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AssigneeNKK Corporation
InventorsMitsuaki Uesugi, Shoji Yoshikawa, Masaichi Inomata, Tsutomu Kawamura, Takahiko Oshige, Hiroyuki Sugiura, Akira Kazama, Tsuneo Suyama, Yasuo Kushida, Shuichi Harada, Hajime Tanaka, Osamu Uehara, Shuji Kaneto, Masahiro Iwabuchi, Kozo Harada, Shinichi Tomonaga, Shigemi Fukuda
Estimating the term…
The defect marking method comprises the steps of: installing a surface defect tester to detect surface flaw and a marker device to apply marking at defect position, in a continuous processing line of steel sheet; detecting the surface flaw on the steel sheet using the surface defect tester; determining defect name, defect grade, defect length, and defect position in the width direction of the steel sheet, on the basis of thus detected flaw information, further identifying the defect in terms of harmful defect, injudgicable defect, and harmless defect; applying tracking of the defect position for each of the harmful defect and the injudgicable defect; and applying marking to the defect position. The defect marking device comprises a defect inspection means having plurality of light-receiving parts and a signal processing section, and a marking means.
A method for marking a defect, comprising the steps of:
A method for marking a defect, comprising the steps of:
A method for marking a defect comprising the steps of:
A method for marking a defect comprising the steps of:
A method for producing a defect-marked steel coil, comprising the steps of:
A method for producing a defect-marked steel coil, comprising the steps of:
A defect-marked steel coil, having a mark made by marking a harmful defect at a defect position on a steel sheet by pressing a felt impregnated with ink on the steel sheet to fix the ink on a surface of the steel sheets,
Dependencies are inferred from the claim text.
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Measuring, gauging, indicating, counting, or marking devices specially adapted for use in the production or manipulation of material in…
Investigating the presence of flaws or contamination: in moving material, e.g. running paper or textiles
Manufacture of metal sheets, wire, rods, tubes, profiles or like semi-manufactured products
Investigating or analysing materials by determining their chemical or physical properties
Term ended 22 Feb 2022 (estimated)
The present invention relates to a method for marking defect on a steel sheet in a steel making process line and to a device therefor.
Cold-rolled steel sheets manufactured by cold-rolling are subjected to inspection of surface defects over the whole length of coil thereof for quality assurance. JP-A-5-196581, (the term “JP-A” referred herein signifies the “Unexamined Japanese patent publication”), discloses a method for detecting surface defects and internal defects of steel sheets. According to the disclosure, detection of the surface defects on a steel sheet is conducted by scanning the surface of steel sheet which is running through a manufacturing line, in width direction thereof by laser light, by converting the reflected light to voltage intensity using a photoelectric transfer device such as CCD element, then by judging the presence/absence and the degree of the defect based on the voltage signals. The internal defects of a steel sheet are detected by computing the defect depth in the thickness direction of the steel sheet and the defect size using a magnetic particle tester. Usually, the result of the defect inspection is displayed on a CRT or the like as information in terms of defect position, defect name, defect grade, and the like, or is printed in a document.
It is impossible to obtain products completely free from defects. Consequently, the products are shipped after removing portions of harmful defect for the buyer concerned on the basis of the defect information displayed on a CRT or the like in the manufacturing line, or after removing the portions of harmful defect for the buyer concerned by applying re-inspection in succeeding stage on the basis of the above-described defect information. Alternatively, a document of the above-described harmful detect information is submitted to the buyer concerned, together with the coil that contains harmful defect portions, thus letting the buyer remove the harmful defects.
FIG. 1 illustrates an arrangement of main facilities of the first coiling line for steel sheet relating to the Best Mode 1 according to the present invention.
FIG. 2 illustrates an arrangement of main facilities of the second coiling line for steel sheet relating to the Best Mode 1 according to the present invention.
FIG. 3 illustrates an arrangement of main facilities of the third coiling line for steel sheet relating to the Best Mode 1 according to the present invention.
The main constitution of the Best Mode 1 is the following.
(1) A defect marking method comprises the steps of: installing a surface defect tester to detect surface flaw, an ink marker device to apply marking by an ink at defect position, and an internal defect tester to detect internal defect of a steel sheet, in a continuous processing line of the steel sheet; detecting the surface flaw on the steel sheet using the surface flaw tester; calculating to determine defect name, defect grade, defect length, and defect position in width direction of the steel sheet, on the basis of thus detected flaw information, further identifying the defect in terms of harmful defect, injudicable defect, and harmless defect; detecting the internal flaw of the steel sheet using the internal defect tester; calculating to determine the defect length and the defect position in the width direction of the steel sheet, on the basis of thus detected flaw information, further identifying the defect in terms of harmful defect and harmless defect; applying tracking of the defect position for each of the harmful defect and the injudicable defect; and applying marking with ink to the defect position at a moment that the defect reaches the ink marker device.
(2) A defect marking method comprises that, in the method for defect marking of (1), the surface flaw is subjected to identification of harmful defect, injudicabie defect, and harmless defect, on the basis of the defect name, the defect grade, the defect length, the defect position in width direction of the steel sheet, the defect position on each of front face and rear face of the steel sheet, and the use of the steel sheet, and that the internal flaw is subjected to identification of harmful defect and harmless defect, on the basis of the defect length, the defect position in the width direction of the steel sheet, and the use of the steel sheet.