鉄と鋼
Online ISSN : 1883-2954
Print ISSN : 0021-1575
ISSN-L : 0021-1575
83 巻, 11 号
選択された号の論文の14件中1~14を表示しています
  • 木村 久雄, 月橋 文孝
    1997 年 83 巻 11 号 p. 689-694
    発行日: 1997/11/01
    公開日: 2009/06/19
    ジャーナル フリー
    The effect of K2O addition to the CaO-CaF2-SiO2 flux on the phosphorus partition ratio between CaO-CaF2-SiO2 flux doubly saturated with CaO and 3CaO·SiO2 and carbon saturated iron melts has been investigated at 1473, 1523 and 1573K by a chemical equilibration technique. The partition ratio increases with increasing the K2O content. The phosphate capacity of CaO-K2O-CaF2-SiO2 flux was compared with various basic fluxes. The activity of K2O in the CaO-CaF2-SiO2 system doubly saturated with CaO and 3CaO·SiO2 has been determined at 1573K which rangs from 10-13 to 10-12.
  • 伊東 裕恭, 日野 光兀, 萬谷 志郎
    1997 年 83 巻 11 号 p. 695-700
    発行日: 1997/11/01
    公開日: 2010/05/07
    ジャーナル フリー
    The previous literature thermodynamic values for deoxidation equilibrium relation shows a loop of reciprocal Ω shape in the figure which shows the relation between calcium and oxygen dissolved in liquid iron. This means one concentration of calcium corresponds to two or more concentration of oxygen and vice versa. This discrepancy between predicted and measured results is due to an incomplete expression of the activities of dissolved calcium and oxygen in current literature. It causes by use of only 1st order interaction parameters to express the activities of calcium and oxygen. In the present work, the deoxidation equilibrium of calcium was studied to develop values for the 1st and 2nd order interaction parameters including cross products too. As the result, the thermodynamic values of calcium deoxidation obtained was in good agreement with the observed values.
  • 金沢 敬, 平城 正, 川本 正幸, 中井 健, 花崎 一治, 村上 敏彦
    1997 年 83 巻 11 号 p. 701-706
    発行日: 1997/11/01
    公開日: 2009/06/19
    ジャーナル フリー
    In order to cast high quality slabs with high productivity, high speed casting technology has been investigated with a pilot continuous casting machine capable of casting 50 to 100 tons of molten steel. The results can be summarized as follows;
    (1) High casting speed of 5.0 m/min for low carbon steel has been achieved with low viscosity powder. The powder consumption is small, from 0.1 to 0.2 kg/m2, but stable casting has been conducted.
    (2) Longitudinal crack has been occured even if for low carbon steel at up to 4.0 m/min. When the heat flux in mold increased critical value, longitudinal crack occured.
    (3) The control of the heat fluxes through the mold can be achieved by using the powder with appropriate properties.
  • 西岡 浩樹, 村山 武昭, 小野 陽一
    1997 年 83 巻 11 号 p. 707-712
    発行日: 1997/11/01
    公開日: 2009/06/19
    ジャーナル フリー
    Parameter fitting with the Marquardt method was applied to simultaneous measurements of thermal diffusivity, specific heat and thermal conductivity with the halogen flash method.
    Thermal diffusivity, specific heat and thermal conductivity of dense Al2O3 samples (8.55mm in diameter and 10mm in thickness) were measured with the above method. The influence of radiation from the side of the sample on thermal diffusivity was examined with two kinds of analytical solutions (cylinder and infinite plate). The heat loss by radiation from the side of the sample was negligible in this work. The measurement results agreed well with reference values.
  • 荒井 正浩, 足立 吉隆, 中森 俊夫, 薄木 智亮
    1997 年 83 巻 11 号 p. 713-718
    発行日: 1997/11/01
    公開日: 2009/06/19
    ジャーナル フリー
    The formation and growth of the iron-zinc compound phases, especially Γ1-Fe5Zn21 and Γ-Fe3Zn10, at 773K in galvannealed coatings on the titanium-stabilized interstitial free (IF) steel and the interstitial-free rephosphorized (IFP) steel have been investigated by means of the cross-sectional SEM observation. The formation order of Γ1 phase and Γ phase was different between the substrates; on the IFP steel substrate, the formation of Γ phase was retarded, which resulted in the prior formation of Γ1 phase. The formation and growth of Γ1 phase, on which little influence of phosphorus in steel was observed, is considered to be controlled by the diffusion of iron atoms across the Γ11 interface, which is controlled by the diffusion-coefficient change and the iron-concentration gradient of δ1 phase. The reactionrate analysis reveals that Γ phase on the IF steel substrate grows by moving the Γ/substrate interface toward the substrate by the diffusion of zinc atoms from the coating into the substrate and that early formation and rapid growth in the earlier stages of alloying reaction are caused by moving Γ/Γ1 interface toward the Γ1 phase by the diffusion of iron atoms from the substrate to the coating. Both formation and growth of Γ phase on the IFP steel substrate were retarded, comparing to those on the IF steel substrate, which suggest that both solid-soluted and grain-boundary segregated phosphorus in the IFP substrate interferes the zinc diffusion from the coating into the substrate.
  • 園家 啓嗣, 島崎 宗治
    1997 年 83 巻 11 号 p. 719-724
    発行日: 1997/11/01
    公開日: 2009/06/19
    ジャーナル フリー
    The erosion tests were carried out in the MITI SUS310J1TB material used to be utility boiler, and erosion properties were considered by simulating the temperature gradient profile between bed material and specimen surface. The results obtained are as follows.
    (1) The erosion tester that enables temperature gradient between bed material and specimen surface was developed.
    (2) There is a maximum erosion wastage at intermediate temperature in both case of the specimen with temperature gradient and the one without temperature gradient.
    (3) Cooling method change the erosion wastage curve (erosion wastage vs temperature) and lowers the peak temperature at maximum wastage.
  • 金井 洋, 岡 襄二
    1997 年 83 巻 11 号 p. 725-730
    発行日: 1997/11/01
    公開日: 2009/06/19
    ジャーナル フリー
    Surface structure of polyester film cured by melamine-formaldehyde resin (MF) was investigated by X-ray photoelectron spectroscopy. We found that paints containing polyester resin having low hydroxyl values, highly methylated MF and strong acid catalyst neutralized by volatile amines gave film surface having higher nitrogen concentration, which meant higher MF concentration. A mechanism for MF enrichment in the surface was proposed as the following. In the paints containing volatile amines, as amines vaporized easily near the surface in the curing period, acidity near the surface increased with decreasing amine concentration. High acidity near the surface accelerated self-condensation reaction of highly methylated MF having high reaction rate under existence of strong acid catalyst. MF diffused from the bulk of the film to the surface because MF concentration near the surface decreased, and then MF condensates are concentrated in the surface.
  • 金井 洋, 岡 襄二, 堤 正也
    1997 年 83 巻 11 号 p. 731-735
    発行日: 1997/11/01
    公開日: 2009/06/19
    ジャーナル フリー
    In polyester resin films cured by melamine-formaldehyde resin (MF), MF concentration in the surface of films was measured by X-ray photoelectron spectroscopy (XPS). The MF concentration in the surface increased as the following parameters increased; MF concentration in paints, catalyst concentration, baking temperature (peak metal pemperature), and film thickness. Performance of the prepainted steel sheets having MF enriched films were also evaluated. Stain resistance and T-bend ability of prepaited steel sheets improved with increasing MF concentration in the surface of the films. MF enriched films were found to have both excellent formability and stain resistance.
  • 千葉 昂, 西田 稔, 森園 靖浩, 今村 喜八郎
    1997 年 83 巻 11 号 p. 736-741
    発行日: 1997/11/01
    公開日: 2009/06/19
    ジャーナル フリー
    The high temperature stability of an explosively welded Ti/SUS420J1 stainless steel clad was assessed by studying microstructures and bonding strengths of the clads with changing the annealing temperature. Compounds formed at their bonding interfaces consisted of TiC, FeTi, and/or Fe2Ti phases depending on the annealing conditions. The TiC layer formed at the boundary acts as an barrier for the diffusion of the base metals across the bonding interface under the 1000°C annealing and prevents the growth of intermetallic compounds, (FeTi and Fe2Ti) and of β-Ti. The specimens formed TiC layer at the bonding interface sustained high bonding strength even by high temperature annealing. Diffusion barrier effect diminished above 1050°C annealing due to the dissolution of TiC layer in γ matrix and the strength decreased. The diffusion barrier effect of the TiC layer was discussed on the basis of phase diagrams and physical properties of TiC compound.
  • 遠藤 孝雄, 石 建中, 芳須 弘, 門馬 義雄
    1997 年 83 巻 11 号 p. 742-747
    発行日: 1997/11/01
    公開日: 2009/06/19
    ジャーナル フリー
    Using the constitutive equations derived from a strain rate versus creep strain relationship, the extrapolation of creep life from an accelerated creep range to a long-term creep range was made of a 2.25Cr-1Mo steel, and the results were compared with the long-term creep data. It was found that the extrapolated creep life is in good agreement with the long-term creep data below 823K. However, the extrapolated creep life becomes much longer than the measured one above 823K. To explain the discrepancy between them, the effect of oxidation during creep on the life was numerically examined with the aid of the constitutive equations and an empirical equation for the reduction of cross-sectional area given as a function of expose time and temperature. It was made clear that the creep life compensated by the effect of oxidation is well in accordance with the measured one at any temperatures. These results suggest that the effect of oxidation on creep life is much larger than the effect of structural degradation on a long-term creep life.
  • 高木 周作, 三浦 和哉, 古君 修, 小原 隆史, 加藤 俊之, 谷村 眞治
    1997 年 83 巻 11 号 p. 748-753
    発行日: 1997/11/01
    公開日: 2009/06/19
    ジャーナル フリー
    Stain rate sensitivity of deformation behavior in various sheet steels were investigated in order to find out the suitable steel for automotive anti-crash parts. Dual phase steels consisted of ferrite and martensite phases absorbed higher energy at strain rate of 2 × 103/s with lower yield strength at strain rate of 2 × 10-2/s, compared with other steels. Higher energy absorption of dual phase steels was due to high strain rate sensitivity of yield strength and n-value. Increase of volume fraction or large surface area of martensite phase in dual phase steel led higher strain rate sensitivity in work hardenability as well as yield strength.
  • 山崎 一正, 水山 弥一郎
    1997 年 83 巻 11 号 p. 754-759
    発行日: 1997/11/01
    公開日: 2009/06/19
    ジャーナル フリー
    Influence of retained austenite and strain on delayed fracture of ultra-high strength steel sheets with tensile strength of 1200MPa class was investigated. Volume of retained austenite in the steel was changed by annealing at various temperature. Plastic strain was induced by bending. The tendency of delayed fracture was observed by measuring the time to fracture when the steel was cathodically charged with hydrogen. Occurrence of delayed fracture is affected by the volume of retained austenite; the steel that has a large amount of retained austenite has a susceptibility to delayed fracture. When the steel had no plastic strain, delayed fracture was not observed in it, but as the steel was plastically deformed, delayed fracture occurred. Increasing the strain, a strong susceptibility for delayed fracture was shown. Delayed fracture was affected by applied stress after plastic deformation; increasing applied stress, a strong susceptibility for delayed fracture was shown. Existence of retained austenite, plastic deformation and applied stress a re necessary to occurrence of delayed fracture of ultra-high strength steel sheet.
  • 高澤 幸治, 野戸 滋, 田頭 孝介
    1997 年 83 巻 11 号 p. 760-765
    発行日: 1997/11/01
    公開日: 2009/06/19
    ジャーナル フリー
    The interaction between copper atom and carbon atom in 0.03mass% carbon steels, containing from 0 to 0.55mass% copper, has been studied by the measurement of electrical resistivity and its deviation from Matthiessen's rule (DMR). The electrical resistivity measured at 77K and 273K decreases during isothermal aging at 523K for all steels which were quenched from 973K in the ferrite single phase region. Its DMR increases during aging for steels except copper-freesteel. The increments of the DMR increases with the increase of copper content of steels. These phenomena can be explained in terms of Cu-C pairs in the solid solution of the present steels, analogous to Mn-N pairs in Fe-Mn-N alloys. The Cu-C pairs may be formed in as-quenched ferrite and be decomposed with the precipitation of cementite during aging. According to the concept, the amount of carbon atoms as Cu-C pairs increases, whereas the amount of carbon atoms as single atom in the solid solution decreases at the solution treatment temperature of 973K as the copper content of steels increases. The formation of Cu-C pairs in the alpha irons is also suggested from the hardness comparison between the present Fe-Cu-C steels and the decarburized Fe-Cu ones just after quenched. The binding energy of a Cu-C pair is calculated to be approximately -5.1 × 10-20J.
  • 佐藤 純一
    1997 年 83 巻 11 号 p. 766-771
    発行日: 1997/11/01
    公開日: 2009/06/19
    ジャーナル フリー
    This report was aimed to give a metatechnical consideration on the significance of iron technology and its industry for the human life. First the philosophical concept of the technological cohesion was tried to be explained from the engineering standpoint. And the various important characteristics of our modern technology which has been environmentalized and their serious effects on the human and the society were made clear. Then it was strongly claimed to establish the "eco-ethica" as our new norm of act in the modern age and the metatechnica as a new discipline beyond all kinds of speciality.
    In the latter part of this research were considered the position of material in the whole technology system and its importance as the first step for the human to introduce and change "nature" citing the examples of iron material. And finally the difficult situation of the iron industry at the age of technological cohesion, ie., the trilemma of iron was clearly suggested with some measures to be taken.
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