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Tetsu-to-Hagané
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ONLINE ISSN: 1883-2954
PRINT ISSN: 0021-1575

Tetsu-to-Hagané Vol. 72 (1986), No. 11

  • Current Status of Continuous Casting Technology and Quality

    Yukiyoshi ITOH

    pp. 1667-1673

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  • Trend of Plastic Material Apprications for Automotive Body Skin Panels

    Masashi IDE, Minoru SANO, Shigeo ARAI

    pp. 1674-1680

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  • Report of Material Working Group, Committee on History of Iron and Steel Science and Technology

    Koji SHIBATA

    pp. 1681-1684

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  • Dephosphorization and Desulfurization of High Chromium Steel and High Manganese Steel with CaC2-CaF2 Flux and Decomposition of CaC2

    Kazuumi HARASHIMA, Yoshimori FUKUDA, Hiroyuki KAJIOKA, Yasushi NAKAMURA

    pp. 1685-1692

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    Abstract

    Fe-C, Fe-Cr-C and Fe-Mn-C melts were treated with CaC2-CaF2 flux by using a rotating MgO crucible containing 1kg metal at 1 550-1600°C under Ar atmosphere. The important factors of dephosphorization and desulfurization of metal with decomposition reaction of CaC2 were studied.
    The degree of dephosphorization, ηP, strongly depended on carbon activity of initial metal, a[C]0, and ηP increased with the decrease of a[C]0, and as a result carbon content in metal increased.
    The value of ηs/fs increased with the decrease of a[C]0, where, ηs the degree of desulfurization and fs is activity coefficient of sulfur in metal.
    The distribution ratio of phosphorus, LP=(%P)/a[P], depended on calcium content in slag or on a[C]0·LP increased with the increase of (%Ca), and with the decrease of a[C]. The decomposition reaction of CaC2 followed the relationship of NCaC2/NCa=k·a2[C] 20min after flux addition.
    CaC2-CaF2 mixture was more effective than only CaC2 flux for dephosphorization of metal.

  • Development of Low Carbon Continuous Cast Steels for Bar and Wire Rod and Its Properties

    Kiyomi TAGUCHI, Eihachiro SUNAMI, Katsuhiko NISHIKAWA, Katsundo TEZUKA, Toyoaki EGUCHI, Yutaka TAMAI, Sadao SHOJI

    pp. 1693-1700

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    Abstract

    For bar and wire rod applications low carbon steels of the continuous cast bloom have been developed. Aluminum content is controlled, using RH degassing process, from 0.003 to 0.01% not only to minimize Al2O3 inclusion but also to prevent the subsurface blowholes in the bloom section. Nitrogen content is also reduced under 0.003% by the hardblowing of LD process and shrouding during casting.
    Comparing the rimmed steel wire rod, this new steel shows the smaller breakage diameter and higher ductility at the high speed continuous wire drawing. At the coldheading test the surface and center of this steel has shown the higher ducidity. At the higher annealing temperature the ferrite grain of this Al-killed steel tends to grow suddenly. Boron addition is effective to the prevention of the abnormal grain growth and brittle behavior of annealed products. Because of the high cleanliness and low segregation of continuous cast bloom, the size and amount of inclusions are smaller and hence the machinability of this steel is not so good. Higher sulphur content is desirable for the higher machinability. The depth of carburization is relatively small. Boron addition increases the austenite grain size and hardenability of carburized products.

  • Effect of Processing Factors on Mechanical Properties of "Pancake" Prepared by HIP and Superplastic Forging from Nickel-Base Alloy Powder

    Shizuo NAKAZAWA, Isao TOMIZUKA, Yutaka KOIZUMI, Michio YAMAZAKI

    pp. 1701-1707

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    Abstract

    Effects of processing factors on the tensile properties and creep properties at 760°C were investigated for "pancakes" (thick circular disks) of a nickel-base superalloy prepared by procedures comprising a powdermaking by using HIP-processing a liquid-helium-cooled rotating disk technique, with or without Attritor treatment, and a superplastic-forging developed specifically for this research. Major points of the obtained results were: (1) The HIP-processed material prepared from under-60-Tyler-mesh powder could be forged in a superplastic way only in a deformation rate of 0.2-0.5×10-4/s, while that from under-150-Tyler-mesh could in a rate of 1× 10-4/s. The product from the cruder powder had a little superior tensile performance to that from the finer powder. (2) The product obtained by a superplastic-forging at lower temperature and higher deformation rate was apparently softer than that at higher temperature and lower deformation rate. The former had a larger elongation by tensile test and a shorter rupture life by creep test. (3) An Attritor pretreatment preceding HIP-treatment facilitated the superplastic-forging but it deteriorated the creep and tensile property drastically.

  • Properties of Zinc-Zinc Chloride Composite Electroplated Steel Sheets

    Ichiro SUZUKI, Sunao WADA

    pp. 1708-1713

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    Abstract

    Zinc-zinc chloride composite electroplated steel sheet was studied; the study was done since basic zinc chlorides are stable compounds in chloride environment. Zinc-zinc chloride composite layer was electro-deposited on steel in 3M ZnCl2 bath, in which colloid of 4Zn(OH)2.ZnCl2 was suspended. The amount of codeposited colloid increased with bath temperature, whereas the crystal grain size, distribution and thickness of deposited metallic zinc became less uniform with increase in bath temperature and current density. The plating condition of 40°C-20A/dm2 increased uniformity of zinc-zinc chloride composite layer and thereby enhanced its corrosion resistance.

  • High Temperature Corrosion Properties of Chromized Austenitic Stainless Steel

    Hirofumi MAKIURA, Hisao FUJIKAWA, Hiroshi YUZAWA

    pp. 1714-1721

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    Abstract

    Studies on the high temperature corrosion behavior of SUS347H in oil fired boiler environments were carried out by laboratory corrosion tests and examinations of the served tube.
    It was observed that chromized SUS347H showed a better corrosion resistance than 18Cr-8Ni austenitic stainless steels when they were precoated with 20/80%V2O5-80/20%Na2SO4 synthetic ash and heated at 600800°C for 5100 h in 1%SO2-5%O2-15%CO2-bal. N2 gas. Chroinized SUS347H reheater tube, which served for about 10 000 h in an oil fired boiler, did not show a significant thickness loss. Cr2O3 scale formed on chromized surface increased high temperature corrosion resistance in oil fired boiler.

  • Nondestructive Measurement of Coated Film-Steel Bond Strength Using Ultrasonic Resonance Frequency Method

    Hironobu KAWASAKI, Shoji SUZUKI

    pp. 1722-1727

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    Abstract

    In order to nondestructively measure the bond strength of coated film on steel surface, ultrasonic resonance method using Fokker bondtester was investigated. The bondtester measures the change in the resonance frequency and the amplitude of the tester and coated film /steel system.
    It was found that the resonance frequency difference between disbonded and bonded coating films on steel showed good correlation with the bondstrength of the bonded coating film on steel measured by a destructive method.
    To applying this method widely, however, the following problems are to be solved in other ways.
    (1) Differences arising from quite strongly bonded films on steel are too small to be detected.
    (2) Film thickness variation causes changes in resonance frequency.
    (3) Bond strength of films which deeply absorb ultrasonic sound is hard to be detected.
    (4) Water uptake in film/steel interface causes resonance frequency change.

  • Effects of Carbon and Manganese on the Deep-drawability of Cold-rolled Steel Sheets

    Koichi OSAWA, Teruo SUZUKI, Kazuo MATSUDO, Kiwami KURIHARA

    pp. 1728-1735

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    Abstract

    Effects of carbon, manganese, and their mutual interaction on the recrystallization texture and deepdrawability (r-value) of cold rolled steels have been studied. Hot bands with various carbon content and carbide morphology were cold-rolled by a reduction of 75%, heated at two different heating rates (100°C/h and 50°C/s), and annealed at 700°C. The results showed that the interaction between carbon and manganese played a significant role in the formation of recrystallization texture: the r-value decreased markedly by the co-existence of solute carbon and manganese, while it did slightly by either of them alone, as in 0.001%C steels or 0.03%Mn steels. The decrease in r-value corresponded to a randomization of the recrystallization texture. The above interaction was found to exert an effect on recovery of substructure, weakening the selectivity in the orientation of recrystallization nuclei.
    The improvement of r-value under the combination of coarsening of cementite in hot band by high temperature coiling and rapid heating annealing is fully explained by decline of the interaction between solute carbon and manganese resulting from the retarded dissolution of carbide.

  • Effect of Microstructure on Mechanical Property of Ferrite-Bainite-Martensite Tri-phase Steel

    Shunichi HASHIMOTO, Kazuhiro MIMURA, Takuo HOSODA, Masatoshi SUDO

    pp. 1736-1743

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    Abstract

    A study has been made of the effects of chemical composition and coiling temperature on the mechanical properties of as-hot-rolled Tri-phase steel which possesses combined advantageous properties of both dual-phase steel and ferrite-bainite steel.
    At least 2% of martensite in volume fraction is necessary to obtain low yield ratio of less than 0.7, and low yield point elongation of less than 1%. On the other hand, the volume fraction of martensite has to be controlled less than 10% in order to get high stretch flangeability.
    Tri-phase steel sheets composed of ferrite, bainite and 2-10% of martensite exhibit low yield ratio, low yield point elongation and good stretch flangeability, and are able to be produced by lowering the coiling temperature under than 250°C using C-Si-Mn steels. The steels used in this experiment are mainly Cr free steels, because the addition of Cr results in the deterioration of paintability and increases the production cost.

  • Effect of Specimen Size on Intergranular Mode Fracture Toughness of Cr-Mo-V Steel in the Transition Temperature Region

    Keiichi SHIMOMURA, Tetsuo SHOJI, Hideaki TAKAHASHI, Kiyoshi SAITO

    pp. 1744-1750

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    Abstract

    A determination procedure of intergranular mode fracture toughness has been studied on the basis of elastic-plastic fracture mechanics and by use of AE technique to detect an onset of microscopic pop-in cracking at the crack front. Experiments were performed on a steam turbine rotor steel (Cr-Mo-V steel) at 150°C, and four different sizes of compact tension specimens having the thickness of 10 mm(0.4TCT), 25 mm(1TCT), 50 mm(2TCT), and 100 mm(4TCT) were used. In combination with the fractographic observation on fractured surfaces, the fracture toughness determined by AE technique, JiAE, was proposed as the critical J-integral value characterizing an onset of a microscopic intergranular mode pop-in fracture, and its size effects was discussed. Each lower value of KJAE(=√E·JiAE/(1-υ2)) obtained from smaller specimens such as 0.4TCT and 1TCT specimens was coincident with that from the large specimens. Furthermore, the toughness values of 2TCT and 4TCT specimens, KIC(AE), met the size requirement for the plane-strain fracture toughness, and were about 76 percent of the valid KIC. This evidence suggests that the fracture toughness by AE technique proposed here is a suitable parameter to the toughness value of the brittle fracture initiation more conservative than the plane-strain fracture toughness value.

  • Analysis of Alloy Electroplated Film by Glow Discharge Spectrometry

    Yoshiro MATSUMOTO, Nobukatsu FUJINO, Shinichi TSUCHIYA

    pp. 1751-1758

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    Abstract

    Glow discharge spectrometry (GDS) was used to analyze Fe-Zn and Ni-Zn alloy films. In the analysis of the Fe-Zn alloy film, composition and coating weight of the alloy film were accurately determined from the relationship between the normalized Fe intensity ratio, IFe/(IFe+IZn), and Fe% and that between the sputtering rate, qFe-Zn, and Fe%. The region of low wattage discharge in the abnormal glow discharge, in which high depth resolution was obtained, was used for the experiments. This method was also applied to the analysis of Ni-Zn alloy film. In addition, depth-direction analysis of the Fe-Zn alloy film was investigated.

  • Quantitative Analysis of Zn-Fe/Zn-Ni Double-layer Electroplated Steel Sheet by Glow Discharge Spectrometry

    Masatoshi IWAI, Makoto TERADA, Hirohiko SAKAI, Shingo NOMURA

    pp. 1759-1766

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    Abstract

    Double-layer electroplated steel sheet composed of upper Zn-Fe alloy and lower Zn-Ni alloy is analysed quantitatively using glow discharge spectrometry (GDS).
    Increase of discharge current and decrease of Ar pressure, i.e., increase of discharge energy, improves depth resolution. Excess in energy, however, makes discharge unstable and deteriorates depth resolution. As the optimum discharge condition, 30 mA and 22 mbar is adopted. For each element, integrated value of emission intensity and coating weight are linearly related. Accuracy of these calibration curves (σd) is 1.5 g/m2 for 1050 g/m2 of Zn, 0.15 g/m2 for 17 g/m2 of Ni, and 0.34 g/m2 for 214 g/m2 of Fe. In this experiment, no effect of co-exsisting elements on the emission intensity of Zn is observed. Coating weight and composition of each layer obtained by GDS agree well with those analysed by atomic absorption spectrometry.
    These results show that GDS can be applied to the quantitative analysis of this product.

  • Quantitative Analysis of Zn-Fe Alloy Electroplated Layer on Steel Sheets by Glow Discharge Spectrometry

    Yasuko FURUNUSHI, Yoshiharu OHASHI

    pp. 1767-1774

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    Abstract

    Grimm-type glow discharge spectrometry (GDS) was used for in-depth quantitative analysis of Zn-Fe alloy electroplated layer on steel sheets.
    In order to improve the in-depth resolution of GDS data, Zn-Fe alloy mono-layer electrodeposits on Cu were measured under various discharge conditions and by changing the dimensions of the discharge lamp, such as the thickness of anode pipe and the distances between anode pipe and the sample.
    According to this experiment, the most suitable conditions for getting the good in-depth resolution were determined as follows:
    ·Thickness of anode pipe: 3.5 mm
    ·Distance between anode pipe and sample: 0.1 mm
    ·Discharge condition: 3 Torr-40 mA
    Calibration curve method was adopted for determining both Fe concentration and the sputter rate for the determined Fe concentration.
    By the improvement of in-depth resolution and the establishment of the quantitative analysis method of GDS for the measurement of Zn-Fe alloy electroplated layer, GDS will be widely used as the surface analysis technique for various plated metals.

  • Quantitative Analysis of Electrodeposit on Steel by Secondary Ion Mass Spectrometry

    Toshiko SUZUKI, Yoshiharu OHASHI, Kouzou TSUNOYAMA

    pp. 1775-1781

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    Abstract

    A method was developed for quantitative analysis of electrodeposits on steels by using Secondary Ion Mass Spectrometry. The technique was based on calibration curve method. The sputtered depth was estimated considering the variation of the sputter rate with the composition of alloys.
    Linear calibration curves were obtained for Zn-Fe and Fe-Ni alloy electrodeposits. This fact indicated that the matrix effect was negligible for these alloy electrodeposits. The calibration curve obtained for the Fe-Ni alloy electrodeposits coincided well with that obtained for the ISIJ Fe-Ni reference samples made for fluorescence X-ray spectrometry. Remarkable variation of the sputter rate with Zn concentration was observed for the Zn-Fe alloy electrodeposits, while the sputter rate for the Fe-Ni alloy electrodeposits was almost constant. The total coated weight was obtained by accumulating the depth sputtered during each measuring period from the surface to the interface.

  • Analysis of Corrosion Layers on Electrodeposited Zn-Ni (13wt%) Alloys Using AES, SAM, XPS, SEM and XRD

    Yasuo FUKUDA, Yasuo TSUCHIYA, Masaji TERASAKA, Kazuhide NAKAOKA, Tomihiro HARA

    pp. 1782-1789

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    Abstract

    Corrosion layers on electrodeposited Zn-Ni(13wt%) alloys are analyzed using Auger Electron Spectroscopy(AES), Scanning Auger Spectrometer(SAM), X-ray Photoelectron Spectroscopy(XPS), Scanning Electron Microscope(SEM), and X-ray Diffraction(XRD). It was found that surfaces of the alloys corroded by SST (salt spray test) were covered with zinc oxide and zinc hydroxide, and their inner layers consisted of γ phase alloy and ZnCl2·4Zn(OH)2. On the other hand, the surface layer of the alloys immersed in 5% NaCl solution consisted of ZnO and ZnCl2·4Zn(OH)2. It is pointed out that the enrichment of Ni between the surface and the inner layers does not occur. Chlorine does not exist in the surface layer of the alloys corroded by SST but does in the inner layer. As for the samples immersed in 5% NaCl solution, it is found in the surface layer as well as in the inner layer. It is emphasized that the corrosion mechanism is completely different between SST and immersion in 5% NaCl solution. Chlorine in the inner layer of the alloys corroded by SST is homogeneously distributed. From above results, the mechanism of corrosion by SST for the alloy is discussed.

    Recommended Articles: Quality Improvement by the Application of a Stirrer (Direct Current and Static Magnetic Field Method) to Continuous Casting Bloom [ View more ]

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  • Development of On-line Analysis System for Electrogalvanizing Baths

    Noriko YASUI, Akira YAMAMOTO, Eiko YASUHARA, Yasuharu MATSUMURA, Tadahiro ABE, Kazuaki MIYACHI, Yoshikazu MAKINO

    pp. 1790-1797

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    Abstract

    Control of concentration of each constituent in plating bath is indispensable to guarantee the product quality of electrogalvanizing steel sheet. An on-line analysis system of electrogalvanizing baths was developed using a microdroplet analysis method. This system consists of a sampling unit, a multichannel fluorescent X-ray spectrometer, and a computer. The plating solution is sampled, diluted by pure water and dropped onto the formed filter paper. Then it is dried and analyzed in a vacuum with fluorescent X-ray spectrometer. The sequence of these operations and the data processing proceed automatically by control of the computer. The characteristics of this system are as follows.
    (1) Analysis in a vacuum enables to analyze light elements.
    (2) Sufficient correction for the interactions among elements improves the accuracies of both light and heavy elements.
    (3) Various plating solutions and chemical treatment solutions are analyzed in parallel.
    (4) The state analysis of Cr3+ and Cr6+ is made automatically.
    (5) The coating weight and composition of the electroplated film are also analyzed at intervals of the analysis of plating solutions.
    This system was installed at the electrogalvanizing line in Chiba Works in April 1985, and has been successfully operating.

  • 情報の洪水

    渡辺 忠雄

    pp. 1797-1797

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  • Evaluation Method on Photodegradation of Paint Films by Using ESR Spectrometer

    Shingo OKAMOTO, Kiyoshi HIKITA, Hiroaki OHYA-NISHIGUCHI

    pp. 1798-1803

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    Abstract

    Radicals are generated in paint films by UV-irradiation.
    In order to investigate whether bisphenol A/epichlorohydrin type epoxy resin is able to be the radical trapping agent, the clear films prepared as the mixtures of the epoxy resin and polyester/melamine resin were exposed under ultra-high pressure mercury arc lamp (Main wave length, 365 nm) at room temperature and the relative concentrations of phenoxyl radical generated were measured by ESR spectrometer.
    It was clarified that the epoxy resin was able to be adopted as a suitable radical trapping agent of paint films.
    Using the epoxy resin as the radical trapping agent, the relative concentrations of phenoxyl radical for seven clear films, i.e, four kind of silicone modified polyesters (modified quantity; 50%, 35%, 20% and unmodified) and three kinds of acrylic resin, fluoro carbon resin and acrylic resin/fluorocarbon resin were tested with the same method as that mentioned above.
    For comparison, gloss retentions and color differences of these paint films were measured after outdoor exposure at Omaezaki, Shizuoka, Japan for 6 to 24 months.
    The relative concentrations of the phenoxyl radical estimated by ESR spectrometer, and gloss retentions and color differences of exposed paint films were nicely correlated one another, which shows that the ESR method has a high potential to determine quickly the photodegradation of paint films.

  • スペースステーション計画と材料開発/米国留学雑感

    澤岡 昭, 安藤 禎一

    pp. 1804-1807

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  • 抄録

    石井 邦彦, 永田 和宏, 京野 純郎, 岸本 哲, 田中 秀雄

    pp. 1810-1812

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  • © 1986 The Iron and Steel Institute of Japan

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