巻号一覧
50 巻, 11 号
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宮 声凱, 入戸野 修1986 年 50 巻 11 号 p. 935-942
発行日: 1986年
公開日: 2008/04/04
ジャーナル フリーIron films deposited at oblique incidence by a facing targets type d.c. sputtering apparatus were investigated, and their characteristic features of microstructure and magnetic properties were compared with those of the films prepared by the evaporation method. Iron films 25 to 250 nm thick were deposited on cleaved rock salt and on a glass plate under the Ar gas pressure of 4×10−1 Pa at normal temperature. The deposition rates ranged from 0.83 to 0.13 nm/s at incidence angles ranging from 0 to 80° (0.44π). The microstructure of films was observed by a transmission electron microscope (TEM) and by a scanning electron microscope (SEM). The magnetization curves were measured by a vibrating sample magnetometer (VSM), and Ms, Hc and Mr⁄Ms were evaluated in two directions lying in the film plane. The domain structures were studied by the Bitter pattern technique and Lorentz electron microscopy. The films show a structure composed of columnar crystallites having no preferred axis. The magnetization anisotropy occurs in the film plane at an incidence angle of 35°, and a coercive force increases remarkably above 50°, although a difference in coercive force between 70° film and 80° film was not large, unlike the case of the evaporation method. The magnetization axis is nearly in the film plane. The coercive forces Hc\varparallel and Hc⊥ depend on the film thickness: When the incidence angle is 70°, the former increases and the latter decreases with increasing film thickness, and they reverse their values at about 160 nm thickness. The deposited films are polycrystalline, and their Bitter patterns are quite similar to those of amorphous ferromagnetic thin films.抄録全体を表示PDF形式でダウンロード (3471K) -
臼井 誠, 浅野 滋1986 年 50 巻 11 号 p. 943-949
発行日: 1986年
公開日: 2008/04/04
ジャーナル フリーAn X-ray diffraction study was performed on three kinds of fcc Fe-Mn alloys (30%Mn, 42%Mn and 55%Mn) charged cathodically with hydrogen. In all the Fe-Mn alloys, a hydrogen-induced transformation to an hcp εH phase was observed after hydrogen charging, but any fcc hydride was not found. This is analogous to the case of austenitic stainless steels but different from the case of fcc Fe-Ni alloys.
The hydrogen-induced εH phase was unstable and decomposed during room temperature aging in air. It disappeared completely in the stable Fe-42%Mn and Fe-55%Mn alloys. On the other hand, in the metastable Fe-30%Mn alloy, the εH phase changed continuously to the ε martensite that was a stable phase at room temperature. The miscibility gap was not detected between the hcp εH phase and the hcp ε martensite in the Fe-Mn alloys, as has been reported in austenitic stainless steels. Therefore, the εH phase does not seem to be the hydride but shoud be regarded as the hydrogen-dissolved state of the ε martensite.抄録全体を表示PDF形式でダウンロード (1057K) -
高木 節雄, 加藤 康, 徳永 洋一1986 年 50 巻 11 号 p. 950-955
発行日: 1986年
公開日: 2008/04/04
ジャーナル フリーThe embrittling behavior in 6-10 mass%Mn steels with lath martensitic structure has been investigated by Charpy impact tests, scanning electron microscopy and scanning Auger microscopy. Specimens water quenched from the solution temperature (1373 K) fracture in the transgranular cleavage mode at a low temperature below 280 K. If the cooling rate from the solution temperature is small, however, the steel becomes to fracture in the intergranular mode, resulting in rise of the ductile-brittle transition temperature. It has also been shown that the grain boundary brittleness does not occur in the austenite field but proceeds during slow cooling below the Ms temperature. Auger spectrum analysis of the intergranular fracture surfaces has failed to identify elements embrittling grain boundaries, but has showed an increase in the total amount of B, C and N with lowering cooling rate. Even water quenched specimens become to fracture in the intergranular mode, if they are tempered in the low temperature range from 450 K to 700 K.
As a result, for high manganese martensitic steels, it seems that the grain boundary strength is slightly higher than the transgranular cleavage fracture strength. If the grain boundaries are only additionaly weakened by segregation of interstitial impurities, it is, therefore, expected that cracks tend to propagate along weaker grain boundaries.抄録全体を表示PDF形式でダウンロード (1512K) -
大橋 鉄也, 半澤 宏1986 年 50 巻 11 号 p. 956-960
発行日: 1986年
公開日: 2008/04/04
ジャーナル フリーAn approximate method is proposed for a solution of local elastic stress that occurs near grain boundary planes by an effect of elastic anisotropy. In this method, the local stress is represented by a sum of internal stresses of grain boundary dislocations which are virtually introduced to satisfy the elastic compatibility condition on grain boundary planes. Stress distribution in a bicrystal of shear incompatible type is calculated by this method and the result agreed well with the one obtained by the finite element method. Employing this method, stress distribution is calculated for bicrystals of various aspect ratios, and it is shown that stress singularity at an edge of grain boundary planes in bicrystals of this type is in the order of logr. The last part of this paper shows that an effect of the elastic incompatibility stresses on movement of lattice dislocations near grain boundary planes can be estimated through an insight into interaction between the lattice and the virtual dislocations.抄録全体を表示PDF形式でダウンロード (649K) -
古川 稔, 美浦 康宏, 根本 実1986 年 50 巻 11 号 p. 961-968
発行日: 1986年
公開日: 2008/04/04
ジャーナル フリーThe effects of testing temperature and strain rate on the yield stress of an aged Al-Li-Cu-Mg-Zr alloy has been investigated at temperatures between 77 and 523 K and over the strain rate range of 1.77×10−4 s−1 to 1.77×10−2 s−1. The deformation-induced dislocation structure was examined by transmission electron microscopy. In the specimens as-quenched, under-aged or aged nearly to the peak strength, dislocations move as pairs when the alloy is deformed at 290 K. In the over-aged specimens, dislocations move as single dislocations and tangle during deformation. For the alloy under-aged or aged nearly to its peak strength, the yield stress decreases with increasing testing temperature from 77 K to 290 K, and the positive temperature dependence of yield stress is observed in the temperature range from 290 K to 450 K. Within this temperature range, dislocations move in pairs cutting the δ′-L12 ordered particles. The yield stress decreases with increasing testing temperature above 450 K, and dislocations move as single dislocations. The serrated yielding characteristic is observed for specimens as-quenched, under-aged and aged nearly to the peak strength. At testing temperatures below 423 K, the yield stress is almost independent of strain rate at peak-aged and over-aged stages. For the under-aged stage, the strain rate dependence of the yield stress is negative at the temperature range within which the positive temperature dependence of yield stress appears. At testing temperatures above 473 K, the yield stress increases linearly with the logarithm of strain rate at any aging stage, and the strain rate dependence increases with increasing testing temperature.抄録全体を表示PDF形式でダウンロード (2091K) -
内山 休男, 羽坂 雅之, 古賀 秀人1986 年 50 巻 11 号 p. 969-973
発行日: 1986年
公開日: 2008/04/04
ジャーナル フリーTo obtain the information about the effect of cooling methods after coating on the corrosion behaviour of Zn-Al alloy coated steel sheet, two Zn-Al alloys, Zn-50 mass%Al and Zn-60 mass%Al, with several matrix structures were immersed in 2%HCl and 3%NaCl solutions at 308 K, and the corrosion behaviour of these alloys was examined.
(1) In the case of HCl solution, the mass of the samples decreases independently of the cooling conditions and the type of the alloy, while in the case of NaCl solution, it increases and a white product is formed.
(2) In the case of Zn-50 mass%Al alloy, the mass loss in HCl solution decreases as the cooling rate becomes slower, while the mass gain in NaCl solution increases.
(3) In the case of Zn-60 mass%Al alloy, the mass loss in HCl solution is highest when the alloy is cooled to room temperature in 15 h, and is smallest when the alloy is held in the α phase region and then is water-quenched.
(4) In each solution, a Zn-rich portion corrodes preferentially to an Al-rich one.
As-mentioned above, the corrosion behaviour of Zn-Al alloy depends on the matrix structure. Therefore, that of Zn-Al alloy coated steel sheet also depends on the cooling conditions after coating.抄録全体を表示PDF形式でダウンロード (1228K) -
中村 博昭, 笠原 章1986 年 50 巻 11 号 p. 974-978
発行日: 1986年
公開日: 2008/04/04
ジャーナル フリーThe electrical conductivity of a scandium sulfide disk prepared so carefully as to avoid any contamination has been measured at temperatures ranging from 773 to 1223 K and at sulfur partial pressures ranging from 10−7 to 104 Pa. It has been found that scandium sulfide is an n-type semiconductor and the sulfur pressure dependence of the conductivity in the temperature range higher than 993 K differs from that of in the temperature range lower than 993 K. The specific conductivity (S/m) is expressed as follows;
(This article is not displayable. Please see full text pdf.)
\ oindentwhere P is expressed in Pa and R in J/mol.
The observed sulfur pressure dependence is attributed to fully ionized scandium interstitials in the high temperature range and to monovalent impurity ions in the low temperature range.抄録全体を表示PDF形式でダウンロード (622K) -
安藤 繁, 中山 泰宏, 下尾 聰夫, 木村 弘1986 年 50 巻 11 号 p. 979-986
発行日: 1986年
公開日: 2008/04/04
ジャーナル フリーThe carbon deposition behavior on iron in vacuum carburizing, or by pyrolysis reaction of CH4 at low pressures and at 1313 K has been studied to elucidate the effect of the deposited carbon on carburization. It has been found that filmy carbon and filamentous carbon form on thin iron foils but the deposition of filamentous carbon is retarded for a thick specimen. A mathematical model has been developed to predict carbon concentration profiles. The comparison between calculated and observed carbon concentration profiles indicates that the continuation of carburization or diffusion in vacuum after the surface has been covered with filmy carbon results in excessive carburization. This may be caused by the fact that excessive cementite formed at the surface by the reaction of filmy carbon with iron substrate dissolves into iron bulk during the subsequent carburization or diffusion process in vacuum.抄録全体を表示PDF形式でダウンロード (1945K) -
下尾 聰夫, 安藤 繁, 木村 弘1986 年 50 巻 11 号 p. 987-992
発行日: 1986年
公開日: 2008/04/04
ジャーナル フリーThe rate of SiS evolution from silicate slag has been investigated. The slag was melted in a graphite crucible as a reductant under an atmosphere of argon. The amount of SiS generated was measured by thermogravimetry and chemical analysis.
The relation between the loss of SiS from the slag and the reaction time is approximately shown in a linear relationship, when the variation in the concentration of S is relatively slight. The rate of SiS evolution decreases linearly with increasing slag basicity. The rate is proportional to both the initial content of S and the activity of SiO2 in slag. The apparent activation energy varies from 300 to 430 kJ/mol with the slag composition. The generation of SiS is intimately related to the evolution of SiO from the slag.
It is considered that a certain chemical process is the rate-determining step in the evolution of SiS from the silicate slag.抄録全体を表示PDF形式でダウンロード (772K) -
片山 博1986 年 50 巻 11 号 p. 993-998
発行日: 1986年
公開日: 2008/04/04
ジャーナル フリーChromic oxide (Cr2O3) pellets with different pore structures were reduced with hydrogen in the temperature range from 1423 to 1623 K. The pore-radius distributions of unreduced and partially reduced pellets were measured by the mercury penetration method, and fractures of partially reduced pellets were observed by the use of SEM.
Since it was observed that the reduction proceeded topochemically under the formation of a relatively clear interface between a reduced sheel and a not reacting core, the reduction rate was analysed on the basis of a not reacting core model, in which the diffusion through the gaseous film around pellet, the intraparticle diffusion and the chemical reaction were taken into account.
The rate constant of chemical reaction was increased with the decrease of grain size of Cr2O3 in pellet, while the activation energy was 148∼166 kJ/mol and almost unchanged with the grain size. The intraparticle diffusivity and the labyrinth factor were highly influenced by the pore size, and their temperature-dependence was considerably greater than that in the reduction of iron oxide pellet with hydrogen. In the reduction of pellet composed of fine-grain Cr2O3, pore-shrinkage resulting from sintering occurred in the reduced layer so that the resistance of intraparticle diffusion was larger.抄録全体を表示PDF形式でダウンロード (1488K) -
松田 史朗, 細谷 敬三, 杉本 克久1986 年 50 巻 11 号 p. 999-1008
発行日: 1986年
公開日: 2008/04/04
ジャーナル フリーIn order to investigate the effect of hysteresis of applied potential on the nature and thickness of surface oxide film, ellipsometric measurements have been performed in-situ on Ti electrodes under anodic and cathodic polarization in 0.5 kmol·m−3H2SO4. The determination of optical constants for metallic Ti and Ti hydride, which are indispensable for the calculation of thickness and optical constants of the films formed on these materials, has also been performed using the tribo-ellipsometric technique.
In case of simple anodic oxidation started from a corrosion potential, the refractive indices of optical constants for anodic oxide films on metallic Ti decreased and the growth rates of the films per unit voltage increased with increasing potential.
When a Ti electrode covered with an anodic oxide film was polarized to cathodic potentials, a decrease in thickness and changes in optical constants for the film immediately occurred. That is, the refractive index and extinction coefficient of optical constant for the film changed from 2.0 to 1.8 and from 0 to 0.1, respectively, indicating changes in the composition and structure of the film. The formation of hydride layer also occurred simultaneously under the film. The film on the hydride layer disappeared after prolonged strong cathodic polarization.
Furthermore, Ti electrode covered with hydride layer, which was formed by cathodic polarization, was polarized to anodic potentials. The formation of anodic oxide films were found on the hydride layer. The refractive index of optical constants for the anodic oxide films on the hydride layer were smaller than those for the films on metallic Ti.抄録全体を表示PDF形式でダウンロード (1313K) -
水野 忠彦1986 年 50 巻 11 号 p. 1009-1016
発行日: 1986年
公開日: 2008/04/04
ジャーナル フリーThe adsorption of chloride ions on iron in borate buffer solution have been studied using radiotracer technique.
The results obtained are summarized as follows:
(1) The adsorption of chloride ions occurs on bare iron and passive iron surfaces with an increase of the potential.
(2) The amount of the adsorption of chloride ions, Γ, increases linearly with concentration of Cl− in the solution.
(3) The minimum concentration of NaCl electrolyte required to cause breakdown of passive film on iron surfaces was found to be 1 mol/m3, which corresponds to about 8×10−6 mol/m2 of chloride ions concentration on iron surfaces. The higher NaCl concentration in solutions and the larger amount of chloride ions on iron surfaces are needed at lower electrode potentials.
(4) Penetration mechanism of chloride ions for the iron passive film breakdown hardly explains the experimental details.抄録全体を表示PDF形式でダウンロード (1062K) -
稲数 直次, 北村 昌彦, 松本 英幹1986 年 50 巻 11 号 p. 1016-1022
発行日: 1986年
公開日: 2008/04/04
ジャーナル フリーThe correlation between the texture and the mechanical properties of squarely extruded aluminium alloy has been investigated by means of the determination of X-ray pole figures and the measurement of various mechanical properties.
The extruded bar having square cross section is composed of the ⟨111⟩+⟨100⟩ duplex fiber texture, and the tensile strength of this specimen is the highest in comparison with that of the other specimens, because of the strengthening of the ⟨111⟩ fiber axial component.
The extruded plate is composed of a part of the rolling texture, that is, the {011}⟨112⟩ and {146}⟨112⟩ components. It suggests that straining condition in extrusion is similar to that in rolling.
The impact value of this specimen is the highest, because of the anisotropy of the grain.
The extruded bar maintaining a rectangular cross section is composed of the unstable orientations which are {011}⟨322⟩ and {146}⟨18 12 11⟩, therefore the mechanical properties are inferior to that of the other specimens.抄録全体を表示PDF形式でダウンロード (1610K)
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