巻号一覧
43 巻, 6 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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増本 量, 沢谷 昭八, 比内 正勝1979 年 43 巻 6 号 p. 471-474
発行日: 1979年
公開日: 2008/04/04
ジャーナル フリーThe internal friction Q−1 was measured by an inverted torsion pendulum for Fe-Cr alloys containing 0∼35%Cr. The measured frequency and the maximum shear strain amplitude γm were 1.1 Hz, and 0.7∼167×10−6, respectively. Generally, the Q−1 value first increases gradually with increasing γm and then sharply increases. In the case of alloys heated at 1200°C, Q−1 goes through a maximum and then decreases.
In Fe-Cr alloys slowly-cooled after heating at 800∼1200°C, the Q−1 value shows two maxima at the compositions of 5%Cr and 15%Cr and increases with increasing heating temperature. An Fe-15%Cr alloy exhibits the highest Q−1 value of 68×10−3 (γm=80×10−6) when slowly-cooled after heating at 1200°C. Besides, the Q−1 value in the rapidly-cooled state shows a maximum only at the composition of 20%Cr.
The variation in the rigidity modulus G with γm is quite similar to that of Q−1. Therefore, fairly large values of Q−1 in Fe-Cr alloys are probably attributable to magnetomechanical hysteresis.抄録全体を表示PDF形式でダウンロード (293K) -
木原 諄二, 鳥阪 泰憲1979 年 43 巻 6 号 p. 474-479
発行日: 1979年
公開日: 2008/04/04
ジャーナル フリーThe strain-tempering by direct electrical resistance heating (heating time=0.25 s) was performed on the cold drawn wire of prestressed concrete steel.
Stress relaxation decreases without impairing of the mechanical properties such as total elongation, reduction of area, ultimate tensile strength and proof stress up to a strain-tempering temperature of 598 K.
It is assumed that the improvement in relaxation behaviour by strain-tempering is not mainly due to the strain aging by free C and N, but due to microscopic structure change generated by strain tempering stress with some thermal energy.抄録全体を表示PDF形式でダウンロード (428K) -
永井 宏, 村井 照幸, 岡林 真, 三谷 裕康1979 年 43 巻 6 号 p. 479-485
発行日: 1979年
公開日: 2008/04/04
ジャーナル フリーThe isothermal oxidation behavior of Fe-20Cr alloys with addition of 0.1,0.2,0.5,0.7,1.0 and 1.4 wt%Y was studied in air over the temperature range of 1273∼1373 K by weight gain measurement, scanning electron microscopy, X-ray diffraction, electron probe microanalysis and ion microanalysis.
It was found that 0.1%Y addition or more increased oxidation resistance at 1273 K and 0.7%Y or more remarkably at 1323 and 1373 K compared to the base Fe-20Cr binary alloy. Generally an addition of 0.7%Y gave the best improvement in the oxidation resistance. Cr2O3 was the major oxide formed on the alloys which exhibited a good oxidation resistance. Internal oxidation layer of Y2O3 was observed beneath the Cr2O3 scale of Y containing alloys. The growth of internal oxidation layer depth obeyed a parabolic rate law and the rate increased with increasing oxidation temperature and decreased with increasing Y content in the alloys.
The ion microanalyser was used to analyse Y2O3 and Fe2O3 contents in Cr2O3 scales formed on Fe-20Cr-Y alloys after 1h oxidation. Y2O3 content increased, while Fe2O3 content remarkably decreased with increasing Y content in the alloy and slightly increased again over 0.7%Y. The Fe2O3 content in the scale formed after 1h oxidation and the weight gain of Fe-20Cr-Y alloys after 20h oxidation showed the same dependency on Y content in the alloys.
The improvement effects of Y addition on the oxidation resistance of Fe-20Cr alloy were discussed from the view points of stabilization of Cr2O3 with dissolving Y2O3 and enrichment of internally oxidized particles beneath the scale.抄録全体を表示PDF形式でダウンロード (733K) -
小松 周一, 中村 新一, 中橋 昌子1979 年 43 巻 6 号 p. 485-491
発行日: 1979年
公開日: 2008/04/04
ジャーナル フリーH-shaped carbides precipitated in Cr-Mo-V steel were studied by electron microscopy and X-ray energy spectrometry. The results show that carbides consist of two different types, granular and needle-like carbides. The former carbide was V4C3 and the latter was Mo2C. The Mo2C precipitated on {111} habit planes of V4C3 with the orientation relationships (00.1)Mo2C\varparallel(\bar111)V4C3 and [10.0]Mo2C\varparallel[110]V4C3. In this steel, various Mo2C-V4C3 carbides were observed. When V4C3 has a pair of the Mo2C needles, it is H-shaped, because the Mo2C needles grow in parallel on the opposite {111}V4C3 planes such as (1\bar11)V4C3 and (\bar11\bar1)V4C3. When V4C3 has two pairs of the needles, it shows a #-shaped feature because of the two paralleld pairs.
The growing direction of the Mo2C in the matrix seemed to have some relevance to the extent of the misfit between Mo2C and matrix.
It was also clarified by the creep rupture test that Mo2C-V4C3 carbides were thermally stable during the creep rupture test.抄録全体を表示PDF形式でダウンロード (1118K) -
高橋 平七郎, 竹山 太郎, 原 敬道1979 年 43 巻 6 号 p. 492-499
発行日: 1979年
公開日: 2008/04/04
ジャーナル フリーAn Investigation of the nucleation sites and the structures of microvoids and microcrack formed in iron poly-crystal and single crystal in the process of the precipitation of hydrogen molecules was carried out by means of scanning and transmission electron microscopy.
Hydrogen molecules precipitated in the metal and caused it to expand to form blisters or cracks on the specimen surface during cathodic charging. The frequency of the blister nucleation was increased by the introduction of plastic strain. Besides microvoids, microcracks which were seemed to be generated as a result of the void growing were observed at greater depths in the metal membrane. In the vicinity of the microvoids, plastic deformation occurred with a consequent increase in high dislocation density and slip bands initiated from the voids along either {110} or {112} planes. Furthermore, in iron polycrystalline, microcracks were also generated at grain boundaries and the interfaces of the crack consisted of zigzag steps on {110} or {112} planes besides the interface dislocations.
The above results show that hydrogen atoms supersaturated would be preferentially absorbed on dislocations and/or grain boundary, and then microvoids and microcracks with {110} or {112} crack interface would be formed by the hydrogen precipitation as molecules.抄録全体を表示PDF形式でダウンロード (1594K) -
松田 勝彦, 真嶋 宏1979 年 43 巻 6 号 p. 499-505
発行日: 1979年
公開日: 2008/04/04
ジャーナル フリーThe dependence of the apparent rate constant on the initial concentration of cupric ions and the effect of the peeling-off of cemented copper on the rate constant have been studied experimentally. Rate curves were measured by means of a specific cupric ion electrode referred to a saturated calomel electrode. Also, the diffusion flux of cupric ions was analyzed as functions of reaction time and cupric ion concentration.
The rate curve for copper cementation consists of three portions : an initial linear stage, a final linear stage, and a transitional portion between these two stages. The amount of cemented copper, whose protrusion can decrease the diffusion path length of cupric ions, was found to be independent of the initial concentration of cupric ions. The diffusion flux, which is closely related to the initial cupric ion concentration, decreases exponentially at the initial stage of the reaction and then increases abruptly at the starting point of the transition stage, followed by the initiation of peeling-off of the cemented copper. Further, the lapse of time cause the decrease of the flux.
The rate constant should be independent of the initial concentration of the cupric ion. Nevertheless, the final rate constants appeared to depend on the initial cupric ion concentration, whereas no such a dependence was observed for the initial stage. On the other hand, the amount of peeled-off copper exhibits a similar tendency to the final rate constants. The effect of initial concentration on the final rate constant might be attributed to the hydrodynamic turbulence in a boundary layer.抄録全体を表示PDF形式でダウンロード (599K) -
増本 量, 村上 雄悦, 中村 直司1979 年 43 巻 6 号 p. 506-513
発行日: 1979年
公開日: 2008/04/04
ジャーナル フリーMagnetic properties, electrical resistivity and hardness were studied on Fe-Mo alloys containing less than 14.1%Mo and Fe-W alloys containing less than 13.8%W. All the alloys used in this study were water quenched from various temperatures at 900∼1200°C, cold drawn by more than 50% reductions in area, and then reheated at 400∼1000°C for less than 5 h.
The results indicated that the magnetic properties of those alloys depended remarkably on the concentration of added Mo or W, the quenching temperature, the reduction rate, the reheating temperature and the reheating time. An Fe-10.2%Mo alloy reheated at 800°C for 30 min after water quenching from 1000°C and subsequent cold drawing of 97.2% reduction exhibited the following values: B8=1.62 T at 8 kA·m−1, Br=1.49 T, Br⁄B8=0.92, Hc=1.91 kA·m−1, \sqrt(BH)max⁄BrHc=0.83, ρ=0.251 μΩ·m and Hv=290. Also, an Fe-10.2%W alloy reheated at 700°C for 60 min after water quenching from 1000°C and subsequent cold drawing of 97.2% reduction exhibited the following values: B8=1.79 T, Br=1.71 T, Br⁄B8=0.95, Hc=1.75 kA·m−1, \sqrt(BH)max⁄BrHc=0.86, ρ=0.215 μΩ·m and Hv=275.抄録全体を表示PDF形式でダウンロード (924K) -
沢本 章, 林 安徳, 大谷 南海男1979 年 43 巻 6 号 p. 513-519
発行日: 1979年
公開日: 2008/04/04
ジャーナル フリーDamaging of materials by hydrogen absorption cannot be overlooked in considering the influence of hydrogen on the mechanical properties of iron and steels. In the present work the mechanical properties of steel specimens, with various carbon contents and heat treatments, were examined paying attention to damage by charging of hydrogen. Stress relaxation and creep tests were carried out during electrochemical charging of hydrogen.
The results were discussed referring to the direct observations of the surface and interior of the specimens, and to the amount of hydrogen extracted in glycerine. Soft materials, i.e. low carbon and annealed ones, are easily damaged by hydrogen charging; even with an applied stress far below the yield stress, the stress relaxation and creep elongation by hydrogen charging are markedly observed. The damage is accompanied with slip deformation due to the activation of the dislocation sources by charging of hydrogen. The amount of hydrogen stored in the defects formed by hydrogen charging is, therefore, considerable in the soft materials.抄録全体を表示PDF形式でダウンロード (755K) -
名越 敏郎, 林 安徳, 大谷 南海男1979 年 43 巻 6 号 p. 520-526
発行日: 1979年
公開日: 2008/04/04
ジャーナル フリーA. C. impedance measurements were applied to study the anodic behavior of Ni rich alloys in connection with their corrosion resistance. The impedance of Ni rich alloy electrodes in the potential regions of active, passive and transpassive states was measured in a 0.1N H2SO4 solution over a wide range of frequencies, 10−2 to 10−4 Hz. Electrical circuits equivalent to the electrode kinetics were estimated from the results either in the from of a parallel RC circuit or in the form of a series connection of two parallel RC circuits or in the form of a parallel RCL circuit. The corrosion resistance of the materials used was discussed in terms of the equivalent electrical parameters corresponding to the anodic dissolution process. Alloying Ni with Cr was revealed to be more effective for the resistance to corrosion in the active and passive states than alloying Ni with Fe, Co and Cu. In the transpassive state, however, alloying Ni with Cr has no effect on the resistance to corrosion.抄録全体を表示PDF形式でダウンロード (537K) -
榊 孝, 崎山 和孝1979 年 43 巻 6 号 p. 527-531
発行日: 1979年
公開日: 2008/04/04
ジャーナル フリーA series of polarization and immersion tests on iron-chromium alloys with varing chromium contents were carried out in 48%-NaOH solution at various temperatures and the results obtained are summarized as follows.
(1) The dissolution at acitive state decreases with increasing chromium content in alloys and does not occur when the chromium content is over 13% at 100°C and 24% at 140°C. (2) On increasing chromium content, the dissolution as FeO2− ion decreases. (3) At higher potentials, chromium in alloys easily dissolves as CrO42− ion and have no effect to inhibit the dissolution of iron in alloys. (4) Natural electrode potential of alloys containing up to 13%Cr are about Eh=−0.9 V. At 140°C, the natural electrode potential of a 18%Cr-Fe alloy shows a low potential of active state. (5) The corrosion rate logarithmically increases with increasing temperature. (6) The corrosion resistance severly increases with increasing Cr content over 25%. Especially, a 30%Cr-Fe alloy shows excellent resistance.抄録全体を表示PDF形式でダウンロード (356K) -
美馬 源次郎, 猪子 富久治, 安宅 健1979 年 43 巻 6 号 p. 531-537
発行日: 1979年
公開日: 2008/04/04
ジャーナル フリーIn order to examine the controlling factors for the initiation of fatigue cracks along crystal boundaries, four samples of aluminum bicrystals were tested by the bending fatigue testing machine under constant strain amplitude 0.2% and cyclic frequencies of 30.4 Hz.
It has been confirmed that the initiation of the fatigue cracks along the crystal boundaries occurs under the following condition: (a) the planes of the crystal boundaries are {111}. (b) the slip bands which correspond to either the primary slip system or the secondary one, are remarkably activated along the boundaries. On the other hand, it may be recognized that the magnitude of twist angle on the boundaries was not a dominant factor. It has a tendency for the fatiuge cracks to initiate earlier along these boundaries than in component crystals.抄録全体を表示PDF形式でダウンロード (712K) -
長村 光造, 村上 陽太郎1979 年 43 巻 6 号 p. 537-545
発行日: 1979年
公開日: 2008/04/04
ジャーナル フリーAbsolute small angle X-ray scattering (SAXS) measurement was performed for the aged Al-Zn alloys for 60 to 180 ks at room temperature and for 60 ks at 373 K. Assuming the log-normal size distribution, the mean radius and the standard deviation were calculated from the observed Guinier and Porod Radii. The mean radius changed from 1.3 to 3.4 nm depending on the alloy concentration in the alloys with the composition of 2.0 to 10.0 at%Zn. The average standard deviation was 1.26 and 1.20 at room temperature and 373 K, respectively. Absolute integrated intensity was used to determine the solute concentrations (m1 and m2) in and outside the zones by considering the correction of the atomic size. Results followed as m1=0.721 and m2=0.0175 at room temperature, and m1=0.706 and m2=0.031 at 373 K, respectively. The correlation function, which means the convolution against the fluctuation of electron density in the space, was derived from the experimental scattering intensity. Its function was well explained by the theoretical values calculated on the basis of the two phase model. The week maximum appeared in the radial distance of 10 to 20 nm was suggested to correspond to the nearest interparticle interference.抄録全体を表示PDF形式でダウンロード (733K) -
三木 雅道, 天野 嘉次1979 年 43 巻 6 号 p. 545-550
発行日: 1979年
公開日: 2008/04/04
ジャーナル フリーThe characteristics of the grain boundary reaction in Cu-30%Ni-0.5%Be alloy aged isothermally at temperatures of 673 to 873 K after water quenching from 1323 K were investigated by optical and electron microscopic observations, hardness measurements and the X-ray diffraction method. The results obtained are as follows:
(1) The incubation periods were observed in the nodule increase curves, and then the nodule increased rapidly along with the second stage of hardening due to the precipitation of the γ′ phase in the matrix and engulfed the matrix entirely. It is considered that the increase of the lattice strain in the matrix due to the precipitation of the γ′ phase acts mainly as a driving force for nodule growth.
(2) The pearlitic structure which consisted of the equilibrium α phase and the equilibrium γ phase (NiBe) was observed in the nodule from the time of nodule formation and scarecely changed with the progress of aging.
(3) The amount of the nodule, X, could be represented by Johnson-Mehl’s equation: X=1−exp(−btn), where t is the aging time and b and n are constants, and 1.5∼1.1 were obtained as the n’s value.
(4) The value of apparent activation energy for nodule growth was about 185 kJ/mol (44 kcal/mol).抄録全体を表示PDF形式でダウンロード (757K) -
三木 雅道, 天野 嘉次1979 年 43 巻 6 号 p. 551-557
発行日: 1979年
公開日: 2008/04/04
ジャーナル フリーThe characteristics of the grain boundary reaction in Cu-30%Ni-2∼3%Al alloys aged isothermally at temperatures of 623 to 973 K after water quenching from 1323 K were investigated by optical and electron microscopy, hardness measurement and the X-ray diffraction method. The results obtained are as follows:
(1) The nodule began to grow prior to the beginning of hardening of the matrix, and almost stopped to grow under the influence of a rapid increase of the wavelength of the modulated structure in the matrix and did not engulf the matrix entirely.
(2) At the early stage of aging, a light and shade structure with fiber-shaped θ phases which waved periodically was observed in the nodule, and at the later stage of aging, this structure changed to the structure with granuler θ phases. Also the lattice parameter of α phase in the nodule changed with the progress of aging.
(3) The amount of the nodule, X, could be represented by Johnson-Mehl’s equation: X=1−exp(−btn), where t is the aging time and b and n are constants, n’s value being about 0.6 at each aging temperature.
(4) The apparent activation energy for nodule growth was about 130 kJ/mol (31 kcal/mol).抄録全体を表示PDF形式でダウンロード (993K) -
浅岡 憲三, 三浦 維四1979 年 43 巻 6 号 p. 557-562
発行日: 1979年
公開日: 2008/04/04
ジャーナル フリーTensile deformation of the composite alloys was studied macroscopically by the elastic-plastic finite element simulation. The stress-strain curves, tensile strength, elongation at fracture, and the change of the stress distribution as the increasing load were then calculated from the mechanical properties of the constituents of the composite alloys. And, the relation between the volume fraction of the second phase and the tensile deformation of the composite alloys was studied.
The sintered composition of tungusten carbide and cobalt have a simple microstructure consisting of particles of WC dispersed in the matrix of a Co. There is a great disparity in the mechanical properties between these constituents. So, simulation was computed for the tensile deformation of WC-Co alloys, and the results were compared with the experimental data. For the Young’s modulus and stress-strain curves, simulation showed good agreement with the experimental results in every volume fraction. The tensile strength, the elongation at fracture, and the initial fracture phase were calculated by this simulation, and the results agreed well with the experimental data of Nishimatsu-Gurland. It was concluded that the macroscopical deformation and fracture of the composite alloys can be estimated with good accuracy by this method.抄録全体を表示PDF形式でダウンロード (579K) -
田岡 忠美, 中島 文夫, 平野 豊, 片岡 宏久, 有田 一敏, 越 章夫1979 年 43 巻 6 号 p. 563-568
発行日: 1979年
公開日: 2008/04/04
ジャーナル フリーA hard tension/compression tester has been constructed in the specimen holder of a high temperature microscope, without any interference with the functional features of the microscope including the side-entry goniostage. A noticeable advantage of the microscope was the in-situ observation of metallurgical phenomena at every stage of the load-elongation curves at high temperatures. The specific features are as follows:
(1) The standard specimen for tension/compression test is 5 mm in gauge length, 2 mm in width and 0.5∼1 mm in thickness.
(2) The maximum load is 100 kg.
(3) The maximum stroke is 5 mm.
(4) The cross head displacement speed is kept at the given value in six steps such as 0.025,0.020,0.015,0.010,0.005 and 0.0025 mm/s during elongation of specimens, independently of changing load.
(5) The spring constant of the tester is estimated larger than 700 kg/mm or 7×106 N/m
This tester was successfully applied to observing and recoding metallugical phenomena such as formation of the strain-induced martensite at 250°C in Fe-22%Ni alloy and the giant slip bands at 450°C during the serrated elongation of Cu-10 at%Al single crystal.抄録全体を表示PDF形式でダウンロード (1006K) -
相根 博道, 沖 憲典1979 年 43 巻 6 号 p. 569-575
発行日: 1979年
公開日: 2008/04/04
ジャーナル フリーThermodynamic implication of the equibrium phase diagram for order-disorder phase transitions in Fe-Al alloy has been investigated by a statistical approach employing the Bragg-Williams approximation, in which the magnetic interactions are taken into account in the first and the second nearest neighbor iron atoms as well as the usual atomic interactions up to the second nearest neighbors. It is shown in the calculated diagram that the appearance of the two-phase field with α and B2 phases is caused by the competition of both the magnetic and atomic interactions, with a ferromagnetic interaction between the nearest neighbor iron atoms and an antiferromagnetic interaction between the second nearest neighbor iron atoms. It is also suggested from the inflection of the configurational free energy curve that spinodal decomposition is expected within the two-phase field with α and B2 phases in accordance with the result of our previous experimental observation.抄録全体を表示PDF形式でダウンロード (502K)
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