巻号一覧
41 巻, 8 号
選択された号の論文の17件中1～17を表示しています
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西原 公, 高瀬 篤夫1977 年 41 巻 8 号 p. 751-755
発行日: 1977年
公開日: 2008/04/04
ジャーナル フリーIn this paper the abnormal behavior of stress relaxation during the rapid heating transformation of commercial pure iron, hypoeutectoid steel (S 45 C) and eutectoid steel (SK 5) has been examined using the apparatus originally designed for stress relaxation measurements. The stress relaxation rate-time curve during the rapid heating transformation was measured and analysed with respect to the transformation superplastic deformation. The main results obtained are as follows:
(1) During the thermal cycle across the A1 or A3 transformation temperature, the stress relaxed perfectly independant of initial stress.
(2) In pure iron two maximum rates of stress relaxation rate appeared at 630°C and near the starting temperature of A3 transformation, but only one maximum rate appeared in S 45 C and SK 5 at the starting temperature of A1 transformation. All the rates of stress relaxation depend on the initial stress and the heating rate.
(3) By the stress-relaxation method, the mechanical behavior of transformation superplasticity can be described by the equation in the form
(This article is not displayable. Please see full text pdf.)
\ oindentwhere \dotγ is the strain rate, K is a constant, τ is the applied stress, and n is the stress exponent.抄録全体を表示PDF形式でダウンロード (359K) -
添野 浩, 土屋 正利1977 年 41 巻 8 号 p. 756-760
発行日: 1977年
公開日: 2008/04/04
ジャーナル フリーPrecipitation in 14Ni-5∼15Co-5Mo, 14Ni-7.5Co-7Mo and 14Ni-5Co-10Mo maraging steels has been investigated as a function of cobalt or molybdenum content by measuring the change in electrical resistivity at liquid nitrogen temperature. Age-hardning has also been measured in some of the maraging steels, and the relation between tensile strength and resistivity decrease has been investigated.
The results can be interpreted satisfactorily in terms of two precipitation stages. The precipitates formed in a low temperature region and in a high temperature region are named as the phase-L and the phase-H, respectively. In the low temperature region, the phase-L is precipitated in the early stage of isothermal aging and is gradually converted into the phase-H with the lapse of aging time. In the high temperature region, it is considered that the phase-H is precipitated from a solid solution without the precipitation of the phase-L. The temperature where the phase-L is precipitated in the early stage increases with increasing cobalt or molybdenum content. The line of demarcation between the precipitation of the phase-L and that of the phase-H is determined as a function of cobalt content in 14Ni-5∼15Co-5Mo maraging steels.抄録全体を表示PDF形式でダウンロード (386K) -
鈴木 俊夫, 梅田 高照, 木村 康夫, 椙山 正孝1977 年 41 巻 8 号 p. 761-766
発行日: 1977年
公開日: 2008/04/04
ジャーナル フリーThe structures of copper, Cu-10 wt%Ni alloy and Cu-8 wt%Sn alloy solidified from the supercooled melts have been investigated. The growth morphology of a dendrite and the coarsening of dendrite arms have been discussed, and the following results are obtained.
(1) At small or intermediate supercooling, the shape of a dendrite is a cone which consists of a primary stem, secondary stems and ternary stems. At large supercooling, thin dendrites grow isotropically from the nucleation point.
(2) The grain refinement by small supercooling is due to the remelting of dendrites, and the coarse grains formed by intermediate supercooling consist of a dendrite element. At large supercooling, the isotropic growth of thin dendrites causes the grain refinement.
(3) The coarsening of dendrite arms occurs mainly on the ternary or quaternary stems near the grain boundary, and the dendrite arm spacing is nearly proportional to the 1/3 power of the local solidification time as in the case of the unidirectional solidification.抄録全体を表示PDF形式でダウンロード (768K) -
高田 佐太一, 佐久間 健人, 西沢 泰二1977 年 41 巻 8 号 p. 766-772
発行日: 1977年
公開日: 2008/04/04
ジャーナル フリーThe dislocation structure resulting from the diffusion of interstitial carbon in nickel single crystals has been studied by means of electron microscopy. The randomly distributed dislocations accommodating the lattice parameter gradients are observed in the diffusion zone. The results of Burgers vector determination have revealed that a great part of dislocations and their Burgers vectors exist on slip planes. The dislocation structure is quite different from that in substitutional diffusion. This difference is associated with the mechanism of dislocation motion at the diffusion temperature. In the case of interstitial diffusion, the dislocations are likely to transfer by the glide mechanism in the early stages of diffusion. Detailed studies on the change in dislocation structure with diffusing time have made it clear that the annihilation of the dislocations does not occur immediately after the disappearance of the concentration gradient.抄録全体を表示PDF形式でダウンロード (1954K) -
佐久間 健人, 高田 佐太一, 西沢 泰二1977 年 41 巻 8 号 p. 773-777
発行日: 1977年
公開日: 2008/04/04
ジャーナル フリーThe change in stress distribution during interstitial diffusion has been examined in carburized nickel single crystal sheets. It was found that the stress was left in crystals for a fairly long time after the concentration gradient disappeared. The result indicates that the distribution of dislocations in the diffusion zone does not correspond to the stress field due to the concentration gradient. This phenomenon is related to the fact that the motion of dislocations cannot follow the change in stress field due to the interstitial diffusion. The experimental result can be explained satisfactorily by the idea that the climb mechanism controlled the overall rate of dislocations in the diffusion zone.抄録全体を表示PDF形式でダウンロード (670K) -
江島 辰彦, 小笠原 正俊1977 年 41 巻 8 号 p. 778-784
発行日: 1977年
公開日: 2008/04/04
ジャーナル フリーSurface tensions of MgCl2-NaCl and MgCl2-RbCl binary melts have been measured by means of the maximum bubble pressure method over the temperature ranges of liquidus to 935°C. The results obtained are summarized as follows:
(1) For both systems, the surface tension shows an approximately linear decrement with increasing temperature at each composition. The surface tension and its temperature coefficient of molten MgCl2 are relatively low as compared with those of other chlorides, but these are markedly increased by the addition of NaCl or RbCl.
(2) The surface enthalpy per unit area and the surface entropy per unit area are monotonously increased by the addition of NaCl, but show notable inflections at 40 and 70 mol% RbCl in the MgCl2-RbCl system.
(3) The excess surface tension calculated on the basis of a modified Guggenheim equation shows positive values over the entire range of composition in the MgCl2-NaCl system, indicating that this system can be treated as a nearly ideal solution. But in the MgCl2-RbCl system, it shows positive values in the range of 0∼30 mol% RbCl and negative values in the range of 30∼100 mol% RbCl due to the trend of complexation.
(4) When alkali chlorides are added to MgCl2, the behavior of the surface tensions of these systems can be classified into two groups, the system having the cation of smaller ionic radius than that of Mg2+ ion and the one having a larger cationic radius.抄録全体を表示PDF形式でダウンロード (576K) -
江島 辰彦, 岩崎 和春, 斎藤 元治1977 年 41 巻 8 号 p. 784-791
発行日: 1977年
公開日: 2008/04/04
ジャーナル フリーViscosity coefficients of molten MgCl2-KCl and CaCl2-KCl mixtures have been precisely measured by using the oscillating vessel method over the temperature ranges of 590∼880°C and 715∼880°C, respectively. The equation derived by Knappwost was used to calculate the viscosity coefficient from the logarithmic decrement and the oscillating period of the vessel. The results obtained are summarized as follows:
(1) For both systems, the viscosity coefficient shows a negative temperature gradient over the entire range of composition. In the molten CaCl2-KCl system the viscosity coefficient is lowest in pure KCl and increases with increasing CaCl2 content over the entire range of composition. On the other hand, for the MgCl2-KCl system, the composition dependence of viscosity is not monotonous as in the case of the CaCl2-KCl system. The viscosity coefficient does not show any significant change within the composition range of 0∼33 mol% MgCl2, but it increases markedly with increasing MgCl2 content beyond that composition range. The maximum value is obtained at the composition of 80 mol% MgCl2. The temperature gradient of the viscosity coefficient for the MgCl2-KCl system is negative but is not so large as in the case of CaCl2-KCl.
(2) The measured viscosity coefficients of molten KCl and MgCl2 coincide with the values reported by the other investigators, but the value for molten CaCl2 is slightly higher.
(3) The composition dependences of viscosity coefficients, activation energies and other physicochemical properties can well be explained by considering the changes due to the constituent chemical species of these systems.抄録全体を表示PDF形式でダウンロード (642K) -
近崎 充夫, 添野 浩1977 年 41 巻 8 号 p. 791-795
発行日: 1977年
公開日: 2008/04/04
ジャーナル フリーPrecipitation in Fe-20 wt%Cr-25 wt%Ni-(0.41, 0.50, 0.58) wt%Be austenitic steels has been investigated by microscopy and hardness measurement. Besides the homogeneous precipitation, the cellular precipitation is observed. It is also found that the cellular precipitation increases with increasing Be content.
Effects of small amounts of additional elements on the cellular precipitation have been investigated. Cellular precipitation is markedly suppressed by adding a small amount of Nb or Zr. Recrystallization of cold worked Fe-20 wt%Cr-25 wt%Ni austenitic steels containing a small amount of quaternary additional elements has also been investigated. The results show that the elements which raise the recrystallization temperature of the Fe-20 wt%Cr-25 wt%Ni steel have a tendency to suppress the cellular precipitation in the Fe-20 wt%Cr-25 wt%Ni steels containing 0.41 to 0.58 wt%Be.抄録全体を表示PDF形式でダウンロード (495K) -
江口 豊明, 諸住 正太郎1977 年 41 巻 8 号 p. 795-802
発行日: 1977年
公開日: 2008/04/04
ジャーナル フリーDiffusion coefficients of hydrogen in the Group V transition metals, i. e. vanadium, niobium and tantalum, and those in vanadium alloys containing chromium, iron, niobium and titanium were measured in the temperature range of 500∼1100°C by the absorption method. The following results were obtained:
(1) Diffusion data at high temperatures in the Group V transition metals in the present experiment coincided well with data obtained at low temperatures by different methods, e.g. electrical resistivity, etc., but not with data at moderate temperatures measured by the same absorption method.
(2) Below some critical temperature of the metals (540 to 700°C), the values of diffusion coefficient deviated downward from the linearity of Arrhenius plots. This deviation might be attributed to the effect of surface layers, probably oxide films, of the specimens, which would depress the absorption process of hydrogen in the metals.
(3) The diffusion coefficient of hydrogen in vanadium was decreased by alloying chromium, iron or niobium, but increased by addition of 40 at.% titanium.
(4) Variations of the vibrational frequency term, D0, and the activation energy, ΔHD, with the alloy concentration were almost parallel to that of the electric specific heat coefficient so far reported. Therefore, it was concluded that the screening of proton by electrons seemed to play an important role in the diffusion process, as with the case of the solubility of hydrogen in the metals.抄録全体を表示PDF形式でダウンロード (556K) -
家守 伸正, 片山 巖, 幸塚 善作1977 年 41 巻 8 号 p. 803-808
発行日: 1977年
公開日: 2008/04/04
ジャーナル フリーEmf measurements of the following galvanic cells with the solid electrolyte (ZrO2+CaO) were carried out to determine the standard molar free energies of formation of NiO (s), Cu2O (s, l) and CoO (s) from their solid and liquid metals and oxygen gas:
(This article is not displayable. Please see full text pdf.)
\ oindentEmf differences between Cell(I) and Cell(II), Cell(I) and Cell(III) were compared with emf of the following cells:
(This article is not displayable. Please see full text pdf.)
\ oindentThe results were expressed by the following equations:
(This article is not displayable. Please see full text pdf.)
\ oindentThey compared with previously reported values.抄録全体を表示PDF形式でダウンロード (478K) -
岡本 篤彦, 中島 耕一1977 年 41 巻 8 号 p. 808-813
発行日: 1977年
公開日: 2008/04/04
ジャーナル フリーIron and copper single crystals were studied with the aid of the X-ray divergent beam method after various stages of cathodic polarization. The stress-strain analysis of the various stages of hydrogenation disclosed an anisotropy of strain distribution in the matrix. The maximum strain direction of the principal strain was found to coincide with one of the ⟨111⟩ directions for the iron crystal and one of the ⟨100⟩ directions for the copper crystal, respectively. The elastic stored energy occurring during the hydrogen absorption in the matrix increased with charging time. The strain distribution became highly assymmetric with time, especially in iron single crystals. The anisotropy was explained in terms of the formation of platelet segregation of hydrogen atoms in the matrix.抄録全体を表示PDF形式でダウンロード (449K) -
長谷川 英雄, 中島 耕一1977 年 41 巻 8 号 p. 813-820
発行日: 1977年
公開日: 2008/04/04
ジャーナル フリーThe effect of lattice strain on hydrogen diffusion in Pd was investigated in the range of 23∼68°C by an electrochemical method. The solubility of hydrogen in Pd increased slightly due to deformation. The activation energy for hydrogen diffusion was determined to be 5350 cal/mol, which was not affected by deformation. The diffusion coefficient was found to be represented by D=1.32×10−3exp(−5350⁄RT) cm2sec−1 in the annealed state. But it decreased slightly with increasing deformation, suggesting that the interaction energy of hydrogen atoms with trapping sites is very small. Further, the effect of hydrogen on the mechanical properties was examined, and the result showed that the hydrogen content had a strong influence on the mechanical properties; the tensile elongation was increased by addition of hydrogen within the solubility limit, but a further addition of hydrogen resulted in the formation of hydride in the matrix and reduced the tensile elongation. It was found that the effect of hydrogen addition was particularly remarkable in the cold worked state than in the annealed state.抄録全体を表示PDF形式でダウンロード (739K) -
増本 量, 沢谷 昭八, 比内 正勝1977 年 41 巻 8 号 p. 820-823
発行日: 1977年
公開日: 2008/04/04
ジャーナル フリーThe measurements of internal friction Q−1 and mechanical properties have been carried out for open-melted Fe-Mo alloys containing 0∼16%Mo. The Q−1 values linearly increase with the maximum shear strain amplitude εm and decrease after reaching a peak at εm=about 1.2×10−4. This peak heights gradually diminish with increasing tensile load. The Q−1 values are as small as 0.5×10−3 in the cold-worked state, while they are considerably large in the annealed state and increase with annealing temperature. The highest Q−1 value of 58×10−3 is obtained with an Fe-6%Mo alloy annealed at 1200°C for 1 h.
The results obtained indicate that Q−1 increases with measuring temperature and decreases rapidly with external magnetic field. The fairly large value of Q−1 in these alloys are mainly due to the effect of magnetomechanical hysteresis. The mechanical strengths of Fe-Mo alloys increase with Mo content, for example, an Fe-6%Mo alloy shows a tensile strength of 390 MPa and a yield strength of 200 MPa, an elongation of 29% and Vickers hardness 135, when subjected to annealing at 1000°C for 1 h.抄録全体を表示PDF形式でダウンロード (326K) -
辻川 茂男, 久松 敬弘1977 年 41 巻 8 号 p. 823-829
発行日: 1977年
公開日: 2008/04/04
ジャーナル フリーRotary bending fatigue tests of Type 304 steel bars were conducted potentiostatically in 1 N H2SO4 solution containing 0.5 M NaCl at 25°C. Under the stress amplitude of 14.6 kg/mm2 which is lower than the fatigue limit in air, growing cracks that lead smooth specimens to failure initiated at the three potential zones: I (near the corrosion potential), II (the active-passive transition region) and III (the pitting region), each of which has been known as the potential range over which stress corrosion cracking might be expected to occur. Cracks are found to initiate from a surface which is dissolving. Zones I and II determined on the basis of the fracture tests using smooth specimens are the potential ranges where the growth of cracks over a depth, l*\simeq30∼40 μm, can be secured. Then, l* is considered to be the critical depth for the initiation of growing cracks, and the crack growth rate at the depth of l*, \dotl(l*), to be that of initiating cracks. The relation, I(hkl)≤\dotl(l*), seems to be a quantitative requirement for the active dissolution rate on {hkl} planes, I(hkl), for crack initiation. In the potential range where higher cracking tendencies were observed there is a clear indication of the (100) faceting dissolution on the crack surfaces. Initiating cracks penetrate along {100} planes in the surface grains. In the later stages, also, cracking was found to follow crystallographic paths.抄録全体を表示PDF形式でダウンロード (749K) -
辻川 茂男, 久松 敬弘1977 年 41 巻 8 号 p. 829-837
発行日: 1977年
公開日: 2008/04/04
ジャーナル フリーRotary bending fatigue tests of Type 304 steel in 1 N H2SO4 containing 0.5 M NaCl at 25°C were conducted in order to study the corrosion crack initiation at the site of a growing pit, in comparison with that in the active potential range. Cracks are found to initiate even at a potential of 0.42 V which is more noble than the critical pitting potential, Vc=0.41 V (SCE). In the study of the crack initiation at the pits growing at the potentials less noble than Vc, the following procedures were adopted. The precracks with appropriate depths, which had been introduced into the specimen at −0.45 V, developed into hemispherical pits and continued to grow at the passive potentials. Such growing pits are considered to be equivalent to the natural pits growing in the same potential range. The occurrence of crack initiation at the bottom of the growing pits increased markedly in the potential range between 0.1 and 0.3 V under the condition of potential descent at the sweep rate of 240 min/V. The fact that the less noble the potential the less deep pits issue cracks could be explained from the requirement that initiating crack must have a growth rate higher than the dissolution rate at the pit bottom. The initiation sites of cracks were observed to be small crystallographic pits with mixed facets of {111} and {100} formed at the bottom of growing pits during the potential descent. The (100) faceting dissolution at the wall of crystallographic pits would play an important role in crack initiation, as it does in crack initiation in the active potential range.抄録全体を表示PDF形式でダウンロード (1255K) -
井垣 謙三, 西根 士郎1977 年 41 巻 8 号 p. 837-843
発行日: 1977年
公開日: 2008/04/04
ジャーナル フリーThe pressure-composition-temperature relations for niobium selenides NbSex were determined by annealing under controlled selenium vapor pressure in the composition range x=1.48∼2.00. Five phases were confirmed. Single crystals of these phases were grown by the chemical transport method, and their structures were determined by X-ray diffraction. Their ranges of stability are:
(1) Hexagonal 4 H phase: above 5 Torr Se2 partial pressure at 900°C for x=2.00.
(2) The phase below 5 Torr Se2 partial pressure for x=1.99∼2.00 is a 2 H structure but probably different from 2 H (b) structure proposed by F. Jellinek, designated as 2 H (β).
(3) Rhombohedral 3 R phase: 1.80<x<1.86 at 1000°C and 1.79<x<1.91 at 900°C.
(4) Hexagonal 2 H (a) phase: 1.68<x<1.82 at 1100°C and 1.66<x<1.76 at 1000°C.
(5) Monoclinic Nb2Se3 phase: 1.48<x<1.52 at 1100°C and 1000°C.
Within the stability range of the 3 R and 2 H (a) phases, the composition varies with Se2 pressure. These variations can be explained on statistical thermodynamic grounds by assuming that excess Nb atoms randomly occupy the octahedral interstitial sites of a stoichiometric NbSe2 structure.抄録全体を表示PDF形式でダウンロード (793K) -
井垣 謙三, 西根 士郎1977 年 41 巻 8 号 p. 843-849
発行日: 1977年
公開日: 2008/04/04
ジャーナル フリーSingle crystals with controlled composition were prepared at varying selenium vapor pressures. The relations between composition and electrical properties-resistivity and superconducting transition temperature- were studied:
(1) In the defect structures of 2 H(β) and 4 H phases, both interstitial Nb atoms and Nb vacancies are considered to exist, and from the residual resistivity ratio (RRR) it is concluded that Nb interstitials predominate at low selenium pressures, and Nb vacancies predominate at high selenium pressures. The pressure of Se2 corresponding to the stoichiometric composition of the 4 H phase is about 102 Torr at 900°C, and that of the 2 H(β) phase is about 102 Torr at 1000°C. The superconducting transition temperature shows a maximum of 6.61 K for the 4 H phase and 7.60 K for the 2 H(β) phase at the stoichiometric composition, and these transition temperatures decrease as the composition deviates in either way from stoichiometry.
(2) In the 3 R and 2 H(a) phases, no superconducting transition is observed down to 1.6 K because of the large concentration of defects (mainly Nb interstitials).
(3) In the Nb2Se3 phase, the measurement of RRR shows that Nb interstitials predominate at low selenium pressures and Nb vacancies predominate at high selenium pressures. The superconducting transition temperatures show a maximum of 2.47 K at the stoichiometric composition, and transition temperatures decrease with increasing deviation from stoichiometry.抄録全体を表示PDF形式でダウンロード (512K)
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