鉄と鋼
Online ISSN : 1883-2954
Print ISSN : 0021-1575
ISSN-L : 0021-1575
76 巻, 10 号
選択された号の論文の21件中1~21を表示しています
  • 榊原 路晤
    1990 年 76 巻 10 号 p. 1587-1596
    発行日: 1990年
    公開日: 2010/02/16
    ジャーナル フリー
  • 渡辺 徹, 清水 保雄
    1990 年 76 巻 10 号 p. 1597-1606
    発行日: 1990年
    公開日: 2009/06/30
    ジャーナル フリー
  • 鈴木 増雄
    1990 年 76 巻 10 号 p. 1607-1612
    発行日: 1990年
    公開日: 2009/06/30
    ジャーナル フリー
  • 松下 貢
    1990 年 76 巻 10 号 p. 1613-1622
    発行日: 1990年
    公開日: 2009/06/30
    ジャーナル フリー
  • 長 隆郎
    1990 年 76 巻 10 号 p. 1623-1632
    発行日: 1990年
    公開日: 2010/02/16
    ジャーナル フリー
  • 奥野 攻, 米山 隆之, 浜中 人士
    1990 年 76 巻 10 号 p. 1633-1641
    発行日: 1990年
    公開日: 2009/06/30
    ジャーナル フリー
  • 川口 尊三, 栗山 和益, 佐藤 駿, 高田 耕三
    1990 年 76 巻 10 号 p. 1642-1649
    発行日: 1990年
    公開日: 2009/06/30
    ジャーナル フリー
    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.
  • 坂井 敏彦, 前田 正史
    1990 年 76 巻 10 号 p. 1650-1655
    発行日: 1990年
    公開日: 2009/06/30
    ジャーナル フリー
    The sulfide capacity ( CS2- = (%S2-)·(PO2 /PS2 ) 1/2) of CaO-CaCl2 fluxes for compositions up to XCaO = 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 XCaO= 0.2 by extrapolating temperature to 1300°C.
  • 久間 英典, 伊藤 公允, 川上 正博
    1990 年 76 巻 10 号 p. 1656-1663
    発行日: 1990年
    公開日: 2009/06/30
    ジャーナル フリー
    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.
  • 月橋 文孝, 中村 右英, 折本 隆, 佐野 信雄
    1990 年 76 巻 10 号 p. 1664-1671
    発行日: 1990年
    公開日: 2009/06/30
    ジャーナル フリー
    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-Csatd. 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-Csatd. 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 PO2.5 was also calculated.
    Furthermore, in order to calculate the above mentioned phosphate capacities, the activity coefficient of phosphorus in carbon saturated iron, fP, at hot metal temperature was determined by measuring the partition of phosphorus between CaO-CaF2-SiO2 fluxes and Fe-Csatd. 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:
    logfP = -386/T + 0.891
    The relationship between phosphate capacity and sulfide capacity is also discussed for various fluxes.
  • 渡邊 雅俊, 井口 〓孝, 萬谷 志郎
    1990 年 76 巻 10 号 p. 1672-1679
    発行日: 1990年
    公開日: 2010/02/16
    ジャーナル フリー
    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 H2O1/2.
    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, DH2O, were evaluated, and the effects of slag composition and temperature on DH2O 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.
  • 井上 亮, 水渡 英昭
    1990 年 76 巻 10 号 p. 1680-1687
    発行日: 1990年
    公開日: 2010/02/16
    ジャーナル フリー
    塩化鉄焙焼酸化鉄をNa2O-B2O3系フラックスに溶解し急冷して得たガラス試料を再加熱することにより,高純度α-Fe2O3微粒子を得る実験を行い,以下の結果を得た.
    1)結晶化温度が高いほど,その温度における各不純物濃度の極小値に達するまでの時間は短い.ただし, Ca, Ti濃度は結晶化時間に依存せず一定である.
    2)いずれの結晶化温度においても,XNa2O/XB2O3 = 1/4の試料を処理した場合に低い不純物濃度を示した.
    3)低温での結晶化処理において,いずれの組成のガラス試料でも初期に楕円球状の結晶が析出する.より高温では,XNa2O/XB2O3 = 1/2の試料からは六角板状結晶が生成しC軸方向に成長する.XNa2O/XB2O3 = 1/3, 1/4の試料からは多面体結晶が晶出し,三次元的に成長した.
    4)得られた結晶の表面層に不純物が濃化する現象が認められた.この表面層を酸処理で除去することにより,さらに高純度なα-Fe2O3が得られた.
  • 朴 奉勲, 水渡 英昭
    1990 年 76 巻 10 号 p. 1688-1695
    発行日: 1990年
    公開日: 2010/02/16
    ジャーナル フリー
    α-Fe2O3結晶-Na2O-B2O3系フラックス間のMnの分配に関する実験を温度,フラックス組成を変化させて行い,固-液相間の反応平衡について考察を行った.本研究で得られた結果を要約すると以下のとおりである.
    1)平衡Mn濃度を持ったα-Fe2O3結晶がOstwald成長機構により成長した.
    2)結晶中のT. Mn濃度とフラックス中のそれとは比例関係にあった.
    3)T.Mnに関する分配係数の温度依存性は正であり,そのフラックス組成依存性は認められなかった.
    4)α-Fe2O3結晶中はMn3+として,フラックス中はMn2+が支配的に存在し,気相との反応よりは固-液相間でFeとMnの交換反応平衡が成立すると考えられる.
  • 小塚 敏之, 木下 誠, 鞭 巌, 浅井 滋生
    1990 年 76 巻 10 号 p. 1696-1703
    発行日: 1990年
    公開日: 2009/06/30
    ジャーナル フリー
    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.
  • 宮沢 賢二
    1990 年 76 巻 10 号 p. 1704-1711
    発行日: 1990年
    公開日: 2009/06/30
    ジャーナル フリー
    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.
  • 本田 弘之, 新家 光雄, 小林 俊郎, 村岡 義章
    1990 年 76 巻 10 号 p. 1712-1719
    発行日: 1990年
    公開日: 2009/06/30
    ジャーナル フリー
    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.
  • 篠田 哲守, 崔 乾, 三島 良直, 鈴木 朝夫
    1990 年 76 巻 10 号 p. 1720-1727
    発行日: 1990年
    公開日: 2009/06/30
    ジャーナル フリー
    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.
  • 冨村 宏紀, 高木 節雄, 徳永 洋一
    1990 年 76 巻 10 号 p. 1728-1735
    発行日: 1990年
    公開日: 2009/06/30
    ジャーナル フリー
    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.
  • 山口 隆生, 藤田 清比古
    1990 年 76 巻 10 号 p. 1736-1742
    発行日: 1990年
    公開日: 2009/06/30
    ジャーナル フリー
    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.
  • 橋本 嘉雄, 蓮香 要, 南野 繁, 篠原 和充
    1990 年 76 巻 10 号 p. 1743-1749
    発行日: 1990年
    公開日: 2010/02/16
    ジャーナル フリー
    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.
  • 武内 朋之
    1990 年 76 巻 10 号 p. 1750-1752
    発行日: 1990年
    公開日: 2009/06/30
    ジャーナル フリー
feedback
Top