日本金属学会誌
Online ISSN : 1880-6880
Print ISSN : 0021-4876
ISSN-L : 0021-4876
41 巻, 9 号
選択された号の論文の17件中1~17を表示しています
  • 三輪 敬之, 小野 秀隆
    1977 年 41 巻 9 号 p. 851-855
    発行日: 1977年
    公開日: 2008/04/04
    ジャーナル フリー
    The TTA (Time-Temperature-Austenitization) diagram was determined for a commercial pure iron, an eutectoid steel and various hypo-eutectoid steels (0.1, 0.4 and 0.6% carbon), using a newly designed experimental apparatus previously reported.
    It has been observed that in the TTA diagram the starting time of the transformation shifts to the left side with the increased over-heating and finally reaches 0 sec at 950°C in the commercial pure iron, and at 840°C in the hypo-eutectoid and eutectoid steels. Therefore there exists an upper limiting temperature at the zero-time axis that coincides with the upper limit of the transformation start on super-rapid heating.
    The transformation finish line with the degree of over-heating in the hypo-eutectoid steel shifts to the left side above Ae3, but it does not show the same behaviour below Ae3; in other words, there is a refraction point at the Ae3 point. It follows that the shape of the finish line in hypo-eutectoid steel is different from those in pure iron and eutectoid steel.
  • 大内 義昭, 加藤 栄一
    1977 年 41 巻 9 号 p. 855-865
    発行日: 1977年
    公開日: 2008/04/04
    ジャーナル フリー
    The Knudsen cell-mass spectrometer combination is used to study the thermodynamic properties of liquid PbO-SiO2, PbO-CaO-SiO2, PbO-MgO-SiO2, PbO-BaO-SiO2, PbO-NiO-SiO2, and PbO-CoO-SiO2 systems. First, the activities of PbO in binary melts are determined in the temperature range from 800 to 1020°C by application of the monomer-dimer technique. The results obtained are in good agreement with the previous results obtained by other methods. Second, the ratios of the activities of PbO in the ternary silicate melts containing 50 mol% SiO2 to that in the corresponding binary silicate melt are determined by the same technique in the temperature range from 1050 to 1250°C.
    The obtained results are discussed on the basis of the thermodynamic model of silicate melts derived by the application of a quasi-chemical treatment to the random network model of silicates. The results obtained indicate that the standard free energy change of reaction (1) of a ternary melt is not
    (This article is not displayable. Please see full text pdf.)
    \ oindentgiven by the arithmatic mean of those of the parent binary melts. The activity ratios obtained from PbO-BaO-SiO2 and PbO-NiO-SiO2 melts are compared with viscosities and activation energies of viscous flow of these melts on the basis of the model mentioned above. The behavior of these properties of these melts below XBaO or XNiO=0.10 indicates that the silicate ions in these melts are more highly depolymerized than in the corresponding binary PbO-SiO2 melts, and consequently NiO in the ternary melt is apparently more basic than PbO in the melt in contrast with NiO which is more acidic than PbO in binary silicate melts. The apparent changes of basicities of basic oxides in the other ternary melts are also discussed.
  • 大内 義昭, 吉田 俊明, 加藤 栄一
    1977 年 41 巻 9 号 p. 865-874
    発行日: 1977年
    公開日: 2008/04/04
    ジャーナル フリー
    The densities of melts in the PbO-MgO-SiO2, PbO-CaO-SiO2, PbO-SrO-SiO2, PbO-BaO-SiO2 and PbO-NiO-SiO2 systems containing 33 and 50 mol% SiO2 have been measured in the temperature range from 1000 to 1200°C. The Archimedean method was applied, and buoyancy measurement was carried out for each melt with both a small and a large bob. The measurement with a large bob was also carried out. The results obtained are summarized as follows:
    There is little deviation from the additivity in the molar volume of melts for the pseudo binary systems PbO·SiO2-MgO·SiO2, PbO·SiO2-CaO·SiO2, PbO·SiO2-SrO·SiO2, PbO·SiO2-BaO·SiO2 and 2PbO·SiO2-2CaO·SiO2. Each of the Mg, Ca, Sr and Ba systems containing 33 and 55% SiO2, shows a linear relationship between the molar volume of the melts and the cube of the cation radius. The same relationship holds for the Ni system containing 50 mol% SiO2. The molar volumes of PbO-SiO2 melts containing 33 and 50 mol% SiO2 shift from the linear relationship to high molar volumes.
    The results obtained are discussed on the basis of the thermodynamic model of silicate melts derived by the application of a quasi-chemical treatment to the random network model of silicates. It is shown that in the systems containing alkali earth metal oxide the accommodation of metal cations within the structure of lead silicate melts has direct effects upon the molar volume of these melts. It is also deduced from the results that the decrease of the oxygen density caused by the depolymerization of silicate anions has no effect upon the molar volume of these melts. In the PbO-NiO-SiO2 system containing 50 mol% SiO2, NiO in the silicate melts is found to behave as if it were an alkali earth metal oxide. The behavior of NiO agrees very well with that anticipated from the results of activity and viscosity measurements.
  • 関根 和喜
    1977 年 41 巻 9 号 p. 874-882
    発行日: 1977年
    公開日: 2008/04/04
    ジャーナル フリー
    The Cosserat medium supporting the asymmetric stresses and couple stresses and having a rigid microstructure was employed as a continuum model of crystals deforming by slip and rotations. And, a new theory of crystal plasticity, generalizing the maximum external work and minimum internal work principles of Bishop-Hill, was formulated on the basis of the Cosserat theory. The method for obtaining the solution of lattice rotations under constrained plastic deformation was introduced by using a mathematical technique of non-linear optimization problems. The proposed theory was applied to predict the development of shear deformation texture in fcc metals. Finally, the physical mechanism of lattice rotations during plastic deformation was discussed in terms of the concept of disclinations which are rotational type of Volterra’s dislocations.
  • 野口 文男, 植田 安昭, 柳ヶ瀬 勉
    1977 年 41 巻 9 号 p. 883-889
    発行日: 1977年
    公開日: 2008/04/04
    ジャーナル フリー
    The mechanism of CaO dissolution into molten slag was studied by applying the hot-filament method to melt about 5 mg of slag samples on the electrically heated Pt-Rh filament.
    The results indicate that the molten slag migrates between the CaO crystal and a newly formed 2 CaO·SiO2 layer through the cracks as seen in CaO-SiO2 system. In the case of higher Fe2O3 content, the layers of the compounds 2 CaO·SiO2 and 3 CaO·SiO2 formed around the CaO crystal were not continuous but looked more like particles, which promoted the dissolution of CaO. In the case of higher MgO content (30% CaO-50% SiO2-20% MgO), no compound layer was observed on the CaO crystal, and Akermanite was formed around CaO in only the quenched sample.
    The effect of additions of chlorides (MgCl2, CaCl2, LiCl, NaCl) upon the dissolution rate of CaO was studied in the CaO-SiO2 system. The results have revealed that among the chlorides, MgCl2 is most effective in breaking the compound layer formed arround CaO, but less in extent than CaF2 addition.
  • 岸 輝雄, 榊原 安英, 小幡 義彦, 堀内 良
    1977 年 41 巻 9 号 p. 890-897
    発行日: 1977年
    公開日: 2008/04/04
    ジャーナル フリー
    An experimental estimate was made of the amplitude distribution for acoustic emission peak due to the Bauschinger effect. It was found that the backward yielding occured inhomogeneously during the strain region of this Bauschinger AE peak region and the number of backward yielding sites could be given by analysing the peak profile. From these results, a new method was proposed to obtain the mean back stress component in flow stress, which controls the Bauschinger effect and/or fatigue hardening. The obtained mean back stress was 15∼16% of the flow stress in Al and Cu, 22% in α-Brass and 37% in SUS 304, independent of the amount of pre-strain and strain rate. The same experimental result on the mean back stress was obtained in single crystals. The low temperature annealing resulted in an decrease of the mean back stress without affecting other hardening causes. It can be suggested that the origin of back stress is connected with the primary slip dislocations around some inhomogeneities such as cell boundaries, sessile dislocations and precipitates.
  • 岸 輝雄, 加藤 明, 栗林 一彦, 堀内 良
    1977 年 41 巻 9 号 p. 897-904
    発行日: 1977年
    公開日: 2008/04/04
    ジャーナル フリー
    The amplitude distribution of acoustic emission due to plastic deformation was studied in relation to deformation properties of Al, Cu, Al-Mg, Al-Si, α-Brass, α-Fe and SUS 304. The integrated distribution function of AE amplitudes can be given by
    (This article is not displayable. Please see full text pdf.)
    \ oindentwhere I(Vt) shows the cumulative number of ringdown countings, whose amplitude are equal to or greater than a given threshold voltage Vt, m and k are constants defined as the threshold exponent and the threshold pre-exponent respectively. The threshold exponents may be classified to three categories: 0.5, 1 and 2, respectively. The case of m=2, which represents Gaussian distribution, was observed in high purity Cu and Al, and corresponds to the so-called continuous-type of AE. The case of m=0.5, on the other hand, corresponds to the burst-type of AE and was observed in SUS 304 and Al-Si alloy. The case of m=1 shows the mixture mode of continuous and burst-type of AE, and was observed in Al-Mg, α-Brass and α-Fe.
    These threshold exponent m values are strongly connected with the metallurgical factors, which control the flow deformation, such as Peierls potential, solute atoms, dispersion particles, and stacking fault energy. The variation of m values between 0.5 and 2.0 can be explained by simple AE models, characterized by the terms of stress concentration and the frictional stress.
    The stress concentration (elastic stored energy) controls the magnitude of discontinuos deformation. The frictional stress controls the relaxation rate of the energy release.
  • 川勝 一郎, 北山 誠二
    1977 年 41 巻 9 号 p. 904-911
    発行日: 1977年
    公開日: 2008/04/04
    ジャーナル フリー
    For the diffusion bonding of stainless steel used with Ni-P plating in place of insert metal, the weldability and the relation between bonding processes and bonding strength for various bonding times have been investigated. The results obtained are as follows:
    (1) Bonding processes are classified into two stages according to the microstructure. The first stage depends on the decreasing phenomena of Ni-Ni3P eutectic structure and the formation of an intermetallic compound at the bonded zone. On the second stage, intermetallic compound can be seen and chemical composition in the bonded zone is homogenized gradually.
    (2) Weldability of bonded joints between similar metals at 880°C is not so good, but the bonding strength increased with bonding time gradually.
    (3) In the case of SUS 304-DCuP 1 joints and SUS 430-DCuP 1 joints, their weldabilities are better than those of SUS 304 and SUS 430 joints. The bonding strength of SUS 304-DCuP 1 joints bonded at 900°C for 30 min is 23∼25 kg/mm2 and that of SUS 430-DCuP 1 joints bonded at 900°C for 30 min is 18∼20 kg/mm2.
    (4) In the case of SUS 430 joints, the diffusion phenomenon of phosphorus into the base metal was observed and many intermetallic compounds were formed in the bonded zone. The bonding strength in this case is weaker than that of SUS 304 joints.
  • 矢畑 昇, 葉山 房夫
    1977 年 41 巻 9 号 p. 912-919
    発行日: 1977年
    公開日: 2008/04/04
    ジャーナル フリー
    The nature and mechanism of the formation of the hard patch formed on the rubbed surface of carbon steels under a moderate sliding condition in air have been studied.
    The results obtained are as follows:
    (1) The hardness of the hard patch increased with carbon content, and this change with tempering temperature decreased more slowly than the conventional martensite.
    (2) In general the hard patch contained fine oxide fragments. The hard patch was not observed in pure iron and austenitic stainless steel unhardened by the normal heat treatment.
    (3) The hard patch formed a sharp boundary with the substrate, but electron microscopy revealed that the transition was continuous.
    (4) It was suggested that the hard patch might bring about a reduction in the wear rate of the steels.
  • 黒木 英憲, 小林 由定, 徳永 洋一
    1977 年 41 巻 9 号 p. 920-926
    発行日: 1977年
    公開日: 2008/04/04
    ジャーナル フリー
    The α structures of sintered irons containing 10∼300 ppm of carbon and oxygen, obtained by the Ar3 transformation, were observed by optical microscopy.
    Standard samples were compacted from the powder containing 0.15% of carbon and sintered at 1100°C, followed by cooling at a rate of 30°C/sec. They had a density of 7.15±0.02 g/cm3 and contained 10∼20 ppm of carbon and 100∼250 ppm of oxygen. Another powder containing 0.75% of carbon was mixed with the one above mentioned to obtain the samples of higher carbon contents.
    The α structures were coarse and columnar for lower carbon-contents (<40 ppm), coarse and equiaxed for medium contents (40 ppm<C<150 ppm), and fine and equiaxed for higher contents (>150 ppm).
    Taking into considaration a probable thermal-gradient within the sample during cooling and the subsequent nucleation of the α phase at lower-temperature portions, the experimental results could be explained as follows.
    For lower carbon-contents, less long-range diffusion might be needed than for higher carbon contents, for the progress of the Ar3 transformation. Therefore, the massive α might grow more rapidly than, for example, the proeutectoid α in mild steel, resulting into coarse columnar structures.
    For higher carbon-contents, envelopes, rich in carbon, should be produced ahead of the growing α grains, because of the difference in solubility of carbon between the γ and the α phases, as already proposed by Rathenau and de Jong. Then, according to the theory of solidification from liquids, the so-called constitutional super-cooling should be produced in the γ region close to the α/γ interface, leading to the nucleation of the α phase. This nucleation could result into fairly equiaxed structures. The above described mechanism might be applied to many irons of commercial purities with no columnar structure.
  • 笹野 久興, 花木 道夫, 木村 啓造
    1977 年 41 巻 9 号 p. 927-933
    発行日: 1977年
    公開日: 2008/04/04
    ジャーナル フリー
    Strain aging behaviour in α-solid solution titanium alloys containing various substitutional elements has been investigated.
    The yield phenomena due to the strain aging become more prominent with increasing substitutional solute and oxygen contents and also with increasing difference from titanium in regard to the atomic radius of the substitutional solute. Assuming that the strain aging phenomena are caused by the interaction of substitutional-interstitial pairs with screw dislocations, a theory has been proposed. The theory seems to give agreement with the results obtained.
  • 笹野 久興, 木村 啓造
    1977 年 41 巻 9 号 p. 933-939
    発行日: 1977年
    公開日: 2008/04/04
    ジャーナル フリー
    The effect of deformation twinning on the mechanical properties of α-solid solution titanium alloys containing various substitutional elements has been investigated. The results obtained are summarized as follows:
    (1) Almost all of the twins observed in the specimen deformed below 25°C are identified as {11\bar22}.
    (2) The easiness of {11\bar22} twinning increases with the decrease of c/a ratio.
    (3) Stress-strain curves show a linear work hardening character and a large work hardening rate with deformation twinning.
    (4) If the prestrain at −196°C and the subsequent deformation at 25°C are added, the total elongation and the work hardening rate become greater than those of a specimen deformed only at 25°C.
    (5) The increase of the work hardening rate is considered to be due to the number of the twin than the volume fraction of the twin. The effect of deformation twinning on the mechanical properties is similar to that of grain size refinning.
  • 中谷 功, 能勢 宏, 増本 剛
    1977 年 41 巻 9 号 p. 939-944
    発行日: 1977年
    公開日: 2008/04/04
    ジャーナル フリー
    Magnetic properties of CuCr2Se4 single crystals have been investigated. The saturation magnetic moment at 0 K is 5.07 μB per formula. The magnetocrystalline anisotropy constants K1 and K2 are −6.9×105 and −0.9×105 erg/cc, respectively, at 5.1 K. In order to examine the effects of annealing on the magnetocrystalline anisotropy, the ferromagnetic resonance at room temperature is measured after annealing in vacuum and in Se-atmosphere, respectively. It is found that the absolute values of K1 and K2 decrease after annealing in vacuum and increase toward the initial values after annealing in Se-atmosphere.
    The above results are discussed on the basis of the ionic model.
  • 菊池 潮美, 杉江 善典, 横山 秀樹, 足立 正雄
    1977 年 41 巻 9 号 p. 944-950
    発行日: 1977年
    公開日: 2008/04/04
    ジャーナル フリー
    Copper-15 at% Al alloy single crystals with the ⟨001⟩ axis were deformed in tension at 873 and 973 K. The stress-strain curve exhibits a rapid work hardening initially and then levels off after several percent strain. In this stage, the condition of steady state deformation was satisfied. In the steady-state stage, the internal and effective stress levels were determined by the stress dip test using an extrapolation technique. Dislocation substructures formed in this stage were observed by the etch pit technique. The results obtained are as follows:
    (1) The axial orientation is stable during the entire period of deformation and the slip occurs on the four {111} planes at the same time.
    (2) In the steady-state stage, a cellular dislocation structure was built up. The dislocation density was proportional to the square of the applied stress. The cell size was inversely proportional to the square root of the dislocation density and to the applied stress.
    (3) The strain rate was proportional to the nth power of the applied stress, n being 3.8 at 873 K, or 3.6 at 973 K. These values are small in comparison with the Cu-Al alloy single crystals oriented for a single slip system. The difference in n arises from the difference of the dislocation structure between these alloys formed in the steady-state stages.
    (4) The ratio of the internal stress to the applied stress was 0.65∼0.8, depending on the applied stress monotonously.
    (5) The parameter m*, the effective stress sensitivity of dislocation glide velocity, was found to be nearly unity. This result indicates that high-temperature deformation of Cu-Al alloys is controlled by the viscous motion of dislocation in spite of the high n value.
  • 亀田 和夫, 坂入 専司, 吉田 芳男
    1977 年 41 巻 9 号 p. 950-955
    発行日: 1977年
    公開日: 2008/04/04
    ジャーナル フリー
    Activities of tin in liquid gold-tin alloys have been determined for NSn=0.17∼0.90, over the temperature range of 944∼1256 K, by the following E.M.F. method:
    (This article is not displayable. Please see full text pdf.)
    The activities of both components for the Au-Sn system demonstrate a considerable negative deviation from Raoult’s law over the whole concentration range.
    In the alloys with NSn=0.30∼0.80, there are remarkable variations in partial enthalpy and entropy of tin with temperature, as discussed with reference to previous investigations. The reason for this is considered to be due to the ordered structure of the alloy which persists above the liquidus temperature.
    These strongly temperature dependent anomalies are explained by the existence of AuSn, AuSn2, AuSn4-compound clusters in the melt.
    With increasing temperature the clusters dissociate and the anomalies disappear. The effects of compound cluster formation in liquid alloys on thermodynamic properties are discussed.
    In addition, other thermodynamic functions are calculated on the basis of the results obtained.
  • 財満 鎮雄, 八木 博行, 服部 聡
    1977 年 41 巻 9 号 p. 956-961
    発行日: 1977年
    公開日: 2008/04/04
    ジャーナル フリー
    In order to investigate the influence of cutting temperature on the behavior of built-up edge in aluminium machining, the temperature distribution in the cutting tool has been measured from the change in the melting condition of the thermopaint coated on the joint tool seam with rise in cutting temperature. The results obtained are as follows.
    When the built-up edges grow and remain on the tool face, the temperature distribution in the tool is identical in shape to that in the tool without built-up edges, and the influence of built-up edges on the shape of the temperature distribution in the tool is not very remarkable. The dimensions of built-up edges decrease gradually with rise in cutting temperature owing to the rise in cutting speed, the increase in depth of cut, etc., and when the cutting temperature approaches a certain temperature, the built-up edges will decrease in dimensions, especially in length, and the built-up edges will disappear above that temperature. In the case of cylindrical specimens 5083, the temperature at which built-up edges in the tool tip disappear is about 320°C regardless of differences in the cutting condition such as the cutting speed and the depth of cut. From the softening curve on annealing and the index of line broadening in diffracted X-ray intensity, it is evident that the recrystallization temperature of the workpiece is in the range of 300∼350°C. This temperature is confirmed to be nearly equal to the above-mentioned recrystallization temperature of the workpiece.
  • 増本 量, 中村 直司
    1977 年 41 巻 9 号 p. 961-964
    発行日: 1977年
    公開日: 2008/04/04
    ジャーナル フリー
    Fe-Cr-Co alloys containing less than 30% chromium and less than 70% cobalt were heated in vacuum over the temperature range of 500∼1000°C for 1 h and then furnace-cooled after cold-drawing by about 98% reduction in area. Measurements of the strain gauge factor and electrical properties at room temperature were carried out for the alloys.
    Generally, with increasing annealing temperature, the strain gauge factors of the Fe-Cr-Co alloys decreased gradualy to a minimum at about 500°C and increased sharply to a maximum at 800°C. In this system, an Fe-15%Cr-30%Co alloy showed a maximum strain gauge factor of 7.3, and an electrical resistivity of 0.78 μΩm at room temperature and its temperature coefficient of 100×10−5/°C. The thermo-electromotive force relative to copper was −1.2 μV/°C for this alloy.
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