JPH09133664A - Ultrasonic flaw detection method - Google Patents
Ultrasonic flaw detection methodInfo
- Publication number
- JPH09133664A JPH09133664A JP28877495A JP28877495A JPH09133664A JP H09133664 A JPH09133664 A JP H09133664A JP 28877495 A JP28877495 A JP 28877495A JP 28877495 A JP28877495 A JP 28877495A JP H09133664 A JPH09133664 A JP H09133664A
- Authority
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- Japan
- Prior art keywords
- inspected
- flaw detection
- ultrasonic flaw
- detection method
- lead
- 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 Ultrasonic Waves (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は超音波探傷法に関
し、特に自動車や機械部品等の凹凸形状を有する小型被
検査物における、傾斜した表面の内部に存在する欠陥の
超音波探傷の際に発生する超音波の反射や屈折による検
出能の低下を防止した超音波探傷法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic flaw detection method, and in particular, it occurs when a flaw existing inside an inclined surface is ultrasonically flaw-detected in a small inspected object having an uneven shape such as an automobile or a mechanical part. The present invention relates to an ultrasonic flaw detection method that prevents a decrease in detectability due to reflection or refraction of ultrasonic waves.
【０００２】[0002]
【従来の技術】超音波探傷法は、パルス状の超音波信号
を探触子を通じて被検査物内に送り込み、内部欠陥部ま
たは底面より反射して戻って来る状況を、ブラウン管上
のパルスエコーの高さや本数として読み取り、欠陥の有
無を判断する。そのため、超音波探傷においては欠陥へ
の超音波の入力およびその減衰を反射や屈折のない状態
で精度よく把握する必要がある。しかし、自動車や機械
部品の小型被検査物においては、その凹凸形状から傾斜
面の下部で材料内部に存在する欠陥を超音波探傷する
際、傾斜表面での反射や屈折が大きいため、超音波を照
射しても部品内部の欠陥に十分到達せず欠陥エコーとし
ての超音波エネルギーが減少して分解能が著しく低下す
る場合があった。2. Description of the Related Art In the ultrasonic flaw detection method, a pulsed ultrasonic signal is sent into an object to be inspected through a probe and reflected by an internal defect or the bottom surface and returned to the inspection object by a pulse echo on a cathode ray tube. The height and the number are read to determine the presence or absence of defects. Therefore, in ultrasonic flaw detection, it is necessary to accurately grasp the input and attenuation of ultrasonic waves to a defect without reflection or refraction. However, in small inspected objects such as automobiles and mechanical parts, when ultrasonic flaw detection is performed on defects existing inside the material at the lower part of the inclined surface due to the uneven shape, ultrasonic waves are generated because the reflection and refraction on the inclined surface are large. In some cases, even if irradiated, the defect inside the component was not sufficiently reached, the ultrasonic energy as a defect echo was reduced, and the resolution was significantly lowered.
【０００３】上記の問題点を解決する超音波探傷技術と
して、例えば特開昭５７−１０８６５９号公報には、内
部に欠陥を有する被探傷物に、ポリエステル樹脂よりな
る中間媒体を流し込み、探傷器で探傷することにより、
表面の粗い被探傷物に対しても、この表面をグラインダ
ー等で表面処理することなく探傷を行うことができる超
音波探傷法が開示されている。As an ultrasonic flaw detection technique for solving the above-mentioned problems, for example, Japanese Patent Laid-Open No. 57-108659 discloses a flaw detector in which an intermediate medium made of polyester resin is poured into an object having a defect inside. By flaw detection,
There is disclosed an ultrasonic flaw detection method capable of performing flaw detection on an object having a rough surface without performing surface treatment on the surface with a grinder or the like.
【０００４】しかし、この技術においても、被探傷物の
表面に凹凸に起因する傾斜部分が存在すると、超音波は
この傾斜部分で反射や屈折する性質があるため、被探傷
物とポリエステル樹脂の界面で反射や屈折が起こる。こ
のとき、反射や屈折の度合が大きいと欠陥の検出能力が
低下する。従来技術では、例えば被探傷物が鋳鋼であ
り、ポリエステル樹脂をコーティングした場合には、反
射や屈折の度合が大きくなり、超音波探傷法による検出
能力の低下は避けられない。以上のような従来技術にお
ける問題点から、被探傷物の表面の凹凸形状の影響を解
消し、超音波の反射や屈折を防止して検出精度を向上し
た超音波探傷方法の開発が望まれていた。However, even in this technique, when an inclined portion due to unevenness exists on the surface of the flaw-detected object, ultrasonic waves have the property of being reflected or refracted at this inclined portion. Reflection and refraction occur. At this time, if the degree of reflection or refraction is large, the defect detection capability is reduced. In the prior art, for example, when the flaw detection object is cast steel and coated with a polyester resin, the degree of reflection and refraction becomes large, and a decrease in detection capability due to the ultrasonic flaw detection method cannot be avoided. From the problems in the conventional techniques as described above, it is desired to develop an ultrasonic flaw detection method that eliminates the influence of the uneven shape of the surface of the flaw detection object and prevents the reflection and refraction of ultrasonic waves to improve the detection accuracy. It was
【０００５】[0005]
【発明が解決しようとする課題】本発明の目的は、上記
の従来技術の問題点に鑑み、超音波の反射や屈折を防止
する方法を検討し、小型でかつ凹凸形状を有する被検査
物の高精度超音波探傷法を提供する。SUMMARY OF THE INVENTION In view of the above problems of the prior art, an object of the present invention is to investigate a method for preventing reflection and refraction of ultrasonic waves, and to make an object to be inspected small and having an uneven shape. Provides a high-precision ultrasonic flaw detection method.
【０００６】また、本発明の他の目的は、凹凸形状の影
響を解消するために、導波物質を中間媒体として介在さ
せ、それらの界面での超音波の反射や屈折の度合を、中
間媒体との音響インピーダンスの差から検討し、その最
適組み合わせによって前記高精度超音波探傷法を提供す
る。さらに、本発明の別の目的は、前記導波物質の中間
媒体の形状および使用方法を検討し、簡便でかつ繰り返
し使用可能な導波体による前記高精度超音波探傷法を提
供する。Another object of the present invention is to interpose a waveguiding material as an intermediate medium in order to eliminate the influence of the uneven shape, and to determine the degree of reflection and refraction of ultrasonic waves at the interface between them. The high-precision ultrasonic flaw detection method is provided by examining the difference in acoustic impedance between the above and the optimum combination. Further, another object of the present invention is to investigate the shape and use method of the intermediate medium of the waveguide material, and provide the high-precision ultrasonic flaw detection method using a waveguide body which is simple and can be repeatedly used.
【０００７】[0007]
【課題を解決するための手段】上記の目的は、表面に凹
凸部を有する被検査物の欠陥を高精度に検出する超音波
探傷法であって、前記被検査物の検査表面が平坦となる
ように、音響インピーダンスの値が前記被検査物と同一
または近似する導波物質によって、前記検査表面を覆う
ことを特徴とする欠陥を高精度に検出する超音波探傷法
によって達成される。The above object is an ultrasonic flaw detection method for detecting a defect of an object to be inspected having an uneven portion on the surface with high accuracy, and the inspection surface of the object to be inspected is flat. As described above, it is achieved by an ultrasonic flaw detection method for detecting a defect, which is characterized by covering the inspection surface with a waveguide material whose acoustic impedance value is the same as or close to that of the inspection object, with high accuracy.
【０００８】また、上記の目的は、前記の高精度に検出
する超音波探傷法において、前記導波物質が固体であ
り、被検査物に対向する面は該被検査物の凹凸部と合致
する凹凸形状を有し、前記導波物質と被検査物を前記凹
凸部で、一体密着を可能となし、かつ超音波の入射面側
表面を平坦に形成することを特徴とする欠陥を高精度に
検出する超音波探傷法によっても達成される。さらに、
上記の目的は、前記の高精度に検出する超音波探傷法に
おいて、前記導波物質が液体であることを特徴とする欠
陥を高精度に検出する超音波探傷法によっても達成され
る。また、上記の目的は、前記の高精度に検出する超音
波探傷法において、前記一体密着の際、前記導波物質と
被検査物との界面に発生する空隙を防止するために、該
界面に軟質材料を介在させ、かつ該軟質材料の音響イン
ピーダンスの値を導波物質の値と同一または近似させる
ことを特徴とする欠陥を高精度に検出する超音波探傷法
によっても達成される。[0008] Further, the above-mentioned object is, in the ultrasonic flaw detection method for detecting with high precision described above, the waveguiding material is solid, and the surface facing the object to be inspected coincides with the uneven portion of the object to be inspected. Highly accurate defects having a concavo-convex shape, capable of integrally adhering the waveguiding material and the object to be inspected at the concavo-convex portion, and forming a flat surface on the incident surface side of ultrasonic waves. It is also achieved by the ultrasonic flaw detection method. further,
The above object is also achieved by the ultrasonic flaw detection method for detecting a defect characterized in that the waveguide material is a liquid, with high precision in the ultrasonic flaw detection method for detecting with high precision. Further, the above-mentioned object is, in the ultrasonic flaw detection method for detecting with high accuracy, in order to prevent voids generated at the interface between the waveguide material and the inspection object at the time of the integral adhesion, It is also achieved by an ultrasonic flaw detection method for detecting a defect with high accuracy, which is characterized in that a soft material is interposed and the value of the acoustic impedance of the soft material is made equal to or close to the value of the waveguiding substance.
【０００９】また、上記の目的は、前記の高精度に検出
する超音波探傷法において、前記導波物質が鉛系ガラス
粉末を分散した樹脂からなり、かつ被検査物が鉛からな
ることを特徴とする欠陥を高精度に検出する超音波探傷
法によっても達成される。Further, the above object is characterized in that, in the ultrasonic flaw detection method with high accuracy, the waveguide material is made of a resin in which lead-based glass powder is dispersed, and the inspection object is made of lead. It can also be achieved by an ultrasonic flaw detection method that detects defects with high precision.
【００１０】[0010]
【発明の実施の形態】前述のごとく、従来方法でも超音
波の入射角度を傾斜させることにより、検出し難い位置
にある欠陥を検出することは可能であった。しかし、被
検査物表面の凹部の傾斜部分と平坦部分にまたがった下
方内部に欠陥が存在する場合、探触子を走査すると傾斜
部分と平坦部分で超音波の入射角度が変化するため、正
確な検出ができないという問題点があった。したがっ
て、このような被検査物を測定するには平面を平坦化す
ることが必要不可欠と考えられる。そこで本発明では、
被検査物と超音波特性が近い物質で作った導波体を被検
査物に取り付けることにより表面を平坦化して、超音波
の反射や屈折を防止して分解能を大幅に向上させること
を可能としたものである。BEST MODE FOR CARRYING OUT THE INVENTION As described above, even in the conventional method, it is possible to detect a defect at a position that is difficult to detect by inclining the incident angle of the ultrasonic wave. However, when there is a defect in the lower part of the surface of the object to be inspected, which extends over the inclined portion and the flat portion of the concave portion, scanning the probe changes the incident angle of the ultrasonic wave between the inclined portion and the flat portion. There was a problem that it could not be detected. Therefore, it is considered necessary to flatten the plane in order to measure such an inspection object. Therefore, in the present invention,
By attaching a waveguide made of a material that has ultrasonic characteristics close to those of the object to be inspected to the object to be inspected, the surface can be flattened and the reflection and refraction of ultrasonic waves can be prevented, greatly improving the resolution. It was done.
【００１１】すなわち、本発明では表面に凹凸がある被
検査物に導波体を形成し、表面を平坦化する。また、被
検査物の材質に応じて音響インピーダンスを適合させた
導波体を用いることにより、欠陥検出能力を大きく向上
させたものである。このため、本発明では、被検査物と
音響インピーダンスの値が同一または近似している導波
物質で表面を覆ったため表面の凹凸の影響を受けること
なく、精度良く欠陥を検出を可能とする。この導波体
は、硬化性樹脂をマトリックスとして鉛系ガラス粉末を
添加することにより、被検査物に合わせて音響インピー
ダンス値を最適化する。なおこの導波体は透明で被検査
物との接合状態がわかり易いという特長も併せもつ。こ
れにより、被検査物と導波体の界面での超音波の反射や
屈折が大きく低減され、欠陥の検出能力が大幅に向上す
る。That is, in the present invention, a waveguide is formed on an object to be inspected having an uneven surface to flatten the surface. In addition, the defect detection capability is greatly improved by using a waveguide whose acoustic impedance is adapted according to the material of the inspection object. Therefore, in the present invention, since the surface is covered with the waveguide material whose acoustic impedance value is the same as or similar to that of the object to be inspected, it is possible to detect the defect with high accuracy without being affected by the unevenness of the surface. In this waveguide body, a lead-based glass powder is added with a curable resin as a matrix to optimize the acoustic impedance value according to the object to be inspected. This waveguide is also transparent and has the feature that it is easy to see the bonding state with the object to be inspected. As a result, the reflection and refraction of ultrasonic waves at the interface between the object to be inspected and the waveguide are greatly reduced, and the defect detection capability is greatly improved.
【００１２】さらに、本発明では、導波体を繰り返し使
用する場合、被検査物の凹凸の形状に微妙な違いがある
と、被検査物と導波体の間に空隙が生じるため超音波の
反射や屈折が起こり検出能力が低下する。そこで軟質な
材料をその空隙に塗布また圧着して薄い整合層を形成す
ることにより、検出能力の低下を防止できる。この整合
層の音響インピーダンスは、導波体のそれに近い値とす
る。すなわち、同一形状の被検査物に対しては、何回も
同じ導波物質を用いることができ、効率良く低コストに
欠陥の検出ができる。Further, in the present invention, when the waveguide is repeatedly used, if there is a subtle difference in the shape of the unevenness of the object to be inspected, a gap is generated between the object to be inspected and the waveguide, and the ultrasonic wave Reflection and refraction occur and the detection ability is reduced. Therefore, a soft material is applied to the voids or pressure-bonded to form a thin matching layer, so that the detection capability can be prevented from lowering. The acoustic impedance of this matching layer is close to that of the waveguide. That is, the same waveguide material can be used many times for the inspection object having the same shape, and the defect can be detected efficiently and at low cost.
【００１３】また、本発明では、被検査物を水浸法で検
査する場合、表面に凹凸がある被検査物に導波体を形成
する手段として、水よりも比重が大きくかつ不溶性の液
体を用いる。この液体は被検査物の凹凸部に充填され、
表面は平坦化される。この場合、液体であるため、固体
の場合のように別途導波物質を作製する必要がなく、ま
た液体であるため、凹凸が小さくとも十分浸透し、検出
精度が向上する。なお液体は、被検査物に合わせて最適
な音響インピーダンス値のものを用いる。この方法は導
波体の形成が容易であり、また凹凸の形状に微妙な違い
がある被検査物にも使用できるというメリットがある。
さらに、本発明では、水浸法の水の替わりに、被検査物
にあわせて音響インピーダンス値を最適化した液体を用
いる。この方法では導波体を形成することなく、液体と
被検査物の界面での反射や屈折を防止できる。したがっ
て水浸法と同様の測定法で高精度な測定が可能である。Further, according to the present invention, when an inspection object is inspected by a water immersion method, an insoluble liquid having a specific gravity higher than that of water is used as a means for forming a waveguide on the inspection object having an uneven surface. To use. This liquid is filled in the uneven parts of the inspection object,
The surface is flattened. In this case, since it is a liquid, it is not necessary to separately prepare a waveguiding material as in the case of a solid, and since it is a liquid, it penetrates sufficiently even if the unevenness is small and the detection accuracy is improved. The liquid has an optimum acoustic impedance value according to the object to be inspected. This method has an advantage that the waveguide can be easily formed and that it can be used for an object to be inspected having a slight difference in the shape of the unevenness.
Furthermore, in the present invention, instead of water in the water immersion method, a liquid whose acoustic impedance value is optimized according to the object to be inspected is used. With this method, reflection or refraction at the interface between the liquid and the object to be inspected can be prevented without forming a waveguide. Therefore, highly accurate measurement is possible by the same measurement method as the water immersion method.
【００１４】ここで、本発明の音響インピーダンスは下
記式のように表され、その数値例は表１のとおりであ
り、音響インピーダンスは実際材料で測定可能な物性値
である。 音響インピーダンス＝ρ×Ｃ（ρ：密度、Ｃ：音速、単
位：ｇ／cm2s）Here, the acoustic impedance of the present invention is represented by the following formula, numerical examples thereof are as shown in Table 1, and the acoustic impedance is a physical property value that can be actually measured with a material. Acoustic impedance = ρ × C (ρ: density, C: speed of sound, unit: g / cm 2 s)
【００１５】[0015]
【表１】 [Table 1]
【００１６】また、本発明での表面の平坦度は、超音波
を前提としているので、表面粗さの最大高さと最大深さ
の差で、超音波波長の１／２以下の平坦度であればよ
い。また、本発明の導波物質のマトリックスとしての樹
脂は、上記の他に、通常の熱可塑性樹脂および不均一ポ
リマー系等の一般的な樹脂組成物が適用可能であること
は勿論である。また、前記音響インピーダンスを調整す
る際の、各種混合物の粒子径は超音波波長より小さけれ
ば、通常、超音波への影響は無い。以下、本発明につい
て実施例によって添付の図面に基づいてさらに詳述す
る。Further, since the surface flatness in the present invention is premised on ultrasonic waves, the difference between the maximum height and the maximum depth of the surface roughness should be less than 1/2 of the ultrasonic wavelength. Good. Further, as the resin as the matrix of the waveguiding material of the present invention, in addition to the above, it is needless to say that a general resin composition such as an ordinary thermoplastic resin and a heterogeneous polymer system can be applied. Further, when the particle size of each mixture when adjusting the acoustic impedance is smaller than the ultrasonic wavelength, there is usually no influence on the ultrasonic waves. Hereinafter, the present invention will be described in more detail by way of examples with reference to the accompanying drawings.
【００１７】[0017]
実施例１ 本実施例の被検査物２の断面図を図１に示す。本実施例
の被検査物２は材質はＰｂからなる板状である。導波体
１として、エポキシ樹脂をマトリックスとし、それに鉛
系ガラス粉末を添加したものを使用した。その作製方法
は、まず、エポキシ樹脂溶液に平均粒子径が０．１〜５
００μｍの鉛系ガラス粉末を５〜８０wt％添加して充分
混合した後、硬化剤を添加し、外周部を導波体保持用の
枠３ａ、３ｂで囲った被検査物２の凹部５を含む上部に
流し込んだ後、硬化させた。このとき樹脂の表面は平坦
になるように水平に保持する必要がある。これを水中に
て図２の水浸Ｃスコープ法で超音波探傷を行なった。Example 1 FIG. 1 shows a cross-sectional view of an inspection object 2 of this example. The inspected object 2 of this embodiment is a plate made of Pb. As the waveguide body 1, one in which an epoxy resin is used as a matrix and lead-based glass powder is added thereto is used. The preparation method is as follows. First, the epoxy resin solution has an average particle size of 0.1 to 5
After adding 5 to 80 wt% of a lead-based glass powder of 00 μm and thoroughly mixing it, a hardening agent is added and the outer peripheral portion is surrounded by frames 3a and 3b for holding a waveguide, and the recessed portion 5 of the inspection object 2 is included. After pouring on top, it was cured. At this time, the surface of the resin needs to be held horizontally so as to be flat. This was subjected to ultrasonic flaw detection in water by the water immersion C scope method shown in FIG.
【００１８】導波体１の音響インピーダンス（ρＣ）結
果を、鉛系ガラス粉末の粒子径２０μm の場合について
図３に、欠陥の検出限界を図４に、さらに鉛系ガラス粉
末の粒子径の影響を、鉛系ガラスの添加量６０wt％の場
合について図５にそれぞれ示す。図３から、鉛系ガラス
の添加量に伴いρＣが向上する。しかし、添加量が６０
wt％以上では、鉛系ガラス粉末の保持性が著しく低下す
るため不適であった。このため鉛系ガラスの添加量の好
ましい範囲は０〜６０wt％である。The results of the acoustic impedance (ρC) of the waveguide 1 are shown in FIG. 3 for the case where the particle diameter of the lead-based glass powder is 20 μm, the defect detection limit is shown in FIG. 4, and the influence of the particle diameter of the lead-based glass powder is shown. 5 is shown in FIG. 5 for the case where the amount of lead-based glass added is 60 wt%. From FIG. 3, ρC improves with the addition amount of the lead-based glass. However, the addition amount is 60
If it is more than wt%, the retention of the lead-based glass powder is significantly reduced, which is not suitable. Therefore, the preferable range of the addition amount of the lead-based glass is 0 to 60 wt%.
【００１９】図４では鉛系ガラスの添加量、すなわちρ
Ｃの向上に従い内部欠陥の検出限界が大きく向上し、ガ
ラス６０wt％で５０μｍとなる。これは、鉛系ガラス添
加量が無い時の検出限界１０００μｍ（通常の検出限
界）と比べると著しく性能が向上すると言える。したが
って、検出限界を１０００μｍより向上させるためには
鉛系ガラス添加量は少なくとも５wt％以上が必要であ
る。また、図５から鉛系ガラスの粒子径が２００μｍ以
上では欠陥の検出限界が大きく低下するため、１０００
μｍ以下の欠陥を検出するためには、鉛系ガラス粒子径
を２００μｍ以下にする必要がある。また粒子径が０．
１〜２０μｍの範囲では、検出限界は５０μｍと一定で
ある。In FIG. 4, the amount of lead glass added, that is, ρ
As the content of C is improved, the detection limit of internal defects is greatly improved, and the glass becomes 60 μm at 50 μm. It can be said that this is a marked improvement in performance as compared with the detection limit of 1000 μm (normal detection limit) when the lead-based glass is not added. Therefore, in order to improve the detection limit to more than 1000 μm, the amount of lead-based glass added must be at least 5 wt%. In addition, as shown in FIG. 5, when the particle diameter of the lead-based glass is 200 μm or more, the detection limit of defects is significantly lowered.
In order to detect defects of μm or less, the lead-based glass particle diameter needs to be 200 μm or less. Further, the particle size is 0.
In the range of 1 to 20 μm, the detection limit is constant at 50 μm.
【００２０】以上より、本発明の好ましい範囲は、エポ
キシ樹脂に対する鉛系ガラスの添加量は５〜６０wt％、
鉛系ガラスの平均粒子径は０．１〜２００μｍである。
なお、本実施例は水浸法の結果であるが、他の超音波探
傷法を採用してもよく、例えば、探触子を直接被検査物
に取り付ける直接接触法にも適用可能である。From the above, in the preferred range of the present invention, the amount of the lead-based glass added to the epoxy resin is 5 to 60 wt%,
The average particle size of lead-based glass is 0.1 to 200 μm.
Although the present embodiment is the result of the water immersion method, another ultrasonic flaw detection method may be adopted, and for example, it is also applicable to the direct contact method in which the probe is directly attached to the inspection object.
【００２１】実施例２ 本実施例では、実施例１で作製した導波体を被検査物か
ら取り外し、別の被検査物に取り付けた。本実施例の被
検査物は、実施例１のそれと比べて凹凸の形状が微妙に
異なるため、導波体と被検査物の間の密着界面に僅かな
空隙が形成された。そこで、その界面の空隙の影響を無
くすために、シリコーン系グリスに平均粒子径が０．１
〜５００μｍの鉛系ガラス粉末を５〜８０wt％添加し、
十分混合したペーストを導波体と被検査物の間に塗布し
て、空隙に充填した。この場合の塗布厚さは１０〜５０
μｍである。この整合層の有無について水中にて超音波
探傷を行った。鉛系ガラス粉末の粒子径２０μm の場合
についての結果を図６に示す。この図から、整合層によ
って前記空隙による検出能力低下が、実施例１と同等の
レベルに回復することが分かる。これはペーストが整合
層として、被検査物と導波体の一体密着を可能としたこ
とによる。なお、鉛系ガラス添加量が６０wt％以上では
シリコーン系グリス中での鉛系ガラスの保持性が大きく
低下し不適であった。また鉛系ガラス添加量と検出限界
の関係は実施例１の図４とほとんど同じであった。Example 2 In this example, the waveguide prepared in Example 1 was removed from the object to be inspected and attached to another object to be inspected. Since the inspected object of the present example has a slightly different shape of the unevenness as compared with that of Example 1, a slight void was formed at the contact interface between the waveguide and the inspected object. Therefore, in order to eliminate the influence of voids at the interface, the silicone-based grease has an average particle size of 0.1.
5 ~ 80wt% of lead glass powder of ~ 500μm is added,
A sufficiently mixed paste was applied between the waveguide and the object to be inspected to fill the space. The coating thickness in this case is 10 to 50.
μm. Ultrasonic flaw detection was performed in water for the presence or absence of this matching layer. FIG. 6 shows the result when the particle diameter of the lead-based glass powder was 20 μm. From this figure, it can be seen that the matching layer restores the decrease in detection capability due to the voids to a level equivalent to that of the first embodiment. This is because the paste serves as a matching layer and enables the object to be inspected and the waveguide to be integrally adhered. If the amount of lead-based glass added was 60 wt% or more, the retention of the lead-based glass in the silicone-based grease was greatly reduced, which was not suitable. The relationship between the amount of lead-based glass added and the detection limit was almost the same as in FIG. 4 of Example 1.
【００２２】以上より、本実施例においても好ましい範
囲は、シリコーン系グリスに対する鉛系ガラス粉末の添
加量５〜６０wt％、鉛系ガラス粉末の粒子径は０．１〜
２００μｍである。なお、前記ペーストの替わりに厚さ
が１０〜１００μｍ程度のシリコーンゴムをマトリック
スとする薄いシートを用いても同様の効果が得られた。
作製方法は酸化硬化性のシリコーン溶液に鉛系ガラス粉
末を添加して十分混合した後、ドクターブレード法で厚
さが１０〜１００μｍのシート状にした。これを空気中
に放置して硬化させると、軟質なシートが得られた。こ
のシートを適当な大きさに切断し、実施例１で作製した
導波体と被検査物の間にはさんで適当な圧力を加えて密
着させた。これを超音波探傷した結果では、検出限界傾
向が図６と同等であることが示された。なお、前記シリ
コーン溶液に対する鉛系ガラス粉末の添加量および平均
粒子径は前記ペーストと同一条件であり本発明の好まし
い範囲とした。From the above, in the preferred range of the present embodiment, the amount of the lead-based glass powder added to the silicone-based grease is 5 to 60 wt%, and the particle size of the lead-based glass powder is 0.1 to 10.
200 μm. The same effect was obtained by using a thin sheet having a silicone rubber matrix of about 10 to 100 μm instead of the paste.
A lead glass powder was added to an oxidation-curable silicone solution and mixed sufficiently, and then formed into a sheet having a thickness of 10 to 100 μm by a doctor blade method. When this was left in the air to cure, a soft sheet was obtained. This sheet was cut into an appropriate size, and was sandwiched between the waveguide body produced in Example 1 and the object to be inspected to bring them into close contact with each other by applying an appropriate pressure. The result of ultrasonic flaw detection showed that the detection limit tendency was equivalent to that in FIG. The amount of lead-based glass powder added to the silicone solution and the average particle size were the same conditions as those for the paste, and were within the preferred range of the present invention.
【００２３】また、本実施例の方法を用いれば、実施例
１のエポキシ樹脂をマトリックスとする導波体を少なく
とも１個作製すれば、それを付け替えることにより複数
の被検査物を測定することが可能となる。本実施例の方
法においても、水浸法のみならず探触子を直接被検査物
に取り付ける直接接触法にも適用可能である。Further, by using the method of the present embodiment, if at least one waveguide having the epoxy resin of the embodiment 1 as a matrix is manufactured, it is possible to replace it and measure a plurality of objects to be inspected. It will be possible. The method of the present embodiment can be applied not only to the water immersion method but also to the direct contact method in which the probe is directly attached to the object to be inspected.
【００２４】実施例３ 本実施例では、水よりも比重が大きくかつ水に不溶性な
液体として、水銀を用いた。水銀を被検査物の凹部分を
含む上部に流し込み、水中にて超音波探傷を行った。水
銀は水よりも比重が大きくかつ不溶性のため、水中にお
いて被検査物の凹部分に充填されたまま表面が平坦な状
態で保たれる。超音波探傷の結果、欠陥の検出限界値は
５０μｍで、これはエポキシ樹脂のみの導波体での検出
限界１０００μｍと比較して著しい性能向上を示したと
言える。このことは水銀のρＣ＝１．９８×１０6 であ
り、樹脂よりもより被検査物の値に近いため検出能力が
向上したことによる。このように、水銀のような液体の
導波体を用いることにより、凹部の形状に違いがある被
検査物でも、各々に合った導波体を形成する必要がない
ため、容易にかつ高精度な測定が可能である。Example 3 In this example, mercury was used as a liquid having a specific gravity higher than that of water and insoluble in water. Mercury was poured into the upper portion of the inspection object including the concave portion, and ultrasonic flaw detection was performed in water. Since mercury has a higher specific gravity than water and is insoluble, the surface of the inspected object is kept flat while being filled in the concave portion of the inspection object. As a result of ultrasonic flaw detection, the detection limit value of defects is 50 μm, which can be said to show a significant improvement in performance as compared with the detection limit of 1000 μm in the waveguide containing epoxy resin alone. This is because mercury has ρC = 1.98 × 10 6, which is closer to the value of the object to be inspected than the resin, and thus the detection ability is improved. As described above, by using a liquid waveguide such as mercury, it is not necessary to form a waveguide suitable for each inspected object having a different shape of the concave portion. Various measurements are possible.
【００２５】実施例４ 本実施例では、被検査物を浸す液体として、ヨウ化メチ
レン液を用いた。まずこの液体に鉛系ガラス粉末（粒子
径２０μｍ）を５〜６０wt％添加し、さらに分散剤を適
量添加して十分攪拌混合した液体を作製した。鉛系ガラ
ス粉末はヨウ化メチレン液中では溶解することなく分散
状態にある。この液体に被検査物を浸して水浸Ｃスコー
プ法と同様の方法で超音波探傷を行った。鉛系ガラス粉
末の粒子径２０μm の場合についての結果を、図７およ
び図８に示す。Example 4 In this example, a methylene iodide solution was used as a liquid for immersing the object to be inspected. First, 5 to 60 wt% of lead-based glass powder (particle diameter 20 μm) was added to this liquid, an appropriate amount of a dispersant was further added, and the liquid was sufficiently stirred and mixed to prepare a liquid. The lead-based glass powder is in a dispersed state without being dissolved in the methylene iodide solution. An object to be inspected was dipped in this liquid, and ultrasonic flaw detection was performed by the same method as the water immersion C scope method. The results for the case where the particle diameter of the lead-based glass powder is 20 μm are shown in FIGS. 7 and 8.
【００２６】図７から、鉛系ガラス粉末の添加量に伴い
ρＣが向上した。しかし添加量が４０wt％以上では鉛系
ガラス粉末が凝集して沈殿し、分散性が大きく低下した
ため不適であった。また、図８から鉛系ガラスの添加
量、すなわちρＣの向上に従い内部欠陥の検出限界が大
きく向上する。これより１０００μｍ以下の欠陥検出に
は鉛系ガラス粉末の添加量の範囲は５wt％以上である。
また粒子径と検出限界の関係は実施例１の図５とほぼ同
様の傾向であった。以上から本発明の好ましい範囲は、
ヨウ化メチレン液に対する鉛系ガラスの添加量を５〜４
０wt％、鉛系ガラスの粒子径は０．１〜２００μｍであ
る。本実施例の方法を用いれば、凹形状の異なる被検査
物でも水浸法と同様に連続測定が可能となる。From FIG. 7, ρC was improved with the addition amount of the lead-based glass powder. However, if the addition amount is 40 wt% or more, the lead-based glass powder is agglomerated and precipitated, and the dispersibility is greatly reduced, which is not suitable. Further, from FIG. 8, the detection limit of internal defects is greatly improved as the amount of lead glass added, that is, ρC is increased. From this, the range of the addition amount of the lead-based glass powder is 5 wt% or more for detecting defects of 1000 μm or less.
The relationship between the particle size and the detection limit was almost the same as that in FIG. 5 of Example 1. From the above, the preferred range of the present invention is
The amount of lead-based glass added to the methylene iodide solution should be 5 to 4
The particle diameter of the lead-based glass is 0.1 wt. By using the method of the present embodiment, it is possible to perform continuous measurement even on inspection objects having different concave shapes, as in the water immersion method.
【００２７】上記の実施例１〜４は、材質がＰｂからな
る被検査物であるが、本発明はＰｂのみならず、Ｆｅ、
Ａｌ、Ｚｎ、Ｓｎ、ステンレスおよびその他の合金等の
金属材料、さらに石英ガラス、チタン酸バリウム磁器な
どのセラミックス材料における内部欠陥検出にも適用可
能である。その場合には、被検査材料の音響インピーダ
ンスと、同一または近似した音響インピーダンスを持つ
導波体を用いればよい。The above-mentioned Examples 1 to 4 are inspection objects made of Pb, but the present invention is not limited to Pb, but Fe,
It is also applicable to the detection of internal defects in metallic materials such as Al, Zn, Sn, stainless steel and other alloys, and also in ceramic materials such as quartz glass and barium titanate porcelain. In that case, a waveguide having an acoustic impedance that is the same as or similar to the acoustic impedance of the material to be inspected may be used.
【００２８】[0028]
【発明の効果】本発明によって、表面に凹凸形状を有す
る被検査物の、傾斜面内部に存在する欠陥を高精度で検
出可能とする。また、樹脂の導波体を付け替えることが
できるため、少なくとも１個の導波体があればよく、全
ての被検査物について作製する時間と費用の省略化が可
能である。さらに、液体導波体を使用することによって
前記導波体を形成する時間と費用が大幅に省ける。According to the present invention, it is possible to detect with high accuracy a defect existing inside an inclined surface of an object to be inspected having an uneven surface. Moreover, since the resin waveguide can be replaced, at least one waveguide is sufficient, and the time and cost for manufacturing all the inspection objects can be reduced. Moreover, the use of liquid waveguides saves a great deal of time and money in forming said waveguides.
【図１】本発明に係る被検査物および導波体の一体密着
形状を示す図である。FIG. 1 is a diagram showing an integrated contact shape of an inspection object and a waveguide according to the present invention.
【図２】本発明に係る超音波探傷の水浸Ｃスコープ法の
概要を示す図である。FIG. 2 is a diagram showing an outline of a water immersion C scope method for ultrasonic flaw detection according to the present invention.
【図３】本発明に係る鉛系ガラス添加量と音響インピー
ダンスとの関係を示す図である。FIG. 3 is a diagram showing the relationship between the amount of lead-based glass added and the acoustic impedance according to the present invention.
【図４】本発明に係る鉛系ガラス添加量と検出限界との
関係を示す図である。FIG. 4 is a diagram showing a relationship between a lead glass addition amount and a detection limit according to the present invention.
【図５】本発明に係る鉛系ガラスの平均粒子径との関係
を示す図である。FIG. 5 is a diagram showing a relationship with the average particle diameter of the lead-based glass according to the present invention.
【図６】本発明に係る整合層有無による鉛系ガラス添加
量と検出限界との関係を示す図である。FIG. 6 is a diagram showing the relationship between the amount of lead-based glass added and the detection limit with and without a matching layer according to the present invention.
【図７】本発明の実施例４に係り、液体をヨウ化メチレ
ン液とした場合の鉛系ガラス添加量と音響インピーダン
スとの関係を示す図である。FIG. 7 is a graph showing the relationship between the amount of lead-based glass added and the acoustic impedance when the liquid is methylene iodide, according to Example 4 of the present invention.
【図８】本発明の実施例４に係り、液体をヨウ化メチレ
ン液とした場合の鉛系ガラス添加量と検出限界との関係
を示す図である。FIG. 8 is a graph showing the relationship between the amount of lead glass added and the detection limit when the liquid is methylene iodide, according to Example 4 of the present invention.
１…導波体 ２…被検査物 ３ａ、３ｂ…導波体保持用枠 ４…内部欠陥 ５…凹部 ６…超音波探触子 ７…水層 ８…容器 DESCRIPTION OF SYMBOLS 1 ... Waveguide 2 ... Inspected object 3a, 3b ... Waveguide holding frame 4 ... Internal defect 5 ... Recess 6 ... Ultrasonic probe 7 ... Water layer 8 ... Container
Claims (5)
高精度に検出する超音波探傷法であって、該被検査物の
検査表面が平坦となるように、音響インピーダンスの値
が該被検査物と同一または近似する導波物質によって、
該検査表面を覆うことを特徴とする欠陥を高精度に検出
する超音波探傷法。1. An ultrasonic flaw detection method for detecting a defect of an object to be inspected having a concavo-convex portion on the surface with high accuracy, wherein the value of the acoustic impedance is set so that the surface of the object to be inspected becomes flat. Depending on the waveguide material that is the same as or close to the object to be inspected,
An ultrasonic flaw detection method for detecting a defect with high accuracy, which covers the inspection surface.
であり、被検査物に対向する面は該被検査物の凹凸部と
合致する凹凸形状を有し、前記導波物質と被検査物を前
記凹凸部で、一体密着を可能となし、かつ超音波の入射
面側表面を平坦に形成することを特徴とする欠陥を高精
度に検出する超音波探傷法。2. The waveguide material according to claim 1, wherein the waveguiding material is solid, and a surface facing the object to be inspected has an uneven shape that matches an uneven portion of the object to be inspected. An ultrasonic flaw detection method for detecting a defect with high accuracy, which is characterized in that a surface of an incident surface of an ultrasonic wave is formed flat by allowing the object to be integrally adhered to the uneven portion.
であることを特徴とする欠陥を高精度に検出する超音波
探傷法。3. The ultrasonic flaw detection method according to claim 1, wherein the waveguide material is a liquid, and the defect is detected with high accuracy.
前記導波物質と被検査物との界面に発生する空隙を防止
するために、該界面に軟質材料を介在させ、かつ該軟質
材料の音響インピーダンスの値を導波物質の値と同一ま
たは近似させることを特徴とする欠陥を高精度に検出す
る超音波探傷法。4. The method according to claim 2, wherein when the one body is closely attached,
In order to prevent voids generated at the interface between the waveguiding material and the object to be inspected, a soft material is interposed at the interface, and the value of the acoustic impedance of the soft material is made equal to or close to the value of the waveguiding material. An ultrasonic flaw detection method that detects defects with high accuracy.
ガラス粉末を分散した樹脂からなり、かつ被検査物が鉛
からなることを特徴とする欠陥を高精度に検出する超音
波探傷法。5. The ultrasonic flaw detection method according to claim 2, wherein the waveguiding material is made of a resin in which lead-based glass powder is dispersed, and the inspection object is made of lead. .
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP28877495A JPH09133664A (en) | 1995-11-07 | 1995-11-07 | Ultrasonic flaw detection method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP28877495A JPH09133664A (en) | 1995-11-07 | 1995-11-07 | Ultrasonic flaw detection method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH09133664A true JPH09133664A (en) | 1997-05-20 |
Family
ID=17734550
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
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| JP2007285910A (en) * | 2006-04-18 | 2007-11-01 | Toyota Motor Corp | Method of manufacturing welded component |
| JP2012202867A (en) * | 2011-03-25 | 2012-10-22 | Kumamoto Univ | Inspection apparatus and inspection method |
| CN102818854A (en) * | 2011-06-08 | 2012-12-12 | 波音公司 | Geometry compensating transducer attachments for ultrasonic inspection of chamfers or countersunk surfaces |
| WO2014119436A1 (en) | 2013-02-01 | 2014-08-07 | 三菱重工業株式会社 | Ultrasonic flaw detection jig, ultrasonic flaw detection method, and manufacturing method for ultrasonic flaw detection jig |
| JP2015090281A (en) * | 2013-11-05 | 2015-05-11 | パナソニックＩｐマネジメント株式会社 | Ultrasonic measuring method and apparatus |
| JP2016217716A (en) * | 2015-05-14 | 2016-12-22 | 日産自動車株式会社 | Ultrasonic wave measuring device and ultrasonic wave measuring method |
| JP2020063976A (en) * | 2018-10-17 | 2020-04-23 | 三菱重工業株式会社 | Inspection method of windmill blade |
| US10815801B2 (en) | 2016-03-11 | 2020-10-27 | Ihi Corporation | Turbine nozzle |
| US11480156B2 (en) | 2018-10-17 | 2022-10-25 | Mitsubishi Heavy Industries, Ltd. | Method of evaluating quality of wind turbine blade |
-
1995
- 1995-11-07 JP JP28877495A patent/JPH09133664A/en active Pending
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH11295278A (en) * | 1998-04-09 | 1999-10-29 | Aspect:Kk | Device and method for detecting flaw in surface and interior of turbine blade |
| JP2007285910A (en) * | 2006-04-18 | 2007-11-01 | Toyota Motor Corp | Method of manufacturing welded component |
| JP2012202867A (en) * | 2011-03-25 | 2012-10-22 | Kumamoto Univ | Inspection apparatus and inspection method |
| CN102818854A (en) * | 2011-06-08 | 2012-12-12 | 波音公司 | Geometry compensating transducer attachments for ultrasonic inspection of chamfers or countersunk surfaces |
| WO2014119436A1 (en) | 2013-02-01 | 2014-08-07 | 三菱重工業株式会社 | Ultrasonic flaw detection jig, ultrasonic flaw detection method, and manufacturing method for ultrasonic flaw detection jig |
| US10067098B2 (en) | 2013-02-01 | 2018-09-04 | Mitsubishi Heavy Industries, Ltd. | Ultrasonic flaw detection jig, ultrasonic flaw detection method and method of manufacturing ultrasonic flaw detection jig |
| JP2015090281A (en) * | 2013-11-05 | 2015-05-11 | パナソニックＩｐマネジメント株式会社 | Ultrasonic measuring method and apparatus |
| JP2016217716A (en) * | 2015-05-14 | 2016-12-22 | 日産自動車株式会社 | Ultrasonic wave measuring device and ultrasonic wave measuring method |
| US10815801B2 (en) | 2016-03-11 | 2020-10-27 | Ihi Corporation | Turbine nozzle |
| JP2020063976A (en) * | 2018-10-17 | 2020-04-23 | 三菱重工業株式会社 | Inspection method of windmill blade |
| US11480156B2 (en) | 2018-10-17 | 2022-10-25 | Mitsubishi Heavy Industries, Ltd. | Method of evaluating quality of wind turbine blade |
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