JPH08160008A - Non-destructive inspecting method for defect - Google Patents
Non-destructive inspecting method for defectInfo
- Publication number
- JPH08160008A JPH08160008A JP30058794A JP30058794A JPH08160008A JP H08160008 A JPH08160008 A JP H08160008A JP 30058794 A JP30058794 A JP 30058794A JP 30058794 A JP30058794 A JP 30058794A JP H08160008 A JPH08160008 A JP H08160008A
- Authority
- JP
- Japan
- Prior art keywords
- fine particles
- film
- replica
- ferromagnetic material
- magnetized
- 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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Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、フェライト系鉄鋼材料
の非破壊検査方法に関し、さらに詳しくは各種機械部品
などに使用されるフェライト系鉄鋼材料に発生するき裂
状の欠陥を定量的に評価することのできる、機械部品の
非破壊検査方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-destructive inspection method for ferritic steel materials, and more specifically, for quantitatively evaluating crack-like defects occurring in ferritic steel materials used for various machine parts. And a non-destructive inspection method for mechanical parts.
【０００２】[0002]
【従来の技術】フェライト系鉄鋼材料よりなる各種機械
部品は、長時間の使用、繰り返し荷重の負荷等により疲
労損傷が生じる。例えば、火力発電プラントにおいて
は、近年の原子力発電プラントの伸長によって、基底負
荷運用から中間負荷運用化されており、起動停止及び負
荷変化が頻繁に行われるようになって、その際に生じる
温度変動による熱応力の繰り返しによって、疲労損傷の
蓄積が問題となっている。このような疲労損傷において
は、表面にき裂が生じて、これが進展してついには破断
に至るので、設備の保全管理においてはき裂を如何に早
期に検出するかが問題となる。従来からフェライト系鉄
鋼材料よりなる各種機械部品などに発生するき裂状の欠
陥の非破壊検査方法としては、磁粉探傷法、染色浸透探
傷法、超音波探傷法等が用いられている。また、これら
の部品の表面の微小き裂の長さを計測する方法として
は、レプリカ法が多用されている。2. Description of the Related Art Various mechanical parts made of ferritic steel materials suffer fatigue damage due to long-term use, repeated load, and the like. For example, in thermal power plants, due to the recent expansion of nuclear power plants, base load operation has been changed to intermediate load operation, and start-stop and load changes have become frequent, resulting in temperature fluctuations that occur at that time. Accumulation of fatigue damage has become a problem due to repeated thermal stress due to. In such fatigue damage, a crack is generated on the surface, which propagates and finally breaks. Therefore, how to detect the crack early becomes a problem in maintenance management of equipment. Conventionally, a magnetic powder flaw detection method, a dye penetrant flaw detection method, an ultrasonic flaw detection method and the like have been used as a nondestructive inspection method for crack-like defects that occur in various machine parts made of ferritic steel materials. The replica method is often used as a method for measuring the length of a minute crack on the surface of these parts.
【０００３】[0003]
【発明が解決しようとする課題】磁粉探傷法、染色浸透
探傷法、超音波探傷法等の非破壊検査方法は簡便な方法
であるが、このうち磁粉探傷法及び染色浸透探傷法につ
いては検出感度は高いが、そのままでは微小なき裂長さ
の計測は困難であり、また、超音波探傷法では、定量的
にき裂の検出が可能であるが、１ｍｍ以下のき裂に関し
ては検出感度が低かった。また、レプリカ法は微小なき
裂の長さを精度よく検出できるが、検出するためには供
試材の表面を鏡面になるまで研磨する必要があることか
ら、工程に長時間を要するとともに、例えば長時間の運
転により酸化や腐食を受け表面の凹凸が激しくなるなど
該供試材の表面状態が悪い場合は鏡面研磨するまでに供
試材表面を研磨、除去することから微小なき裂を除去し
てしまう可能性があった。Nondestructive inspection methods such as the magnetic particle flaw detection method, the dye penetrant flaw detection method, and the ultrasonic flaw detection method are simple methods. Among them, the magnetic particle flaw detection method and the dye penetrant flaw detection method have a detection sensitivity. Although it is high, it is difficult to measure a minute crack length as it is. Further, the ultrasonic flaw detection method can quantitatively detect cracks, but the detection sensitivity is low for cracks of 1 mm or less. . In addition, although the replica method can accurately detect the length of a minute crack, the surface of the sample material needs to be polished until it becomes a mirror surface in order to detect it. If the surface condition of the test material is poor due to oxidation and corrosion resulting from long-term operation and the surface roughness becomes severe, minute cracks are removed by polishing and removing the surface of the test material before mirror polishing. There was a possibility that it would end up.
【０００４】本発明は前記従来技術における問題点を解
消し、前記の非破壊検査方法と同等程度の簡便さで、供
試材表面を特に前処理することなく、レプリカ法と同様
の精度で機械部品表面に発生するき裂を検出し、その長
さを定量的に評価できる方法、例えば火力発電プラント
のような大型機械部品の疲労損傷等の結果生じる初期の
微小なき裂を簡便に検出、評価するための方法を提供す
るものである。The present invention solves the above-mentioned problems in the prior art, is as simple as the above nondestructive inspection method, and does not require any pretreatment of the surface of the test material, and has the same precision as the replica method. A method that can detect cracks generated on the surface of parts and quantitatively evaluate their length, for example, easily detect and evaluate initial small cracks resulting from fatigue damage of large mechanical parts such as thermal power plants. It provides a way to do this.
【０００５】[0005]
【課題を解決するための手段】本発明は（１）供試材の
調査対象箇所の表面を清浄にして強磁性材料の微粒子を
分散させたコロイド液を塗布して該表面に強磁性材料の
微粒子のコロイド液を均一に付着させた後、前記供試材
の調査対象箇所を含む領域を磁化させ、乾燥させた後レ
プリカフィルム材料を溶剤に溶解した溶液を噴霧し、乾
燥固化させてフィルム層を形成させ、次いで強磁性材料
の微粒子と一体化したレプリカフィルムを供試材表面か
ら剥離させ、該剥離フィルムを観察して欠陥部に集積し
た磁化された強磁性材料の微粒子のパターンを観察する
ことにより供試材中の欠陥を検出、評価することを特徴
とするフェライト系鉄鋼材料の表面欠陥の非破壊検査法
及び（２）強磁性材料の微粒子がマグネタイトの微粒子
である前記（１）のフェライト系鉄鋼材料の表面欠陥の
非破壊検査法である。According to the present invention, (1) a colloidal liquid in which fine particles of a ferromagnetic material are dispersed by cleaning the surface of a site to be investigated of a sample material and applying the ferromagnetic material to the surface is applied. After uniformly depositing a colloidal solution of fine particles, magnetize a region of the sample material including the investigation target portion, and after drying, spray a solution of a replica film material dissolved in a solvent, dry and solidify the film layer. Then, the replica film integrated with the fine particles of the ferromagnetic material is peeled off from the surface of the sample material, and the peeled film is observed to observe the pattern of the magnetized ferromagnetic fine particles accumulated in the defect portion. Non-destructive inspection method for surface defects of ferritic steel materials, which is characterized by detecting and evaluating defects in the test material, and (2) the fine particles of the ferromagnetic material are fine particles of magnetite (1) It is a non-destructive test method for surface defects ferritic steel material.
【０００６】本発明は、前記従来技術の非破壊検査方法
の中で表面き裂の検出感度が最も高い磁気探傷法に着目
してなされたものである。磁気探傷法のうち最も一般的
に用いられている磁粉探傷法では、通常磁粉に蛍光塗料
を含ませておき、き裂部からの漏洩磁束に集積した磁粉
から発する蛍光を目視で検出してき裂の有無を評価す
る。これに対して、本発明では調査対象材料（供試材）
の表面に強磁性材料の微粒子をコロイド液の状態で均一
に付着させておき、供試材の調査対象箇所を含む領域を
磁化して、き裂部からの漏洩磁束をによってき裂部付近
に集積した強磁性材料の微粒子のパターンを、そのまま
の状態でレプリカフィルムに移し取り、顕微鏡により観
察して供試材中の欠陥を検出、評価するようにしてい
る。The present invention was made by paying attention to the magnetic flaw detection method having the highest detection sensitivity of surface cracks among the above-mentioned conventional nondestructive inspection methods. In the most commonly used magnetic particle flaw detection method among the magnetic flaw detection methods, the magnetic powder is usually made to contain a fluorescent paint, and the fluorescence emitted from the magnetic particles accumulated in the leakage flux from the crack portion is visually detected to detect cracks. Evaluate the presence or absence. On the other hand, in the present invention, the material to be investigated (test material)
Fine particles of ferromagnetic material are evenly adhered to the surface of the sample in the state of colloidal liquid, magnetize the region of the sample material including the investigation target area, and the leakage magnetic flux from the crack part causes the magnetic field near the crack part. The pattern of the fine particles of the accumulated ferromagnetic material is transferred to the replica film as it is, and observed under a microscope to detect and evaluate the defects in the sample material.
【０００７】供試材表面に強磁性材料の微粒子を付着さ
せる方法としては、強磁性材料の微粒子を分散させたコ
ロイド液を塗布する方法が好都合である。強磁性材料の
微粒子としてはマグネタイトの微粒子が好ましい。As a method for adhering the fine particles of the ferromagnetic material to the surface of the test material, a method of applying a colloidal liquid in which the fine particles of the ferromagnetic material are dispersed is convenient. As the fine particles of the ferromagnetic material, fine particles of magnetite are preferable.
【０００８】このようにして強磁性材料の微粒子を付着
させた状態で、必要によりコロイド液を塗布しながら、
電磁石などの磁化装置を用いて供試材の対象部に磁場を
与えると、き裂部からの漏洩磁束によって強磁性材料が
磁化され、き裂部付近に集積し、き裂の形状に応じたパ
ターンが形成される。In this way, with the fine particles of the ferromagnetic material adhered, if necessary, applying a colloidal liquid,
When a magnetic field is applied to the target part of the test material using a magnetizing device such as an electromagnet, the ferromagnetic material is magnetized by the leakage magnetic flux from the crack and accumulates in the vicinity of the crack, depending on the shape of the crack. A pattern is formed.
【０００９】次いで表面を乾燥させた後、アセチルセル
ロースなどのレプリカフィルムに使用される材料を酢酸
メチルなどの溶剤に溶解した溶液を噴霧し、乾燥させて
レプリカフィルムを形成させる。このフィルムを剥離す
れば、供試材表面に付着した強磁性材料の微粒子も前記
のパターンを形成した状態でフィルム中に取り込まれて
剥離する。このようにしてレプリカフィルムに転写され
た磁化パターンを顕微鏡により観察し、計測することに
よって供試材中の欠陥を検出し、定量的に評価すること
ができる。Next, after the surface is dried, a solution prepared by dissolving the material used for the replica film such as acetylcellulose in a solvent such as methyl acetate is sprayed and dried to form a replica film. When this film is peeled off, the fine particles of the ferromagnetic material attached to the surface of the sample material are also taken into the film in the state where the above pattern is formed and peeled off. By observing and measuring the magnetization pattern thus transferred to the replica film with a microscope, the defect in the sample material can be detected and quantitatively evaluated.
【００１０】[0010]
【作用】本発明の構成による作用、効果は以下のとおり
である。 １）ベース技術として磁気探傷法を採用したことによ
り、レプリカ法のように表面を平滑にする必要がないこ
とから調査箇所の前処理が極めて容易であるとともに、
平滑化処理により微小な表面欠陥を削除してしまう恐れ
がない。 ２）従来の磁粉探傷法では蛍光磁粉を目視で検出してい
たため微小な欠陥を検出できず、また、検出された欠陥
の寸法を定量的に計測することが極めて困難であったの
に対し、き裂部からの漏洩磁束により供試材表面に付着
させた強磁性材料の微粒子にパターンを形成させ、その
磁化パターンをレプリカフィルムに移し取って顕微鏡で
観察するようにしたことから、欠陥の寸法を光学顕微鏡
で直接計測することができるほか、計測結果を写真など
によって記録することができるようになる。 ３）強磁性材料の微粒子を直接供試材の調査対象部分に
分散、付着させているので、漏洩磁束の検出精度が高
い。The operation and effect of the structure of the present invention are as follows. 1) By adopting the magnetic flaw detection method as the base technology, it is not necessary to make the surface smooth unlike the replica method, so that the pretreatment of the surveyed area is extremely easy, and
There is no risk of removing minute surface defects by the smoothing process. 2) In the conventional magnetic particle flaw detection method, since the fluorescent magnetic powder was visually detected, minute defects could not be detected, and it was extremely difficult to quantitatively measure the size of the detected defects. The size of the defect was determined by forming a pattern on the particles of the ferromagnetic material attached to the surface of the sample material by the magnetic flux leaking from the crack, transferring the magnetization pattern to a replica film, and observing it with a microscope. Can be directly measured with an optical microscope, and the measurement results can be recorded by photographs. 3) Since the fine particles of the ferromagnetic material are directly dispersed and adhered to the investigation target portion of the sample material, the accuracy of detecting the magnetic flux leakage is high.
【００１１】４）従来の磁粉探傷法では表面の凹部に沈
降した磁粉による、供試材の欠陥には対応しない磁粉の
集積が欠陥検出精度を低下させるが、本発明の方法では
欠陥部以外の、表面の形状等により若干の磁粉の集積が
あるものの、強磁性微粒子のため漏洩磁束の影響が強く
欠陥部が漏洩磁束により鮮明に検出できる。また、疑似
模様はアルコール洗浄等により容易に除去される。 ５）欠陥の判定は漏洩磁束を転写したレプリカフィルム
を顕微鏡に装着して行うことから、任意の場所で行うこ
とができ、大型機器の現場などの狭隘な環境において欠
陥判定を行う必要がなく、検査装置のロボット化が容易
である。 ６）従来の磁粉探傷法は欠陥検査が目視によっているた
め、正確な検査データの記録が困難であるが、本発明の
方法では磁化された領域に集積した強磁性体の微粒子を
レプリカフィルムに転写し光学顕微鏡で観察することに
よって、欠陥を観察、計測することから、顕微鏡組織の
写真撮影によって検査結果を正確に記録することができ
る。4) In the conventional magnetic particle flaw detection method, accumulation of magnetic particles that do not correspond to defects in the sample material due to the magnetic particles settled in the recesses on the surface lowers the defect detection accuracy. Although there is some accumulation of magnetic powder due to the shape of the surface, etc., because of the ferromagnetic fine particles, the influence of the leakage magnetic flux is strong and the defect can be clearly detected by the leakage magnetic flux. Further, the pseudo pattern is easily removed by cleaning with alcohol or the like. 5) Defect determination is performed by mounting a replica film on which a leakage magnetic flux has been transferred on a microscope, so that it can be performed at any place, and it is not necessary to perform defect determination in a narrow environment such as the site of large equipment. The inspection device can be easily robotized. 6) In the conventional magnetic particle flaw detection method, it is difficult to record accurate inspection data because the defect inspection is conducted visually. However, the method of the present invention transfers the ferromagnetic fine particles accumulated in the magnetized region to the replica film. Since the defect is observed and measured by observing with an optical microscope, the inspection result can be accurately recorded by taking a photograph of the microscopic structure.
【００１２】[0012]
【実施例】以下実施例により本発明の方法をさらに具体
的に説明する。機械部品として多用されている炭素鋼を
供試材として、欠陥の検出、評価試験を行った。この供
試材から図１に示す形状の疲労試験片１を作製し（図１
中の数値は試験片の寸法を表し、単位はｍｍである）、
供試材の表面状態を実際に使用された機械部品と同様に
するために、大気中で５００℃で１００時間の加熱処理
を施し酸化被膜を形成させた。その後、機械部品の使用
状態を模擬するために室温で、総歪み範囲０．８％の保
持なし引張圧縮疲労試験を行い、表面に疲労損傷による
表面き裂を導入した。EXAMPLES The method of the present invention will be described in more detail with reference to the following examples. Using carbon steel, which is widely used as mechanical parts, as a test material, defects were detected and evaluation tests were conducted. A fatigue test piece 1 having the shape shown in FIG. 1 was produced from this test material (see FIG.
(The numerical value inside represents the size of the test piece, the unit is mm),
In order to make the surface state of the test material similar to that of the mechanical parts actually used, heat treatment was performed in the air at 500 ° C. for 100 hours to form an oxide film. Then, in order to simulate the usage state of the mechanical parts, a tensile-compression fatigue test without holding in a total strain range of 0.8% was performed at room temperature, and a surface crack due to fatigue damage was introduced on the surface.
【００１３】所定の繰り返し数で試験を中断した試験片
について、表面をワイヤブラシで清浄にし、マグネタイ
トの微粒子を分散させたコロイド液（日本フェロフルイ
ド株式会社製、強磁性流体、カタログ No.P-0701 を使
用）を薄く塗布した。その後乾燥させることなく、その
試験片のマグネタイト微粒子のコロイド液が付着した領
域を含む領域を電磁石を用いて一定時間（この例では１
２０秒）磁化させた。表面を乾燥させた後、この磁化さ
せた領域にアセチルセルロースを酢酸メチル（純度９５
％、不純物は水その他）に溶解させた溶液（過飽和状態
の液）を噴霧し、溶剤を揮散させて表面にレプリカフィ
ルム層を形成させた。その状態を図２に示す。図２にお
いて１は疲労試験片、２は表面に付着したマグネタイト
微粒子、３は形成させたアセチルセルロースのフィルム
層（レプリカフィルム）である。次いで、試験片からレ
プリカフィルムをマグネタイト微粒子とともに剥離さ
せ、台板に固定させ、フィルム上に形成された磁化パタ
ーンを光学顕微鏡で観察した。For a test piece whose test was interrupted at a predetermined number of repetitions, the surface was cleaned with a wire brush, and a colloidal liquid in which fine particles of magnetite were dispersed (manufactured by Nippon Ferrofluid Co., Ltd., ferrofluid, Catalog No. P- 0701 was used). Then, without drying, the region including the region to which the colloidal liquid of magnetite fine particles of the test piece adhered was used for a certain time (1 in this example by using an electromagnet).
It was magnetized for 20 seconds. After drying the surface, acetyl cellulose was added to this magnetized area with methyl acetate (purity 95%).
%, Impurities were water and the like), and a solution (supersaturated liquid) dissolved in the solution was sprayed to volatilize the solvent to form a replica film layer on the surface. The state is shown in FIG. In FIG. 2, 1 is a fatigue test piece, 2 is magnetite fine particles attached to the surface, and 3 is a film layer (replica film) of acetyl cellulose formed. Then, the replica film was peeled off together with the magnetite fine particles from the test piece, fixed on a base plate, and the magnetization pattern formed on the film was observed with an optical microscope.
【００１４】観察結果の概略図を図３に示す。試験片に
生成したき裂に対応して、マグネタイト微粒子の集積し
た線状の領域４が観察された。そこで、この領域の顕微
鏡写真を撮影し、写真上で最大の線状領域の長さを計測
した。一方、試験片表面の酸化被膜をグラインダ、研磨
紙、ダイヤモンドペーストを用いてレプリカが採取でき
るように鏡面研磨した後、５％硝酸エタノール溶液でエ
ッチングして、レプリカを採取し、これを光学顕微鏡で
観察して同様の方法で最大き裂長さを計測した。さら
に、これらの試験で使用したのと同じ試験片を酸化処理
（大気中、５００℃で１００時間の加熱処理）を行うこ
となく、表面を鏡面研磨した後、同様の条件で疲労試験
を行い、同様の条件で疲労試験を中断した試験片からレ
プリカを採取し、該レプリカを顕微鏡に装着して転写さ
れたき裂の長さを計測した。A schematic diagram of the observation results is shown in FIG. Corresponding to the cracks formed on the test piece, linear regions 4 in which magnetite fine particles were accumulated were observed. Therefore, a micrograph of this region was taken, and the length of the largest linear region on the photo was measured. On the other hand, the oxide film on the surface of the test piece was mirror-polished using a grinder, polishing paper and diamond paste so that a replica could be collected, and then etched with a 5% nitric acid ethanol solution to collect a replica, which was then observed with an optical microscope. It was observed and the maximum crack length was measured by the same method. Further, the same test piece used in these tests was subjected to a fatigue test under the same conditions after mirror-polishing the surface without oxidation treatment (heat treatment at 500 ° C. in air for 100 hours). A replica was taken from a test piece in which the fatigue test was interrupted under the same conditions, the replica was mounted on a microscope, and the length of the transferred crack was measured.
【００１５】図４に各供試材について、前記３種類の手
法による最大き裂長さ計測結果に基づく、各供試材の最
大き裂長さと寿命消費率との関係を示す。繰り返し荷重
を受ける機械部品には疲労損傷と呼ばれる繰り返し荷重
による損傷が進展していく。この損傷が、機械部品とし
て機能しなくなるまで進展した状態又はき裂長さが各々
の機械部品によって決まる使用限界の長さまで成長した
状態を寿命消費率１００％とし、使用中の機械部品が使
用開始後検査時までに受けた荷重の繰り返し数（中断繰
り返し数）の寿命消費率１００％に達する繰り返し数
（破断繰り返し数）に対する割合を寿命消費率（中断寿
命率）と定義する。FIG. 4 shows the relationship between the maximum crack length and the life consumption rate of each test material, based on the maximum crack length measurement results obtained by the above-mentioned three types of methods. Mechanical components that are subjected to repeated loading, called fatigue damage, develop due to repeated loading. The life consumption rate is 100% when the damage progresses until it no longer functions as a machine part or when the crack length grows to the limit of use determined by each machine part. The ratio of the number of repetitions of the load received until the inspection (repetition number of interruptions) to the number of repetitions (repetition number of breaks) reaching 100% of the life consumption rate is defined as the life consumption rate (interruption life rate).
【００１６】図４から、酸化被膜付着まま試験片の本発
明方法によって計測した表面き裂長さは、酸化処理を行
うことなく疲労試験を行った試験片についてレプリカに
よる方法で測定したものと同等のき裂長さとなってお
り、本発明方法によってレプリカ法と同様の精度で、し
かもレプリカ採取の場合に必要な鏡面研磨、酸化被膜除
去等の前処理を行うことなく、き裂長さを計測できるこ
とが明らかになった。一方、酸化被膜が付着した試験片
の酸化被膜を除去した後に採取したレプリカからの最大
き裂長さは長さ６ｍｍ以上は上記二つの方法で計測した
き裂長さとほぼ同１の長さとなったが、これよりも小さ
いき裂の長さは他よりも短く、また上記二つの方法で検
出された０．３ｍｍ以下のき裂は検出できなかった。以
上の結果から、酸化や腐食が生じて表面粗度が粗い実機
部品においては、従来微小な表面き裂の長さを非破壊的
に検出する唯一の方法であったレプリカ法よりも本発明
で開発した方法はより短いき裂長さのき裂を精度よく検
出できることが明らかとなった。From FIG. 4, the surface crack length measured by the method of the present invention of the test piece with the oxide film adhered is the same as that measured by the replica method on the test piece which was subjected to the fatigue test without oxidation treatment. It is the crack length, and it is clear that the method of the present invention can measure the crack length with the same accuracy as the replica method, and without performing pretreatment such as mirror polishing and oxide film removal necessary for replica collection. Became. On the other hand, the maximum crack length from the replica taken after removing the oxide film of the test piece to which the oxide film was adhered was 6 mm or more, which was almost the same as the crack length measured by the above two methods. The length of cracks smaller than this was shorter than the others, and cracks of 0.3 mm or less detected by the above two methods could not be detected. From the above results, in the actual machine parts where the surface roughness is rough due to oxidation or corrosion, the present invention is more effective than the replica method, which is the only method that nondestructively detects the length of the minute surface crack. It was clarified that the developed method can detect cracks with shorter crack lengths accurately.
【００１７】[0017]
【発明の効果】以上、詳述したように、本発明方法によ
ればレプリカ法よりも高い精度で、機械部品の表面に生
成する微小なき裂の長さを、レプリカ法のように供試材
の表面を研磨することなく検出できることから、機械部
品の非破壊検査法の精度向上ならびに効率化に寄与する
ことができる。疲労損傷は、部品の表面に微小なき裂が
発生し、これが成長して破壊に至るものである。したが
って、荷重の繰り返し数とき裂の大きさ（表面き裂の大
きさ）とには図４に示すような相関性がある。本発明の
方法により使用中の機械部品の疲労による微小なき裂の
表面長さを測定することが可能となり、その大きさから
使用中の機械部品の寿命消費率、すなわち測定時まで
に、破壊あるいは初期に設定したき裂長さの限界値に達
するまでの寿命のどの程度を消費したかを推定すること
ができる。例えば、火力発電プラントにおいては、疲労
き裂の進展によって耐圧部の上記漏れが発生するとプラ
ントを計画外に停止して、漏洩部分を検出するとともに
その補修を行わなければならず、予定外のプラントの停
止によって、計画発電量に見合う他の発電設備の起動を
余儀なくされるほか、設備に余裕がない場合には、大規
模な停電に至る可能性があり、本発明によって非破壊検
査技術の精度が上がることによってこのような事態を避
けることができる。As described above in detail, according to the method of the present invention, the length of a minute crack formed on the surface of a mechanical component can be measured with a higher accuracy than that of the replica method, as in the replica method. Since the surface can be detected without polishing, it can contribute to improvement in accuracy and efficiency of the nondestructive inspection method for mechanical parts. Fatigue damage is the formation of minute cracks on the surface of a component, which grows and leads to destruction. Therefore, there is a correlation as shown in FIG. 4 between the number of repeated loads and the crack size (surface crack size). By the method of the present invention, it becomes possible to measure the surface length of a minute crack due to fatigue of a mechanical part in use, and the life consumption rate of the mechanical part in use from its size, that is, by the time of measurement, destruction or It is possible to estimate how much of the life is consumed until the crack length limit value set in the initial stage is reached. For example, in a thermal power plant, if the above-mentioned leakage of the pressure-resistant portion occurs due to fatigue crack growth, the plant must be stopped unplanned, and the leakage portion must be detected and repaired. The suspension of the other causes the other power generation equipment commensurate with the planned amount of power generation to be started, and if the equipment does not have a margin, it may lead to a large-scale power failure. This can be avoided by raising the.
【図１】実施例で使用した炭素鋼製の疲労試験片の寸
法、形状を示す概略図。FIG. 1 is a schematic view showing dimensions and shapes of carbon steel fatigue test pieces used in Examples.
【図２】試験片表面にマグネタイト微粒子を付着させ、
さらにアセチルセルロースフィルム層を形成させた状態
を示す説明図。[Fig. 2] Attaching magnetite fine particles to the surface of the test piece,
Explanatory drawing which shows the state which further formed the acetyl cellulose film layer.
【図３】疲労試験片中断材からアセチルセルロースフィ
ルム上に転写された磁化パターンの光学顕微鏡観察の概
略図。FIG. 3 is a schematic diagram of an optical microscope observation of a magnetization pattern transferred from an interrupted material of a fatigue test piece onto an acetyl cellulose film.
【図４】実施例で作製した試料について計測した最大き
裂長さと中断寿命比（寿命消費率）との関係を示すグラ
フ。FIG. 4 is a graph showing the relationship between the maximum crack length and the interruption life ratio (life consumption rate) measured for the samples manufactured in the examples.
Claims (2)
て強磁性材料の微粒子を分散させたコロイド液を塗布
し、該表面に強磁性材料の微粒子のコロイド液を均一に
付着させた後、前記供試材の調査対象箇所を含む領域を
磁化させ、乾燥させた後レプリカフィルム材料を溶剤に
溶解した溶液を噴霧し、乾燥固化させてフィルム層を形
成させ、次いで強磁性材料の微粒子と一体化したレプリ
カフィルムを供試材表面から剥離させ、該剥離フィルム
を観察して欠陥部に集積した磁化された強磁性材料の微
粒子のパターンを観察することにより供試材中の欠陥を
検出、評価することを特徴とするフェライト系鉄鋼材料
の表面欠陥の非破壊検査法。1. A colloidal liquid in which fine particles of a ferromagnetic material are dispersed is applied by cleaning the surface of a test object to be examined, and a colloidal liquid of fine particles of a ferromagnetic material is uniformly attached to the surface. After that, the region including the investigation target portion of the sample material is magnetized and dried, and then a solution of a replica film material dissolved in a solvent is sprayed and dried and solidified to form a film layer, and then fine particles of a ferromagnetic material. Defects in the specimen are detected by peeling the replica film integrated with the specimen from the specimen surface, and observing the peeling film to observe the pattern of magnetized ferromagnetic material particles accumulated in the defect portion. , Non-destructive inspection method for surface defects of ferritic steel materials characterized by evaluation.
粒子であることを特徴とする請求項１に記載のフェライ
ト系鉄鋼材料の表面欠陥の非破壊検査法。2. The nondestructive inspection method for surface defects of a ferritic steel material according to claim 1, wherein the ferromagnetic material particles are magnetite particles.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP30058794A JPH08160008A (en) | 1994-12-05 | 1994-12-05 | Non-destructive inspecting method for defect |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP30058794A JPH08160008A (en) | 1994-12-05 | 1994-12-05 | Non-destructive inspecting method for defect |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH08160008A true JPH08160008A (en) | 1996-06-21 |
Family
ID=17886643
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP30058794A Withdrawn JPH08160008A (en) | 1994-12-05 | 1994-12-05 | Non-destructive inspecting method for defect |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH08160008A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003294716A (en) * | 2002-03-29 | 2003-10-15 | Hitachi Ltd | Inspection method of turbine |
| JP2008216045A (en) * | 2007-03-05 | 2008-09-18 | Nippon Steel Corp | Method and apparatus for observing surface properties of magnetic band |
| CN111982967A (en) * | 2020-08-22 | 2020-11-24 | 核动力运行研究所 | Permanent magnet-based magnetic saturation pulse eddy current infrared nondestructive evaluation method |
| CN113334754A (en) * | 2021-07-01 | 2021-09-03 | 唐汉聪 | Surface film coating process for ink printing paper |
-
1994
- 1994-12-05 JP JP30058794A patent/JPH08160008A/en not_active Withdrawn
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003294716A (en) * | 2002-03-29 | 2003-10-15 | Hitachi Ltd | Inspection method of turbine |
| JP2008216045A (en) * | 2007-03-05 | 2008-09-18 | Nippon Steel Corp | Method and apparatus for observing surface properties of magnetic band |
| CN111982967A (en) * | 2020-08-22 | 2020-11-24 | 核动力运行研究所 | Permanent magnet-based magnetic saturation pulse eddy current infrared nondestructive evaluation method |
| CN113334754A (en) * | 2021-07-01 | 2021-09-03 | 唐汉聪 | Surface film coating process for ink printing paper |
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