JPS57124244A - Detection for surface flaw of steel product - Google Patents

Detection for surface flaw of steel product

Info

Publication number
JPS57124244A
JPS57124244A JP1003881A JP1003881A JPS57124244A JP S57124244 A JPS57124244 A JP S57124244A JP 1003881 A JP1003881 A JP 1003881A JP 1003881 A JP1003881 A JP 1003881A JP S57124244 A JPS57124244 A JP S57124244A
Authority
JP
Japan
Prior art keywords
shadows
slab
irradiation
cracking
flaw
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
JP1003881A
Other languages
Japanese (ja)
Other versions
JPH0520695B2 (en
Inventor
Takeo Yamada
Mitsuaki Uesugi
Shigeki Komori
Haruo Miyano
Masato Yoshino
Hajime Yamashita
Yasuteru Tsushima
Isoshirou Ishida
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
HIYUUTEC KK
HIYUUTETSUKU KK
JFE Engineering Corp
Original Assignee
HIYUUTEC KK
HIYUUTETSUKU KK
NKK Corp
Nippon Kokan Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by HIYUUTEC KK, HIYUUTETSUKU KK, NKK Corp, Nippon Kokan Ltd filed Critical HIYUUTEC KK
Priority to JP1003881A priority Critical patent/JPS57124244A/en
Publication of JPS57124244A publication Critical patent/JPS57124244A/en
Publication of JPH0520695B2 publication Critical patent/JPH0520695B2/ja
Granted legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/84—Systems specially adapted for particular applications
    • G01N21/88—Investigating the presence of flaws or contamination
    • G01N21/89—Investigating the presence of flaws or contamination in moving material, e.g. running paper or textiles
    • G01N21/8901—Optical details; Scanning details

Landscapes

  • Engineering & Computer Science (AREA)
  • Textile Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Investigating Materials By The Use Of Optical Means Adapted For Particular Applications (AREA)

Abstract

PURPOSE:To prevent the shadows in normal parts including oscillation marks and dents and to generate the shadows in cracking flaw parts by setting the irradiation angles of irradiation light to the surface of steel product at prescribed angles. CONSTITUTION:The illuminating light from illuminators 8, 8 irraidates a cracking flaw 1 on the surface of a slab S from both side directions at a right angle thereto, and the images thereof are picked up by an image pickup device 9 provided on the perpendicular line on the surface of the slab S. The upper limit angle for the irradiation angle theta of the irradiation light is so determined that the direct incident light of illumination into the cracking flaw part is small and that the width of the shadow produced in the cracking flaw part exceeds the resolution on the slab surface of a photoelectric converter, and the lower limit thereof is so determined that the shadows of the illumination are not made by oscillation marks and dents. The concrete angle theta for these are, for example, 40 deg.<theta< 50 deg. to detect a longitudinal cracking flaw having >=0.5mm. opening width by discriminating the same from a dent when a photoelectric converter of 0.3mm. surface resolution of slabs is used.
JP1003881A 1981-01-26 1981-01-26 Detection for surface flaw of steel product Granted JPS57124244A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP1003881A JPS57124244A (en) 1981-01-26 1981-01-26 Detection for surface flaw of steel product

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP1003881A JPS57124244A (en) 1981-01-26 1981-01-26 Detection for surface flaw of steel product

Publications (2)

Publication Number Publication Date
JPS57124244A true JPS57124244A (en) 1982-08-03
JPH0520695B2 JPH0520695B2 (en) 1993-03-22

Family

ID=11739217

Family Applications (1)

Application Number Title Priority Date Filing Date
JP1003881A Granted JPS57124244A (en) 1981-01-26 1981-01-26 Detection for surface flaw of steel product

Country Status (1)

Country Link
JP (1) JPS57124244A (en)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH01237441A (en) * 1987-11-17 1989-09-21 Hitachi Cable Ltd Method for detecting foreign matter on the surface of long body and for measuring size thereof
JPH07234187A (en) * 1994-02-24 1995-09-05 G T C:Kk Method and device for detecting surface detect of glass substrate
KR100426864B1 (en) * 1999-12-13 2004-04-13 주식회사 포스코 Measuring system and its method for a subject with self calibraion function
JP2006023123A (en) * 2004-07-06 2006-01-26 Hokkai Can Co Ltd Defect inspection method and its device
JP2006177789A (en) * 2004-12-22 2006-07-06 Jfe Steel Kk Inspection device of rolling roll flaw
JP2007114135A (en) * 2005-10-24 2007-05-10 Jfe Steel Kk Method and device for detecting slab longitudinal crack
CN112444490A (en) * 2021-02-01 2021-03-05 深圳宜美智科技股份有限公司 Hole plugging defect detection method based on image detection and hole plugging defect detection equipment

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS524887A (en) * 1975-06-30 1977-01-14 Sanyo Kiko Kk Optical surface scar inspector
JPS5265494A (en) * 1975-11-26 1977-05-30 Nippon Steel Corp Method of detecting surface flaw of hot steel material

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS524887A (en) * 1975-06-30 1977-01-14 Sanyo Kiko Kk Optical surface scar inspector
JPS5265494A (en) * 1975-11-26 1977-05-30 Nippon Steel Corp Method of detecting surface flaw of hot steel material

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH01237441A (en) * 1987-11-17 1989-09-21 Hitachi Cable Ltd Method for detecting foreign matter on the surface of long body and for measuring size thereof
JPH07234187A (en) * 1994-02-24 1995-09-05 G T C:Kk Method and device for detecting surface detect of glass substrate
KR100426864B1 (en) * 1999-12-13 2004-04-13 주식회사 포스코 Measuring system and its method for a subject with self calibraion function
JP2006023123A (en) * 2004-07-06 2006-01-26 Hokkai Can Co Ltd Defect inspection method and its device
JP4516788B2 (en) * 2004-07-06 2010-08-04 北海製罐株式会社 Defect inspection method and apparatus
JP2006177789A (en) * 2004-12-22 2006-07-06 Jfe Steel Kk Inspection device of rolling roll flaw
JP2007114135A (en) * 2005-10-24 2007-05-10 Jfe Steel Kk Method and device for detecting slab longitudinal crack
CN112444490A (en) * 2021-02-01 2021-03-05 深圳宜美智科技股份有限公司 Hole plugging defect detection method based on image detection and hole plugging defect detection equipment
CN112444490B (en) * 2021-02-01 2021-04-16 深圳宜美智科技股份有限公司 Hole plugging defect detection method based on image detection and hole plugging defect detection equipment

Also Published As

Publication number Publication date
JPH0520695B2 (en) 1993-03-22

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