Tetsu-to-Hagane

Development of the Technology on Heat Recovery from Molten Slag of Blast Furnace

Michiaki SAKAKIBARA

1990 Volume 76 Issue 10 Pages 1587-1596
Published: 1990
Released on J-STAGE: February 16, 2010

DOIhttps://doi.org/10.2355/tetsutohagane1955.76.10_1587

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Relationship between Crystallographic Structure of Plating Alloy Films and Thermal Equilibriam Diagram

Tohru WATANABE, Yasuo SHIMIZU

1990 Volume 76 Issue 10 Pages 1597-1606
Published: 1990
Released on J-STAGE: June 30, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.76.10_1597

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Critical Phenomena in Phase Transformation and Fractals

Masuo SUZUKI

1990 Volume 76 Issue 10 Pages 1607-1612
Published: 1990
Released on J-STAGE: June 30, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.76.10_1607

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Dendritic Crystal Growth and Self-similar Fractals

Mitsugu MATSUSHITA

1990 Volume 76 Issue 10 Pages 1613-1622
Published: 1990
Released on J-STAGE: June 30, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.76.10_1613

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Particulate Reinforced Composite from View-point of Chemical Stability of Particle

Takao CHOH

1990 Volume 76 Issue 10 Pages 1623-1632
Published: 1990
Released on J-STAGE: February 16, 2010

DOIhttps://doi.org/10.2355/tetsutohagane1955.76.10_1623

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Titanium Alloys in Dental and Medical Field

Osamu OKUNO, Takayuki J. YONEYAMA, Hitoshi HAMANAKA

1990 Volume 76 Issue 10 Pages 1633-1641
Published: 1990
Released on J-STAGE: June 30, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.76.10_1633

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Improvement of Sintering of Iron Ore Fines by Producing Pseudo-particles with Different CaO Content

Takazo KAWAGUCHI, Kazuyoshi KURIYAMA, Shun SATO, Kouzo TAKATA

1990 Volume 76 Issue 10 Pages 1642-1649
Published: 1990
Released on J-STAGE: June 30, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.76.10_1642

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The authors already reported that CaO segregation in raw materials by the separated granulation method improved reduction degradation without worsening reducibility of iron are sinter. This report presents the sintering method mixing two types of pseudo-particles : one contained high CaO content with limestone, scale and Australian iron ores, the other contained low CaO content with return fine, coke breeze and iron ores. "The segregated granulation method" improved the Reduction Degradation of Sinter (RDI) and the permeability of sinter bed in sintering pot test, DL test machine experiment and commercial plant test. The permeability improvement depends on the classification of ore brands. The RDI improvement depends on decrease in the volume of secondary hematite and the co-existence area of secondary hematite and calcium ferrite. "The separated granulation method" is applied to Kashima No. 2 Sinter Plant and contributed to improve the sintering of iron are fines.

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Sulfide Capacity of CaO-CaCl₂ Molten Fluxes

Toshihiko SAKAI, Masafumi MAEDA

1990 Volume 76 Issue 10 Pages 1650-1655
Published: 1990
Released on J-STAGE: June 30, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.76.10_1650

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The sulfide capacity ( C_S^2- = (%S^2-)·(P_O₂ /P_S₂ ) ^1/2) of CaO-CaCl₂ fluxes for compositions up to X_CaO = 0.2 has been determined at 1000°C to 1250°C by equilibrating the molten fluxes, molten silver and CO-CO₂-Ar mixtures. The sulfide capacity ranged from-4.5 to-2.7 and increases with increasing both CaO content and temperature. A linear relationship between the carbonate capacity and the sulfide capacity was observed on a logarithmic scale.
The sulfur partition between carbon saturated iron and the fluxes has been calculated as 1800 at X_CaO= 0.2 by extrapolating temperature to 1300°C.

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Electrode Reaction on the Electrolysis of Titanium in LiCl-KCl Eutectic Melt

Hidenori KUMA, Koin ITO, Masahiro KAWAKAMI

1990 Volume 76 Issue 10 Pages 1656-1663
Published: 1990
Released on J-STAGE: June 30, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.76.10_1656

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Cathodic reduction of Ti ions and anodic oxidation of Cl ion were investigated in LiCl-KCl eutectic melt. The experiments were carried out under argon atmosphere at higher temperature than 500°C with addition of TiCl₃ and/or Ti chips. The results are summarised as follows.
Two waves on linear sweep voltammograms were observed when TiCl₃ was added to the melt. The first reduction wave appears at the potential near-0.6V, and is attributed to the step of Ti³⁺ → Ti²⁺. The second reduction wave appears at-1.1V corresponding to the step of Ti²⁺ → Ti⁰. Reduction rate of Ti²⁺ → Ti⁰ was proportional to concentration of Ti²⁺. The reduction potentials at which Ti³⁺ → Ti²⁺ and Ti²⁺ → Ti⁰ reductions take place are in good agreement with the theoretical ones calculated from the thermodynamic data. The oxidation of Cl^- → Cl⁰ takes place at + 1.0V which corresponds well to the theoretical oxidation potential. Electrodeposit at-1.2V in the melt containing Ti²⁺ was found to be titanium metal, by EPMA analysis.

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Thermodynamics of Phosphorus for the CaO-BaO-CaF₂-SiO₂ and CaO-Al₂O₃ Systems

Fumitaka TSUKIHASHI, Migiei NAKAMURA, Takashi ORIMOTO, Nobuo SANO

1990 Volume 76 Issue 10 Pages 1664-1671
Published: 1990
Released on J-STAGE: June 30, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.76.10_1664

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The effect of BaO addition to the CaO-CaF₂-SiO₂ melts on the phosphorus partition ratio between CaO-CaF₂-SiO₂ melts doubly saturated with CaO and 3CaO·SiO₂ and Fe-C_satd. melts was investigated at 1300°C by using a chemical equilibration technique. The partition ratio increases with increasing the BaO content. The addition of 26%BaO enhances the partition ratio six times.
The phosphorus partition ratio between CaO-Al₂O₃ fluxes and Fe-C_satd. melts was measured at 1500°C. The phosphorus partition increases with increasing CaO content and its phosphate capacity ranges from 10¹⁹ to 10²¹.The activity coefficient of PO_2.5 was also calculated.
Furthermore, in order to calculate the above mentioned phosphate capacities, the activity coefficient of phosphorus in carbon saturated iron, f_P, at hot metal temperature was determined by measuring the partition of phosphorus between CaO-CaF₂-SiO₂ fluxes and Fe-C_satd. melts and that between the same fluxes and silver at different oxygen partial pressures. The activity coefficient of phosphorus in carbon saturated iron is expressed as follows:
logf_P = -386/T + 0.891
The relationship between phosphate capacity and sulfide capacity is also discussed for various fluxes.

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Dissolution of Water Vapor in Liquid Aluminates

Masatoshi WATANABE, Yasutaka IGUCHI, Shiro BAN-YA

1990 Volume 76 Issue 10 Pages 1672-1679
Published: 1990
Released on J-STAGE: February 16, 2010

DOIhttps://doi.org/10.2355/tetsutohagane1955.76.10_1672

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The solubilities of water vapor and the rates of water vapor dissolution in liquid CaO-Al₂O₃, CaO-MgO-Al₂O₃, CaO-SrO-Al₂O₃ and CaO-BaO-Al₂O₃ slags have been measured by using a thermobalance at the temperature ranging from 1773 K to 1973 K.
The solubilities of water vapor in liquid aluminate slags were shown with water vapor capacities, defined by K' = (%H₂O)_s/P _H₂O^1/2.
The rate controlling step of the water vapor dissolution into aluminate slags are considered to be diffusion of water in bulk slag. The apparent diffusion coefficients of water vapor, D_H₂O, were evaluated, and the effects of slag composition and temperature on D_H₂O were discussed.
Water vapor capacity increases and the apparent diffusion coefficient of water vapor decreases with increasing alkaline earth oxide content in the aluminates. The effect of alkaline earth oxide on increase in water vapor capacity follows the order of cation radius (Ba²⁺ >Sr²⁺ >Ca²⁺ >Mg²⁺ ), and that on decrease in the diffusion coefficient follows the same order.

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Purification of Roasted Iron Oxide Product from Waste Pickling Liquor by Glass-Ceramic Method

Ryo INOUE, Hideaki SUITO

1990 Volume 76 Issue 10 Pages 1680-1687
Published: 1990
Released on J-STAGE: February 16, 2010

DOIhttps://doi.org/10.2355/tetsutohagane1955.76.10_1680

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The experiment has been carried out for the purification of α-Fe₂O₃ by the glass-ceramic method. After melting the roasted product of the waste pickling liquor with Na₂O-B₂O₃ fluxes having the Na₂O/B₂O₃ (mole ratio) = 1/2-1/5, the glass samples obtained by rapid quenching crystallized at temperatures ranging from 550 to 1 000°C for 55 s to 24 h. The separation of the precipitated α-Fe₂O₃ from the flux was conducted by wet chemical treatment with water and dilute HCl solution, after which high purity and fine α-Fe₂O₃ crystals were obtained. The impurity contents, Fe yield, and crystal shape and size have been investigated as a function of crystallization time, temperature and flux compositions. Dissolution of the crystallized fine α-Fe₂O₃ particles by dilute HCl solution in stepwise manner, and subsequent analysis of impurities in each stage showed that the contents of Si, Na, B, Ca, and Al were enriched on the crystal surface.

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Partition of Manganese between α-Fe₂O₃ Crystal and Na₂O-B₂O₃ Melts

Bong-hoon PARK, Hideaki SUITO

1990 Volume 76 Issue 10 Pages 1688-1695
Published: 1990
Released on J-STAGE: February 16, 2010

DOIhttps://doi.org/10.2355/tetsutohagane1955.76.10_1688

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A study has been made of the partition of Mn between α-Fe₂O₃ crystal and sodium borate fluxes at the temperatures ranging from 800°C to 1100°C as a function of flux compositions.
The total Mn content in a-Fe₂O₃ is linearly related to that in flux in the range of the present T. Mn contents in both phases. The temperature dependence of the partition coefficient κ_{T. Mn} = (wt%Mn) _solid/(wt%Mn)_liquid was found to be positive. It was found that Mn is present as Mn³⁺ in α-Fe₂O₃ crystal and Fe and Mn in flux are present as Fe³⁺ and Mn²⁺, respectively. On the basis of the mutual interaction of the Mn³⁺/Mn²⁺ and Fe³⁺/Fe²⁺ redox pairs: Fe³⁺ (s)+ Mn²⁺ (l) = Mn³⁺ (s) + Fe²⁺ (l), the partition between solid and liquid phases with a different valency state has been discussed.

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Damping Behavior of Molten Metal Wave Motion in Imposition of Stationary Magnetic Field Parallel to the Wave Vector

Toshiyuki KOZUKA, Makoto KINOSHITA, Iwao MUCHI, Shigeo ASAI

1990 Volume 76 Issue 10 Pages 1696-1703
Published: 1990
Released on J-STAGE: June 30, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.76.10_1696

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Suppression of wave motion by imposing stationary magnetic field, is attractive since magnetic field can act on molten metal without any contact with contamination source and stationary magnetic field requires smaller investment and running costs than alternating magnetic field does. This technique is applicable to some processes such as a twin roll, a single roll, a conventional continuous casting and an electromagnetic casting, in which the surface wave molten metal leads to instabilities of the operation and surface defects.
In this work, basic equations describing wave motion under stationary magnetic field imposed parallelly to the wave vector are derived taking into account the three-dimensional velocity distribution. A dispersion relation under the condition suffering the stationary magnetic field is derived so as to get a damping coefficient of wave motion. And the results of this theoretical analysis are valified by experimental works measuring the damping coefficient.

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Stress Analysis and Shape Study of Keyways in Journals of Large Sized Backup Rolls

Kenji MIYAZAWA

1990 Volume 76 Issue 10 Pages 1704-1711
Published: 1990
Released on J-STAGE: June 30, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.76.10_1704

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Though a keyway in the journal of a large sized backup roll is an area where stress is usually concentrated, there are a few studies on strength of keyways.
In this paper the stress analysis in the corner of keyway bottom and the improvement of keyway shape for stress reduction were studied by the two-dimensional photoelastic method.
The main results obtained are as follows:
1) A repeated tensile and compressive stress work in the corner of keyway bottom. However, no stress enough to break the keyway occurs under the usual rolling load. When the high circumferential impact load is inflicted repeatedly, there is a probability of keyway breakage.
2) To improve the strength of the corner of keyway bottom, it is effective to apply a larger curvature radius to the corner. And from scope of this study it became clear that the corner radius of 15 mm min brought a satisfactory result.

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Effect of Thermomechanical Treatment Conditions on Mechanical Properties of Ti-10V-2Fe-3Al Alloys

Hiroyuki HONDA, Mitsuo NIINOMI, Toshiro KOBAYASHI, Yoshiaki MURAOKA

1990 Volume 76 Issue 10 Pages 1712-1719
Published: 1990
Released on J-STAGE: June 30, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.76.10_1712

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We examined Near β type Ti-10V-2Fe-3Al alloys applied to newly proposed thermomechanical treatment. Tensile tests, Charpy impact tests and dynamic fracture toughness tests were carried out on these treated specimens in order to compare their mechanical properties and toughness with those of typical STA treated (1033 K, 1h, WQ + 783K, 8h, AC) specimens. Alloys conducted with new thermomechanical treatment of 973K, 1h, WQ + 75%C.R + 1033K, 5s, WQ + 783 K, 8h, AC exhibited greater strength and toughness compared with typical STA treated alloys. Toughness of the former, in particular, was considerably greater than that of the latter. Dynamic fracture toughness and dynamic tearing modulus of thermomechanical treated alloys increased considerably with increasing solution treatment temperature after cold rolling of 75% compared with those of typical STA treated alloys.
This increse in toughness was considered to be caused by micro cracking near the crack tip, tortuosity of main crack and formation of secondary cracks. Eventually, newly proposed thermomechanical treatment in this study was found to be effective for improving the toughness of Ti-10V-2Fe-3Al alloys.

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Correlation between the Solution Hardening and the Solid Solubility in Binary fcc Dilute Alloys

Tetsumori SHINODA, Guen CHOI, Yoshinao MISHIMA, Tomoo SUZUKI

1990 Volume 76 Issue 10 Pages 1720-1727
Published: 1990
Released on J-STAGE: June 30, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.76.10_1720

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The authors have already shown that the rate of solid solution hardening in binary Ni-X alloys for such solute X as having solid solubility was larger than that as making continuous solid solutions for the same atomic size misfit parameter. Also it has been shown that the degree of solid solution hardening could be correlated with the extent of solid solubility of a solute X. In the present work, further evidence for such correlation is sought after by literature survey on Cu-X and Au-X alloys and by an investigation on the solid solution hardening in Ni-Au and Ni-Pd alloys. It is shown that the former is true for at least in Cu-X alloys and the latter is so in all the binary systems examined. The reason to provide extra hardening for a solute with limited solubility to the solvent is relevant in nature to some properties which increase with increasing size misfit parameter and are well correlated with atomic interaction parameter between a solute and a solvent atoms.

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Process of Reversion and Mechanical Properties in Metastable Austenitic Stainless Steels Containing Molybdenum

Kouki TOMIMURA, Setsuo TAKAKI, Youichi TOKUNAGA

1990 Volume 76 Issue 10 Pages 1728-1735
Published: 1990
Released on J-STAGE: June 30, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.76.10_1728

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Effect of molybdenum on the behavior of reversion of deformation induced martensite to austenite and the mechanical properties of specimens containing reversed austenite were investigated within (15.5 13)% Cr-11%Ni-(02.5)%Mo steels by means of transmission electron microscopy, magnetic analysis and tensile testing. Reversion treatment of martensite to austenite was performed at a higher heating rate using a salt bath and at lower heating rate using an electric furnace. The results obtained are as follows.
(1) The steels used almost transform to lath martensite ( a') from austenite (γ) by 90% cold rolling at 290 K. Effect of molybdenum on y stability against deformation is almost same as that of chromium.
(2) The temperature range for reversion rises with increasing molybdenum content.
(3) In case of 923 K annealing at a higher heating rate, a process of reversion is changed from a martensitic type to a diffusional one with increasing molybdenum content. A 13%Cr-11%Ni-2.5%Mo steel which reverts to γ by a diffusional process has an ultra fine austenitic structure with a mean grain size of 0.2 μm giving a high 0.2% proof stress of 0.8 GPa, tensile strength of 1.0 GPa, and elongation of 30%.
(4) In case of 923 K annealing at a lower heating rate, a' reverts to γ by a diffusional process at lower heating temperatures. Therefore, molybdnum content of 0.5% is enough to obtain a high strergth steel.

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The Spectral Emissivity of Steels Heated in Oxidizing Atmospheres

Takao YAMAGUCHI, Kiyohiko FUJITA

1990 Volume 76 Issue 10 Pages 1736-1742
Published: 1990
Released on J-STAGE: June 30, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.76.10_1736

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The spectral emissivity ε_{(λ, T)} is required when thermal radiation pyrometers are used to determine the true temperature of a subject. If the surfaces of steels are heated in air, the values of ε_{(λ, T)} changes in dependence on the oxidized condition of the surfaces. However, oxidizing conditions have not been exactly controlled in studies on the spectral emissivity of oxidized surfaces of steels. So, reported values of ε_{(λ, T)} are rather unreliable and sometimes unavailable.
In the present study, the values of ε_{(λ, T)} on the surfaces of commercial steels, that is, JIS S09CK, SUS430, SUS304, and SKH3, which were heated in controlled atmospheres of different oxygen partial pressures, were measured at temperatures from 1000°C to 1300°C and in the wavelength region from 0.34 to 0.94 μm.
Experimental results were examined by the equation concerning to free electrons and the lattice vibration and constants which are used to calculate the values of ε_{(λ, T)} were determined.

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Effect of Processing Conditions on the Ferrite Grain Size of Low Carbon Nb-Ti Steel Annealed at High Temperatures

Yoshio HASHIMOTO, Kaname HASUKA, Sigeru MINAMINO, Kazumitsu SHINOHARA

1990 Volume 76 Issue 10 Pages 1743-1749
Published: 1990
Released on J-STAGE: February 16, 2010

DOIhttps://doi.org/10.2355/tetsutohagane1955.76.10_1743

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In order to prevent orange-peel appearing in a surface of stainless clad steel, the effects of various processing parameters on ferrite grain size have been investigated on a low carbon-niobium-titanium steel which is suited for a base material to be clad with stainless steel. Based on the results obtained, three kinds of processes have been proposed, among which the following two have been selected from practical stand point.
(1) The steel containing 0.05% niobium is annealed at temperature higher than 1 000°C and cooled with a rate of 2540°C/s.
(2) The steel is annealed within the temperature of ferrite range.
In the former case, the annealing at higher temperature than the conventional can be applied resulting in better ductility of the surface stainless layer.
In the latter case, the steel will be low cost and has good drawability for the small amount of alloying elements, and has great benifit that the steel is available more easily because of mass production as a popular high drawable steel. The proposed processes have successfully been applied to produce the clad steel sheets of laboratory scale and mill production scale, respectively.

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[title in Japanese]

[in Japanese]

1990 Volume 76 Issue 10 Pages 1750-1752
Published: 1990
Released on J-STAGE: June 30, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.76.10_1750

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