Tetsu-to-Hagane
Online ISSN : 1883-2954
Print ISSN : 0021-1575
ISSN-L : 0021-1575
Volume 79, Issue 7
Displaying 1-21 of 21 articles from this issue
  • Sensing Systems and Intelligent Sensors
    Hiro YAMASAKI
    1993 Volume 79 Issue 7 Pages 741-749
    Published: July 01, 1993
    Released on J-STAGE: June 30, 2009
    JOURNAL FREE ACCESS
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  • Yoichi TAMURA
    1993 Volume 79 Issue 7 Pages 750-758
    Published: July 01, 1993
    Released on J-STAGE: June 30, 2009
    JOURNAL FREE ACCESS
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  • Chitaka MANABE, Masaru AKAMATSU, Satoshi YANAI, Norio SUZUKI, Katsuhir ...
    1993 Volume 79 Issue 7 Pages 759-764
    Published: July 01, 1993
    Released on J-STAGE: June 30, 2009
    JOURNAL FREE ACCESS
    In order to measure the temperature of surface treated steel strips at a low temperature range by radiation thermometry, the following items were investigated;
    (1)Shielding method of stray radiation energy from environment.
    (2)Estimation method of emissivity of measured objects.
    This stray radiation energy has been eliminated by a water cooled shielding flange. And, a new emissivity measuring system has been developed. The system uses a radiation source to irradiate the measured object surface. This radiation is reflected and scattered by the object surface. The system has three detectors, and these detect scattered radiation energy by different solid angles. Hemispherical reflectance of the object surface is calculated by these three detected radiation energies, and the emissivity of the object surface is estimated by means of Kirchhoff's law. The estimated emissivities are compared with values measured by a spectrometer. The results show the obvious relationship between measured values by this system and these by spectrometer.
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  • Hiroyuki SERIU, Yasuhiko MASHINO, Yasuhisa NAKAJIMA, Hiroyuki OGAWA
    1993 Volume 79 Issue 7 Pages 765-771
    Published: July 01, 1993
    Released on J-STAGE: June 30, 2009
    JOURNAL FREE ACCESS
    In order to measure the emissivity of cold strip in the furnace of Continuous Annealing Line (herein "CAL"), an approach using the temperature measuring roll and radiation pyrometer has been applied at the Chiba works. The temperature measuring roll is a hearth roll in which some thermocouples are installed. The thermocouples are buried inside surface of the hearth roll. The signals of roll temperature are taken out via slip rings which are equipped at the end of the roll axle. There is very small temperature gradient across the roll shell on which the strip contacts, and the heat flux in the transverse direction is also small. Therefore, at the portion enough inside from the strip edge, the roll temperature can be equal to the strip temperature. The emissivity can be calculated from the measured values of the temperature measuring roll and the radiation pyrometer which are equipped same position. The temperature measuring roll has been used since the CAL operation started and the emissivities of various grades of strips have already evaluated.
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  • Fumio TANAKA, Hisashi OHIRA, Masahiro MASUDA, Koichi MARUYAMA, Mitsuma ...
    1993 Volume 79 Issue 7 Pages 772-778
    Published: July 01, 1993
    Released on J-STAGE: June 30, 2009
    JOURNAL FREE ACCESS
    New radiation thermometry systems have been developed and applied to continuous annealing and continuous galvanizing lines. The new method, which is referred to as the TRACE method, uses a prior knowledge about the functional relationship between two spectral emissivities of target materials. Temperature and emissivities of galvannealed steel, whose emissivity variation is mainly caused by the change in surface roughness due to the growth of ironzinc alloy crystals, are measured by dual-spectral type TRACE systems. Polarized type TRACE systems are useful in measuring those of oxidizing cold-rolled steel, whose emissivity variation is mostly attributed to the oxidation.
    Principle of measurement of the TRACE method, and the recent development of PbS-polarized TRACE system and scanning type of Ge-PbS dual spectral TRACE system are discussed.
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  • Toshiyuki YAMAMOTO, Kazuo HIRAMOTO, Chihiro UEMATU, Jun UEDA
    1993 Volume 79 Issue 7 Pages 779-785
    Published: July 01, 1993
    Released on J-STAGE: June 30, 2009
    JOURNAL FREE ACCESS
    The multiwavelength pyrometry problem of inaccuracy in determining the true temperature has been analysed in detail. The results of this analysis and a comparison with numerical simulation results show that a proper calculation method of a temperature and a certain knowledge on the emissivity of the target surface are indispensable to an accurate temperature determination. On the basis of this study a new multiwavelength pyrometer for the use of the galvanneal process is developed with a careful design. In spite of the greately changing characteristics of the target surface emissivity in the galvanneal process, where zinc-coated steel sheet is rapidly annealed to produce desirable intermetallic coated layer and the surface of the zinc layer changes from highly specular reflectivity with emissivity near 0.1 to a nearly diffuse reflectivity with emissivity as high as 0.7, this new pyrometer is effectively applied and the measurement accuracy is confirmed to be ±10% for temperature and ±10% for emissivity by laboratory simulations and on-line tests.
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  • Fumihiko ICHIKAWA
    1993 Volume 79 Issue 7 Pages 786-793
    Published: July 01, 1993
    Released on J-STAGE: June 30, 2009
    JOURNAL FREE ACCESS
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  • Akio NAGAMUNE, Kouichi TEZUKA, Mitsutake SATO, Yasushi KANEDA, Ichirou ...
    1993 Volume 79 Issue 7 Pages 794-799
    Published: July 01, 1993
    Released on J-STAGE: June 30, 2009
    JOURNAL FREE ACCESS
    A high-resolution version of the M-sequence modulated microwave level meter has been developed. This level meter consists of a continuous wave radar where the carrier is modulated by the M-sequence (Maximal-length-sequence). Employing two M-seq. which are the same in code but generated by the slightly different clock frequencies, the implementation of the cross-correlation between the received and the reference signals can be simple, and high sensitivity and accuracy can be obtained. Moreover, using high resolution M-sequence which is a three-valued random signal in stead of the conventional two-valued M-sequence, a high resolution in tearms of range is obtained and it becomes easy to distinguish the desired signal and unwanted signals which may be receiving and transmitting anntena leakage or reflection from walls nearby.
    Due to the improvement of resolution of the level meter, its application has been widely ranged for iron and steel making process. Covering a level measurement of the molten iron in a moving ladle, a molten steel level meter in a tundish of the Horizontal Continuous Casting (HCC), and foamed slag level measurement in a converter, the effectiveness of the sophisticated level meter is confirmed.
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  • Fumihiko ICHIKAWA, Makoto OKUNO, Takashi ISHIKAWA, Toshisada TAKECHI
    1993 Volume 79 Issue 7 Pages 800-807
    Published: July 01, 1993
    Released on J-STAGE: June 30, 2009
    JOURNAL FREE ACCESS
    An on-line roll profile meter has been developed to measure the surface contour of the work roll in a hot strip finishing mill. The system consists of a sensor head with twenty ultrasonic distance meters, a sensor head scanner, a signal processing unit and a computer. The ultrasonic distance meter uses a water column as sound propagation medium. Ten distance meters measure the distribution of distance between the roll surface and the reference surface of the sensor head. Other ten distance meters monitor the straightness of the reference surface. A tensioned wire is used as the reference of the straightness. Each distance meter can measure the sound velocity directly in the water column to compensate for the error due to the sound velocity variation. The off-line and on-line measurements were carried out at the No. 2 hot strip mill in Chiba Works of Kawasaki Steel. The results showed that the measuring accuracy was less than ±10μm.
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  • Jiro MATSUO, Takumi MURAMATSU, Toshiyuki MATSUMI, Takaaki KAWAKAMI, Ha ...
    1993 Volume 79 Issue 7 Pages 808-814
    Published: July 01, 1993
    Released on J-STAGE: June 30, 2009
    JOURNAL FREE ACCESS
    A plate flatness meter based on the laser moiré method has been developed. A large grating is installed above a plate transfer line, a laser beam is directed through a concave lens onto the plate on the transfer line. Moiré fringes that conform to the surface profile of the plate are formed on the plate. The flatness of the plate as it is transferred can be measured to a high accuracy of ±1.0mm(2σ).
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  • Kiyohiko KAWAGUCHI, Tadayo INOUE, Kenn INOUE, Hiroyuki MATOBA
    1993 Volume 79 Issue 7 Pages 815-822
    Published: July 01, 1993
    Released on J-STAGE: June 30, 2009
    JOURNAL FREE ACCESS
    There has been a demand for the development of a device to quickly measure the dimensions of products on hot rolling production lines in large shape mills.
    A hot rolling dimension measurement device incorporating six laser displacement meters which has been introduced at the Kashima Steel Works of Sumitomo Metal Industries enables noncontact, high-speed, high-precision measurements of hot-rolled products to be taken, thus solving the problems associated with the reduction in efficienc caused by the need to measure the dimensions of products by taking a sample and making manual measurements.
    This paper reports on the development, measurement principles, equipment summary and measurement results for this device.
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  • Toshiyuki MATSUMI
    1993 Volume 79 Issue 7 Pages 823-832
    Published: July 01, 1993
    Released on J-STAGE: June 30, 2009
    JOURNAL FREE ACCESS
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  • Hitoshi AIZAWA, Yoshimi FUKUTAKA, Yasuhiko MASHINO, Hidekazu MIYAKE
    1993 Volume 79 Issue 7 Pages 833-840
    Published: July 01, 1993
    Released on J-STAGE: June 30, 2009
    JOURNAL FREE ACCESS
    In steel industry, customers' request for better quality of product surface has recently become very keen, which inevitably requires more strict inspections of the products before shipping.
    Though human eyes, which have been widely used for in-process product visual inspections, are an excellent sensor, organoleptic visual tests have drawbacks. A human inspector may overlook flaws in case of even momentary distraction. In addition, today's demands for better performance and higher throughput on production and inspection far exceed the ability of human visual tests, in most cases.
    Consequently, visual tests are being replaced by ASIs (Automatic Surface Inspectors) using optical apparatuses. There still remain, however, some flaws ASIs are not able to detect because of their low signal level. We have, therefore, kept trying to detect those flaws by developing and improving signal and image processing techniques for ASIs.
    In this paper, described are some of the new technologies of this kind, which have been developed or tested in Kawasaki Steel Corporation; a floating-threshold-level signal processing method, a high precise definition TV monitor system, an on-line ASI performance test system, and Fractal analysis for the scanning waveform of ASIs.
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  • Hideya TANABE, Yasuhiro MATSUFUJI, Junichi YOTSUJI, Seigo ANDO, Katsuy ...
    1993 Volume 79 Issue 7 Pages 841-846
    Published: July 01, 1993
    Released on J-STAGE: June 30, 2009
    JOURNAL FREE ACCESS
    The leakage magnetic flux inspection method is effective for detecting minute inclusions in light gauge steel sheets. However it has been not put to practical use at on-line manufacturing processes, because the sensitivity of conventional magnetic sensors was not enough to detect such minute inclusions.
    Then we have developed a new high sensitivity magnetic sensor which has higher sensitivity by 100 times in comparison with conventional ones, and have realized an on-line inspection system for detecting minute inclusions in light gauge steel sheets.
    For higher detectability and higher speed inspection, we had to make clear the influence of stray magnetic field and the change of magnetic field generated by the travelling of light gauge steel sheets.
    We have analyzed changes of magnetic field at the on-line inspection of light gauge steel sheets running at very high speed by computer calculation programs. On these results, we have developed a shield technique from stray magnetic disturbance and on-line high speed inspection technique.
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  • Izumi KOSAKAI, Takayoshi TADA, Muneaki HIRATA, Hideaki KAMEI, Kenji AB ...
    1993 Volume 79 Issue 7 Pages 847-854
    Published: July 01, 1993
    Released on J-STAGE: June 30, 2009
    JOURNAL FREE ACCESS
    Various automatic surface inspection systems for bars and wire rods have been developed and installed by steel makers and wire makers to meet severe requirements for the surface quality.
    This paper describes the current and future technologies for automatic surface inspection systems for billets, bars, wire rods and wires.
    This paper also describes the recent modification of an automatic inspection system for square billets using Magnetic-particle Testing in Kobe Works, to improve the detection rate of short surface flaws. By using the liatest image processing devices, short surface flaws with the length of 10mm and the depth of 0.3mm can be detected.
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  • Mitsuo YOSHIDA, Junichi FUJISAWA, Kazuomi TOMITA, Masahiro OIKAWA, Tet ...
    1993 Volume 79 Issue 7 Pages 855-862
    Published: July 01, 1993
    Released on J-STAGE: June 30, 2009
    JOURNAL FREE ACCESS
    Demand for products manufactured by processing wire rods and round bars, particularly automotive parts, has been remarkably increasing. At the same time, requirements for dimensional accuracy and guarantee of surface and inner quality of such parts have become increasingly diversified and severe.
    To meet these requirements, Nippon Steel Corporation has developed and put into practive various advanced inspection equipments and techniques for processing of billets, wire rods and round bars under the policy of "user-in" and "parts-in".
    In this paper, newly developed inspection methods for eddy current testing and magnetic leakage flux testing are introduced.
    The first is miniaturization of probe, suppression of electro-magnetic noise and self-check by signal observation for eddy current testing. The second is reduction of bar-end dead zone for magnetic leakage flux testing.
    These new techniques are put into practive inspection equipments for an "automatic finishing line (AFL) for wire rods" and a "finish production inspection system (FPIS) for round bars".
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  • Hideya TANABE, Katsuyuki NISHIFUJI
    1993 Volume 79 Issue 7 Pages 863-868
    Published: July 01, 1993
    Released on J-STAGE: June 30, 2009
    JOURNAL FREE ACCESS
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  • Kazuo FUJISAWA, Riichi MURAYAMA, Fumio YAMAMOTO, Koichi TAYA, Hidekazu ...
    1993 Volume 79 Issue 7 Pages 869-876
    Published: July 01, 1993
    Released on J-STAGE: February 16, 2010
    JOURNAL FREE ACCESS
    An on-line measurement system of r-value for cold-rolled steel sheets was developed by measuring the average propagation time of low frequency S0 mode Lamb wave. In this paper, the principle of nondestructive r-value measurement and results of the various experiments are described. In the first experiment, we investigated characteristics of various kinds of EMATs (Electromagnetic Acoustic Transducers) in order to select the optimum EMAT type for on-line measurement. As a results, we developed the on-line measurement system using magnetostrictive type EMATs which measures the r-value with a 3mm gap between the sensor case and the steel sheet. The capability for estimating texture and for measuring r-value was investigated by using a lot of samples. After this analysis, we investigated the effests of measuring conditions such as sheet traveling speed, the sheet temperature and the sensor gap on the measurement accuracy. The on-line test was also done in the continuous annealing line by using test and product coils. Finally it was confirmed that applying this system, the r-value can be measured continuously in the production line with the accuracy of 3σ=0.2.
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  • Takao HYOGUCHI, Toshio AKAGI, Katsuhiro KAWASHIMA, Atsushi YOSHIWARA, ...
    1993 Volume 79 Issue 7 Pages 877-882
    Published: July 01, 1993
    Released on J-STAGE: February 16, 2010
    JOURNAL FREE ACCESS
    An on-line nondestructive measurement technique for r-value (plastic strain ratio), which evaluates the press formability of cold-rolled steel sheets, has been developed. This technique uses a thickness resonance mode electromagnetic acoustic transducer (EMAT), which can measure the ratio of three different mode ultrasonic resonance frequencies. The in-plane average Young's modulus is calculated from three frequencies and the elastic stiffnesses of an iron single crystal C011, C012, C044. The in-plane average r-value is obtained from the in-plane average Young's modulus. A good correspondence was obtained between the in-plane average r-value measured by this method and the in-plane average r-value measured by tensile testing. We have proved by experiment that the effects of temperature, tensile stress and moving speed of steel sheets are negligible for practical on-line use.
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  • Norio SUZUKI, Hiroyuki TAKAMATSU, Akio ARAI, Satoshi YANAI, Takeo OGAW ...
    1993 Volume 79 Issue 7 Pages 883-889
    Published: July 01, 1993
    Released on J-STAGE: June 30, 2009
    JOURNAL FREE ACCESS
    Laser ultrasonic techniques are attractive for in line characterization of material, because they can transmit and recieve ultrasound with fully non-contact condition to the target. Especially, the system, using Fabry-Perot interferometer, is widely studied because of its apllicability to the evaluation of the rough surface material and its wide-band detectability.
    In this paper, the detectability of the vibration and the characteristics of laser generated ultrasound are investigated with constructed laser ultrasonic system, using Fabry-Perot interferometer. And grain size of thin steel plates are evaluated from the frequency spectra of the attenuation constant of laser ultrasound.
    It is proved that the vibration on the rough surface can be detected with this system, and the grain size of thin steel plates can be measured with faily good accuracy, but pre-processing of the signal is needed, such as the selection of the orders of the deformation free multiple echos and low-cut filtering.
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  • Atsushi MORI, Norio SHIRATA, Kengo SENOO, Kouki ASANO, Yoshihiro MORIK ...
    1993 Volume 79 Issue 7 Pages 890-895
    Published: July 01, 1993
    Released on J-STAGE: June 30, 2009
    JOURNAL FREE ACCESS
    It is well known that the quality control of cold rolling oil is very important. In order to keep quality of strip surface, coolant and iron concentration of cold rolling oil, and coating oil value were measured by chemical analysis. But it was not enough to keep quality. Because it needed long time and was not often carried out. So management on-line analyzers for cold rolling oil have been developed, consisting of fully automatic coolant concentration measuring system, magnetic balance system and coating oil analysis system.
    Coolant concentration measuring system : After the cold rolling oil was resoluted by acid addition and was centrifugal separated, and the surface oil measured by picture treatment method.
    Iron concentration analysis system : The iron concentration was measured by the magnetic balance method.
    Coating oil analysis system : After irradiate the ultraviolet rays for a sheet, measure the fluorescence from coating oil.
    These newly developed on-line analyzers have greatly contributed to the improvement of quality control and the decrease of operators loads of the cold strip mill operation.
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