JPS6382358A - Magnetic powder-based flaw detection - Google Patents
Magnetic powder-based flaw detectionInfo
- Publication number
- JPS6382358A JPS6382358A JP22883386A JP22883386A JPS6382358A JP S6382358 A JPS6382358 A JP S6382358A JP 22883386 A JP22883386 A JP 22883386A JP 22883386 A JP22883386 A JP 22883386A JP S6382358 A JPS6382358 A JP S6382358A
- Authority
- JP
- Japan
- Prior art keywords
- image
- flaw
- periphery
- inspected
- ground
- 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.)
- Pending
Links
- 238000001514 detection method Methods 0.000 title claims abstract description 11
- 239000006247 magnetic powder Substances 0.000 title abstract 3
- 239000000463 material Substances 0.000 claims abstract description 41
- 239000006249 magnetic particle Substances 0.000 claims description 26
- 238000000034 method Methods 0.000 claims description 19
- 230000001678 irradiating effect Effects 0.000 claims description 9
- 239000000203 mixture Substances 0.000 claims 1
- 229910000831 Steel Inorganic materials 0.000 abstract description 16
- 239000010959 steel Substances 0.000 abstract description 16
- 238000010586 diagram Methods 0.000 description 12
- 230000015572 biosynthetic process Effects 0.000 description 4
- 238000003786 synthesis reaction Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 2
- 239000000284 extract Substances 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
Landscapes
- Investigating Materials By The Use Of Optical Means Adapted For Particular Applications (AREA)
- Investigating Or Analyzing Materials By The Use Of Magnetic Means (AREA)
Abstract
Description
【発明の詳細な説明】
(産業上の利用分野〕
本発明は磁化させた被検査材の表面に蛍光磁粉を付着さ
せ、その付着させた磁粉から発せられる光の輝度値の高
低に基づいて被検査材の傷を検出する方法に関する。Detailed Description of the Invention (Industrial Field of Application) The present invention involves attaching fluorescent magnetic particles to the surface of a magnetized material to be inspected, and detecting the intensity of light based on the level of the brightness value of light emitted from the attached magnetic particles. The present invention relates to a method for detecting flaws in a test material.
磁化させた被検査材の表面に蛍光磁粉を付着させ、その
蛍光磁粉の模様を紫外線照射してテレビカメラで撮像し
、撮像した画像を処理して傷を検出する磁粉探傷方法に
ついては、特開昭59−226853号にて開示されて
いる。A magnetic particle flaw detection method in which fluorescent magnetic particles are attached to the surface of a magnetized material to be inspected, the pattern of the fluorescent magnetic particles is irradiated with ultraviolet rays and imaged with a television camera, and the captured images are processed to detect flaws is disclosed in Japanese Patent Application Publication No. It is disclosed in No. 59-226853.
この特開昭59−226853号にて開示されている方
法の要旨は以下の通りである。まず被検査材たる鋼材を
磁化させ、次にその表面に蛍光磁粉を付着させる。する
と、傷が存在する部分には漏洩磁束が生じているので、
その部分に蛍光磁粉が多く付着する。そして鋼材の表面
に紫外線を照射して、蛍光磁粉から発せられる光をテレ
ビカメラで検出し、各部分の輝度値を測定する。そし才
基準値よりも輝度値が高い部分を傷として検出する。The gist of the method disclosed in JP-A-59-226853 is as follows. First, the steel material to be inspected is magnetized, and then fluorescent magnetic particles are attached to its surface. Then, leakage magnetic flux occurs in the part where the scratch exists, so
Many fluorescent magnetic particles adhere to that area. The surface of the steel material is then irradiated with ultraviolet light, the light emitted from the fluorescent magnetic particles is detected by a television camera, and the brightness value of each part is measured. A portion where the luminance value is higher than the brightness reference value is detected as a flaw.
ビレット等の鋼材は上述した如き磁扮探傷検査の後、研
削処理され、その後残存傷を検出する目的で、再び磁粉
探傷検査が施される。ところでこの2度目の磁粉探傷検
査の際に蛍光磁粉を付着させると、研削処理により生じ
た研削部の辺縁に蛍光磁粉かたまり、その部分を傷とし
て誤検出するという問題点があった。A steel material such as a billet is subjected to a grinding process after being subjected to the magnetic particle flaw detection as described above, and then subjected to a magnetic particle flaw detection again for the purpose of detecting any remaining flaws. However, when fluorescent magnetic particles are attached during this second magnetic particle flaw detection test, there is a problem in that fluorescent magnetic particles aggregate around the edge of the ground portion produced by the grinding process, and this area is erroneously detected as a flaw.
本発明はかかる事情に鑑みてなされたものであり、研削
処理後の被検査材に可視光を照射してその画像を撮像し
、その画像を2値化、拡大処理して研削処理に伴う研削
部の辺縁を抽出し、紫外線を照射して得た画像から抽出
した研削部の辺縁をマスク処理にて除去することにより
、研削処理後の被検査材においても、研削部の辺縁を傷
として検出することがなく、正確に傷検出が行える磁粉
探傷方法を提供することを目的とする。The present invention has been made in view of the above circumstances, and involves irradiating the inspected material after grinding with visible light to capture an image, binarizing and enlarging the image, and then performing the grinding process associated with the grinding process. By extracting the edges of the ground part and using mask processing to remove the edges of the ground part extracted from the image obtained by irradiating ultraviolet rays, the edges of the ground part can be removed even in the inspected material after grinding. It is an object of the present invention to provide a magnetic particle flaw detection method that can accurately detect flaws without detecting them as flaws.
本発明に係る磁粉探傷方法は、一部が研削されて、研削
部と非研削部とが混在する被検査材を磁化し、該被検査
材に蛍光磁粉を付着させ、該!!l!I★査材に紫外線
を照射して被検査材の画像を得、蛍光磁粉の輝度値の高
低に基づき前記′ItL検査材の傷を検出する方法にお
いて、前記被検査材の表面に可視光を照射して被検査材
の画像を得、該画像を2値化、拡大処理して研削部の辺
縁を抽出し、紫外線を照射して得た画像から抽出した研
削部の辺縁をマスク処理にて除去し、研削部の辺縁を除
去した画像における蛍光磁粉の輝度値の高低に基づき被
検査材の傷を検出することを特徴とする。The magnetic particle flaw detection method according to the present invention magnetizes a material to be inspected which is partially ground and has both ground and non-ground parts, and attaches fluorescent magnetic particles to the material to be inspected. ! l! In the method of obtaining an image of the material to be inspected by irradiating the material with ultraviolet rays and detecting flaws in the material to be inspected based on the level of brightness value of fluorescent magnetic particles, visible light is applied to the surface of the material to be inspected. Obtain an image of the inspected material by irradiating the image, binarize and enlarge the image to extract the edge of the ground part, and mask the edge of the ground part extracted from the image obtained by irradiating ultraviolet rays. The method is characterized in that flaws in the inspected material are detected based on the level of brightness value of the fluorescent magnetic particles in the image with the edges of the ground portion removed.
本発明では、磁化されて蛍光磁粉を付着された被検査材
に紫外線を照射して画像を得る。また可視光を照射して
同様に画像を得る。後者の画像を2値化、拡大処理して
研削部の辺縁を抽出する。In the present invention, an image is obtained by irradiating ultraviolet rays onto a material to be inspected that has been magnetized and has fluorescent magnetic particles attached thereto. An image is also obtained in the same way by irradiating visible light. The latter image is binarized and enlarged to extract the edge of the grinding part.
前者の画像から抽出した研削部の辺縁をマスク処理にて
除去する。そうすると傷の部分だけが高輝度となり、正
確に傷を検出できる。The edges of the grinding portion extracted from the former image are removed by mask processing. In this way, only the scratched area becomes highly bright, allowing accurate scratch detection.
以下、本発明をその実施例を示す図面に基づいて具体的
に説明する。第1図は本発明方法を実路するための装置
の模式図であり、図中1は、第2図に斜視図で示す、表
面傷を検査すべき被検査材たる鋼材である。鋼材1は研
削されて磁化され、更に傷を検査すべき表面に蛍光磁粉
が付着されている。また第2図において、図中斜ljA
部分が研削部、破線Aが研削部の辺縁、実線Bが表面傷
を示し、研削部内には研削処理に伴う図示しない研削跡
が存在する。DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below based on drawings showing embodiments thereof. FIG. 1 is a schematic diagram of an apparatus for carrying out the method of the present invention, and numeral 1 in the figure indicates a steel material to be inspected for surface flaws, as shown in a perspective view in FIG. 2. The steel material 1 is ground and magnetized, and fluorescent magnetic particles are attached to the surface to be inspected for flaws. In addition, in Fig. 2, the diagonal ljA in the figure
The part shows the ground part, the broken line A shows the edge of the ground part, the solid line B shows the surface flaw, and there are grinding marks (not shown) in the ground part due to the grinding process.
S’A材1の上方には適長離隔して鋼材1の画像を得る
テレビカメラ2が設けである。テレビカメラ2を挟む位
置で、m材lの斜め上方には可視光を出射する蛍光燈3
.紫外線を出射するブラックライト4が設けてあり、蛍
光燈3またはブラックライト4からの照明による鋼材1
の画像がテレビカメラ2にて得られるようになっている
。またブランクライト4の紫外線照射方向前方にはジャ
ック5が設けられており、このシャッタ5の開閉によ/
)鋼材1への紫外線の照射が調節される。なお、各脇射
光に伴う影響を除外するために、蛍光燈3゜ブラックラ
イト4は同時に鋼材1の同一部分を照射しないようにな
っている。A television camera 2 is provided above the S'A material 1 at an appropriate distance apart to take an image of the steel material 1. A fluorescent light 3 that emits visible light is placed diagonally above the material M at a position sandwiching the television camera 2.
.. A black light 4 that emits ultraviolet light is provided, and the steel material 1 is illuminated by the fluorescent light 3 or the black light 4.
images can be obtained by the television camera 2. In addition, a jack 5 is provided in front of the blank light 4 in the direction of ultraviolet irradiation, and the opening and closing of the shutter 5
) Irradiation of ultraviolet rays to the steel material 1 is adjusted. In addition, in order to eliminate the influence of each side light, the fluorescent lamp 3° black light 4 is designed not to illuminate the same part of the steel material 1 at the same time.
また、20はテレビカメラ2にて得られた画像を画像処
理する画像処理装置であり、画像処理装置20には、蛍
光燈3からの可視光照射に伴う画像を2値化、拡大処理
して研削部の辺縁を抽出する辺縁抽出器6、辺縁抽出器
6にて得られた画像を記憶する辺縁両像記すa器7、ブ
ラックライト4からの紫外線照射に伴う画像を記憶する
傷画像記↑9器8、辺縁両像記憶器7及び傷画像記1.
9器80両像を同一タイミング(画像対象部分が同一)
にてマスク合成するマスク合成器9、マスク合成器9の
画像を2値化する2値化画像器10が具備されている。Further, 20 is an image processing device that processes the image obtained by the television camera 2. An edge extractor 6 extracts the edge of the grinding part, an edge extractor 7 stores the image obtained by the edge extractor 6, a device 7 records images obtained by the edge extractor 6, and stores an image caused by ultraviolet irradiation from the black light 4. Wound image record ↑9 device 8, marginal double image memory device 7, and wound image record 1.
Same timing for 9 and 80 images (image target area is the same)
A mask synthesizer 9 performs mask synthesis and a binarization image unit 10 binarizes the image of the mask synthesizer 9.
更に、2値化画像器10には、2値化画像器10にて2
値化された画像に基づき鋼材1の表面傷を検出する傷検
出器21が接続されている。Furthermore, the binarization imager 10 has two
A flaw detector 21 is connected to detect surface flaws on the steel material 1 based on the valued image.
次に本発明方法の具体的手順について説明する。Next, the specific procedure of the method of the present invention will be explained.
研削された鋼材1は磁化され、傷を検査すべき表面に蛍
光磁粉が付着される。鋼材1は蛍光燈3から可視光を照
射されで、テレビカメラ2にて撮像され、その画像が得
られる。テレビカメラ2にて得られた画像は画像処理装
置20に具備される辺縁抽出器6に入力され、辺縁抽出
器6にてその画像は2値化、拡大処理されて、研削部の
辺縁が抽出される。The ground steel material 1 is magnetized and fluorescent magnetic particles are attached to the surface to be inspected for flaws. The steel material 1 is irradiated with visible light from a fluorescent lamp 3, and an image is taken by a television camera 2 to obtain an image. The image obtained by the television camera 2 is input to the edge extractor 6 included in the image processing device 20, and the image is binarized and enlarged by the edge extractor 6 to determine the edge of the grinding part. The edges are extracted.
ここで画像上における2値化、拡大及び辺縁抽出処理に
ついて具体的に説明する。テレビカメラ2にて撮像して
得られた画像は例えば縦横256画素からなり、各画素
は輝度レベルの高さにより2値化される。第3図はテレ
ビカメラ2にて得られた画像の2値化処理後の画像の一
部を示す模式図であり、図中Oの部分は輝度が低レベル
の部分、つまり非研削部または研削部内で可視光が乱反
射する部分を表し、1の部分は輝度が高レベルの部分、
つまり研削部の研削跡(a)を表しており、各画素は0
.1の何れかに区別されることになる。Here, the binarization, enlargement, and edge extraction processing on an image will be specifically explained. The image captured by the television camera 2 consists of, for example, 256 pixels in the vertical and horizontal directions, and each pixel is binarized depending on the brightness level. FIG. 3 is a schematic diagram showing a part of the image obtained by the television camera 2 after the binarization process. It represents the part where visible light is diffusely reflected inside the part, and the part numbered 1 is the part with a high level of brightness.
In other words, it represents the grinding trace (a) of the grinding part, and each pixel is 0
.. It will be classified as either 1.
次に第3図の如き2値化処理画像を拡大処理する。Next, the binarized image as shown in FIG. 3 is enlarged.
拡大処理とはOである1個の画素の周囲に位置する8個
の画素の内少な(とも1 (flitの画素が1であれ
ば、そのOである画素が1に変換されることである。第
4図は第3図に示すz値化画像を拡大処理して得た画像
の模式図であり、研削部はこの拡大処理により内部が埋
め込まれた画像となる。次に、第4図の如き研削部の形
状を示す画像に基づき、研削部の辺縁を抽出する。(第
5図はその辺縁の位置を示す画1象の模式図である。)
そして研削部の辺縁位置は辺縁画像記憶器7に画像記↑
、つされる。Enlargement processing means that out of the eight pixels located around one pixel that is O, a small number (all 1) (if the pixel of flit is 1, that pixel that is O is converted to 1) Fig. 4 is a schematic diagram of an image obtained by enlarging the z-valued image shown in Fig. 3, and the grinding part becomes an image in which the inside is embedded by this enlarging process.Next, Fig. 4 The edges of the grinding section are extracted based on an image showing the shape of the grinding section, such as (Figure 5 is a schematic diagram of the image showing the position of the edge).
Then, the edge position of the grinding part is recorded as an image in the edge image memory 7↑
, will be taken.
一方、鋼材1はブラックライト4から紫外線を照射され
て、テレビカメラ2にて撮像され、その画像が得られる
。テレビカメラ2にて得られた画像は画像処理装置20
に具備される傷画像記憶器8に入力されて、画像記憶さ
°れる。(第6図はその傷画像の模式図である。)
次にマスク合成′a9にて、傷画像記憶器8の画像に同
一タイミング(画像対象部分が同一)で辺縁両像記す、
Q器7の画像がマスク合成される。2値化画像器10は
、マスク合成器9におけるマスク合成後の画像を2値化
する。第7図は2値化処理後の画像の模式図であり、研
削部の辺縁はマスクさ−れているので、高輝度の1とな
る部分は傷部分のみである。On the other hand, the steel material 1 is irradiated with ultraviolet rays from a black light 4, and is imaged by a television camera 2 to obtain the image. The image obtained by the television camera 2 is processed by an image processing device 20.
The image is input to a flaw image storage device 8 provided in the image storage device 8, and is stored as an image. (FIG. 6 is a schematic diagram of the flaw image.) Next, in mask synthesis 'a9, both edge images are written on the image in the flaw image storage device 8 at the same timing (the image target area is the same).
The images of the Q device 7 are combined with a mask. The binarization imager 10 binarizes the image after mask synthesis in the mask synthesizer 9. FIG. 7 is a schematic diagram of the image after the binarization process, and since the edges of the grinding portion are masked, the portions where the brightness becomes 1 are only the scratched portions.
最後に第7図の如き2値化処理画@!図に基づき、傷検
出器21にて表面傷が抄出される。Finally, a binarized image as shown in Figure 7! Based on the figure, surface flaws are detected by the flaw detector 21.
以上詳述した如く本発明方法では、研削部の辺縁をマス
ク処理するので、研削処理後の被検査材においても研削
部の辺縁を傷として誤検出する虞れがなく、正確に被検
査材の表面傷を検出することができる。As detailed above, in the method of the present invention, the edge of the ground part is masked, so there is no risk of erroneously detecting the edge of the ground part as a flaw even in the inspected material after grinding, and it is possible to accurately inspect the edge of the ground part. It is possible to detect surface scratches on materials.
第1図は本発明方法を実施するための装置の模式図、第
2図は鋼材の斜視模式図、第3図は2値化処理画像の模
式図、第4図は第3図を拡大処理して得た画像の模式図
、第5図は辺縁を示す画像の模式図、第6図は蛍光磁粉
によって得られる傷画像の模式図、第7図はマスク合成
後の2値化画像の模式図である。
】・・・鋼材 2・・・テレビカメラ 3・・・蛍光燈
4・・・ブラックライト 5・・・シャンク 20・
・・画像処理装置 21・・・傷検出器
纂2図
第3図
第6図
地7図Fig. 1 is a schematic diagram of an apparatus for carrying out the method of the present invention, Fig. 2 is a perspective schematic diagram of a steel material, Fig. 3 is a schematic diagram of a binarized image, and Fig. 4 is an enlarged version of Fig. 3. Figure 5 is a schematic diagram of an image showing the edges, Figure 6 is a schematic diagram of a scratch image obtained by fluorescent magnetic particles, and Figure 7 is a binary image after mask synthesis. It is a schematic diagram. ]...Steel 2...TV camera 3...Fluorescent light 4...Black light 5...Shank 20.
...Image processing device 21...Flaw detector collection Figure 2 Figure 3 Figure 6 Map 7
Claims (1)
被検査材を磁化し、該被検査材に蛍光磁粉を付着させ、
該被検査材に紫外線を照射して被検査材の画像を得、蛍
光磁粉の輝度値の高低に基づき前記被検査材の傷を検出
する方法において、 前記被検査材の表面に可視光を照射して被 検査材の画像を得、該画像を2値化、拡大処理して研削
部の辺縁を抽出し、紫外線を照射して得た画像から抽出
した研削部の辺縁をマスク処理にて除去し、研削部の辺
縁を除去した画像における蛍光磁粉の輝度値の高低に基
づき被検査材の傷を検出することを特徴とする磁粉探傷
方法。[Claims] 1. Magnetize a material to be inspected that has been partially ground and has a mixture of ground and non-ground parts, and attach fluorescent magnetic particles to the material to be inspected;
In the method of obtaining an image of the inspected material by irradiating the inspected material with ultraviolet rays and detecting flaws in the inspected material based on the level of brightness value of fluorescent magnetic particles, the surface of the inspected material is irradiated with visible light. Obtain an image of the inspected material, binarize and enlarge the image to extract the edge of the ground part, and mask the edge of the ground part extracted from the image obtained by irradiating ultraviolet rays. A magnetic particle flaw detection method, which detects flaws in a material to be inspected based on the level of brightness of fluorescent magnetic particles in an image obtained by removing the edges of a grinding part.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP22883386A JPS6382358A (en) | 1986-09-26 | 1986-09-26 | Magnetic powder-based flaw detection |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP22883386A JPS6382358A (en) | 1986-09-26 | 1986-09-26 | Magnetic powder-based flaw detection |
Publications (1)
Publication Number | Publication Date |
---|---|
JPS6382358A true JPS6382358A (en) | 1988-04-13 |
Family
ID=16882571
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP22883386A Pending JPS6382358A (en) | 1986-09-26 | 1986-09-26 | Magnetic powder-based flaw detection |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS6382358A (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH02228542A (en) * | 1989-03-01 | 1990-09-11 | Toyota Motor Corp | Automatic magnetic particle inspection device |
JPH04223262A (en) * | 1990-12-25 | 1992-08-13 | Nippon Denji Sokki Kk | Processing method of image in fluorescent magnetic powder flaw detection |
ES2108617A1 (en) * | 1994-11-17 | 1997-12-16 | Tecnologico Robotiker Centro | Procedure and machine for automatically detecting cracks in iron parts. |
JP2007017376A (en) * | 2005-07-11 | 2007-01-25 | Ishikawajima Harima Heavy Ind Co Ltd | Fluorescent flaw detector and fluorescent flaw detecting method |
JP2007017377A (en) * | 2005-07-11 | 2007-01-25 | Ishikawajima Harima Heavy Ind Co Ltd | Fluorescent flaw detector and fluorescent flaw detecting method |
-
1986
- 1986-09-26 JP JP22883386A patent/JPS6382358A/en active Pending
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH02228542A (en) * | 1989-03-01 | 1990-09-11 | Toyota Motor Corp | Automatic magnetic particle inspection device |
JPH04223262A (en) * | 1990-12-25 | 1992-08-13 | Nippon Denji Sokki Kk | Processing method of image in fluorescent magnetic powder flaw detection |
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