742A - Defect inspection - Google Patents
Defect inspectionInfo
- Publication number
- JPS63101742A JPS63101742A JP24742886A JP24742886A JPS63101742A JP S63101742 A JPS63101742 A JP S63101742A JP 24742886 A JP24742886 A JP 24742886A JP 24742886 A JP24742886 A JP 24742886A JP S63101742 A JPS63101742 A JP S63101742A
- Authority
- JP
- Japan
- Prior art keywords
- potential difference
- terminals
- crack
- terminal
- shape
- 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.)
- Granted
Links
- 230000007547 defect Effects 0.000 title claims description 12
- 238000007689 inspection Methods 0.000 title claims description 9
- 238000009826 distribution Methods 0.000 claims abstract description 46
- 238000005259 measurement Methods 0.000 claims abstract description 24
- 239000011159 matrix material Substances 0.000 claims abstract description 7
- 238000000034 method Methods 0.000 claims description 25
- 230000005684 electric field Effects 0.000 claims description 19
- 238000005336 cracking Methods 0.000 abstract description 5
- 238000003466 welding Methods 0.000 abstract description 4
- 230000002457 bidirectional effect Effects 0.000 abstract 1
- 238000001514 detection method Methods 0.000 description 9
- 238000010586 diagram Methods 0.000 description 7
- 239000002184 metal Substances 0.000 description 6
- 230000007797 corrosion Effects 0.000 description 5
- 238000005260 corrosion Methods 0.000 description 5
- 238000012806 monitoring device Methods 0.000 description 5
- 238000003860 storage Methods 0.000 description 5
- 238000012360 testing method Methods 0.000 description 4
- 238000002592 echocardiography Methods 0.000 description 3
- 239000011810 insulating material Substances 0.000 description 3
- 239000012774 insulation material Substances 0.000 description 3
- 230000000694 effects Effects 0.000 description 2
- 239000000523 sample Substances 0.000 description 2
- 238000011144 upstream manufacturing Methods 0.000 description 2
- 229920002494 Zein Polymers 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000005242 forging Methods 0.000 description 1
- 238000001093 holography Methods 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 239000012212 insulator Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000001308 synthesis method Methods 0.000 description 1
- 239000005019 zein Substances 0.000 description 1
- 229940093612 zein Drugs 0.000 description 1
Landscapes
- Investigating Or Analyzing Materials By The Use Of Electric Means (AREA)
- Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は金属構造部材に発生したき裂の形状を検出する
き裂検出技術に係り、特に配管内面の表面き裂の形状を
管外面からオンラインで精度よく検出するのに好適な装
置に関する。[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a crack detection technique for detecting the shape of a crack that occurs in a metal structural member, and in particular, the present invention relates to a crack detection technique for detecting the shape of a crack that occurs on a metal structural member. The present invention relates to a device suitable for accurate online detection.
〔従来技術〕
従来のき裂検出方法としては超音波探傷法がある。超音
波探傷法にも種々あり、端部ピークエコー法、開口合成
法、ホログラフィ法などがある。[Prior Art] As a conventional crack detection method, there is an ultrasonic flaw detection method. There are various ultrasonic flaw detection methods, including the edge peak echo method, aperture synthesis method, and holography method.
それぞれ特徴を有しているが、き裂の検出で特に重要な
き裂先端からのエコーが得られないことがあり、その場
合き裂の形状を判定できないという欠点があった。また
、運転中は配管周辺に断熱材が巻いであるため探触子を
走査することができないため検出することは不可能であ
る０本発明に関連したポテンシャル法によるき製形状検
出については、特開昭５８−２１５５４５き裂検出装ｆ
ｉ！（三菱重工業）があるが、き裂の有無が定性的に判
定できるだけで形状を検出することは不可能である。Each method has its own characteristics, but there are cases in which echoes from the crack tip, which are particularly important for crack detection, cannot be obtained, and in that case, the shape of the crack cannot be determined. In addition, during operation, the probe cannot scan because the insulation material is wrapped around the piping, making detection impossible. 1975-215545 Crack detection device f
i! (Mitsubishi Heavy Industries), but it is only possible to qualitatively determine the presence or absence of a crack, but it is impossible to detect the shape.
上記従来技術は、超音波法の場合き裂先端近傍からの反
射エコーが得られない、あるいは運転中は探触子を設置
できないという物理的な問題があり、ポテンシャル法の
場合き裂周辺に生じる特異な電場の乱れを正確に把握し
ていなかったために、き裂形状を検出できないという問
題があった１本発明の目的は配管内面に生じた表面き裂
の形状をポテンシャル法により運転中に検出することに
ある。The above conventional techniques have physical problems such as the inability to obtain reflected echoes from near the crack tip in the ultrasonic method, or the inability to set up the probe during operation, and the potential problem in which reflected echoes occur near the crack tip. There was a problem that the crack shape could not be detected because the unique electric field disturbance was not accurately grasped.1 The purpose of the present invention is to detect the shape of surface cracks that occur on the inner surface of the pipe during operation using the potential method. It's about doing.
上述の目的は、部材表面に相互に離間した１組の給電端
子対により直流電流を印加し、該給電端子対の間におい
て１組または複数組の電位差測定端子対を設けて電位差
を測定し、該電位差から欠陥の形状を検出する方法にお
いて、き裂が発生する恐れのある構造物の表面に給電端
子と電位差測定端子を兼用する端子をマトリクス状に配
置し、給電する端子と電位差を測定する端子を切り換え
検査方法を使用することにより達成される。The above purpose is to apply a direct current to the surface of a member through a pair of power supply terminals spaced apart from each other, and to measure the potential difference by providing one or more pairs of potential difference measuring terminals between the pair of power supply terminals. In this method of detecting the shape of a defect from the potential difference, terminals that serve both as power supply terminals and potential difference measurement terminals are arranged in a matrix on the surface of a structure where cracks may occur, and the potential difference with the power supply terminals is measured. This is accomplished by switching terminals and using testing methods.
被検体面の電位差分布を測定するために、給電と電位差
測定を兼用する端子を配管の外面にマトリクス状に配置
して、給電端子と電位差測定端子を切り換えることによ
り配管外面の軸方向と局方向の電位差分布を測定して表
面き裂形状を精度良く判定できる。In order to measure the potential difference distribution on the surface of the specimen, terminals that serve both for power supply and potential difference measurement are arranged in a matrix on the outside surface of the pipe, and by switching between the power supply terminal and the potential difference measurement terminal, the axial and local directions of the outside surface of the pipe can be measured. By measuring the potential difference distribution, the surface crack shape can be determined with high accuracy.
以下、本発明の一実施例を説明する。第１図は本発明の
配管のき要監視装置の一実施例を示すもので、第２図は
配管のき要監視装置の制御・測定・演算システムの系統
図である。３はコンピュータ、４はデータやプログラム
を記憶させるためのハードディスク等の外部記憶装置、
２はＣＲＴである。コンピュータ３はインターフェース
５やＧＰ−ＩＢインターフェース６を介して計測装置を
制御したり、測定値を取り込んで処理し、結果隔で直流
電流供給用と電位差測定用を兼用した端子２０がスポッ
ト溶接等により取り付けである。An embodiment of the present invention will be described below. FIG. 1 shows an embodiment of the piping monitoring device of the present invention, and FIG. 2 is a system diagram of the control, measurement, and calculation system of the piping monitoring device. 3 is a computer; 4 is an external storage device such as a hard disk for storing data and programs;
2 is a CRT. The computer 3 controls the measuring device via the interface 5 and the GP-IB interface 6, takes in and processes the measured values, and at each result interval, the terminal 20, which serves both for DC current supply and potential difference measurement, is connected by spot welding or the like. It is installation.
端子２０は通常は耐酸化性材料であるＳ Ｕ Ｓ ３０
４やＳＵＳ ３１６、あるいはＮｉ等の細線を使用する
。端子２０は第１図には示してないが、保温材の内側に
設けた通路を通して保温材の外に導き、１本のケーブル
２１に纏めて測定装置に接続される。この場合、端子２
０は配線途中で配管１や端子同士とは絶縁されていなけ
ればならないので、短い碍子管の仲を通すとか、端子表
面を絶縁物で被覆しなければならない、端子２０を保温
材の外側で束ねて１本のケーブル内に収めても良いが、
保温材の外側では温度が低いので、通常の多芯ケーブル
と接続した方が良い、なお、端子２０は全て給電端子切
り換え用マルチプレクサ−９と２個の電位差測定端子切
り換え用マルチプレクサ−１０，１１の３個のマルチプ
レクサ−に接続され、−ノ
流はコンピュータ３により、インターフェース５を介し
て制御される電流極性変換装置８により、その極性を切
り換えられてマルチプレクサ−９に供給され、更に電流
供給先が振り分けられて特定の端子２０に電流が供給さ
れる。多数の端子２０の間の電位差は１台、または２台
のマルチプレクサ−１０，１１により測定する端子を切
り換えられて微小電位差計１２に接続されて測定される
。Terminal 20 is typically an oxidation resistant material SUS 30
Use a thin wire such as 4, SUS 316, or Ni. Although the terminals 20 are not shown in FIG. 1, they are led out of the heat insulating material through a passage provided inside the heat insulating material, and are connected together to a single cable 21 to a measuring device. In this case, terminal 2
0 must be insulated from the piping 1 and the terminals during the wiring, so it is necessary to pass it through a short insulator tube, cover the terminal surface with an insulating material, or bundle the terminals 20 outside of the insulation material. It is also possible to fit it into one cable, but
Since the temperature outside the insulation material is low, it is better to connect it with a normal multi-core cable. Note that all terminals 20 are connected to the multiplexer 9 for switching the power supply terminal and the multiplexers 10 and 11 for switching the two potential difference measurement terminals. The current is connected to three multiplexers, the polarity of which is switched by a current polarity converter 8 controlled by the computer 3 via the interface 5, and then supplied to the multiplexer 9. Current is distributed and supplied to specific terminals 20 . The potential difference between the many terminals 20 is measured by switching the terminals to be measured using one or two multiplexers 10 and 11 and connecting them to the minute potentiometer 12.
測定された電位差はＧＰ−ＩＢゼインーフェース６を介
してコンピュータ３に転送される。コンピュータ３は後
述の方法により配管の軸方向１周方向の電位差分布より
き裂の形状を判定する。ここで、マルチプレクサ−９，
１０，１１および微小電位差計１２はＧＰ−ＩＢゼイン
ーフェース６あるいはインターフェース５を介してコン
ピュータ３により制御されるものである。The measured potential difference is transferred to the computer 3 via the GP-IB zein interface 6. The computer 3 determines the shape of the crack from the potential difference distribution in one circumferential direction in the axial direction of the pipe using a method described later. Here, multiplexer 9,
10, 11 and the micropotentiometer 12 are controlled by the computer 3 via the GP-IB Zein interface 6 or interface 5.
第３図には配管外面における端子２０の配置の展開図を
、第４図には軸方向断面を示す、一般に原子カプラント
や化学プラントにおける欠陥は応力腐食割れや腐食疲労
によるものである。応力腐食割れは溶接部近傍の引張残
留応力が存在するところに発生し、腐食疲労は残留応力
に加えて形状が不連続である溶接金属のルート部に発生
する。FIG. 3 shows a developed view of the arrangement of the terminals 20 on the outer surface of the pipe, and FIG. 4 shows an axial cross section.Generally, defects in atomic couplants and chemical plants are caused by stress corrosion cracking and corrosion fatigue. Stress corrosion cracking occurs where tensile residual stress exists near the weld, and corrosion fatigue occurs at the root of the weld metal, which is discontinuous in shape in addition to residual stress.
そのため、端子２０の配置としては溶接部近傍というこ
とになる。応力腐食割れは溶接熱影響部の周方向に発生
するが、稀に周方向に対して傾いて発生することがある
６本発明のポテンシャル法による欠陥形状検出において
はできれば欠陥に対して垂直に電場を形成し、欠陥をは
さんで電位差分布を測定しなければならない、しかし、
オンラインで端子を固定して電位差分布を測定する場合
、き裂がどの方向に発生するかは予測できないので、端
子２０の配置としては周方向および軸方向の両方向の電
位差分布を測定できるようなものとしなければならない
、その１つの方法が第３図、第４図に示した端子配置で
ある。第３図では端子の位置だけが示してある。前述の
ようにき裂は溶接熱影響部付近に発生するので、この領
域をカバーするように端子２０を軸方向に等間隔で配置
する。Therefore, the terminal 20 is placed near the welding part. Stress corrosion cracking occurs in the circumferential direction of the weld heat-affected zone, but in rare cases it may occur at an angle to the circumferential direction.6 When detecting defect shapes using the potential method of the present invention, the electric field should preferably be perpendicular to the defect. However, the potential difference distribution must be measured across the defect.
When measuring the potential difference distribution online with the terminal fixed, it is impossible to predict in which direction a crack will occur, so the terminal 20 should be arranged in such a way that the potential difference distribution can be measured in both the circumferential and axial directions. One method for achieving this is the terminal arrangement shown in FIGS. 3 and 4. In FIG. 3, only the positions of the terminals are shown. As described above, since cracks occur near the weld heat affected zone, the terminals 20 are arranged at equal intervals in the axial direction so as to cover this region.
同じように周方向にも全周に渡って端子２０を等間隔で
配置する。即ち、端子２０をマトリクス状？に配置する
。このとき軸方向の配置においては両こ、端の端子は給
電端子としてしか使用しないので。Similarly, the terminals 20 are arranged at equal intervals in the circumferential direction over the entire circumference. In other words, are the terminals 20 arranged in a matrix? Place it in At this time, in the axial direction, the terminals at both ends are used only as power supply terminals.
電場を均一にして測定するために隣の端子とは配管の板
厚以上の間隔を置いて設置した方が良い。In order to make measurements with a uniform electric field, it is better to install the terminal with a distance equal to or greater than the thickness of the pipe from adjacent terminals.
第４図では溶接金属１９の上にも端子２０が配置してあ
るが、溶接金属１９にき裂が発生することはないので、
ここには配置しなくとも良い、また、原子カプラントの
配管の場合、定期検査時に超音波探傷でき裂が発見され
ても、き裂が小さい場合には補修されることなく、継続
して使用されることがある。破壊力学的手法によりき裂
の進展予測がなされており、き裂が大きく進展すること
はないが、しかし、より安全性を高めるということで本
方法によりき裂を監視して行く場合にはき裂の周辺にだ
け端子２０を配置すれば良い。In FIG. 4, the terminal 20 is also placed on the weld metal 19, but since no cracks will occur in the weld metal 19,
In addition, in the case of atomic couplant piping, even if cracks are discovered by ultrasonic testing during periodic inspections, if the cracks are small, they may not be repaired and may continue to be used. Sometimes. Crack growth is predicted using a fracture mechanics method, and cracks do not grow significantly. It is sufficient to arrange the terminals 20 only around the fissure.
電位差分布測定のフローチャートを第５図に示す、初め
に、マルチプレクサ−９を制御することにより配管の軸
方向の両端の給電専用の端子に直流電流を供給し、配管
の軸方向の電場を形成する。The flowchart of potential difference distribution measurement is shown in Figure 5. First, by controlling the multiplexer 9, a DC current is supplied to the terminals dedicated to power supply at both ends of the pipe in the axial direction, thereby forming an electric field in the axial direction of the pipe. .
次に、多数の端子間の電位差の測定である。まず、軸方
向に隣り合った端子間の電位差をマルチプレクサ−１０
，１１により端子を切り換えて測定する０次に周方向に
隣り合った端子間の電位差を測定する。軸方向と周方向
の電位差を１回測定すると、電流極性変換装置ｉｔ８に
より直流電流の極性を切り換えて、再び軸方向と周方向
の電位差を測定する０次に、給電用のマルチプレクサ−
９を切り換えて周方向に電場を形成する０例えば、第６
図に周方向の一断面における端子配列を示したが、初め
に１８０度向いあったＡとＣの端子から直流電流を供給
する。給電端子の周辺では電位低下が顕著で、電場が均
一でないので、電位差を測定しても意味がない、そのた
め、電位差としては第６図に示す例えば■■■■■■１
３ １４ Ｉｓ １６１７ １８の端子間の電位差
を測定する０次にＡ。Next is the measurement of potential differences between multiple terminals. First, the potential difference between terminals adjacent in the axial direction is determined by the multiplexer 10.
, 11 to measure the potential difference between terminals adjacent in the circumferential direction. Once the potential difference between the axial direction and the circumferential direction is measured, the polarity of the DC current is switched by the current polarity converter IT8, and the potential difference between the axial direction and the circumferential direction is measured again.
9 to form an electric field in the circumferential direction. For example, the 6th
The figure shows the terminal arrangement in one section in the circumferential direction, and DC current is first supplied from terminals A and C, which face each other 180 degrees. There is a significant potential drop around the power supply terminal, and the electric field is not uniform, so there is no point in measuring the potential difference.Therefore, the potential difference is as shown in Figure 6, for example, ■■■■■■1
3 14 Is 1617 0th order A that measures the potential difference between the 18 terminals.
Ｃの両端子付近の電位差を測定するために、Ａ。To measure the potential difference near both terminals of A.
Ｃの端子とは９０度離れたＢとＤの端子から直流−電流
を供給し、■■■＠ １１ １２ １９ ２０の端子部
の電位差を測定する。この場合にも供給する直流電流の
極性を変えて、十の電流を流したとき、−の電流を流し
たときの２回測定したものの振幅で評価する。このよう
に給電端子を切り換えることにより均一な電場における
周方向全体の電位差分布を測定することが可能である。Direct current is supplied from the terminals B and D, which are 90 degrees apart from the terminal C, and the potential difference between the terminals at ■■■@11 12 19 20 is measured. In this case as well, the polarity of the supplied DC current is changed, and the amplitude is evaluated by measuring the amplitude twice: when a current of 10 is passed and when a current of - is passed. By switching the power supply terminals in this way, it is possible to measure the potential difference distribution in the entire circumferential direction in a uniform electric field.
測定された電位差はＧＰ−ＩＢインターフェース６を通
じてコンピュータ３に転送され、データ処理される。電
位差分布測定結果に基づき、き裂の形状を判定し、判定
されたき裂の形状をコンピュータ３のＣＲＴ画面上に表
示すると共に、プリンタに結果、およびき製形状のハー
ドコピーを出力させる。The measured potential difference is transferred to the computer 3 through the GP-IB interface 6 and data processed. The shape of the crack is determined based on the potential difference distribution measurement result, and the determined shape of the crack is displayed on the CRT screen of the computer 3, and the printer is caused to output the result and a hard copy of the formed shape.
軸方向と周方向の２方向に電流を流す理由は前述した通
りであるが、以下に詳細を記す、今、き裂が配管の軸方
向に平行に入っている場合、軸方向に電流を流しても電
場は軸方向であるので電場はき裂によって乱されること
はないので、測定される電位差分布はき裂がない場合と
全く同じとなり、き裂はないと判定されてしまうことに
なる。The reason for passing current in two directions, the axial direction and the circumferential direction, is as mentioned above, but the details are as follows.If the crack is parallel to the axial direction of the pipe, then the current is passed in the axial direction. However, since the electric field is in the axial direction, the electric field is not disturbed by the crack, so the measured potential difference distribution will be exactly the same as when there is no crack, and it will be determined that there is no crack. .
ところが、そのような配管の軸方向のき裂に対して周方
向に電流を流すと、周方向電場はき裂によって大きく乱
されるため電位差分布が生じ、そのニ
・電位差分布の乱れ方からき裂の大きさを判定するこ・
ことができる、もし、き裂が配管の軸方向、および周方
向の両方向に対して傾いて発生した場合には両方向から
電流を流して測定された電位差分布からその傾きを含め
て形状を判定することが可能である。However, when a current is passed in the circumferential direction through such an axial crack in the pipe, the circumferential electric field is greatly disturbed by the crack, resulting in a potential difference distribution. If a crack occurs at an angle to both the axial and circumferential directions of the pipe, the size of the crack can be determined from the potential difference distribution measured by passing current from both directions. It is possible to determine the shape including the inclination.
今、軸方向に電流を流しているとき、き裂が配管に発生
していなければ、測定される電位差は軸方向の端子間の
電位差は一定であり、周方向の端子間の電位差は零であ
る。き裂が周方向に発生すると電流はき裂の先端を迂回
して流れるので、配管の外側の方では電流密度が高くな
り、き裂をはさむ軸方向の端子間の電位差はき裂のない
所の端子間の電位差よりも大きい値を取るようになる。Now, when current is flowing in the axial direction, if no cracks occur in the piping, the measured potential difference is that the potential difference between the terminals in the axial direction is constant, and the potential difference between the terminals in the circumferential direction is zero. be. When a crack occurs in the circumferential direction, the current flows around the tip of the crack, so the current density is higher on the outside of the pipe, and the potential difference between the terminals in the axial direction that sandwiches the crack is lower than that in the area where there is no crack. It takes on a value larger than the potential difference between the terminals.
同時にき裂に平行な方向には電位分布が生じるので、周
方向の端子間の電位差は零より大きくなる。At the same time, a potential distribution occurs in the direction parallel to the crack, so the potential difference between the terminals in the circumferential direction becomes larger than zero.
従って、単純にはき裂がないところの電位差を基準電位
差として電位差比が１．０ よりも大きくなった端子間
の間にき裂があると判断され、き裂の発生位置と形状が
電位差分布から判定することが警能である。また、周方
向の電位差が零より大きい端子間にほぼ平行にき裂があ
ると判断され、軸方向の隣の端子間の電位差との比較に
より、上流側の周方向の端子間の電位差が大きければ、
下流側にき裂があると判断され、下流側の端子間の電位
差が大きければ、上流側にき裂があると判断される。た
だし、もしき裂が軸方向に対して傾いている場合には電
位差比が１よりも大きくなっている端子間の中央を結ん
だ所にき裂があると判断される。第７図にき裂位置の判
定方法を示す、第７図で０印は端子２０の位置を示し、
実線はき裂位置を示している。軸方向に電場を加えて電
位差分布を測定すると、き裂をはさむ端子間の電位差が
最も大きくなる。その端子間のどの位置にき裂があるか
は不明であるから、仮にその中央にあるとすると、０印
で示した位置となる０次に、周方向に電場を加えると同
様に◇印の位置にあると判定される００印と◇印の両方
を結んだ結果を破線で示した。第７図では２例を示した
が、いずれの場合も実際のき裂位置と電位差分布から判
定されるき裂位置は大略一致する。Therefore, it is determined that there is a crack between the terminals where the potential difference ratio is greater than 1.0, using the potential difference where there is no crack as the reference potential difference, and the location and shape of the crack are determined by the potential difference distribution. Judging from this is a matter of wisdom. In addition, it is determined that there is a nearly parallel crack between the terminals where the potential difference in the circumferential direction is greater than zero, and a comparison with the potential difference between the adjacent terminals in the axial direction shows that the potential difference between the upstream terminals in the circumferential direction is large. Ba,
It is determined that there is a crack on the downstream side, and if the potential difference between the terminals on the downstream side is large, it is determined that there is a crack on the upstream side. However, if the crack is inclined with respect to the axial direction, it is determined that the crack exists at the point where the center of the terminals where the potential difference ratio is greater than 1 is connected. Fig. 7 shows a method for determining the crack position. In Fig. 7, the 0 mark indicates the position of the terminal 20,
The solid line indicates the crack position. When measuring the potential difference distribution by applying an electric field in the axial direction, the potential difference between the terminals that sandwich the crack becomes the largest. It is unknown where the crack is between the terminals, so if it is in the center, it will be at the position indicated by the 0 mark.If an electric field is applied in the circumferential direction, it will be the same as the ◇ mark. The broken line shows the result of connecting both the 00 mark and the ◇ mark, which are determined to be in position. Two examples are shown in FIG. 7, and in both cases, the actual crack position and the crack position determined from the potential difference distribution approximately match.
き裂に沿った電位差分布からのき製形状決定方法を以下
に示す１表面き裂形状決定法のフローチャートを第８図
に示す、予め、汎用大型計算機により各種アスペクト比
、例えば、ａ ／ ｏ ＝ ｌ 、 ＯｅＯ，５，０，
２５，０，１のき裂について電場を解祈し、き裂と反対
側の表面のき表面に垂直な方向の電位差分布をコンピュ
ータ３の記憶装置、または外部記憶装置４に記憶させて
おく、記憶させる電位差分布の一例としてアスペクト比
ａ ／ ｃ ＝０．５ の各き裂深さに対する電位差分
布を第９図に示す、第８図は板厚ｔ＝２０−の平板の中
央にき裂がある場合についてＦＥＭにより電場を解析し
て得られたものである。板厚ｔで基準化したき裂の深さ
ａ ／ ｔはき裂中央の最深点で０ 、０．１２５゜０
．２５ 、０．３７５．０．５ 、０．６２５および０
．７５である。き裂がない（ａ ／ ｔ ＝ Ｏ）の場
合には電位１− ａる場合にはき裂から離れるにつれて
電位差は段々大きくなり、ある程度前れると電位差増分
はほぼ一定である。これらの電位差分布はｎ次近似して
コンピュータ３、または外部記憶装置４に記憶させてお
く、き製形状決定に当たっては最初に測定されたき裂周
辺の電位差分布から表面き裂長さ２ｃ拳と最大電位差比
Ｖ ／ Ｖｏｍ ａ ｘ を求める。The method for determining the forged shape from the potential difference distribution along the crack is shown below.1 The flowchart of the method for determining the surface crack shape is shown in Figure 8. Various aspect ratios, e.g., a/o = l, OeO,5,0,
25,0,1 cracks, and store the potential difference distribution in the direction perpendicular to the cracked surface on the surface opposite to the crack in the storage device of the computer 3 or the external storage device 4; As an example of the potential difference distribution to be memorized, the potential difference distribution for each crack depth with an aspect ratio a/c = 0.5 is shown in Figure 9. Figure 8 shows a case where a crack is in the center of a flat plate with a thickness t = 20-. This was obtained by analyzing the electric field using FEM for a certain case. The crack depth a/t standardized by plate thickness t is 0 at the deepest point at the center of the crack, 0.125°0.
．． 25, 0.375, 0.5, 0.625 and 0
．． It is 75. When there is no crack (a/t=O), the potential difference is 1-a, and the potential difference gradually increases as the distance from the crack increases, and after a certain distance, the potential difference increment remains almost constant. These potential difference distributions are approximated to the nth order and stored in the computer 3 or external storage device 4. When determining the forging shape, the surface crack length 2c and the maximum potential difference are determined from the first measured potential difference distribution around the crack. Find the ratio V/Voma x.
−例として第１０図にＦＥＭで電場を解析して得もれた
き裂周辺での電位差比分布を示す、き裂のアスペクト比
はａ ／ ｏ ＝ ０ 、２５、最大き裂深さはａ＝１
２．５■（ａ ／ ｔ ＝０．６２５）である、き裂が
ないところでは電位差はほぼ一定であり、そのような箇
所の電位差を基準電位差として電位差比分布を示してあ
る。き裂のあるところでは電位差は大きくなっており、
この部分の電位差分布をｎ次近似する。近似曲線からき
裂の最深点に対応する最大の電位差比Ｖ ／ Ｖ ｏｍ
ａｘを決定する。第１０図の場合にはＶ ／ Ｖｏｍａ
ｘ＝ １ 、３０ が得られた。き裂と反対側の表面
における電位差分布においてはき裂先端近傍では緩やか
に電位差が増えるため、き裂の先端を特定することは困
難である０種々のアスペクト比のき裂について電位差分
布とき裂先端位置との関係を調べた結果、最大電位差比
ＶＺＶｏ■ａＸのピークの約０．１５付近にき裂先端が
あることが分かった。第１０図ではＶ ／ Ｖ ｏｌｌ
ａＸ ＝１．３０ であるノテ、Ｖ ／ Ｖ ｏ ＝
１ ＋ ０ 、３ ＸＯ，１５＝１．０４５と、４次近
似曲線との交点から表面におけるき裂長さ２ｃ傘を求め
ると、２ｃ＝１１０ｍが得られる。- As an example, Figure 10 shows the potential difference ratio distribution around the crack obtained by analyzing the electric field using FEM.The aspect ratio of the crack is a/o = 0, 25, and the maximum crack depth is a = 1
2.5 (a/t = 0.625), where there is no crack, the potential difference is almost constant, and the potential difference ratio distribution is shown using the potential difference at such a location as the reference potential difference. The potential difference is large where there is a crack,
The potential difference distribution in this part is approximated to the nth order. From the approximate curve, the maximum potential difference ratio V/V om corresponding to the deepest point of the crack
Determine ax. In the case of Figure 10, V/Voma
x=1,30 was obtained. In the potential difference distribution on the surface opposite to the crack, the potential difference increases gradually near the crack tip, so it is difficult to identify the crack tip.0 Potential difference distribution and crack tip for cracks with various aspect ratios As a result of examining the relationship with position, it was found that the crack tip was located around 0.15 of the peak of the maximum potential difference ratio VZVo*aX. In Figure 10, V / V oll
Note that aX = 1.30, V / V o =
If the crack length 2c at the surface is determined from the intersection of 1 + 0, 3
次に、第９図に示した電位差分布から各種アスペクト比
ａ ／ ｏのき裂に対する電位差比Ｖ ／ Ｖ 。Next, from the potential difference distribution shown in FIG. 9, the potential difference ratio V/V for cracks with various aspect ratios a/o is determined.
とき裂深さａ ／ ｔの関係を作成するために電位差比
Ｖ ／ Ｖ ｏとアスペクト比ａ ／ ｃの関係を作成
する。この場合、ＦＥＭによる電場解析では板厚ｔ＝２
０ｍの平板について解析しているので、測定端子間距離
ｄに対応した測定位ｒＩｌｄ傘における電位差比Ｖ ／
Ｖ ｏとアスペクト比ａ ／ ｃの関係を作成しなけ
ればならない、従って、被測定部材の板厚ｔ−で補正さ
れたｄ 嘲＝ｄ Ｘ ２Ｑ ／ を串の位置の各き裂深
さａ ／ ｔに対する電位差を求めて電位差比Ｖ ／
Ｖ ｏとアスペクト比ａ ／ Ｏの関係を第１１図のよ
うに作成する。電位差比Ｖ ／ Ｖ ｏとアスペクト比
ａ ／ Ｏの関係は各き裂深さａ ／ を毎にｎ次近似
してコンピュータ３の記憶袋Ｍ４に記憶させる０次に、
を位差比Ｖ ／ Ｖ ｏとアスペクト比ａ ／ Ｃの関
係を用いてアスペクト比ａ ／ ｏ ＝０．５に対する
電位差比Ｖ ／ Ｖ ｏとき裂深さａ ／ ｔの関係の
マスターカーブを第１２図のように作成する。In order to create the relationship between the crack depth a/t, the relationship between the potential difference ratio V/Vo and the aspect ratio a/c is created. In this case, in the electric field analysis using FEM, the plate thickness t=2
Since we are analyzing a flat plate of 0 m, the potential difference ratio V / at the measurement position rIld corresponding to the distance d between the measurement terminals is
A relationship between Vo and the aspect ratio a/c must be created. Therefore, d = d x 2Q / corrected by the plate thickness t of the member to be measured is calculated as each crack depth a / at the skewer position. Find the potential difference with respect to t and calculate the potential difference ratio V /
The relationship between Vo and the aspect ratio a/O is created as shown in FIG. The relationship between the potential difference ratio V/Vo and the aspect ratio a/O is determined by approximating each crack depth a/to the nth order and storing it in the memory bag M4 of the computer 3.
Using the relationship between the phase difference ratio V/Vo and the aspect ratio a/C, the master curve of the relationship between the potential difference ratio V/Vo and the crack depth a/t for the aspect ratio a/o = 0.5 is calculated as the 12th Create as shown.
二の場合にも電位差比Ｖ ／ Ｖ ｏとき裂深さａ ／
ｔの関係はｎ次近似、例えば、５次近似する。このマ
スターカーブに電位差分布を４次近似して得られた最大
電位差比Ｖ／Ｖｏｍａｘ を代入してき裂深さＢｓａを
求める０次で、板厚補正した表面き裂長さ２ｃ・（＝＝
２ｃＸ２０／ｌ＊）によりき裂のアスペクト比ａ拳／Ｃ
串を求め、マスターカーブのアスペクト比ａ ／ ｏと
比較する０両者が一致していなければ、改めて電位差比
Ｖ ／ Ｖ ｏとアスペクト比ａ ／ ｏの関係を用い
てアスペクト比ａ ／ 。In the second case, the potential difference ratio V/V o and the crack depth a/
The relationship of t is approximated to the nth order, for example, to the fifth order. By substituting the maximum potential difference ratio V/Vomax obtained by fourth-order approximation of the potential difference distribution into this master curve, the crack depth Bsa is determined. The surface crack length 2c (==
2cX20/l*), the aspect ratio of the crack is a fist/C
Find the skewer and compare it with the aspect ratio a/o of the master curve. If the two do not match, calculate the aspect ratio a/o again using the relationship between the potential difference ratio V/Vo and the aspect ratio a/o.
’＝ ６ 串／ ｏ拳に対する電位差比Ｖ ／ Ｖ ｏ
とき裂深さａ ／ ｔの関係のマスターカーブを作成し
、最大電位差比Ｖ／Ｖｏｍａｘ を代入してき裂深さ
ａ拳を求める。この作業を両者が一致するまで、例えば
、ｉ ／ ｏとａ＊１０串の差が０．０１以下となるま
で繰り返す、一致したときのアスペクト比に対する電位
差比Ｖ ／ Ｖ ｏとき裂深さａ ／ ｔの関係のマス
ターカーブに各測定位置における電位差比を代入するこ
とによりき裂全体の形状を決定するものである。この場
合電位差比は各測定位置における電位差比を代入しても
良いし、ｎ次近似した電位差比分布を代入しても良い。'= 6 Skewer/o Potential difference ratio for fist V/Vo
A master curve of the relationship between crack depth a/t is created, and the maximum potential difference ratio V/Vomax is substituted to find the crack depth a. Repeat this process until the two match, for example, until the difference between i/o and a*10 is 0.01 or less. When they match, the potential difference ratio to the aspect ratio V/Vo and the crack depth a/ The shape of the entire crack is determined by substituting the potential difference ratio at each measurement position into the master curve of the relationship t. In this case, the potential difference ratio at each measurement position may be substituted for the potential difference ratio, or an nth-order approximated potential difference ratio distribution may be substituted.
第１０図に示したき裂周辺の電位差分布について具体的
に計算した結果を示す、板厚はｔ拳＝２０．０ｍであり
、測定端子間距離はｄ＝２０ｍであるので、ｄ傘＝ｄＸ
２０／を拳＝２０−の位置における各アスペクト比の各
き裂深さに対する電位差を求める。但し、き裂が測定端
子の中央に来るようにして電位差を測定しているので、
２＝ｄａ／２＝１０−の位置の電位差を求め、第１１図
のような電位差比Ｖ ／ Ｖ ｏとアスペクト比ａ／Ｃ
の関係を作成する。これらの関係を用いて第１２図に示
すようにアスペクト比ａ／ａ＝０．５に対する電位差比
Ｖ ／ Ｖ ｏとき裂深さａ ／ ｔの関係のマスター
カーブを作成する。このカーブに最大電位差比Ｖ／Ｖｏ
ｍａｘ＝＝１．３０を代入すると、ａｍ／ｌ＋＝０．７
６となり、ａ−＝１５．２閣が得られる＋＋ ２ｏ＊＝
＋１１０ｍｍよりき裂の７スペクト比はａ・／Ｃ拳＝＝
１５．２１５５＝０．２７６となる。そこで、次にａ
／ ｃ ＝ ０ 、２７６ に対するマスターカーブ
を作成してき裂深さを求めると、ａ””１２．８６ｍｍ
が得られ、ａ拳／Ｃ拳＝０．２３４となる。再び、ａ／
ｃ＝０．２３４ に対するマスターカーブを作成して
き裂深さを求めると、ａ傘＝１２．４閣が得られ、ａ傘
／Ｃ嘲＝０．２２５となり、更に、ａ１０＝０．２２５
に対するマスターカーブを作成してき裂深さを求め
ると、ａ＊；１２．３■が得られ、ａ傘／Ｃ拳＝０．２
２４となり、アスペクト比がほぼ一致する。このように
して求めた表面き裂形状と解析で使用したき裂形状との
対応を第１３図に示す０表面のき裂先端近傍の精度は多
少悪いが、そこを除けば非常に良く一致している。Figure 10 shows the results of specific calculations of the potential difference distribution around the crack.The plate thickness is t=20.0m, and the distance between the measurement terminals is d=20m, so d=dX
Find the potential difference for each crack depth for each aspect ratio at the position where 20/ is fist = 20-. However, since the potential difference is measured with the crack located at the center of the measurement terminal,
Find the potential difference at the position of 2=da/2=10-, and calculate the potential difference ratio V/Vo and aspect ratio a/C as shown in Figure 11.
Create a relationship. Using these relationships, a master curve of the relationship between the potential difference ratio V/Vo and the crack depth a/t for the aspect ratio a/a=0.5 is created as shown in FIG. This curve shows the maximum potential difference ratio V/Vo
By substituting max==1.30, am/l+=0.7
6, and a-=15.2 cabinets are obtained++ 2o*=
From +110mm, the 7spect ratio of the crack is a・/C fist==
15.2155=0.276. Therefore, next a
/ c = 0, 276 Create a master curve and find the crack depth, a""12.86mm
is obtained, and a fist/c fist=0.234. Again, a/
When we create a master curve for c=0.234 and find the crack depth, we get a=12.4, a=0.225, and a10=0.225.
By creating a master curve for and finding the crack depth, a *; 12.3 ■ is obtained, and a umbrella/C fist = 0.2
24, and the aspect ratios are almost the same. Figure 13 shows the correspondence between the surface crack shape obtained in this way and the crack shape used in the analysis.The accuracy near the crack tip on the 0 surface is somewhat poor, but apart from that, they match very well. ing.
直Ｓある場合に適用できるものであって、第７図のよう
に傾いているき裂に対してはそのまま適用できない、そ
のような場合には第７図の０印と◇印の各点の座標点を
最小自乗法により直線近似して垂直方向に対する角度を
求めると共に１両端座標からき裂長さ２ｏ・を求める。This can be applied when there is a straight S, but it cannot be applied directly to a crack that is tilted as shown in Figure 7. In such a case, the points marked 0 and ◇ in Figure 7 should be applied. The coordinate points are linearly approximated by the method of least squares to find the angle with respect to the vertical direction, and the crack length 2o is found from the coordinates at both ends.
この時、き裂の法線方向と電場方向とのなす角度をｅと
すると、電位差比Ｖ／Ｖｏ’ はき裂が電場に対して
直角にあるときの電位差比Ｖ ／ Ｖ ｏよりも小さく
なり、第一次近似としてはＶ／Ｖｏ’ ＝Ｖ／Ｖｏ−
ｃｏｓθとなる。従って、上述の方法でき裂形状を求め
る場合には測定された電位差比Ｖ ／ Ｖ ｏ ’
をｅで補正してＶ／Ｖｏ ＝＝Ｖ／Ｖｏ’ ／ｃｏｓθ
により評価することが必要である。ただし、θが４５’
を超えると精度が悪くなるので、θが４５′よりも小さ
い方の電場についての測定値を使って判定する方が良い
。At this time, if the angle between the normal direction of the crack and the direction of the electric field is e, the potential difference ratio V/Vo' is smaller than the potential difference ratio V/Vo when the crack is perpendicular to the electric field. , as a first approximation, V/Vo' = V/Vo-
It becomes cos θ. Therefore, when determining the crack shape using the above method, the measured potential difference ratio V/V o'
Corrected by e, V/Vo ==V/Vo'/cosθ
It is necessary to evaluate the However, θ is 45'
If the value exceeds 45', the accuracy deteriorates, so it is better to make a determination using the measured value for the electric field where θ is smaller than 45'.
以上述べたように本発明の配管のき裂監視装置に、よれ
ば、被検体面の検査部周辺に一方向と他方！
向に共に等間隔でマトリクス状に配置した測定端子によ
り、被検体の両方向の電位差分布を測定することにより
き裂の位置および形状の検出ができるので、被検体の健
全性を精度良く検査することが可能である。As described above, according to the piping crack monitoring device of the present invention, cracks can be detected in one direction and in the other direction around the inspection part on the surface of the object to be inspected. The position and shape of cracks can be detected by measuring the potential difference distribution in both directions of the test object using measurement terminals arranged in a matrix at equal intervals in both directions, allowing accurate inspection of the health of the test object. is possible.
第１図は本発明による配管のき裂監視装置の外観図、第
２図は第１図のき裂監視装置のシステム系統図、第３図
と第４図は第１図の装置の端子の配置を示す図、第５図
は本発明による電位差分布測定のフローチャート図、第
６図は本発明による周方向の電位差分布測定の場合の給
電端子と測定端子の位置を示す図、第７図は本発明によ
るき袋位置の判定方法を示す図、第８図は本発明による
き裂形状の判定方法のフローチャート、第９図は本発明
のＦＥＭで得られたき裂部材のき裂と反対側の表面にお
ける電位差分布の一例を示すグラフ図、第１０図は本発
明のＦＥＭで得られたき裂部材のき裂と反対側の表面に
おけるき裂周辺の電位差分布グラフ図、第１１図は本発
明による電位差比とアスペクト比の関係の一例を示すグ
ラフ図、第１２ｒ！Ａは本発明による電位差比とき裂深
さの関係を示すグラフ図、第１３図は本発明による解析
に使用したき裂形状と判定されたき裂形状との比較を示
す図である。
１・・・配管、２・・・ＣＲＴ、３・・・コンピュータ
ー、４・・・外部記憶装置、５・・・インターフェース
、６・・・ＧＰ−ＩＢインターフェース、７・・・直流
電源、８・・・電流極性変換装置、９・・・給電端子切
り換え用マルチプレクサ−１１０，１１・・・測定端子
切り換え用マルチプレクサ−１１２・・・微小電位差計
、１９・・・溶接金属、２０・・・端子、２１・・・ケ
ーブル。Fig. 1 is an external view of a piping crack monitoring device according to the present invention, Fig. 2 is a system diagram of the crack monitoring device of Fig. 1, and Figs. 3 and 4 are terminal diagrams of the device of Fig. 1. 5 is a flowchart of potential difference distribution measurement according to the present invention, FIG. 6 is a diagram showing the positions of the power supply terminal and measurement terminal in circumferential potential difference distribution measurement according to the present invention, and FIG. Figure 8 is a flowchart of the method for determining the crack shape according to the present invention, and Figure 9 is a diagram showing the method for determining the crack position according to the present invention. A graph showing an example of the potential difference distribution on the surface. FIG. 10 is a graph showing the potential difference distribution around the crack on the surface opposite to the crack of the cracked member obtained by the FEM of the present invention. FIG. 11 is a graph showing an example of the potential difference distribution on the surface. A graph diagram showing an example of the relationship between potential difference ratio and aspect ratio, 12th r! A is a graph showing the relationship between potential difference ratio and crack depth according to the present invention, and FIG. 13 is a diagram showing a comparison between the crack shape used in the analysis according to the present invention and the determined crack shape. DESCRIPTION OF SYMBOLS 1... Piping, 2... CRT, 3... Computer, 4... External storage device, 5... Interface, 6... GP-IB interface, 7... DC power supply, 8... ...Current polarity converter, 9...Multiplexer for switching power supply terminals 110, 11...Multiplexer for switching measurement terminals 112...Minimum potentiometer, 19...Welding metal, 20...Terminal, 21... Cable.
Claims (1)
直流電流を印加し、該給電端子対の間において１組また
は複数組の電位差測定端子対を設けて電位差を測定し、
該電位差から欠陥の形状を検出する方法において、き裂
が発生する恐れのある構造物の表面に給電端子と電位差
測定端子を兼用する端子をマトリクス状に配置し、給電
する端子と電位差を測定する端子を切り換えて電位差分
布を測定することによりき裂の発生位置とき裂の形状を
検出することを特徴とする欠陥検査方法。 ２、特許請求の範囲第１項記載のものにおいて、給電端
子と測定端子を兼用する端子を配管外面に軸方向並びに
周方向に平行となるようにマトリクス状に配置し、軸方
向の両端に配置した周方向の端子列の間に直流電流を印
加し、その中間に配置してある端子間の軸方向に隣り合
う端子間の電位差分布を測定することにより周方向き裂
の位置と形状を検出することを特徴とする欠陥検査方法
。 ３、特許請求の範囲第１項記載のものにおいて、軸方向
に並んだ１組の端子列と、それに対して１８０度離れて
前記端子列と向い合う１組の端子列との間に直流電流を
印加し、端子間の周方向に隣り合う端子間の電位差分布
を測定することにより軸方向き裂の位置と形状を検出す
ることを特徴とする欠陥検査方法。 ４、特許請求の範囲第３項記載のものにおいて、軸方向
に並んだ１組の端子列と、それに対して１８０度離れて
前記端子列と向い合う１組の端子列との間に直流電流を
印加し、直流電流を供給する端子とその隣りの端子との
間の電位差を除いて周方向に隣り合う端子間の電位差分
布を測定し、前記直流電流を供給する端子列とは互いに
９０度離れた２組の端子列の間に直流電流を印加して、
直流電流を供給する端子とその隣りの端子との間の電位
差を除いて周方向に隣り合う端子間の電位差分布を測定
刷ることにより均一な電場における周方向の電位差分布
を測定することにより軸方向き裂の位置と形状を検出す
ることを特徴とする欠陥検査方法。 ５、特許請求の範囲第１項から第４項記載のものにおい
て、軸方向の両端の端子列から直流電流を印加して軸方
向に隣り合う端子間の電位差を測定し、周方向の端子列
の間に直流電流を印加して周方向に隣り合う端子間の電
位差を測定し、軸方向及び周方向の電位差分布から軸方
向あるいは周方向に対して傾いたき裂の形状を検出する
ことを特徴とする欠陥検査方法。[Claims] 1. Direct current is applied to the surface of the member through a pair of power supply terminals spaced apart from each other, and one or more pairs of potential difference measuring terminals are provided between the pair of power supply terminals to measure the potential difference. measure,
In this method of detecting the shape of a defect from the potential difference, terminals that serve both as power supply terminals and potential difference measurement terminals are arranged in a matrix on the surface of a structure where cracks may occur, and the potential difference with the power supply terminals is measured. A defect inspection method characterized by detecting the location and shape of a crack by switching terminals and measuring the potential difference distribution. 2. In the item described in claim 1, terminals that serve as both power supply terminals and measurement terminals are arranged in a matrix on the outer surface of the pipe so as to be parallel to the axial direction and the circumferential direction, and are arranged at both ends in the axial direction. The position and shape of circumferential cracks are detected by applying a direct current between the circumferential terminal rows and measuring the potential difference distribution between axially adjacent terminals placed in the middle. A defect inspection method characterized by: 3. In the device described in claim 1, a direct current is provided between one set of terminal rows arranged in the axial direction and one set of terminal rows facing the terminal row and separated by 180 degrees with respect to the terminal row. A defect inspection method characterized by detecting the position and shape of an axial crack by applying a voltage and measuring the potential difference distribution between circumferentially adjacent terminals. 4. In the item described in claim 3, a direct current is provided between one set of terminal rows arranged in the axial direction and one set of terminal rows facing the terminal row and separated by 180 degrees with respect to the terminal row. is applied, and the potential difference distribution between the terminals adjacent in the circumferential direction is measured, excluding the potential difference between the terminal that supplies the DC current and the terminal next to it, and the row of terminals that supply the DC current are 90 degrees from each other. Applying a direct current between two sets of distant terminal rows,
By measuring the potential difference distribution between circumferentially adjacent terminals, excluding the potential difference between the terminal that supplies direct current and its neighboring terminal, we can measure the potential difference distribution in the circumferential direction in a uniform electric field. A defect inspection method characterized by detecting the position and shape of a crack. 5. In the device described in claims 1 to 4, a direct current is applied from the terminal rows at both ends in the axial direction to measure the potential difference between the terminals adjacent in the axial direction, and the potential difference between the terminal rows in the circumferential direction is measured. A DC current is applied between the terminals to measure the potential difference between circumferentially adjacent terminals, and the shape of a crack that is inclined to the axial or circumferential direction is detected from the potential difference distribution in the axial and circumferential directions. Defect inspection method.
Priority Applications (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24742886A JPH076936B2 (en) | 1986-10-20 | 1986-10-20 | Defect inspection method |
| PCT/JP1987/000789 WO1988002857A1 (en) | 1986-10-20 | 1987-10-16 | Surface defect inspection method and surface defect inspection apparatus |
| DE3751702T DE3751702T2 (en) | 1986-10-20 | 1987-10-16 | METHOD AND APPARATUS FOR EXAMINING SURFACE DEFECTS |
| EP87906780A EP0289615B1 (en) | 1986-10-20 | 1987-10-16 | Surface defect inspection method and surface defect inspection apparatus |
| US07/235,683 US4914378A (en) | 1986-10-20 | 1987-10-16 | Method and apparatus for inspecting surface defects |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24742886A JPH076936B2 (en) | 1986-10-20 | 1986-10-20 | Defect inspection method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS63101742A true JPS63101742A (en) | 1988-05-06 |
| JPH076936B2 JPH076936B2 (en) | 1995-01-30 |
Family
ID=17163291
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP24742886A Expired - Lifetime JPH076936B2 (en) | 1986-10-20 | 1986-10-20 | Defect inspection method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH076936B2 (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005308544A (en) * | 2004-04-21 | 2005-11-04 | Tokyo Electric Power Co Inc:The | Crack development monitoring device and method by potential difference method |
| JP2007003235A (en) * | 2005-06-21 | 2007-01-11 | Atlus:Kk | Non-destructive inspection method of change in wall thickness of measuring target |
| JP2007064817A (en) * | 2005-08-31 | 2007-03-15 | Denshi Jiki Kogyo Kk | Quenching depth measuring instrument |
| JP2008083038A (en) * | 2006-08-30 | 2008-04-10 | Atlus:Kk | Method of detecting damage of structure made of conductive material |
| JP2015087125A (en) * | 2013-10-28 | 2015-05-07 | 三菱日立パワーシステムズ株式会社 | Damage determination device and damage determination method |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007057448A (en) * | 2005-08-26 | 2007-03-08 | Hitachi Ltd | Flaw monitoring device |
| JP5739649B2 (en) * | 2010-11-25 | 2015-06-24 | Ｊｆｅスチール株式会社 | Crack inspection method for pipe welds and crack inspection apparatus for pipe welds |
-
1986
- 1986-10-20 JP JP24742886A patent/JPH076936B2/en not_active Expired - Lifetime
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005308544A (en) * | 2004-04-21 | 2005-11-04 | Tokyo Electric Power Co Inc:The | Crack development monitoring device and method by potential difference method |
| JP2007003235A (en) * | 2005-06-21 | 2007-01-11 | Atlus:Kk | Non-destructive inspection method of change in wall thickness of measuring target |
| JP2007064817A (en) * | 2005-08-31 | 2007-03-15 | Denshi Jiki Kogyo Kk | Quenching depth measuring instrument |
| JP2008083038A (en) * | 2006-08-30 | 2008-04-10 | Atlus:Kk | Method of detecting damage of structure made of conductive material |
| JP2015087125A (en) * | 2013-10-28 | 2015-05-07 | 三菱日立パワーシステムズ株式会社 | Damage determination device and damage determination method |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH076936B2 (en) | 1995-01-30 |
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