JP2002131287A - Magnetic particle inspection method and device - Google Patents
Magnetic particle inspection method and deviceInfo
- Publication number
- JP2002131287A JP2002131287A JP2000323569A JP2000323569A JP2002131287A JP 2002131287 A JP2002131287 A JP 2002131287A JP 2000323569 A JP2000323569 A JP 2000323569A JP 2000323569 A JP2000323569 A JP 2000323569A JP 2002131287 A JP2002131287 A JP 2002131287A
- Authority
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- Japan
- Prior art keywords
- magnetic
- sheet
- defect
- observation surface
- surface side
- 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
Description
【０００１】[0001]
【発明の属する技術分野】本発明は非破壊検査法に関
し、さらに、詳細には、強磁性材料を磁化し、割れなど
の欠陥の部分に生じる磁気の乱れを検知することにより
材料の欠陥を検出する方法である磁粉探傷法およびその
方法の実施に使用する磁粉探傷装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nondestructive inspection method, and more particularly, to a method for detecting a defect in a material by magnetizing a ferromagnetic material and detecting a magnetic disturbance generated in a defect portion such as a crack. The present invention relates to a magnetic particle flaw detection method which is a method for performing the method and a magnetic particle flaw detection apparatus used for carrying out the method.
【０００２】[0002]
【従来の技術】強磁性体の表面または表面直下に存在す
る欠陥を検出する方法として、被探傷材を磁化し、欠陥
部よりの漏れ磁束に磁粉を吸引させて生じる磁粉模様を
観察することにより欠陥を検出する方法である磁粉探傷
法は広く使用されている。2. Description of the Related Art As a method of detecting a defect existing on or immediately below a surface of a ferromagnetic material, a material to be inspected is magnetized, and a magnetic powder pattern generated by attracting magnetic powder to a leakage magnetic flux from a defect portion is observed. Magnetic particle flaw detection, which is a method for detecting defects, is widely used.
【０００３】この磁粉探傷法は、図８に示すように、強
磁性材である被探傷材３１上に磁石３２を載置し、被探
傷材３１を磁石３２で磁化して表面近傍の欠陥３３の部
分に現れる漏れ磁束３４に磁粉３５を吸引させて磁粉模
様を生じさせ、微小欠陥を可視化させる方法であり、Ｊ
ＩＳ−Ｇ０５６５−１９９２に規定された方法は、磁粉
を被探傷面に空気とともに吹き付けるか、または、磁粉
を均一に分散させた検査液を被探傷面上に静かに流し
て、漏れ磁束が生じている部分に現れる磁粉模様を肉眼
にて直接観察する方法（以下「ＪＩＳの磁粉探傷法」と
いう）である。In this magnetic particle flaw detection method, as shown in FIG. 8, a magnet 32 is placed on a flaw detection target material 31 which is a ferromagnetic material, and the flaw detection target material 31 is magnetized by the magnet 32 to form a defect 33 near the surface. The magnetic flux 35 is attracted to the leakage magnetic flux 34 appearing in the portion of the arrow to generate a magnetic powder pattern, thereby visualizing minute defects.
According to the method specified in IS-G0565-1992, magnetic particles are sprayed on the surface to be inspected together with air, or a test liquid in which the magnetic particles are uniformly dispersed is gently flowed over the surface to be inspected to generate leakage magnetic flux. This is a method of directly observing a magnetic powder pattern appearing in a part where the part is present with the naked eye (hereinafter, referred to as “JIS magnetic particle flaw detection method”).
【０００４】しかし、上記ＪＩＳの磁粉探傷法は、微小
欠陥の検出に使用した場合、漏れ磁束が小さくて磁粉を
吸引する磁力が弱いので、空気あるいは液体とともに磁
粉を流すと、その流れの慣性力のために漏れ磁束部位に
磁粉を吸引しにくく、被探傷材を磁化しながら連続的に
磁粉を流す必要があり、目視で判断できる状態にするに
は時間がかかるという欠点がある。また、被探傷面が傾
斜していると、検査液の重力のために磁粉の移動速度が
速くなり、漏れ磁束に磁粉を吸引するのが困難になり、
特に、被探傷面が鉛直方向であると、洩れ磁束に磁粉を
吸引させるのにかなりの熟練を要する。さらに、被探傷
面が予め十分に清掃されていないと、被探傷面と磁粉模
様とのコントラストがつきにくくなるので、探傷前に被
探傷面を予め十分に清掃しておかなければならないとい
う煩わしい作業が必要であり、探傷作業後には磁粉や液
体の除去と清掃作業が必要である。その上、磁粉の再使
用が不可能であり、経済的に不利である。そして、被探
傷面に凹凸があると、磁粉が凹部に溜まり、疑似模様が
欠陥と誤判断される可能性がある。However, when the magnetic particle flaw detection method of JIS described above is used for detecting a minute defect, the leakage magnetic flux is small and the magnetic force for attracting the magnetic particle is weak. For this reason, it is difficult to attract the magnetic powder to the leaked magnetic flux portion, and it is necessary to continuously flow the magnetic powder while magnetizing the material to be inspected. Also, if the surface to be inspected is inclined, the moving speed of the magnetic powder is increased due to the gravity of the test liquid, and it becomes difficult to attract the magnetic powder to the leakage magnetic flux.
In particular, when the surface to be inspected is in the vertical direction, considerable skill is required to attract the magnetic powder to the leakage magnetic flux. Further, if the surface to be inspected is not sufficiently cleaned in advance, the contrast between the surface to be inspected and the magnetic powder pattern is difficult to be obtained, so that the troublesome operation that the surface to be inspected must be sufficiently cleaned before inspection. After the flaw detection operation, it is necessary to remove and clean the magnetic particles and liquid. In addition, it is impossible to reuse the magnetic powder, which is economically disadvantageous. If the surface to be inspected has irregularities, the magnetic powder accumulates in the concave portions, and the pseudo pattern may be erroneously determined as a defect.
【０００５】また、特公昭６０−３４０６６号公報に
は、図９（ａ）に模式的に示すように、磁粉を分散させ
た検査液３６を密閉された可撓性容器３７に封入し、非
導電性弾性薄膜３８を被探傷材に押しつけ、欠陥部の漏
洩磁束による磁粉模様を非導電性弾性薄膜３８上に画か
せて、この磁粉模様を容器３７の透明部３９を通して観
察する方式のもの（以下「従来の磁粉探傷法１」とい
う）が記載されている。この従来の磁粉探傷法１は、漏
れ磁束の大きい大型欠陥を対象とする場合には適用する
ことが可能である。しかし、一般構造物の微小欠陥の検
出に適用するのは困難である。というのは、従来の磁粉
探傷法１もＪＩＳの磁粉探傷法と同じく、磁粉を吸引す
る漏れ磁束の磁力が小さく、図９（ｂ）に示すように、
被探傷材４０の表面の微小欠陥４１に対応して生じる洩
れ磁束の磁力の及ぶ範囲の検査液中に分散した磁粉を凝
集し、凝集物４２を生じさせても、その凝集量が少ない
ので、探傷前に透明部３９から見た状態を示す図９
（ｃ）と、磁粉の凝集物４２による磁粉模様４３を透明
部３９から見た状態を示す図９（ｄ）との差異はそれほ
ど明瞭でなく（磁粉模様４３がうすくて判別しにく
く）、欠陥の検出が困難である。そこで、検査液中の磁
粉の濃度を高めると、凝集磁粉量は多くなるが、検査液
自体が磁粉により黒ずむなど、磁粉の凝集部分と他の部
分とのコントラストがつきにくくなる。また、連続的に
探傷する場合は、直前の探傷による磁粉の凝集物を再度
均一に分散させなければ、明確な磁粉模様を得ることは
できないが、密閉容器３７内の液体を流動化させること
は難しく、液体と磁粉の相対的な動きを液体の流れによ
り生じさせることも困難である。さらに、凹凸のある面
を探傷する際、非導電性弾性薄膜３８が可撓性を有する
としても、凸部に接触する容器の検査液の高さ（Ｈ）が
減少し、磁粉模様にバラツキが生じ、欠陥の検出感度が
低下する。Japanese Patent Publication No. 60-34066 discloses a test solution 36 in which magnetic powder is dispersed in a sealed flexible container 37, as schematically shown in FIG. A method in which the conductive elastic thin film 38 is pressed against the material to be inspected, a magnetic powder pattern caused by the leakage magnetic flux of the defective portion is drawn on the non-conductive elastic thin film 38, and the magnetic powder pattern is observed through the transparent portion 39 of the container 37 ( Hereinafter, "conventional magnetic particle flaw detection method 1" is described. This conventional magnetic particle flaw detection method 1 can be applied to a large defect having a large leakage magnetic flux. However, it is difficult to apply it to the detection of minute defects in general structures. This is because, similarly to the magnetic particle flaw detection method of JIS, the conventional magnetic particle flaw detection method 1 has a small magnetic force of the leakage magnetic flux for attracting the magnetic particles, and as shown in FIG.
Even if the magnetic powder dispersed in the test solution within the range of the magnetic force of the leakage magnetic flux generated corresponding to the minute defect 41 on the surface of the material to be inspected 40 is aggregated to form the aggregate 42, the amount of aggregation is small, FIG. 9 showing a state viewed from the transparent part 39 before the flaw detection.
The difference between FIG. 9C and FIG. 9D showing the state where the magnetic powder pattern 43 due to the magnetic powder aggregates 42 is viewed from the transparent portion 39 is not so clear (the magnetic powder pattern 43 is so thin that it is difficult to distinguish it). Is difficult to detect. Therefore, when the concentration of the magnetic powder in the test solution is increased, the amount of the agglomerated magnetic powder increases, but the contrast between the agglomerated portion of the magnetic powder and other portions is hardly obtained, such as the test solution itself being darkened by the magnetic powder. Further, in the case of continuous flaw detection, a clear magnetic powder pattern cannot be obtained unless the aggregates of the magnetic powder from the immediately preceding flaw detection are uniformly dispersed again, but the liquid in the closed container 37 cannot be fluidized. It is difficult, and it is also difficult to cause relative movement between the liquid and the magnetic powder by the flow of the liquid. Further, when detecting a surface having irregularities, even if the non-conductive elastic thin film 38 has flexibility, the height (H) of the test solution in the container in contact with the convex portion decreases, and the magnetic powder pattern varies. And the sensitivity of defect detection is reduced.
【０００６】さらに、特公昭６１−４５１８６号公報に
は、図１０（ｂ）に示すように、透明可撓性薄膜４４と
白色可撓性薄膜４５からなる可撓性ベルト４６内の空間
に磁粉を含有する検査液４７を封入し、図１０（ａ）に
示すように、この可撓性ベルト４６を３本の遊動輪４８
と１本の駆動輪４９との間に架け渡し、磁化電極５０に
よって被探傷材５１を連続的に磁化し、無限軌道を構成
する可撓性ベルト４６を被探傷材５１に接触させつつ磁
粉探傷する構成のもの（以下「従来の磁粉探傷法２」と
いう）が記載されている。しかし、この従来の磁粉探傷
法２は、可撓性容器が可撓性ベルトに代わっただけで、
上記した従来の磁粉探傷法１と同様の欠点を有してい
る。Further, Japanese Patent Publication No. 61-45186 discloses that, as shown in FIG. 10B, magnetic powder is formed in a space in a flexible belt 46 comprising a transparent flexible thin film 44 and a white flexible thin film 45. And the flexible belt 46 is connected to three idlers 48 as shown in FIG.
And one driving wheel 49, continuously magnetize the flaw detection material 51 by the magnetized electrode 50, and contact the flexible belt 46 forming an endless track with the flaw detection material 51 while magnetically flaw detecting the magnetic powder. (Hereinafter referred to as “conventional magnetic particle flaw detection method 2”). However, in this conventional magnetic particle flaw detection method 2, only the flexible container is replaced with a flexible belt,
It has the same drawbacks as the conventional magnetic particle flaw detection method 1 described above.
【０００７】そこで、本出願人は、先に、微小欠陥の検
出感度が大きくて微小欠陥の有無の判定が容易な磁粉探
傷法および磁粉探傷装置に関する改良発明について特許
出願を行った（特願平１１−１８９３２８号）。Therefore, the present applicant has previously filed a patent application for an improved invention relating to a magnetic particle flaw detection method and a magnetic particle flaw detection apparatus which has a high sensitivity for detecting a minute defect and makes it easy to determine the presence / absence of a minute defect (Japanese Patent Application No. Hei. 11-189328).
【０００８】一方、特公平３−４０３３９号公報には、
図１１に示すように、ポリエチレンの薄片５２と５３で
形成された容器内を、ポリエチレンの薄片５４によって
小室５５と５６に仕切り、一方の小室５５には磁粉を充
填し、他方の小室５６には化学反応によって硬化する分
散媒を充填し、探傷試験直前に薄片５４からなる仕切を
破って磁粉と分散媒を均一に混合し、この容器を被探傷
材に当接させて分散媒が硬化するまでの間に探傷試験を
行い、分散媒が硬化した後にその容器を被探傷材から取
り外すことを特徴とする、磁粉探傷装置（以下「硬化型
分散媒を使用した従来の磁粉探傷装置」という）が記載
されている。On the other hand, Japanese Patent Publication No. 3-40339 discloses that
As shown in FIG. 11, the inside of the container formed of polyethylene flakes 52 and 53 is partitioned into small chambers 55 and 56 by polyethylene flakes 54. One small chamber 55 is filled with magnetic powder, and the other small chamber 56 is filled with magnetic powder. Filling the dispersion medium which is hardened by the chemical reaction, breaking the partition made of the thin piece 54 just before the flaw detection test, uniformly mixing the magnetic powder and the dispersion medium, and bringing the container into contact with the material to be flaw-detected until the dispersion medium is hardened. A magnetic particle flaw detection device (hereinafter referred to as a "conventional magnetic particle flaw detection device using a hardening type dispersion medium") is characterized in that a flaw detection test is performed during that time and the container is removed from the material to be flawed after the dispersion medium is cured. Has been described.
【０００９】[0009]
【発明が解決しようとする課題】本出願人による改良発
明によれば、微少結果の検出感度を向上させることは可
能であるが、磁気シートに描かれた磁粉模様を肉眼で観
察して欠陥を検出する方法であるため、探傷結果の記録
を残そうとすれば、その磁粉模様をスケッチするか、写
真撮影することにより記録を残すことは可能であるが、
スケッチや写真は時を経るにつれて画像が薄れたり、汚
れたり、または欠損したりすることがあるので、探傷デ
ータを正確に長期間保存することができない。また、探
傷済みの磁気シートに新たな磁気が加わった場合、その
探傷結果が変化するという問題がある。According to the improved invention of the present applicant, it is possible to improve the detection sensitivity of minute results, but it is possible to visually observe the magnetic powder pattern drawn on the magnetic sheet to detect defects. Because it is a detection method, if you want to keep a record of the flaw detection result, it is possible to leave a record by sketching or photographing the magnetic powder pattern,
Sketches and photographs may not be able to store flaw detection data accurately for long periods of time, as images may fade, become dirty, or become lost over time. In addition, when new magnetism is applied to a magnetic sheet that has been inspected, there is a problem that the inspection result changes.
【００１０】さらに、硬化型分散媒を使用した従来の磁
粉探傷装置は、薬品混合による硬化であるため、探傷試
験直前に分散媒と磁粉を均一に混合しなければならない
という煩わしさがある。また、分散媒が硬化するまでの
間に探傷試験を終了しなければならないという時間的な
制約がある。Furthermore, the conventional magnetic particle flaw detection apparatus using a curable dispersion medium involves the inconvenience that the dispersion medium and the magnetic powder must be uniformly mixed immediately before the flaw detection test because the apparatus is cured by mixing chemicals. Further, there is a time constraint that the flaw detection test must be completed before the dispersion medium is cured.
【００１１】本発明は従来の技術の有するこのような問
題点に鑑みてなされたものであって、その目的は、時間
的な制約がなく簡単な手法で探傷試験を行うことが可能
で、探傷結果を確実に長期間保存記録することができる
磁粉探傷法および磁粉探傷装置を提供することにある。
また、本発明の目的は、探傷性能を向上することができ
る磁粉探傷法および磁粉探傷装置を提供することにあ
る。SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and has as its object to perform a flaw detection test by a simple method without any time limitation. An object of the present invention is to provide a magnetic particle flaw detection method and a magnetic particle flaw detection apparatus capable of reliably storing and recording results for a long period.
Another object of the present invention is to provide a magnetic particle flaw detection method and a magnetic particle flaw detection apparatus capable of improving flaw detection performance.
【００１２】[0012]
【課題を解決するための手段】上記目的を達成するため
に本発明は、少なくとも観察面側のシートが透明材料で
形成され、観察面側のシートと反観察面側のシートとの
間を多数の小室に仕切り且つこれらの小室に熱硬化性分
散媒を含む分散媒中に磁粉を分散させたものを封入して
なる磁気シートを採用し、該磁気シートの観察面を被探
傷材の探傷面に当接させるか又は押し当てて密着させ、
被探傷材を磁化手段で磁化すると、被探傷材の表面また
は表面直下に存在する微小欠陥に起因して生じる漏れ磁
束の磁力により磁粉は瞬時に小室内を泳動し、磁気シー
トの観察面に一定の磁粉模様を形成する。次いで、磁気
シートを被探傷材から引き離し、その磁気シートに熱を
加えることにより分散媒を硬化させて観察面側のシート
に画かれた磁粉模様を固定する。According to the present invention, at least a sheet on the observation surface side is formed of a transparent material, and a large number of sheets are formed between the sheet on the observation surface side and the sheet on the opposite observation surface side. A magnetic sheet is used which is divided into small chambers and in which magnetic powder is dispersed in a dispersion medium containing a thermosetting dispersion medium and sealed in these small chambers. Contact or press against
When the material to be inspected is magnetized by the magnetizing means, the magnetic powder instantaneously migrates in the small chamber due to the magnetic force of the leakage magnetic flux caused by the minute defect existing on or immediately below the surface of the material to be inspected, and is fixed on the observation surface of the magnetic sheet. To form a magnetic powder pattern. Next, the magnetic sheet is separated from the material to be inspected, and the dispersion medium is cured by applying heat to the magnetic sheet to fix the magnetic powder pattern drawn on the sheet on the observation surface side.
【００１３】[0013]
【発明の実施の形態】即ち、本発明の方法は、被探傷材
を磁化手段で磁化し、被探傷材の表面または表面直下に
存在する磁束の通過を妨げる欠陥により該欠陥直上の空
間に漏れ磁束を生じさせ、該洩れ磁束で磁粉を吸引する
ことにより形成される磁粉模様に基づいて欠陥を検出す
る磁粉探傷法において、少なくとも観察面側のシートが
透明材料で形成され、観察面側のシートと反観察面側の
シートとの間を多数の小室に仕切り且つこれらの小室に
熱硬化性分散媒を含む分散媒中に磁粉を分散させたもの
を封入してなる磁気シートの観察面を被探傷材の探傷面
に当接させるか又は押し当てて密着させ、次いで、磁気
シートを被探傷材から引き離し、その磁気シートに熱を
加えることにより分散媒を硬化させて観察面側のシート
に画かれた磁粉模様を固定することを特徴としている。DESCRIPTION OF THE PREFERRED EMBODIMENTS That is, according to the method of the present invention, a material to be inspected is magnetized by a magnetizing means, and leakage to a space immediately above the defect is caused by a defect that prevents the passage of a magnetic flux existing on or immediately below the surface of the material. In a magnetic particle flaw detection method that generates a magnetic flux and detects a defect based on a magnetic powder pattern formed by attracting the magnetic powder with the leakage magnetic flux, at least the sheet on the observation surface side is formed of a transparent material, and the sheet on the observation surface side And the sheet on the side opposite to the observation surface are divided into a number of small chambers, and the observation surface of the magnetic sheet, in which magnetic powder is dispersed in a dispersion medium containing a thermosetting dispersion medium, is enclosed in these small chambers, is covered. The magnetic sheet is brought into contact with or pressed against the flaw detection surface of the flaw detection material, and then the magnetic sheet is separated from the flaw detection material, and heat is applied to the magnetic sheet to cure the dispersion medium, thereby forming an image on the sheet on the observation surface side. Magnetic powder It is characterized in that to fix the.
【００１４】次に、本発明による欠陥検出法および本発
明の磁粉探傷装置について説明する。 （１）磁気シート 磁気シートとは、図１（ａ）に示すように、２枚の透明
シート１ａ、１ｂ間に多数の小室２を有し、この小室２
内に微細な磁粉３（図では多数の微細な磁粉が凝集する
ことにより黒い塊で表されている）を分散させた分散媒
４を封入したものであり、一方のシート１ｂに磁粉模様
消去用磁石５を当接させつつ矢示方向に移動させること
により小室内の磁粉３を一方のシート１ｂ側に一様に移
動させ、その結果、他方のシート１ａ側の小室２内には
磁粉３が存在しない状態にされ、シート１ａを観察して
も、図１（ｂ）に示すように、何も見えない。次いで、
図１（ｃ）に示すように、シート１ａに磁石ペン６を当
接させつつ紙面直角方向に移動させると、小室２内の磁
粉３が吸引されてシート１ａ側に移動し、図１（ｄ）に
示すように、シート１ａに瞬時に磁粉模様７を画くこと
ができる。 （２）欠陥の検出 係る構成の磁気シートを用いて、本発明によれば、以下
のようにして欠陥を検出することができる。 ａ．探傷前に小室内の磁粉を観察面とは反対側の面に移
動させた場合 図２（ａ）に示すように、シート１ａに当接させつつ磁
粉模様消去用磁石５を矢示方向に移動させると、小室内
の磁粉３はシート１ａ側に移動してシート１ｂ側の小室
には磁粉が存在しなくなり、図２（ｂ）に示すように、
シート１ｂを観察しても何も見えない。次いで、図２
（ｃ）に示すように、この磁気シートのシート１ｂ側を
被探傷材８上に載置し、適切な磁化手段で被探傷材８を
磁化すると、被探傷材８の表面近傍に欠陥９が存在する
場合、その部分に生じる洩れ磁束により小室２内のシー
ト１ａ側にある磁粉３の一部がシート１ｂ側に吸引され
て、図２（ｄ）に示すように、欠陥９に対応した磁粉模
様１０がシート１ｂ側に現れるのを観察できる。Next, a defect detection method according to the present invention and a magnetic particle flaw detector according to the present invention will be described. (1) Magnetic Sheet As shown in FIG. 1A, a magnetic sheet has a large number of small chambers 2 between two transparent sheets 1a and 1b.
A dispersion medium 4 in which fine magnetic powder 3 (in the figure, represented by a black lump formed by agglomeration of a large number of fine magnetic powder) is sealed, and one sheet 1b is used to erase magnetic powder patterns. By moving the magnet 5 in the direction indicated by the arrow while abutting the magnet 5, the magnetic powder 3 in the small chamber is uniformly moved to the one sheet 1b side. As a result, the magnetic powder 3 is in the small chamber 2 on the other sheet 1a side. Even if the sheet 1a is set in a non-existent state and the sheet 1a is observed, nothing is seen as shown in FIG. Then
As shown in FIG. 1C, when the magnet pen 6 is moved in a direction perpendicular to the paper surface while the magnet pen 6 is in contact with the sheet 1a, the magnetic powder 3 in the small chamber 2 is sucked and moved to the sheet 1a side. As shown in ()), the magnetic powder pattern 7 can be instantaneously drawn on the sheet 1a. (2) Defect Detection According to the present invention, a defect can be detected as follows using the magnetic sheet having the above-described configuration. a. When the magnetic powder in the small chamber is moved to the surface opposite to the observation surface before the flaw detection, as shown in FIG. 2A, the magnetic powder pattern erasing magnet 5 is moved in the direction of the arrow while being in contact with the sheet 1a. Then, the magnetic powder 3 in the small chamber moves to the sheet 1a side, and no magnetic powder is present in the small chamber on the sheet 1b side, as shown in FIG. 2 (b).
Nothing is seen when the sheet 1b is observed. Then, FIG.
As shown in (c), the sheet 1b side of the magnetic sheet is placed on the material to be inspected 8, and the material to be inspected 8 is magnetized by an appropriate magnetizing means. If there is, a part of the magnetic powder 3 on the sheet 1a side in the small chamber 2 is attracted to the sheet 1b side by the leakage magnetic flux generated in that part, and the magnetic powder corresponding to the defect 9 as shown in FIG. It can be observed that the pattern 10 appears on the sheet 1b side.
【００１５】比較的大きい欠陥を検出する場合には、探
傷前に小室内の磁粉を観察面とは反対側の面に移動させ
ておいても、欠陥に対応して生じる漏れ磁束が大きく、
磁粉模様が明瞭に現れやすくなるので、欠陥の判定が比
較的容易である。 ｂ．探傷前に小室内の磁粉を観察面側に移動させた場合 微小欠陥を検出する場合、その漏れ磁束は僅かであり、
磁粉を極力探傷面側に近づけておくことが好ましい。そ
こで、図３（ａ）に示すように、磁粉模様消去用磁石５
をシート１ｂに当接させて矢示方向に移動させると、磁
粉３は磁石５の磁力で吸引されてシート１ｂ側に移動す
るが、小室２外に出ることはできないため、小室２の側
面に多くの磁粉が溜まった状態になり、このシート１ｂ
を観察すると、図３（ｂ）に示すように、全体的に灰色
を呈する状態が見られる。In the case of detecting a relatively large defect, even if the magnetic powder in the small chamber is moved to the surface opposite to the observation surface before the flaw detection, the leakage magnetic flux generated corresponding to the defect is large.
Since the magnetic powder pattern easily appears clearly, it is relatively easy to determine the defect. b. When magnetic powder in the small chamber is moved to the observation surface side before flaw detection When detecting minute defects, the leakage magnetic flux is small,
It is preferable to keep the magnetic powder as close to the flaw detection surface as possible. Therefore, as shown in FIG.
When the magnetic powder 3 is moved in the direction indicated by the arrow in contact with the sheet 1b, the magnetic powder 3 is attracted by the magnetic force of the magnet 5 and moves to the sheet 1b side, but cannot move out of the small chamber 2; A lot of magnetic powder is accumulated, and this sheet 1b
When observing, as shown in FIG. 3 (b), a state of exhibiting gray as a whole is observed.
【００１６】そして、図３（ｃ）に示すように、この磁
気シートのシート１ｂ側を観察面側として被探傷材８上
に載置し、適切な磁化手段で被探傷材８を磁化すると、
被探傷材８に欠陥９が存在する場合、欠陥９を挟んでそ
の両側でＮ極、Ｓ極が形成されるが、欠陥９が微小なも
のである場合、Ｎ極−Ｓ極は極めて接近し、そのため、
欠陥９の部分に生じる漏れ磁束の磁束密度は大きくな
り、しかも、磁束の移動がないので、欠陥９直上の小室
２ａ内にある磁粉のほぼ全量は欠陥９側に引き寄せら
れ、欠陥９直上の小室２ａに隣接する小室２ｂ、２ｃ内
にある磁粉は、小室２ａ側に引き寄せられるので、図３
（ｃ）に示すように、小室２ｂ、２ｃの観察面側には、
磁粉が存在しない領域１１が存在するようになる。Then, as shown in FIG. 3 (c), the magnetic sheet is placed on the material to be inspected 8 with the sheet 1b side as the observation surface side, and the material to be inspected 8 is magnetized by an appropriate magnetizing means.
When a defect 9 exists in the material 8 to be inspected, an N pole and an S pole are formed on both sides of the defect 9. However, when the defect 9 is minute, the N pole and the S pole are extremely close to each other. ,for that reason,
Since the magnetic flux density of the leakage magnetic flux generated in the portion of the defect 9 becomes large and the magnetic flux does not move, almost all of the magnetic powder in the small chamber 2a immediately above the defect 9 is drawn to the defect 9 side, and the small chamber immediately above the defect 9 Since the magnetic powder in the small chambers 2b and 2c adjacent to the small chamber 2a is attracted to the small chamber 2a, the magnetic powder in FIG.
As shown in (c), on the observation surface side of the small chambers 2b and 2c,
The region 11 where the magnetic powder does not exist is present.
【００１７】そこで、観察面側のシート１ｂを観察する
と、図３（ｄ）およびその部分拡大図である図３（ｅ）
に示すように、欠陥に対応する中央部には、黒色の磁粉
模様１２が見られ、この黒色の部分の周囲には白色の部
分１３が存在する様子を観察することができる。このよ
うに、欠陥の存在を知らせる「色のコントラスト」が大
きくなるので、目視で容易に微小欠陥の存在を判定でき
るようになる。When observing the sheet 1b on the observation surface side, FIG. 3D and FIG. 3E which is a partially enlarged view thereof are shown.
As shown in the figure, a black magnetic powder pattern 12 is seen at the center corresponding to the defect, and it can be observed that a white portion 13 exists around the black portion. As described above, the “color contrast” indicating the presence of the defect is increased, so that the presence of the minute defect can be easily determined visually.
【００１８】このような磁気シートを用いれば、磁粉は
小室内を移動するのみであり、探傷面が傾斜している場
合の影響も極小であり、磁粉は欠陥部に生じる漏れ磁束
による磁力により吸引されて、欠陥に対応した磁粉模様
を呈するので、欠陥の検出感度が比較的大きいという効
果がある。また、本発明の方法による磁粉模様は、中心
部に黒色の部分があり、その周囲に白色の部分があると
いう顕著な特徴を有しており、色のコントラスト（白枠
効果）による視覚に訴える効果が大きく、欠陥の判定が
容易であるという効果もある。その他、磁粉模様は瞬時
に形成されるので、欠陥の検出時間が短いという効果も
ある。If such a magnetic sheet is used, the magnetic particles move only in the small chamber, and the influence when the flaw detection surface is inclined is minimal, and the magnetic particles are attracted by the magnetic force due to the leakage magnetic flux generated at the defective portion. As a result, since a magnetic powder pattern corresponding to the defect is exhibited, there is an effect that the defect detection sensitivity is relatively large. Further, the magnetic powder pattern according to the method of the present invention has a remarkable feature that a black portion is present at the center and a white portion is present around the black portion, and appeals to visual sense due to color contrast (white frame effect). There is also an effect that the effect is large and the defect can be easily determined. In addition, since the magnetic powder pattern is formed instantaneously, there is also an effect that the time for detecting a defect is short.
【００１９】上記したように、磁気シートを用いた磁粉
探傷法による磁粉模様は、中心部に黒色の部分があり、
その周囲に白色の部分があるという顕著な特徴を有して
おり、色のコントラスト（白枠効果）による視覚に訴え
る効果が大きく、欠陥の判定が容易である。その場合、
欠陥の大きさに比較して小室が大きすぎると、色のコン
トラストが現れにくくなるので、小さい方が好ましい
が、小さ過ぎると小室の製造コストが高くなるだけでな
く、小室内に含まれる磁粉の量が少なくなり、色のコン
トラストが小さくなるという不都合が生じる。そのた
め、磁粉を分散させた分散媒（水、白灯油またはアルコ
ール類等）を封入する小室の直径は、５〜１０００μｍ
（いわゆるマイクロカプセル相当の大きさ）が好まし
い。As described above, the magnetic particle pattern obtained by the magnetic particle inspection method using the magnetic sheet has a black portion at the center,
It has a remarkable feature that there is a white portion around it, and the effect of appealing to the visual sense by the color contrast (white frame effect) is large, and the defect can be easily determined. In that case,
If the compartment is too large compared to the size of the defect, the color contrast is less likely to appear, so a smaller compartment is preferred, but too small not only increases the production cost of the compartment but also reduces the There is a disadvantage that the amount is reduced and the color contrast is reduced. Therefore, the diameter of the small chamber for enclosing the dispersion medium (water, white kerosene, alcohol, or the like) in which the magnetic powder is dispersed is 5 to 1000 μm.
(A size equivalent to a so-called microcapsule) is preferable.
【００２０】ところで、欠陥の観察結果を保存しようと
する場合、スケッチや写真では上記したような問題があ
り、探傷データを正確に長期間保存することができな
い。しかし、本発明によれば、磁気シートに熱を加える
ことにより分散媒を硬化させて観察面側のシートに画か
れた磁粉模様を固定することにより、探傷結果を確実に
長期間保存記録することができる。Incidentally, when trying to save the observation results of defects, sketches and photographs have the above-mentioned problems, so that flaw detection data cannot be stored accurately for a long period of time. However, according to the present invention, by applying heat to the magnetic sheet to cure the dispersion medium and fix the magnetic powder pattern drawn on the sheet on the observation surface side, the flaw detection result can be reliably stored and recorded for a long period of time. Can be.
【００２１】また、発光塗料をコーティングした磁粉を
用いれば、磁粉模様のコントラストが増すので、欠陥の
検出性能を向上させることができる。以下、本発明の他
の特徴および利点について、図面を参照しながら詳細に
説明する。 （３）本発明の磁粉探傷装置 ａ．磁粉模様の保存記録 図４は本発明に係る磁粉探傷装置の一実施例を示し、図
４（ａ）はその断面図、図４（ｂ）は図４（ａ）の磁気
シートの観察面側を示す平面図である。図４（ａ）にお
いて、１４は電磁石、１５は被探傷材、１６は磁気シー
ルドを構成する極く薄い塗膜である。観察面側の透明プ
ラスチック製のシート１７と反観察面側の透明プラスチ
ック製のシート１８との間に小室（図１〜図３参照）を
多数有し、この小室内に熱硬化性分散媒である熱硬化性
樹脂を含む分散媒中に多数の微細な磁粉を分散させた磁
気シート１９が塗膜１６上に載置されている。塗膜１６
は必ずしも必要なものではないが、欠陥部の漏れ磁束を
減衰させないために、欠陥検出（磁粉模様の明瞭度）の
要求レベルに応じて設けることができる。In addition, when magnetic powder coated with a luminescent paint is used, the contrast of the magnetic powder pattern is increased, so that the defect detection performance can be improved. Hereinafter, other features and advantages of the present invention will be described in detail with reference to the drawings. (3) Magnetic particle flaw detector of the present invention a. 4 shows an embodiment of a magnetic particle flaw detector according to the present invention, FIG. 4 (a) is a cross-sectional view thereof, and FIG. 4 (b) is an observation surface side of the magnetic sheet of FIG. 4 (a). FIG. In FIG. 4A, 14 is an electromagnet, 15 is a material to be inspected, and 16 is an extremely thin coating film constituting a magnetic shield. A large number of small chambers (see FIGS. 1 to 3) are provided between the transparent plastic sheet 17 on the observation surface side and the transparent plastic sheet 18 on the opposite observation surface side, and a thermosetting dispersion medium is provided in the small chamber. A magnetic sheet 19 in which a number of fine magnetic powders are dispersed in a dispersion medium containing a certain thermosetting resin is placed on the coating film 16. Coating film 16
Is not always necessary, but can be provided according to the required level of defect detection (clarity of magnetic powder pattern) in order not to attenuate the leakage flux at the defective portion.
【００２２】そして、図４（ａ）に示す構成の磁粉探傷
装置を用いて、被探傷材１５の表面に存在する微少欠陥
２０を検査した結果、観察面側のシート１７には、図４
（ｂ）に示すような明瞭な磁粉模様２１が現れたのが認
められた。As a result of inspecting the minute defect 20 existing on the surface of the inspection target material 15 using the magnetic particle inspection apparatus having the configuration shown in FIG.
A clear magnetic powder pattern 21 as shown in (b) was observed.
【００２３】そこで、この磁粉模様２１を保存記録する
ために、図５（ａ）に示す小室２２内に熱硬化性樹脂を
含む分散媒２３を封入した磁気シート１９に熱を加える
ことにより、分散媒２３が硬化して、図５（ｂ）に示す
ように、小室２２内の多数の微細な磁粉２４からなる磁
粉模様が固定された。この場合、熱硬化性樹脂としては
フェノール樹脂を使用し、溶剤としてはメチルアルコー
ルを使用した。In order to preserve and record the magnetic powder pattern 21, heat is applied to a magnetic sheet 19 in which a dispersion medium 23 containing a thermosetting resin is sealed in a small chamber 22 shown in FIG. The medium 23 was cured, and a magnetic powder pattern including a large number of fine magnetic powders 24 in the small chamber 22 was fixed as shown in FIG. In this case, a phenol resin was used as the thermosetting resin, and methyl alcohol was used as the solvent.
【００２４】熱硬化性樹脂としては、フェノール樹脂、
ビニルエステル樹脂、ジアリルフタレート樹脂、フラン
樹脂、ポリイミド樹脂、ポリウレタン樹脂、メラミン樹
脂、ユリア樹脂など公知の樹脂を用いることができる。 ｂ．欠陥の検出性能の向上 図６に示すように、小室２２内の分散媒２５中に発光塗
料をコーティングした多数の微細な磁粉２６を分散させ
れば、この観察面側および反観察面側がともに透明プラ
スチック製のシートからなる磁気シート２７に紫外線光
照射ライト２８から紫外線を照射することによって、磁
粉２６によって形成される磁粉模様が発光することでそ
の明度が増すので、欠陥の検出がより容易になる。この
場合、暗室内で磁粉模様を観察すれば、そのコントラス
トが一層増すので好ましい。発光塗料とは、ＺｎＳやＳ
ｒＳなどの蓄光性が大きく、リン（燐）光を発する物質
を主顔料とした塗料に放射性物質を微量添加したもので
あって、可視光や紫外線を照射すると、暗室でも長時間
にわたって発光し、夜光塗料とも呼ばれているものであ
り、本発明は公知の発光塗料を用いることができる。 ｃ．磁粉模様の保存記録と欠陥の検出性能の向上 さらに、熱硬化性樹脂を含む分散媒中に発光塗料をコー
ティングした磁粉を分散させることもできる。このよう
にすれば、熱硬化性樹脂の色が磁粉に似ている場合で
も、欠陥の検出性能が低下することなく良好に微少欠陥
を検出し、且つ磁粉模様の保存記録が可能である。この
場合、熱硬化性樹脂を硬化させるための磁気シートの加
熱は、次のいずれの手順でもよい。As the thermosetting resin, a phenol resin,
Known resins such as a vinyl ester resin, a diallyl phthalate resin, a furan resin, a polyimide resin, a polyurethane resin, a melamine resin, and a urea resin can be used. b. Improvement of Defect Detection Performance As shown in FIG. 6, if a large number of fine magnetic powders 26 coated with a luminescent paint are dispersed in a dispersion medium 25 in a small chamber 22, both the observation surface side and the non-observation surface side are transparent. By irradiating the ultraviolet rays from the ultraviolet light irradiating light 28 to the magnetic sheet 27 made of a plastic sheet, the magnetic powder pattern formed by the magnetic powder 26 emits light to increase its brightness, thereby making it easier to detect defects. . In this case, it is preferable to observe the magnetic powder pattern in a dark room because the contrast is further increased. Luminescent paint is ZnS or S
A substance with a large luminous property such as rS and a phosphorescent (phosphorous) substance as a main pigment, to which a small amount of a radioactive substance has been added. When irradiated with visible light or ultraviolet light, it emits light for a long time even in a dark room, It is also called a luminous paint, and in the present invention, a known luminescent paint can be used. c. Improvement of Storage Record of Magnetic Powder Pattern and Detection of Defects Further, magnetic powder coated with a luminescent paint can be dispersed in a dispersion medium containing a thermosetting resin. In this way, even when the color of the thermosetting resin is similar to the magnetic powder, it is possible to detect fine defects without deteriorating the defect detection performance and to store and record the magnetic powder pattern. In this case, the heating of the magnetic sheet for curing the thermosetting resin may be performed by any of the following procedures.
【００２５】すなわち、磁気シートの観察面を被探傷材
の探傷面に当接して探傷し、磁気シートを被探傷材から
引き離して磁粉模様を観察する前に磁気シートを加熱し
て熱硬化性樹脂を硬化させて磁粉模様を固定し、その
後、磁気シートに紫外線を照射して磁粉模様を発光させ
てもよく、逆に、被探傷材から引き離した磁気シートに
紫外線を照射して磁粉模様を発光させた後、磁気シート
を加熱して熱硬化性樹脂を硬化させることにより磁粉模
様を固定することもできる。 ｄ．磁化手段 図７は、磁化手段の一例を示す図であり、磁化手段とし
て被探傷材１５上に断面「コ」の字状の永久磁石２９を
載置することもできるし、また、陽極側のプレート３０
ａと陰極側のプレート３０ｂとの間に一定の電圧を印加
して磁界を発生させる方式のものを用いることもでき
る。That is, before the magnetic sheet is separated from the material to be inspected and the magnetic powder pattern is observed, the magnetic sheet is heated to form a thermosetting resin. To cure the magnetic powder pattern, and then irradiate the magnetic sheet with ultraviolet light to cause the magnetic powder pattern to emit light. Conversely, the magnetic sheet separated from the material to be inspected is irradiated with ultraviolet light to emit the magnetic powder pattern. After that, the magnetic sheet pattern can be fixed by heating the magnetic sheet to cure the thermosetting resin. d. Magnetizing Means FIG. 7 is a view showing an example of the magnetizing means. As the magnetizing means, a permanent magnet 29 having a U-shaped cross section can be placed on the material to be inspected 15. Plate 30
A type that generates a magnetic field by applying a constant voltage between a and a plate 30b on the cathode side can also be used.
【００２６】[0026]
【発明の効果】本発明は以上のとおり構成されているの
で、つぎの効果を奏する。 （１）請求項１、５記載の発明によれば、時間的な制約
がなく簡単な手法で探傷試験を行うことが可能で、探傷
結果を確実に長期間保存記録することができる磁粉探傷
法および磁粉探傷装置を提供することができる。 （２）請求項２、６記載の発明によれば、探傷性能を向
上することができる磁粉探傷法および磁粉探傷装置を提
供することができる。 （３）請求項３、４、７記載の発明によれば、熱硬化性
分散媒の種類や性状に関係なく、良好に探傷を行い、し
かも探傷結果を確実に長期間保存記録することができる
磁粉探傷法および磁粉探傷装置を提供することができ
る。 （４）請求項８記載の発明によれば、入手が容易である
熱硬化性樹脂を用いるので、磁粉探傷装置のコストの上
昇を抑制することができる。As described above, the present invention has the following advantages. (1) According to the first and fifth aspects of the present invention, it is possible to perform a flaw detection test by a simple method with no time limitation, and to reliably record and record a flaw detection result for a long period of time. And a magnetic particle flaw detector. (2) According to the second and sixth aspects of the invention, it is possible to provide a magnetic particle flaw detection method and a magnetic particle flaw detection apparatus capable of improving the flaw detection performance. (3) According to the third, fourth, and seventh aspects of the present invention, flaw detection can be performed satisfactorily regardless of the type and properties of the thermosetting dispersion medium, and the flaw detection results can be reliably recorded for a long period of time. A magnetic particle inspection method and a magnetic particle inspection apparatus can be provided. (4) According to the invention of claim 8, since the thermosetting resin which is easily available is used, an increase in the cost of the magnetic particle flaw detector can be suppressed.
【図１】磁気シートの使用例を説明する図である。FIG. 1 is a diagram illustrating an example of use of a magnetic sheet.
【図２】本発明による磁粉探傷法の一例を説明する図で
ある。FIG. 2 is a diagram illustrating an example of a magnetic particle flaw detection method according to the present invention.
【図３】本発明による磁粉探傷法の別の例を説明する図
である。FIG. 3 is a diagram illustrating another example of the magnetic particle flaw detection method according to the present invention.
【図４】図４（ａ）は本発明の磁粉探傷装置の要部を示
す断面図、図４（ｂ）はその磁気シートの表面に表され
た磁粉模様の一例を示す図である。FIG. 4A is a cross-sectional view showing a main part of a magnetic particle flaw detector of the present invention, and FIG. 4B is a diagram showing an example of a magnetic particle pattern shown on the surface of the magnetic sheet.
【図５】図５（ａ）は磁気シートを加熱して分散媒を硬
化させる状態を示す断面図、図５（ｂ）は磁気シートを
加熱して分散媒を硬化させ、磁粉模様を固定した状態を
示す図である。FIG. 5A is a cross-sectional view illustrating a state in which a magnetic sheet is heated to cure a dispersion medium, and FIG. 5B is a state in which the magnetic sheet is heated to cure the dispersion medium and a magnetic powder pattern is fixed. It is a figure showing a state.
【図６】磁気シートに紫外線を照射して発光塗料をコー
ティングした磁粉からなる模様が発光する状態を示す図
である。FIG. 6 is a view showing a state in which a pattern made of magnetic powder coated with a luminescent paint by irradiating a magnetic sheet with ultraviolet light emits light.
【図７】磁化手段の一例を示す概略構成図である。FIG. 7 is a schematic configuration diagram illustrating an example of a magnetizing unit.
【図８】磁粉探傷法のメカニズムを説明する図である。FIG. 8 is a diagram illustrating the mechanism of the magnetic particle flaw detection method.
【図９】従来の磁粉探傷装置による磁粉探傷法を説明す
る図である。FIG. 9 is a view for explaining a magnetic particle flaw detection method using a conventional magnetic particle flaw detector.
【図１０】図１０（ａ）は従来の別の磁粉探傷装置の斜
視図であり、図１０（ｂ）はその磁粉探傷装置に使用す
るベルトの断面図である。FIG. 10 (a) is a perspective view of another conventional magnetic particle flaw detector, and FIG. 10 (b) is a cross-sectional view of a belt used for the magnetic particle flaw detector.
【図１１】図１１（ａ）は従来のさらに別の磁粉探傷装
置の平面図、図１１（ｂ）はその断面図である。11A is a plan view of another conventional magnetic particle flaw detector, and FIG. 11B is a cross-sectional view thereof.
２、２２…小室 ３、２４、２６…磁粉 ４、２３、２５…分散媒 ７、１０、１２、２１…磁粉模様 ８、１５、…被探傷材 ９、２０…欠陥 １４…電磁石 １９、２７…磁気シート 2, 22 ... small chamber 3, 24, 26 ... magnetic powder 4, 23, 25 ... dispersion medium 7, 10, 12, 21 ... magnetic powder pattern 8, 15, ... material to be inspected 9, 20 ... defect 14 ... electromagnet 19, 27 ... Magnetic sheet
─────────────────────────────────────────────────────
────────────────────────────────────────────────── ───
【手続補正書】[Procedure amendment]
【提出日】平成１３年１１月９日（２００１．１１．
９）[Submission date] November 9, 2001 (2001.11.
9)
【手続補正１】[Procedure amendment 1]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】全文[Correction target item name] Full text
【補正方法】変更[Correction method] Change
【補正内容】[Correction contents]
【書類名】 明細書[Document Name] Statement
【発明の名称】 磁粉探傷法および磁粉探傷装置Title of the Invention Magnetic Particle Inspection Method and Magnetic Particle Inspection Device
【特許請求の範囲】[Claims]
【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION
【０００１】[0001]
【発明の属する技術分野】本発明は非破壊検査法に関
し、さらに、詳細には、強磁性材料を磁化し、割れなど
の欠陥の部分に生じる磁気の乱れを検知することにより
材料の欠陥を検出する方法である磁粉探傷法およびその
方法の実施に使用する磁粉探傷装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nondestructive inspection method, and more particularly, to a method for detecting a defect in a material by magnetizing a ferromagnetic material and detecting a magnetic disturbance generated in a defect portion such as a crack. The present invention relates to a magnetic particle flaw detection method which is a method for performing the method and a magnetic particle flaw detection apparatus used for carrying out the method.
【０００２】[0002]
【従来の技術】強磁性体の表面または表面直下に存在す
る欠陥を検出する方法として、被探傷材を磁化し、欠陥
部よりの漏れ磁束に磁粉を吸引させて生じる磁粉模様を
観察することにより欠陥を検出する方法である磁粉探傷
法は広く使用されている。2. Description of the Related Art As a method of detecting a defect existing on or immediately below a surface of a ferromagnetic material, a material to be inspected is magnetized, and a magnetic powder pattern generated by attracting magnetic powder to a leakage magnetic flux from a defect portion is observed. Magnetic particle flaw detection, which is a method for detecting defects, is widely used.
【０００３】この磁粉探傷法は、図８に示すように、強
磁性材である被探傷材３１上に磁石３２を載置し、被探
傷材３１を磁石３２で磁化して表面近傍の欠陥３３の部
分に現れる漏れ磁束３４に磁粉３５を吸引させて磁粉模
様を生じさせ、微小欠陥を可視化させる方法であり、Ｊ
ＩＳ−Ｇ０５６５−１９９２に規定された方法は、磁粉
を被探傷面に空気とともに吹き付けるか、または、磁粉
を均一に分散させた検査液を被探傷面上に静かに流し
て、漏れ磁束が生じている部分に現れる磁粉模様を肉眼
にて直接観察する方法（以下「ＪＩＳの磁粉探傷法」と
いう）である。In this magnetic particle flaw detection method, as shown in FIG. 8, a magnet 32 is placed on a flaw detection target material 31 which is a ferromagnetic material, and the flaw detection target material 31 is magnetized by the magnet 32 to form a defect 33 near the surface. The magnetic flux 35 is attracted to the leakage magnetic flux 34 appearing in the portion of the arrow to generate a magnetic powder pattern, thereby visualizing minute defects.
According to the method specified in IS-G0565-1992, magnetic particles are sprayed on the surface to be inspected together with air, or a test liquid in which the magnetic particles are uniformly dispersed is gently flowed over the surface to be inspected to generate leakage magnetic flux. This is a method of directly observing a magnetic powder pattern appearing in a part where the part is present with the naked eye (hereinafter, referred to as “JIS magnetic particle flaw detection method”).
【０００４】しかし、上記ＪＩＳの磁粉探傷法は、微小
欠陥の検出に使用した場合、漏れ磁束が小さくて磁粉を
吸引する磁力が弱いので、空気あるいは液体とともに磁
粉を流すと、その流れの慣性力のために漏れ磁束部位に
磁粉を吸引しにくく、被探傷材を磁化しながら連続的に
磁粉を流す必要があり、目視で判断できる状態にするに
は時間がかかるという欠点がある。また、被探傷面が傾
斜していると、検査液の重力のために磁粉の移動速度が
速くなり、漏れ磁束に磁粉を吸引するのが困難になり、
特に、被探傷面が鉛直方向であると、洩れ磁束に磁粉を
吸引させるのにかなりの熟練を要する。さらに、被探傷
面が予め十分に清掃されていないと、被探傷面と磁粉模
様とのコントラストがつきにくくなるので、探傷前に被
探傷面を予め十分に清掃しておかなければならないとい
う煩わしい作業が必要であり、探傷作業後には磁粉や液
体の除去と清掃作業が必要である。その上、磁粉の再使
用が不可能であり、経済的に不利である。そして、被探
傷面に凹凸があると、磁粉が凹部に溜まり、疑似模様が
欠陥と誤判断される可能性がある。However, when the magnetic particle flaw detection method of JIS described above is used for detecting a minute defect, the leakage magnetic flux is small and the magnetic force for attracting the magnetic particle is weak. For this reason, it is difficult to attract the magnetic powder to the leaked magnetic flux portion, and it is necessary to continuously flow the magnetic powder while magnetizing the material to be inspected. Also, if the surface to be inspected is inclined, the moving speed of the magnetic powder is increased due to the gravity of the test liquid, and it becomes difficult to attract the magnetic powder to the leakage magnetic flux.
In particular, when the surface to be inspected is in the vertical direction, considerable skill is required to attract the magnetic powder to the leakage magnetic flux. Further, if the surface to be inspected is not sufficiently cleaned in advance, the contrast between the surface to be inspected and the magnetic powder pattern is difficult to be obtained, so that the troublesome operation that the surface to be inspected must be sufficiently cleaned before inspection. After the flaw detection operation, it is necessary to remove and clean the magnetic particles and liquid. In addition, it is impossible to reuse the magnetic powder, which is economically disadvantageous. If the surface to be inspected has irregularities, the magnetic powder accumulates in the concave portions, and the pseudo pattern may be erroneously determined as a defect.
【０００５】また、特公昭６０−３４０６６号公報に
は、図９（ａ）に模式的に示すように、磁粉を分散させ
た検査液３６を密閉された可撓性容器３７に封入し、非
導電性弾性薄膜３８を被探傷材に押しつけ、欠陥部の漏
洩磁束による磁粉模様を非導電性弾性薄膜３８上に画か
せて、この磁粉模様を容器３７の透明部３９を通して観
察する方式のもの（以下「従来の磁粉探傷法１」とい
う）が記載されている。この従来の磁粉探傷法１は、漏
れ磁束の大きい大型欠陥を対象とする場合には適用する
ことが可能である。しかし、一般構造物の微小欠陥の検
出に適用するのは困難である。というのは、従来の磁粉
探傷法１もＪＩＳの磁粉探傷法と同じく、磁粉を吸引す
る漏れ磁束の磁力が小さく、図９（ｂ）に示すように、
被探傷材４０の表面の微小欠陥４１に対応して生じる洩
れ磁束の磁力の及ぶ範囲の検査液中に分散した磁粉を凝
集し、凝集物４２を生じさせても、その凝集量が少ない
ので、探傷前に透明部３９から見た状態を示す図９
（ｃ）と、磁粉の凝集物４２による磁粉模様４３を透明
部３９から見た状態を示す図９（ｄ）との差異はそれほ
ど明瞭でなく（磁粉模様４３がうすくて判別しにく
く）、欠陥の検出が困難である。そこで、検査液中の磁
粉の濃度を高めると、凝集磁粉量は多くなるが、検査液
自体が磁粉により黒ずむなど、磁粉の凝集部分と他の部
分とのコントラストがつきにくくなる。また、連続的に
探傷する場合は、直前の探傷による磁粉の凝集物を再度
均一に分散させなければ、明確な磁粉模様を得ることは
できないが、密閉容器３７内の液体を流動化させること
は難しく、液体と磁粉の相対的な動きを液体の流れによ
り生じさせることも困難である。さらに、凹凸のある面
を探傷する際、非導電性弾性薄膜３８が可撓性を有する
としても、凸部に接触する容器の検査液の高さ（Ｈ）が
減少し、磁粉模様にバラツキが生じ、欠陥の検出感度が
低下する。Japanese Patent Publication No. 60-34066 discloses a test solution 36 in which magnetic powder is dispersed in a sealed flexible container 37, as schematically shown in FIG. A method in which the conductive elastic thin film 38 is pressed against the material to be inspected, a magnetic powder pattern caused by the leakage magnetic flux of the defective portion is drawn on the non-conductive elastic thin film 38, and the magnetic powder pattern is observed through the transparent portion 39 of the container 37 ( Hereinafter, "conventional magnetic particle flaw detection method 1" is described. This conventional magnetic particle flaw detection method 1 can be applied to a large defect having a large leakage magnetic flux. However, it is difficult to apply it to the detection of minute defects in general structures. This is because, similarly to the magnetic particle flaw detection method of JIS, the conventional magnetic particle flaw detection method 1 has a small magnetic force of the leakage magnetic flux for attracting the magnetic particles, and as shown in FIG.
Even if the magnetic powder dispersed in the test solution within the range of the magnetic force of the leakage magnetic flux generated corresponding to the minute defect 41 on the surface of the material to be inspected 40 is aggregated to form the aggregate 42, the amount of aggregation is small, FIG. 9 showing a state viewed from the transparent part 39 before the flaw detection.
The difference between FIG. 9C and FIG. 9D showing the state where the magnetic powder pattern 43 due to the magnetic powder aggregates 42 is viewed from the transparent portion 39 is not so clear (the magnetic powder pattern 43 is so thin that it is difficult to distinguish it). Is difficult to detect. Therefore, when the concentration of the magnetic powder in the test solution is increased, the amount of the agglomerated magnetic powder increases, but the contrast between the agglomerated portion of the magnetic powder and other portions is hardly obtained, such as the test solution itself being darkened by the magnetic powder. Further, in the case of continuous flaw detection, a clear magnetic powder pattern cannot be obtained unless the aggregates of the magnetic powder from the immediately preceding flaw detection are uniformly dispersed again, but the liquid in the closed container 37 cannot be fluidized. It is difficult, and it is also difficult to cause relative movement between the liquid and the magnetic powder by the flow of the liquid. Further, when detecting a surface having irregularities, even if the non-conductive elastic thin film 38 has flexibility, the height (H) of the test solution in the container in contact with the convex portion decreases, and the magnetic powder pattern varies. And the sensitivity of defect detection is reduced.
【０００６】さらに、特公昭６１−４５１８６号公報に
は、図１０（ｂ）に示すように、透明可撓性薄膜４４と
白色可撓性薄膜４５からなる可撓性ベルト４６内の空間
に磁粉を含有する検査液４７を封入し、図１０（ａ）に
示すように、この可撓性ベルト４６を３本の遊動輪４８
と１本の駆動輪４９との間に架け渡し、磁化電極５０に
よって被探傷材５１を連続的に磁化し、無限軌道を構成
する可撓性ベルト４６を被探傷材５１に接触させつつ磁
粉探傷する構成のもの（以下「従来の磁粉探傷法２」と
いう）が記載されている。しかし、この従来の磁粉探傷
法２は、可撓性容器が可撓性ベルトに代わっただけで、
上記した従来の磁粉探傷法１と同様の欠点を有してい
る。Further, Japanese Patent Publication No. 61-45186 discloses that, as shown in FIG. 10B, magnetic powder is formed in a space in a flexible belt 46 comprising a transparent flexible thin film 44 and a white flexible thin film 45. And the flexible belt 46 is connected to three idlers 48 as shown in FIG.
And one driving wheel 49, continuously magnetize the flaw detection material 51 by the magnetized electrode 50, and contact the flexible belt 46 forming an endless track with the flaw detection material 51 while magnetically flaw detecting the magnetic powder. (Hereinafter referred to as “conventional magnetic particle flaw detection method 2”). However, in this conventional magnetic particle flaw detection method 2, only the flexible container is replaced with a flexible belt,
It has the same drawbacks as the conventional magnetic particle flaw detection method 1 described above.
【０００７】そこで、本出願人は、先に、微小欠陥の検
出感度が大きくて微小欠陥の有無の判定が容易な磁粉探
傷法および磁粉探傷装置に関する改良発明について特許
出願を行った（特願平１１−１８９３２８号）。Therefore, the present applicant has previously filed a patent application for an improved invention relating to a magnetic particle flaw detection method and a magnetic particle flaw detection apparatus which has a high sensitivity for detecting a minute defect and makes it easy to determine the presence / absence of a minute defect (Japanese Patent Application No. Hei. 11-189328).
【０００８】一方、特公平３−４０３３９号公報には、
図１１に示すように、ポリエチレンの薄片５２と５３で
形成された容器内を、ポリエチレンの薄片５４によって
小室５５と５６に仕切り、一方の小室５５には磁粉を充
填し、他方の小室５６には化学反応によって硬化する分
散媒を充填し、探傷試験直前に薄片５４からなる仕切を
破って磁粉と分散媒を均一に混合し、この容器を被探傷
材に当接させて分散媒が硬化するまでの間に探傷試験を
行い、分散媒が硬化した後にその容器を被探傷材から取
り外すことを特徴とする、磁粉探傷装置（以下「硬化型
分散媒を使用した従来の磁粉探傷装置」という）が記載
されている。On the other hand, Japanese Patent Publication No. 3-40339 discloses that
As shown in FIG. 11, the inside of the container formed of polyethylene flakes 52 and 53 is partitioned into small chambers 55 and 56 by polyethylene flakes 54. One small chamber 55 is filled with magnetic powder, and the other small chamber 56 is filled with magnetic powder. Filling the dispersion medium which is hardened by the chemical reaction, breaking the partition made of the thin piece 54 just before the flaw detection test, uniformly mixing the magnetic powder and the dispersion medium, and bringing the container into contact with the material to be flaw-detected until the dispersion medium is hardened. A magnetic particle flaw detection device (hereinafter referred to as a "conventional magnetic particle flaw detection device using a hardening type dispersion medium") is characterized in that a flaw detection test is performed during that time and the container is removed from the material to be flawed after the dispersion medium is cured. Has been described.
【０００９】[0009]
【発明が解決しようとする課題】本出願人による改良発
明によれば、微少欠陥の検出感度を向上させることは可
能であるが、磁気シートに描かれた磁粉模様を肉眼で観
察して欠陥を検出する方法であるため、探傷結果の記録
を残そうとすれば、その磁粉模様をスケッチするか、写
真撮影することにより記録を残すことは可能であるが、
スケッチや写真は時を経るにつれて画像が薄れたり、汚
れたり、または欠損したりすることがあるので、探傷デ
ータを正確に長期間保存することができない。また、探
傷済みの磁気シートに新たな磁気が加わった場合、その
探傷結果が変化するという問題がある。According to the improved invention of the present applicant, it is possible to improve the detection sensitivity of minute defects, but it is possible to visually observe a magnetic powder pattern drawn on a magnetic sheet to detect defects. Because it is a detection method, if you want to keep a record of the flaw detection result, it is possible to leave a record by sketching or photographing the magnetic powder pattern,
Sketches and photographs may not be able to store flaw detection data accurately for long periods of time, as images may fade, become dirty, or become lost over time. In addition, when new magnetism is applied to a magnetic sheet that has been inspected, there is a problem that the inspection result changes.
【００１０】さらに、硬化型分散媒を使用した従来の磁
粉探傷装置は、薬品混合による硬化であるため、探傷試
験直前に分散媒と磁粉を均一に混合しなければならない
という煩わしさがある。また、分散媒が硬化するまでの
間に探傷試験を終了しなければならないという時間的な
制約がある。Furthermore, the conventional magnetic particle flaw detection apparatus using a curable dispersion medium involves the inconvenience that the dispersion medium and the magnetic powder must be uniformly mixed immediately before the flaw detection test because the apparatus is cured by mixing chemicals. Further, there is a time constraint that the flaw detection test must be completed before the dispersion medium is cured.
【００１１】本発明は従来の技術の有するこのような問
題点に鑑みてなされたものであって、その目的は、時間
的な制約がなく簡単な手法で探傷試験を行うことが可能
で、探傷結果を確実に長期間保存記録することができる
磁粉探傷法および磁粉探傷装置を提供することにある。
また、本発明の目的は、探傷性能を向上することができ
る磁粉探傷法および磁粉探傷装置を提供することにあ
る。SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and has as its object to perform a flaw detection test by a simple method without any time limitation. An object of the present invention is to provide a magnetic particle flaw detection method and a magnetic particle flaw detection apparatus capable of reliably storing and recording results for a long period.
Another object of the present invention is to provide a magnetic particle flaw detection method and a magnetic particle flaw detection apparatus capable of improving flaw detection performance.
【００１２】[0012]
【課題を解決するための手段】上記目的を達成するため
に本発明は、いずれか一方の面側に多数の小室を備え且
つこれらの小室に熱硬化性分散媒を含む分散媒中に磁粉
を分散させたものを封入してなる磁気シートを採用し、
該磁気シートを被探傷材の探傷面に当接させるか又は押
し当てて密着させ、被探傷材を磁化手段で磁化すると、
被探傷材の表面または表面近傍に存在する微小欠陥に起
因して生じる漏れ磁束の磁力により磁粉は瞬時に小室内
を泳動し、磁気シートに一定の磁粉模様を形成する。次
いで、磁気シートを被探傷材から引き離し、その磁気シ
ートに熱を加えることにより分散媒を硬化させて磁気シ
ートに画かれた磁粉模様を固定する。SUMMARY OF THE INVENTION In order to achieve the above object, the present invention is directed to a method for disposing a plurality of small chambers on one of the surfaces and including a thermosetting dispersion medium in these small chambers. Adopt a magnetic sheet made by enclosing a dispersion of magnetic powder in a medium,
The magnetic sheet is brought into close contact against or push or brought into contact with the inspection surface of the test object material, when magnetized in the magnetization means test object material,
The magnetic powder instantaneously migrates in the small chamber due to the magnetic force of the leakage magnetic flux generated due to the minute defect existing on or near the surface of the material to be inspected, and forms a fixed magnetic powder pattern on the magnetic sheet . Next, the magnetic sheet is separated from the material to be inspected, and heat is applied to the magnetic sheet so that the dispersion medium is cured to form a magnetic sheet.
To fix the magnet powder pattern that has been fractionated to over door.
【００１３】[0013]
【発明の実施の形態】即ち、本発明の方法は、被探傷材
を磁化手段で磁化し、被探傷材の表面または表面近傍に
存在する磁束の通過を妨げる欠陥により該欠陥直上の空
間に漏れ磁束を生じさせ、該洩れ磁束で磁粉を吸引する
ことにより形成される磁粉模様に基づいて欠陥を検出す
る磁粉探傷法において、いずれか一方の面側に多数の小
室を備え且つこれらの小室に熱硬化性分散媒を含む分散
媒中に磁粉を分散させたものを封入してなる磁気シート
を準備し、該磁気シートを被探傷材の探傷面に当接させ
るか又は押し当てて密着させ、次いで、磁気シートを被
探傷材から引き離し、その磁気シートに熱を加えること
により分散媒を硬化させて磁気シートに画かれた磁粉模
様を固定することを特徴としている。DESCRIPTION OF THE PREFERRED EMBODIMENTS In the method of the present invention, a material to be inspected is magnetized by a magnetizing means, and leakage to a space immediately above the defect is caused by a defect that prevents passage of a magnetic flux existing on or near the surface of the material to be inspected. In the magnetic particle flaw detection method in which a magnetic flux is generated and a defect is detected based on a magnetic powder pattern formed by attracting the magnetic powder with the leakage magnetic flux, a large number of small
Sheet comprising a chamber and enclosing a dispersion of magnetic powder in a dispersion medium containing a thermosetting dispersion medium in these small chambers
Is prepared, and the magnetic sheet is brought into contact with or pressed against the surface to be inspected of the material to be inspected, and then the magnetic sheet is separated from the material to be inspected, and the dispersion medium is cured by applying heat to the magnetic sheet. Then, the magnetic powder pattern drawn on the magnetic sheet is fixed.
【００１４】次に、本発明による欠陥検出法および本発
明の磁粉探傷装置について説明する。 （１）磁気シート 磁気シートとは、図１（ａ）に示すように、２枚の透明
シート１ａ、１ｂ間に多数の小室２を有し、この小室２
内に微細な磁粉３（図では多数の微細な磁粉が凝集する
ことにより黒い塊で表されている）を分散させた分散媒
４を封入したものであり、一方のシート１ｂに磁粉模様
消去用磁石５を当接させつつ矢示方向に移動させること
により小室内の磁粉３を一方のシート１ｂ側に一様に移
動させ、その結果、他方のシート１ａ側の小室２内には
磁粉３が存在しない状態にされ、シート１ａを観察して
も、図１（ｂ）に示すように、何も見えない。次いで、
図１（ｃ）に示すように、シート１ａに磁石ペン６を当
接させつつ紙面直角方向に移動させると、小室２内の磁
粉３が吸引されてシート１ａ側に移動し、図１（ｄ）に
示すように、シート１ａに瞬時に磁粉模様７を画くこと
ができる。 （２）欠陥の検出 係る構成の磁気シートを用いて、本発明によれば、以下
のようにして欠陥を検出することができる。 ａ．探傷前に小室内の磁粉を被探傷材に当接する面とは
反対側の面に移動させた場合 図２（ａ）に示すように、シート１ａに当接させつつ磁
粉模様消去用磁石５を矢示方向に移動させると、小室内
の磁粉３はシート１ａ側に移動してシート１ｂ側の小室
には磁粉が存在しなくなり、図２（ｂ）に示すように、
シート１ｂを観察しても何も見えない。次いで、図２
（ｃ）に示すように、この磁気シートのシート１ｂ側を
被探傷材８上に載置し、適切な磁化手段で被探傷材８を
磁化すると、被探傷材８の表面近傍に欠陥９が存在する
場合、その部分に生じる洩れ磁束により小室２内のシー
ト１ａ側にある磁粉３の一部がシート１ｂ側に吸引され
て、図２（ｄ）に示すように、欠陥９に対応した磁粉模
様１０がシート１ｂ側に現れるのを観察できる。Next, a defect detection method according to the present invention and a magnetic particle flaw detector according to the present invention will be described. (1) Magnetic Sheet As shown in FIG. 1A, a magnetic sheet has a large number of small chambers 2 between two transparent sheets 1a and 1b.
A dispersion medium 4 in which fine magnetic powder 3 (in the figure, represented by a black lump formed by agglomeration of a large number of fine magnetic powder) is sealed, and one sheet 1b is used to erase magnetic powder patterns. By moving the magnet 5 in the direction indicated by the arrow while abutting the magnet 5, the magnetic powder 3 in the small chamber is uniformly moved to the one sheet 1b side. As a result, the magnetic powder 3 is in the small chamber 2 on the other sheet 1a side. Even if the sheet 1a is set in a non-existent state and the sheet 1a is observed, nothing is seen as shown in FIG. Then
As shown in FIG. 1C, when the magnet pen 6 is moved in a direction perpendicular to the paper surface while the magnet pen 6 is in contact with the sheet 1a, the magnetic powder 3 in the small chamber 2 is sucked and moved to the sheet 1a side. As shown in ()), the magnetic powder pattern 7 can be instantaneously drawn on the sheet 1a. (2) Defect Detection According to the present invention, a defect can be detected as follows using the magnetic sheet having the above-described configuration. a. When the magnetic powder in the small chamber is moved to a surface opposite to the surface in contact with the material to be inspected before the flaw detection, as shown in FIG. When the magnetic powder 3 is moved in the direction indicated by the arrow, the magnetic powder 3 in the small chamber moves to the sheet 1a side and the magnetic powder does not exist in the small chamber on the sheet 1b side, as shown in FIG.
Nothing is seen when the sheet 1b is observed. Then, FIG.
As shown in (c), the sheet 1b side of the magnetic sheet is placed on the material to be inspected 8, and the material to be inspected 8 is magnetized by an appropriate magnetizing means. If there is, a part of the magnetic powder 3 on the sheet 1a side in the small chamber 2 is attracted to the sheet 1b side by the leakage magnetic flux generated in that part, and the magnetic powder corresponding to the defect 9 as shown in FIG. It can be observed that the pattern 10 appears on the sheet 1b side.
【００１５】比較的大きい欠陥を検出する場合には、探
傷前に小室内の磁粉を被探傷材に当接する面とは反対側
の面に移動させておいても、欠陥に対応して生じる漏れ
磁束が大きく、磁粉模様が明瞭に現れやすくなるので、
欠陥の判定が比較的容易である。 ｂ．探傷前に小室内の磁粉を被探傷材に当接する面側に
移動させた場合 微小欠陥を検出する場合、その漏れ磁束は僅かであり、
磁粉を極力探傷面側に近づけておくことが好ましい。そ
こで、図３（ａ）に示すように、磁粉模様消去用磁石５
をシート１ｂに当接させて矢示方向に移動させると、磁
粉３は磁石５の磁力で吸引されてシート１ｂ側に移動す
るが、小室２外に出ることはできないため、小室２の側
面に多くの磁粉が溜まった状態になり、このシート１ｂ
を観察すると、図３（ｂ）に示すように、全体的に灰色
を呈する状態が見られる。When a relatively large defect is detected, even if the magnetic powder in the small chamber is moved to a surface opposite to a surface in contact with the material to be inspected before the flaw detection, a leak generated in response to the defect is generated. Since the magnetic flux is large and the magnetic powder pattern tends to appear clearly,
Defect determination is relatively easy. b. When the magnetic powder in the small chamber is moved to the surface that comes into contact with the material to be inspected before the inspection, When detecting a minute defect, the leakage magnetic flux is small,
It is preferable to keep the magnetic powder as close to the flaw detection surface as possible. Therefore, as shown in FIG.
When the magnetic powder 3 is moved in the direction indicated by the arrow in contact with the sheet 1b, the magnetic powder 3 is attracted by the magnetic force of the magnet 5 and moves to the sheet 1b side, but cannot move out of the small chamber 2; A lot of magnetic powder is accumulated, and this sheet 1b
When observing, as shown in FIG. 3 (b), a state of exhibiting gray as a whole is observed.
【００１６】そして、図３（ｃ）に示すように、この磁
気シートのシート１ｂ側を被探傷材に当接する面側とし
て被探傷材８上に載置し、適切な磁化手段で被探傷材８
を磁化すると、被探傷材８に欠陥９が存在する場合、欠
陥９を挟んでその両側でＮ極、Ｓ極が形成されるが、欠
陥９が微小なものである場合、Ｎ極−Ｓ極は極めて接近
し、そのため、欠陥９の部分に生じる漏れ磁束の磁束密
度は大きくなり、しかも、磁束の移動がないので、欠陥
９直上の小室２ａ内にある磁粉のほぼ全量は欠陥９側に
引き寄せられ、欠陥９直上の小室２ａに隣接する小室２
ｂ、２ｃ内にある磁粉は、小室２ａ側に引き寄せられる
ので、図３（ｃ）に示すように、小室２ｂ、２ｃの被探
傷材に当接する面側には、磁粉が存在しない領域１１が
存在するようになる。Then, as shown in FIG. 3 (c), the sheet 1b side of the magnetic sheet is placed on the material to be inspected 8 as a surface which comes into contact with the material to be inspected, and the material to be inspected is appropriately magnetized. 8
When the defect 9 is present in the material 8 to be inspected, N poles and S poles are formed on both sides of the defect 9. When the defect 9 is minute, the N pole and the S pole are formed. Are very close to each other, so that the magnetic flux density of the leakage magnetic flux generated at the defect 9 increases, and since there is no movement of the magnetic flux, almost all of the magnetic powder in the small chamber 2 a immediately above the defect 9 is drawn to the defect 9 side. Cell 2 adjacent to the cell 2a immediately above the defect 9
b, the magnetic particles within 2c, because it is attracted to the chamber 2a side, as shown in FIG. 3 (c), Komuro 2b, probe be of 2c
A region 11 where no magnetic powder is present is present on the side of the surface that contacts the flaw material .
【００１７】そこで、被探傷材に当接する面側のシート
１ｂを観察すると、図３（ｄ）およびその部分拡大図で
ある図３（ｅ）に示すように、欠陥に対応する中央部に
は、黒色の磁粉模様１２が見られ、この黒色の部分の周
囲には白色の部分１３が存在する様子を観察することが
できる。このように、欠陥の存在を知らせる「色のコン
トラスト」が大きくなるので、目視で容易に微小欠陥の
存在を判定できるようになる。Therefore, when observing the sheet 1b on the side contacting the material to be inspected , as shown in FIG. 3D and its partially enlarged view in FIG. A black magnetic powder pattern 12 can be seen, and it can be observed that a white portion 13 exists around the black portion. As described above, the “color contrast” indicating the presence of the defect is increased, so that the presence of the minute defect can be easily determined visually.
【００１８】このような磁気シートを用いれば、磁粉は
小室内を移動するのみであり、探傷面が傾斜している場
合の影響も極小であり、磁粉は欠陥部に生じる漏れ磁束
による磁力により吸引されて、欠陥に対応した磁粉模様
を呈するので、欠陥の検出感度が比較的大きいという効
果がある。また、本発明の方法による磁粉模様は、中心
部に黒色の部分があり、その周囲に白色の部分があると
いう顕著な特徴を有しており、色のコントラスト（白枠
効果）による視覚に訴える効果が大きく、欠陥の判定が
容易であるという効果もある。その他、磁粉模様は瞬時
に形成されるので、欠陥の検出時間が短いという効果も
ある。If such a magnetic sheet is used, the magnetic particles move only in the small chamber, and the influence when the flaw detection surface is inclined is minimal, and the magnetic particles are attracted by the magnetic force due to the leakage magnetic flux generated at the defective portion. As a result, since a magnetic powder pattern corresponding to the defect is exhibited, there is an effect that the defect detection sensitivity is relatively large. Further, the magnetic powder pattern according to the method of the present invention has a remarkable feature that a black portion is present at the center and a white portion is present around the black portion, and appeals to visual sense due to color contrast (white frame effect). There is also an effect that the effect is large and the defect can be easily determined. In addition, since the magnetic powder pattern is formed instantaneously, there is also an effect that the time for detecting a defect is short.
【００１９】上記したように、磁気シートを用いた磁粉
探傷法による磁粉模様は、中心部に黒色の部分があり、
その周囲に白色の部分があるという顕著な特徴を有して
おり、色のコントラスト（白枠効果）による視覚に訴え
る効果が大きく、欠陥の判定が容易である。その場合、
欠陥の大きさに比較して小室が大きすぎると、色のコン
トラストが現れにくくなるので、小さい方が好ましい
が、小さ過ぎると小室の製造コストが高くなるだけでな
く、小室内に含まれる磁粉の量が少なくなり、色のコン
トラストが小さくなるという不都合が生じる。そのた
め、磁粉を分散させた分散媒（水、白灯油またはアルコ
ール類等）を封入する小室の直径は、５〜１０００μｍ
（いわゆるマイクロカプセル相当の大きさ）が好まし
い。As described above, the magnetic particle pattern obtained by the magnetic particle inspection method using the magnetic sheet has a black portion at the center,
It has a remarkable feature that there is a white portion around it, and the effect of appealing to the visual sense by the color contrast (white frame effect) is large, and the defect can be easily determined. In that case,
If the compartment is too large compared to the size of the defect, the color contrast is less likely to appear, so a smaller compartment is preferred, but too small not only increases the production cost of the compartment but also reduces the There is a disadvantage that the amount is reduced and the color contrast is reduced. Therefore, the diameter of the small chamber for enclosing the dispersion medium (water, white kerosene, alcohol, or the like) in which the magnetic powder is dispersed is 5 to 1000 μm.
(A size equivalent to a so-called microcapsule) is preferable.
【００２０】ところで、欠陥の観察結果を保存しようと
する場合、スケッチや写真では上記したような問題があ
り、探傷データを正確に長期間保存することができな
い。しかし、本発明によれば、磁気シートに熱を加える
ことにより分散媒を硬化させて被探傷材に当接する面側
のシートに画かれた磁粉模様を固定することにより、探
傷結果を確実に長期間保存記録することができる。Incidentally, when trying to save the observation results of defects, sketches and photographs have the above-mentioned problems, so that flaw detection data cannot be stored accurately for a long period of time. However, according to the present invention, by applying heat to the magnetic sheet to harden the dispersion medium and fix the magnetic powder pattern drawn on the sheet on the surface side in contact with the material to be inspected , the flaw detection result can be reliably lengthened. Can be stored for a period.
【００２１】また、発光塗料をコーティングした磁粉を
用いれば、磁粉模様のコントラストが増すので、欠陥の
検出性能を向上させることができる。以下、本発明の他
の特徴および利点について、図面を参照しながら詳細に
説明する。 （３）本発明の磁粉探傷装置 ａ．磁粉模様の保存記録 図４は本発明に係る磁粉探傷装置の一実施例を示し、図
４（ａ）はその断面図、図４（ｂ）は図４（ａ）の磁気
シートの被探傷材に当接する面側を示す平面図である。
図４（ａ）において、１４は電磁石、１５は被探傷材、
１６は磁気シールドを構成する極く薄い塗膜である。被
探傷材に当接する面側の透明プラスチック製のシート１
７とその反対面側の透明プラスチック製のシート１８と
の間に小室（図１〜図３参照）を多数有し、この小室内
に熱硬化性分散媒である熱硬化性樹脂を含む分散媒中に
多数の微細な磁粉を分散させた磁気シート１９が塗膜１
６上に載置されている。塗膜１６は必ずしも必要なもの
ではないが、欠陥部の漏れ磁束を減衰させないために、
欠陥検出（磁粉模様の明瞭度）の要求レベルに応じて設
けることができる。In addition, when magnetic powder coated with a luminescent paint is used, the contrast of the magnetic powder pattern is increased, so that the defect detection performance can be improved. Hereinafter, other features and advantages of the present invention will be described in detail with reference to the drawings. (3) Magnetic particle flaw detector of the present invention a. FIG. 4 shows an embodiment of a magnetic particle flaw detector according to the present invention, FIG. 4 (a) is a cross-sectional view thereof, and FIG. 4 (b) is a material to be detected of the magnetic sheet of FIG. 4 (a). It is a top view which shows the surface side which contacts .
In FIG. 4A, 14 is an electromagnet, 15 is a material to be inspected,
Reference numeral 16 denotes an extremely thin coating film constituting a magnetic shield. Suffered
Transparent plastic sheet 1 on the side contacting the flaw detection material
A large number of small chambers (see FIGS. 1 to 3) are provided between the sheet 7 and the transparent plastic sheet 18 on the opposite side, and a dispersion medium containing a thermosetting resin as a thermosetting dispersion medium in the small chamber. The magnetic sheet 19 in which a large number of fine magnetic powders are dispersed forms the coating film 1
6. The coating film 16 is not always necessary, but in order not to attenuate the leakage magnetic flux at the defective portion,
It can be provided according to the required level of defect detection (clarity of the magnetic powder pattern).
【００２２】そして、図４（ａ）に示す構成の磁粉探傷
装置を用いて、被探傷材１５の表面に存在する微少欠陥
２０を検査した結果、被探傷材に当接する面側のシート
１７には、図４（ｂ）に示すような明瞭な磁粉模様２１
が現れたのが認められた。[0022] Then, by using the magnetic particle apparatus shown in FIG. 4 (a), the result of inspecting a minute defect 20 existing in the surface of the wound material 15 test object, the sheet 17 abutting the surface side test object material Represents a clear magnetic powder pattern 21 as shown in FIG.
Appeared.
【００２３】そこで、この磁粉模様２１を保存記録する
ために、図５（ａ）に示す小室２２内に熱硬化性樹脂を
含む分散媒２３を封入した磁気シート１９に熱を加える
ことにより、分散媒２３が硬化して、図５（ｂ）に示す
ように、小室２２内の多数の微細な磁粉２４からなる磁
粉模様が固定された。この場合、熱硬化性樹脂としては
フェノール樹脂を使用し、溶剤としてはメチルアルコー
ルを使用した。In order to preserve and record the magnetic powder pattern 21, heat is applied to a magnetic sheet 19 in which a dispersion medium 23 containing a thermosetting resin is sealed in a small chamber 22 shown in FIG. The medium 23 was cured, and a magnetic powder pattern including a large number of fine magnetic powders 24 in the small chamber 22 was fixed as shown in FIG. In this case, a phenol resin was used as the thermosetting resin, and methyl alcohol was used as the solvent.
【００２４】熱硬化性樹脂としては、フェノール樹脂、
ビニルエステル樹脂、ジアリルフタレート樹脂、フラン
樹脂、ポリイミド樹脂、ポリウレタン樹脂、メラミン樹
脂、ユリア樹脂など公知の樹脂を用いることができる。 ｂ．欠陥の検出性能の向上 図６に示すように、小室２２内の分散媒２５中に発光塗
料をコーティングした多数の微細な磁粉２６を分散させ
れば、この探傷面側および反探傷面側がともに透明プラ
スチック製のシートからなる磁気シート２７に紫外線光
照射ライト２８から紫外線を照射することによって、磁
粉２６によって形成される磁粉模様が発光することでそ
の明度が増すので、欠陥の検出がより容易になる。この
場合、暗室内で磁粉模様を観察すれば、そのコントラス
トが一層増すので好ましい。発光塗料とは、ＺｎＳやＳ
ｒＳなどの蓄光性が大きく、リン（燐）光を発する物質
を主顔料とした塗料に放射性物質を微量添加したもので
あって、可視光や紫外線を照射すると、暗室でも長時間
にわたって発光し、夜光塗料とも呼ばれているものであ
り、本発明は公知の発光塗料を用いることができる。 ｃ．磁粉模様の保存記録と欠陥の検出性能の向上 さらに、熱硬化性樹脂を含む分散媒中に発光塗料をコー
ティングした磁粉を分散させることもできる。このよう
にすれば、熱硬化性樹脂の色が磁粉に似ている場合で
も、欠陥の検出性能が低下することなく良好に微少欠陥
を検出し、且つ磁粉模様の保存記録が可能である。この
場合、熱硬化性樹脂を硬化させるための磁気シートの加
熱は、次のいずれの手順でもよい。As the thermosetting resin, a phenol resin,
Known resins such as a vinyl ester resin, a diallyl phthalate resin, a furan resin, a polyimide resin, a polyurethane resin, a melamine resin, and a urea resin can be used. b. Improvement of Defect Detection Performance As shown in FIG. 6, if a large number of fine magnetic powders 26 coated with a luminescent paint are dispersed in a dispersion medium 25 in a small chamber 22, both the flaw detection surface side and the anti- flaw detection surface side are transparent. By irradiating the ultraviolet rays from the ultraviolet light irradiating light 28 to the magnetic sheet 27 made of a plastic sheet, the magnetic powder pattern formed by the magnetic powder 26 emits light to increase its brightness, thereby making it easier to detect defects. . In this case, it is preferable to observe the magnetic powder pattern in a dark room because the contrast is further increased. Luminescent paint is ZnS or S
A substance with a large luminous property such as rS and a phosphorescent (phosphorous) substance as a main pigment, to which a small amount of a radioactive substance has been added. When irradiated with visible light or ultraviolet light, it emits light for a long time even in a dark room, It is also called a luminous paint, and in the present invention, a known luminescent paint can be used. c. Improvement of Storage Record of Magnetic Powder Pattern and Detection of Defects Further, magnetic powder coated with a luminescent paint can be dispersed in a dispersion medium containing a thermosetting resin. In this way, even when the color of the thermosetting resin is similar to the magnetic powder, it is possible to detect fine defects without deteriorating the defect detection performance and to store and record the magnetic powder pattern. In this case, the heating of the magnetic sheet for curing the thermosetting resin may be performed by any of the following procedures.
【００２５】すなわち、磁気シートを被探傷材の探傷面
に当接して探傷し、磁気シートを被探傷材から引き離し
て磁粉模様を観察する前に磁気シートを加熱して熱硬化
性樹脂を硬化させて磁粉模様を固定し、その後、磁気シ
ートに紫外線を照射して磁粉模様を発光させてもよく、
逆に、被探傷材から引き離した磁気シートに紫外線を照
射して磁粉模様を発光させた後、磁気シートを加熱して
熱硬化性樹脂を硬化させることにより磁粉模様を固定す
ることもできる。 ｄ．磁化手段 図７は、磁化手段の一例を示す図であり、磁化手段とし
て被探傷材１５上に断面「コ」の字状の永久磁石２９を
載置することもできるし、また、陽極側のプレート３０
ａと陰極側のプレート３０ｂとの間に一定の電圧を印加
して磁界を発生させる方式のものを用いることもでき
る。[0025] That is, testing in contact with a magnetic sheet to the inspection surface of the test object material, by heating the magnetic sheet to cure the thermosetting resin before observing the magnetic powder pattern with pull the magnetic sheet from the test object material The magnetic powder pattern may be fixed, and then the magnetic sheet may be irradiated with ultraviolet light to emit the magnetic powder pattern,
Conversely, after the magnetic sheet separated from the material to be inspected is irradiated with ultraviolet light to emit a magnetic powder pattern, the magnetic sheet can be fixed by heating the magnetic sheet to cure the thermosetting resin. d. Magnetizing Means FIG. 7 is a view showing an example of the magnetizing means. As the magnetizing means, a permanent magnet 29 having a U-shaped cross section can be placed on the material to be inspected 15. Plate 30
A type that generates a magnetic field by applying a constant voltage between a and a plate 30b on the cathode side can also be used.
【００２６】[0026]
【発明の効果】本発明は以上のとおり構成されているの
で、つぎの効果を奏する。 （１）請求項１、５記載の発明によれば、時間的な制約
がなく簡単な手法で探傷試験を行うことが可能で、探傷
結果を確実に長期間保存記録することができる磁粉探傷
法および磁粉探傷装置を提供することができる。 （２）請求項２、６記載の発明によれば、探傷性能を向
上することができる磁粉探傷法および磁粉探傷装置を提
供することができる。 （３）請求項３、４、７記載の発明によれば、熱硬化性
分散媒の種類や性状に関係なく、良好に探傷を行い、し
かも探傷結果を確実に長期間保存記録することができる
磁粉探傷法および磁粉探傷装置を提供することができ
る。 （４）請求項８記載の発明によれば、入手が容易である
熱硬化性樹脂を用いるので、磁粉探傷装置のコストの上
昇を抑制することができる。As described above, the present invention has the following advantages. (1) According to the first and fifth aspects of the present invention, it is possible to perform a flaw detection test by a simple method with no time limitation, and to reliably record and record a flaw detection result for a long period of time. And a magnetic particle flaw detector. (2) According to the second and sixth aspects of the invention, it is possible to provide a magnetic particle flaw detection method and a magnetic particle flaw detection apparatus capable of improving the flaw detection performance. (3) According to the third, fourth, and seventh aspects of the present invention, flaw detection can be performed satisfactorily regardless of the type and properties of the thermosetting dispersion medium, and the flaw detection results can be reliably recorded for a long period of time. A magnetic particle inspection method and a magnetic particle inspection apparatus can be provided. (4) According to the invention of claim 8, since the thermosetting resin which is easily available is used, an increase in the cost of the magnetic particle flaw detector can be suppressed.
【図面の簡単な説明】[Brief description of the drawings]
【図１】磁気シートの使用例を説明する図である。FIG. 1 is a diagram illustrating an example of use of a magnetic sheet.
【図２】本発明による磁粉探傷法の一例を説明する図で
ある。FIG. 2 is a diagram illustrating an example of a magnetic particle flaw detection method according to the present invention.
【図３】本発明による磁粉探傷法の別の例を説明する図
である。FIG. 3 is a diagram illustrating another example of the magnetic particle flaw detection method according to the present invention.
【図４】図４（ａ）は本発明の磁粉探傷装置の要部を示
す断面図、図４（ｂ）はその磁気シートの表面に表され
た磁粉模様の一例を示す図である。FIG. 4A is a cross-sectional view showing a main part of a magnetic particle flaw detector of the present invention, and FIG. 4B is a diagram showing an example of a magnetic particle pattern shown on the surface of the magnetic sheet.
【図５】図５（ａ）は磁気シートを加熱して分散媒を硬
化させる状態を示す断面図、図５（ｂ）は磁気シートを
加熱して分散媒を硬化させ、磁粉模様を固定した状態を
示す図である。FIG. 5A is a cross-sectional view illustrating a state in which a magnetic sheet is heated to cure a dispersion medium, and FIG. 5B is a state in which the magnetic sheet is heated to cure the dispersion medium and a magnetic powder pattern is fixed. It is a figure showing a state.
【図６】磁気シートに紫外線を照射して発光塗料をコー
ティングした磁粉からなる模様が発光する状態を示す図
である。FIG. 6 is a view showing a state in which a pattern made of magnetic powder coated with a luminescent paint by irradiating a magnetic sheet with ultraviolet light emits light.
【図７】磁化手段の一例を示す概略構成図である。FIG. 7 is a schematic configuration diagram illustrating an example of a magnetizing unit.
【図８】磁粉探傷法のメカニズムを説明する図である。FIG. 8 is a diagram illustrating the mechanism of the magnetic particle flaw detection method.
【図９】従来の磁粉探傷装置による磁粉探傷法を説明す
る図である。FIG. 9 is a view for explaining a magnetic particle flaw detection method using a conventional magnetic particle flaw detector.
【図１０】図１０（ａ）は従来の別の磁粉探傷装置の斜
視図であり、図１０（ｂ）はその磁粉探傷装置に使用す
るベルトの断面図である。FIG. 10 (a) is a perspective view of another conventional magnetic particle flaw detector, and FIG. 10 (b) is a cross-sectional view of a belt used for the magnetic particle flaw detector.
【図１１】図１１（ａ）は従来のさらに別の磁粉探傷装
置の平面図、図１１（ｂ）はその断面図である。11A is a plan view of another conventional magnetic particle flaw detector, and FIG. 11B is a cross-sectional view thereof.
【符号の説明】 ２、２２…小室 ３、２４、２６…磁粉 ４、２３、２５…分散媒 ７、１０、１２、２１…磁粉模様 ８、１５、…被探傷材 ９、２０…欠陥 １４…電磁石 １９、２７…磁気シート[Description of Signs] 2, 22 ... small chamber 3, 24, 26 ... magnetic powder 4, 23, 25 ... dispersion medium 7, 10, 12, 21 ... magnetic powder pattern 8, 15, ... material to be inspected 9, 20 ... defect 14 ... Electromagnets 19, 27 ... magnetic sheet
───────────────────────────────────────────────────── フロントページの続き (72)発明者 神岡 光浩 兵庫県神戸市中央区東川崎町３丁目１番１ 号 川崎重工業株式会社神戸工場内 (72)発明者 堺 邦益 兵庫県神戸市中央区東川崎町３丁目１番１ 号 川崎重工業株式会社神戸工場内 (72)発明者 松井 啓年 兵庫県神戸市中央区東川崎町３丁目１番１ 号 川崎重工業株式会社神戸工場内 Ｆターム(参考） 2G053 AA11 AB22 DC03 DC16 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Mitsuhiro Kamioka 3-1-1, Higashikawasaki-cho, Chuo-ku, Kobe-shi, Hyogo Inside the Kobe Plant of Kawasaki Heavy Industries, Ltd. (72) Inventor Kuniyoshi Sakai Higashi-Kawasaki, Chuo-ku, Kobe-shi, Hyogo 3-1-1, Kobe-cho, Kawasaki Heavy Industries, Ltd. Kobe Plant (72) Inventor Hirotoshi Matsui 3-1-1, Higashi-Kawasaki-cho, Chuo-ku, Kobe-shi, Hyogo Prefecture F-term in Kawasaki Heavy Industries, Ltd. 2G053 AA11 AB22 DC03 DC16
Claims (8)
の表面または表面直下に存在する磁束の通過を妨げる欠
陥により該欠陥直上の空間に漏れ磁束を生じさせ、該洩
れ磁束で磁粉を吸引することにより形成される磁粉模様
に基づいて欠陥を検出する磁粉探傷法において、少なく
とも観察面側のシートが透明材料で形成され、観察面側
のシートと反観察面側のシートとの間を多数の小室に仕
切り且つこれらの小室に熱硬化性分散媒を含む分散媒中
に磁粉を分散させたものを封入してなる磁気シートの観
察面を被探傷材の探傷面に当接させるか又は押し当てて
密着させ、次いで、磁気シートを被探傷材から引き離
し、その磁気シートに熱を加えることにより分散媒を硬
化させて観察面側のシートに画かれた磁粉模様を固定す
ることを特徴とする磁粉探傷法。1. A flaw to be detected is magnetized by a magnetizing means, and a defect that prevents passage of a magnetic flux existing on or immediately below the surface of the flaw-detected material generates a leakage magnetic flux in a space immediately above the defect, and the leakage magnetic flux causes a magnetic powder to be generated. In the magnetic particle flaw detection method for detecting a defect based on a magnetic particle pattern formed by sucking a sheet, at least a sheet on the observation surface side is formed of a transparent material, and a gap between the sheet on the observation surface side and the sheet on the opposite observation surface side is formed. Is divided into a number of small chambers, and the observation surface of a magnetic sheet in which magnetic particles are dispersed in a dispersion medium containing a thermosetting dispersion medium is sealed in these small chambers. Alternatively, the magnetic sheet is separated from the material to be inspected by pressing, and then the magnetic sheet is separated from the material to be inspected, and the dispersion medium is hardened by applying heat to the magnetic sheet to fix the magnetic powder pattern drawn on the sheet on the observation surface side. And magnetism Powder testing.
の表面または表面直下に存在する磁束の通過を妨げる欠
陥により該欠陥直上の空間に漏れ磁束を生じさせ、該洩
れ磁束で磁粉を吸引することにより形成される磁粉模様
に基づいて欠陥を検出する磁粉探傷法において、少なく
とも観察面側のシートが透明材料で形成され、観察面側
のシートと反観察面側のシートとの間を多数の小室に仕
切り且つこれらの小室に発光塗料をコーティングした磁
粉を分散させた分散媒を封入してなる磁気シートの観察
面を被探傷材の探傷面に当接させるか又は押し当てて密
着させ、次いで、磁気シートを被探傷材から引き離し、
可視光または紫外線を磁気シートに照射することにより
観察面側のシートに画かれた磁粉模様を発光させること
を特徴とする磁粉探傷法。2. A material to be inspected is magnetized by a magnetizing means, and a defect that prevents passage of a magnetic flux existing on or immediately below the surface of the material to be inspected generates a leakage magnetic flux in a space immediately above the defect. In the magnetic particle flaw detection method for detecting a defect based on a magnetic particle pattern formed by sucking a sheet, at least a sheet on the observation surface side is formed of a transparent material, and a gap between the sheet on the observation surface side and the sheet on the opposite observation surface side is formed. Is divided into a number of small chambers, and the observation surface of the magnetic sheet, in which a dispersion medium in which magnetic powder coated with a luminescent paint is dispersed, is sealed, is brought into contact with or pressed against the flaw detection surface of the material to be detected. Then, the magnetic sheet is separated from the material to be inspected,
A magnetic particle flaw detection method in which a magnetic powder pattern drawn on a sheet on an observation surface side is emitted by irradiating the magnetic sheet with visible light or ultraviolet light.
の表面または表面直下に存在する磁束の通過を妨げる欠
陥により該欠陥直上の空間に漏れ磁束を生じさせ、該洩
れ磁束で磁粉を吸引することにより形成される磁粉模様
に基づいて欠陥を検出する磁粉探傷法において、少なく
とも観察面側のシートが透明材料で形成され、観察面側
のシートと反観察面側のシートとの間を多数の小室に仕
切り且つこれらの小室に熱硬化性分散媒を含む分散媒中
に発光塗料をコーティングした磁粉を分散させたものを
封入してなる磁気シートの観察面を被探傷材の探傷面に
当接させるか又は押し当てて密着させ、次いで、磁気シ
ートを被探傷材から引き離し、可視光または紫外線を磁
気シートに照射することにより観察面側のシートに画か
れた磁粉模様を発光させ、さらに、その磁気シートに熱
を加えることにより分散媒を硬化させて観察面側のシー
トに画かれた磁粉模様を固定することを特徴とする磁粉
探傷法。3. A material to be inspected is magnetized by a magnetizing means, and a defect that prevents passage of a magnetic flux existing on or immediately below the surface of the material to be inspected generates a leakage magnetic flux in a space immediately above the defect. In the magnetic particle flaw detection method for detecting a defect based on a magnetic particle pattern formed by sucking a sheet, at least a sheet on the observation surface side is formed of a transparent material, and a gap between the sheet on the observation surface side and the sheet on the opposite observation surface side is formed. Is divided into a number of small chambers, and these small chambers are sealed with a dispersion of magnetic powder coated with a luminescent paint in a dispersion medium containing a thermosetting dispersion medium. A magnetic powder pattern drawn on the sheet on the observation surface side by irradiating the magnetic sheet with visible light or ultraviolet light, and separating the magnetic sheet from the material to be inspected, and irradiating the magnetic sheet with visible light or ultraviolet light. And applying heat to the magnetic sheet to cure the dispersion medium and fix the magnetic powder pattern drawn on the sheet on the observation surface side.
の表面または表面直下に存在する磁束の通過を妨げる欠
陥により該欠陥直上の空間に漏れ磁束を生じさせ、該洩
れ磁束で磁粉を吸引することにより形成される磁粉模様
に基づいて欠陥を検出する磁粉探傷法において、少なく
とも観察面側のシートが透明材料で形成され、観察面側
のシートと反観察面側のシートとの間を多数の小室に仕
切り且つこれらの小室に熱硬化性分散媒を含む分散媒中
に発光塗料をコーティングした磁粉を分散させたものを
封入してなる磁気シートの観察面を被探傷材の探傷面に
当接させるか又は押し当てて密着させ、次いで、磁気シ
ートを被探傷材から引き離し、その磁気シートに熱を加
えることにより分散媒を硬化させて観察面側のシートに
画かれた磁粉模様を固定し、さらに、可視光または紫外
線を磁気シートに照射することにより観察面側のシート
に画かれた磁粉模様を発光させることを特徴とする磁粉
探傷法。4. A material to be inspected is magnetized by a magnetizing means, and a defect that prevents passage of a magnetic flux existing on or immediately below the surface of the material to be inspected generates a leakage magnetic flux in a space immediately above the defect, and the leakage magnetic flux causes magnetic particles to be generated. In the magnetic particle flaw detection method for detecting a defect based on a magnetic particle pattern formed by sucking a sheet, at least a sheet on the observation surface side is formed of a transparent material, and a gap between the sheet on the observation surface side and the sheet on the opposite observation surface side is formed. Is divided into a number of small chambers, and these small chambers are sealed with a dispersion of magnetic powder coated with a luminescent paint in a dispersion medium containing a thermosetting dispersion medium. Then, the magnetic sheet is separated from the material to be flawed, and the heat is applied to the magnetic sheet to cure the dispersion medium, thereby forming the magnetic powder pattern drawn on the sheet on the observation surface side. A magnetic particle flaw detection method in which a magnetic powder pattern drawn on a sheet on an observation surface side is illuminated by irradiating the magnetic sheet with visible light or ultraviolet light while fixing the magnetic sheet.
の表面または表面直下に存在する磁束の通過を妨げる欠
陥により該欠陥直上の空間に漏れ磁束を生じさせ、該洩
れ磁束で磁粉を吸引することにより形成される磁粉模様
に基づいて欠陥を検出する磁粉探傷装置において、被探
傷材の磁化手段を備え、少なくとも観察面側のシートが
透明材料で形成され、観察面側のシートと反観察面側の
シートとの間を多数の小室に仕切り且つこれらの小室に
熱硬化性分散媒を含む分散媒中に磁粉を分散させたもの
を封入してなる磁気シートを有する磁粉探傷装置。5. A flaw to be detected is magnetized by a magnetizing means, and a defect that prevents passage of a magnetic flux existing on or immediately below the surface of the flaw-detected material generates a leakage magnetic flux in a space immediately above the defect. In the magnetic particle flaw detector which detects a defect based on a magnetic powder pattern formed by sucking, a magnetizing means of the material to be flawed is provided, at least a sheet on the observation surface side is formed of a transparent material, and a sheet on the observation surface side is provided. A magnetic particle flaw detection device having a magnetic sheet in which a space between a sheet on the side opposite to the observation surface is divided into a number of small chambers, and magnetic particles are dispersed in a dispersion medium containing a thermosetting dispersion medium in these small chambers.
の表面または表面直下に存在する磁束の通過を妨げる欠
陥により該欠陥直上の空間に漏れ磁束を生じさせ、該洩
れ磁束で磁粉を吸引することにより形成される磁粉模様
に基づいて欠陥を検出する磁粉探傷装置において、被探
傷材の磁化手段を備え、少なくとも観察面側のシートが
透明材料で形成され、観察面側のシートと反観察面側の
シートとの間を多数の小室に仕切り且つこれらの小室に
発光塗料をコーティングした磁粉を分散させた分散媒を
封入してなる磁気シートを有する磁粉探傷装置。6. A material to be inspected is magnetized by a magnetizing means, and a defect that prevents the passage of a magnetic flux existing on or immediately below the surface of the material to be inspected generates a leakage magnetic flux in a space immediately above the defect, and the magnetic flux is generated by the leakage magnetic flux. In the magnetic particle flaw detector which detects a defect based on a magnetic powder pattern formed by sucking, a magnetizing means of the material to be flawed is provided, at least a sheet on the observation surface side is formed of a transparent material, and a sheet on the observation surface side is provided. A magnetic particle flaw detection device having a magnetic sheet in which a space between a sheet on the side opposite to the observation surface is partitioned into a number of small chambers and a dispersion medium in which magnetic powder coated with a luminescent paint is dispersed is sealed in these small chambers.
の表面または表面直下に存在する磁束の通過を妨げる欠
陥により該欠陥直上の空間に漏れ磁束を生じさせ、該洩
れ磁束で磁粉を吸引することにより形成される磁粉模様
に基づいて欠陥を検出する磁粉探傷装置において、被探
傷材の磁化手段を備え、少なくとも観察面側のシートが
透明材料で形成され、観察面側のシートと反観察面側の
シートとの間を多数の小室に仕切り且つこれらの小室に
熱硬化性分散媒を含む分散媒中に発光塗料をコーティン
グした磁粉を分散させたものを封入してなる磁気シート
を有する磁粉探傷装置。7. A flaw to be detected is magnetized by a magnetizing means, and a defect that prevents passage of a magnetic flux existing on or immediately below the surface of the flaw-detected material generates a leakage magnetic flux in a space immediately above the defect. In the magnetic particle flaw detector which detects a defect based on a magnetic powder pattern formed by sucking, a magnetizing means of the material to be flawed is provided, at least a sheet on the observation surface side is formed of a transparent material, and a sheet on the observation surface side is provided. A magnetic sheet formed by partitioning the sheet on the side opposite to the observation surface into a number of small chambers and enclosing a dispersion of magnetic powder coated with a luminescent paint in a dispersion medium containing a thermosetting dispersion medium in these small chambers. Magnetic particle flaw detector.
請求項５または７記載の磁粉探傷装置。8. The magnetic particle flaw detector according to claim 5, wherein the thermosetting dispersion medium is a thermosetting resin.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2000323569A JP3394517B2 (en) | 2000-10-24 | 2000-10-24 | Magnetic particle inspection method and magnetic particle inspection equipment |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2000323569A JP3394517B2 (en) | 2000-10-24 | 2000-10-24 | Magnetic particle inspection method and magnetic particle inspection equipment |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2002340701A Division JP3614419B2 (en) | 2002-11-25 | 2002-11-25 | Magnetic particle inspection method and magnetic particle inspection device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2002131287A true JP2002131287A (en) | 2002-05-09 |
| JP3394517B2 JP3394517B2 (en) | 2003-04-07 |
Family
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2000323569A Expired - Fee Related JP3394517B2 (en) | 2000-10-24 | 2000-10-24 | Magnetic particle inspection method and magnetic particle inspection equipment |
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| Country | Link |
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| JP (1) | JP3394517B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112229899A (en) * | 2020-09-29 | 2021-01-15 | 深圳市人工智能与机器人研究院 | Defect detection method of ferromagnetic component and related equipment |
| CN112881517A (en) * | 2021-01-14 | 2021-06-01 | 楷钛工业零部件江苏有限公司 | Alloy shell sealing performance testing device |
-
2000
- 2000-10-24 JP JP2000323569A patent/JP3394517B2/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112229899A (en) * | 2020-09-29 | 2021-01-15 | 深圳市人工智能与机器人研究院 | Defect detection method of ferromagnetic component and related equipment |
| CN112881517A (en) * | 2021-01-14 | 2021-06-01 | 楷钛工业零部件江苏有限公司 | Alloy shell sealing performance testing device |
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| Publication number | Publication date |
|---|---|
| JP3394517B2 (en) | 2003-04-07 |
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