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JPS5472095A - Surface flaw detecting method of hot rolled steel - Google Patents

Surface flaw detecting method of hot rolled steel

Info

Publication number
JPS5472095A
JPS5472095A JP13886277A JP13886277A JPS5472095A JP S5472095 A JPS5472095 A JP S5472095A JP 13886277 A JP13886277 A JP 13886277A JP 13886277 A JP13886277 A JP 13886277A JP S5472095 A JPS5472095 A JP S5472095A
Authority
JP
Japan
Prior art keywords
signal
signals
flaws
flaw
signal level
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
JP13886277A
Other languages
Japanese (ja)
Other versions
JPS6261899B2 (en
Inventor
Takeshi Kitagawa
Kane Miyake
Takashi Tsuda
Shinichi Kitamura
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.)
JFE Steel Corp
Fujitsu Ltd
Original Assignee
Fujitsu Ltd
Kawasaki Steel Corp
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 Fujitsu Ltd, Kawasaki Steel Corp filed Critical Fujitsu Ltd
Priority to JP13886277A priority Critical patent/JPS5472095A/en
Publication of JPS5472095A publication Critical patent/JPS5472095A/en
Publication of JPS6261899B2 publication Critical patent/JPS6261899B2/ja
Granted legal-status Critical Current

Links

Landscapes

  • Investigating Or Analyzing Materials Using Thermal Means (AREA)
  • Investigating Materials By The Use Of Optical Means Adapted For Particular Applications (AREA)

Abstract

PURPOSE: To realize precise detection by classifying flaws into convex defects and concave defects, by passing signals obtained by optical scanning into a noise component eliminating circuit, and detecting flaws as defects of higher and lower temperature on the basis of mean signal level of sound parts.
CONSTITUTION: An optical scanning signal A supplied into an input terminal 1 is obtained by the temperature difference between the sound part and defective part of hot rolled steel, and contains flaw signals F1 to F6 and background fluctuations due to unevenness of temperatures. The signal A is passed into a low frequency component eliminating circuit 2 to get rid of background fluctuations, and a signal B is obtained. The temperature unevenness is corrected, and the sound part is expressed by the mean signal level, and signals F1 to F6 are maintained. The signal B is applied to first and second flaw discriminating circuits 3, 5, and a signal C containing flaw signals F1, F5 higher than the mean signal level and a signal D containing flaw signals F2 to F6 lower than the mean signal level are taken out. Eliminating fluctuations due to temperature unevenness, flaw signals divided into convex flaws and concave flaws may be separately taken out at high accuracy.
COPYRIGHT: (C)1979,JPO&Japio
JP13886277A 1977-11-21 1977-11-21 Surface flaw detecting method of hot rolled steel Granted JPS5472095A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP13886277A JPS5472095A (en) 1977-11-21 1977-11-21 Surface flaw detecting method of hot rolled steel

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP13886277A JPS5472095A (en) 1977-11-21 1977-11-21 Surface flaw detecting method of hot rolled steel

Publications (2)

Publication Number Publication Date
JPS5472095A true JPS5472095A (en) 1979-06-09
JPS6261899B2 JPS6261899B2 (en) 1987-12-23

Family

ID=15231863

Family Applications (1)

Application Number Title Priority Date Filing Date
JP13886277A Granted JPS5472095A (en) 1977-11-21 1977-11-21 Surface flaw detecting method of hot rolled steel

Country Status (1)

Country Link
JP (1) JPS5472095A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS62184337A (en) * 1986-02-07 1987-08-12 Mitsubishi Electric Corp Surface flaw detector
JPS62191745A (en) * 1986-02-18 1987-08-22 Mitsubishi Electric Corp Apparatus for detecting surface flaw
JPS63163262A (en) * 1986-12-26 1988-07-06 Toyota Motor Corp Flaw detector

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0432479A (en) * 1990-05-28 1992-02-04 Mitsubishi Electric Corp Method and device for recovering main rope of elevator

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS62184337A (en) * 1986-02-07 1987-08-12 Mitsubishi Electric Corp Surface flaw detector
JPS62191745A (en) * 1986-02-18 1987-08-22 Mitsubishi Electric Corp Apparatus for detecting surface flaw
JPS63163262A (en) * 1986-12-26 1988-07-06 Toyota Motor Corp Flaw detector

Also Published As

Publication number Publication date
JPS6261899B2 (en) 1987-12-23

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