巻号一覧
41 巻, 10 号
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中井 弘, 杉本 寿光1977 年 41 巻 10 号 p. 965-972
発行日: 1977年
公開日: 2008/04/04
ジャーナル フリーThe corrosion of Copper in various Ar-O2-SO2 atmospheres was investigated at 500∼1000°C. In 80%Ar atmospheres, the parabolic rate law was followed, not depending on the ratio O2 to SO2. In 40%Ar atmospheres, generally the reaction kinetics was complex and varied in accordance with the O2 to SO2 ratio and the temperature. Furthermore, the weight-gain vs temperature curves showed a maximum at about 700°C in any given atmosheres. This was considered to be due to the eutectic liquid phase between CuO and CuO·CuSO4.
At 500°C, the scale consisted of an outer CuSO4 layer and an inner Cu2O layer, at 600∼800°C generally it was CuSO4/CuO·CuSO4/CuO/Cu2O/Cu2O-Cu2S/Cu from surface to bulk; and above 900°C it consisted of an outer CuO layer and an inner Cu2O layer.
In all experimental conditions, the maximum weight-gain after corrosion for 2 h was found in a 5%O2-95%SO2 atmosphere at 700∼800°C. In this case, CuO·CuSO4 was produced easily, but CuSO4 was not much produced because of the paucity of oxygen in atmosphere. This CuO·CuSO4 reacts with CuO and makes an eutectic liquid. So the rate of corrosion was very fast in this case.
We found a duplex structure of Cu2O-Cu2S at the nearest part of the scale to the bulk metal formed in a 95%O2-5%SO2 atmosphere at 700°C. This indicates that not a little sulfur diffused from surface to bulk. This result may support the experimental result of Birks et al.抄録全体を表示PDF形式でダウンロード (1157K) -
浅山 行昭1977 年 41 巻 10 号 p. 973-981
発行日: 1977年
公開日: 2008/04/04
ジャーナル フリーThe notch toughness after aging and the structural changes during aging have been investigated on 12Cr-12Co-Ni-Mo maraging stainless steels containing 3∼6%Ni and 2∼5%Mo.
The maximum hardness was obtained by aging at 510∼560°C for 240 min, although the aging temperature was slightly varied with Ni content. On the other hand, a drastic decrease in notch toughness for low Ni or Mo alloys was caused by aging at 450∼500°C, lower than the aging temperature at which a maximum hardness was attained.
In the case of isothermal aging at 480°C, the decrease in notch toughness was observed in all the alloys after a certain incubation period determined by the chemical composition. The incubation period became shorter with decreasing Ni or Mo content.
The alloys, in which the σ phase was precipitated by solution heat treatment at 850°C, exhibited very poor toughness after aging at 450∼500°C, since an incubation period became shoter by the depletion of Mo.
Intermetallic compound R phase has been identified by X-ray diffraction of the residues obtained by dissolving the alloys aged at a temperature higher than 480°C, but no close correlation has been found between precipitation of the R phase and embrittlement.
The embrittlement is thought to be closely related to the formation of Ni- and Co-rich zone and the diffusion of impurities enhancing the temper embrittlement by low temperature aging.抄録全体を表示PDF形式でダウンロード (1203K) -
和田 浩明, 阪本 甲子郎1977 年 41 巻 10 号 p. 981-986
発行日: 1977年
公開日: 2008/04/04
ジャーナル フリーIt is difficult to remove oxygen from iron by a dry H2 treatment in a temperature region of α-iron. In the present study, however, it is found that oxygen as well as carbon and nitrogen in iron can be reduced to less than 1 wt ppm by the dry H2 treatment in a temperature region of δ-iron.
The results obtained are summarized as follows:
(1) The purification described above can be attained by the dry H2 treatment at 1500°C for only 3 h even though the initial oxygen content and the size of rod specimens are as large as 730 wt ppm and 10 mmφ, respectively.
(2) The present purification method can be applied by the use of a less sophisticated apparatus.
(3) When impurity contents are far exceeding the solubility limit, the corresponding diffusion equation can be approximately solved under a quasi-stationary condition. The approximate solution describes very well the present experimental results.抄録全体を表示PDF形式でダウンロード (472K) -
木戸 光夫, 中佐 啓治郎, 武井 英雄1977 年 41 巻 10 号 p. 987-992
発行日: 1977年
公開日: 2008/04/04
ジャーナル フリーThe effect of fatigue accumulation given by partly pulsating tensile stress on the crack initiation time in delayed fracture was investigated using the notched specimen of Ni-Cr-Mo steel quenched and tempered at 200°C. The results obtained are as follows:
(1) The crack initiation time t in delayed fracture is largely prolonged when proper combinations of mean stress σ, stress amplitude σa and fatigue accumulation percent φ are selected in the fatigue accumulation treatment and when the same stress σ as used in the fatigue accumulation is applied to the specimen statically in the delayed fracture test without unloading after fatigue accumulation. Taking σ=125 kg/mm2, σa=35 kg/mm2, φ=10∼50%, for example, the crack initiation does not occur within 100 h under the static stress σ=125 kg/mm2, which indicates that the lower limit stress σscc is increased by about 2.5 times that of the non-fatigue accumulated material.
(2) The variation in the shape of the φ vs t curve with various σ and σa can be classified into three patterns using the parameter σa/σ.
(3) When σ is once decreased to zero after fatigue accumulation, the crack initiation time in the delayed fracture test at the same σ is not so prolonged as that in the case of unloading, and the crack initiation time in the former case is a little longer than that of the non-fatigue accumulated material only when σ, σa and φ in fatigue accumulation are small. Therefore, the unloading after fatigue accumulation is very important for the increase of delayed fracture strength.抄録全体を表示PDF形式でダウンロード (477K) -
今川 博之1977 年 41 巻 10 号 p. 992-998
発行日: 1977年
公開日: 2008/04/04
ジャーナル フリーStress corrosion cracking (SCC) tests of commercial carbon steels were conducted both in a liquid ammonia saturated with NH4CO2NH2 at 30°C for 500 h and in a field liquid ammonia. H2S cracking tests for the same specimens were also carried out. The results obtained are as follows:
(1) In the liquid NH3-NH4CO2NH2 SCC of quenched steels occurs if the hardness of the specimens is high, and the increase of carbon content accelerated SCC. This result is similar to that in H2S cracking tests.
(2) In a liquid NH3 SCC of quenched steels tends to occur if the content of alloying elements in the steels is high, even though their hardness is low. Nickel in the steels has the most remarkable effect on SCC and many corrosion cracks in the liquid NH3 were observed on the steels containing Ni.
(3) Tempering above 300°C after quenching decreases markedly the susceptibility to SCC of all the types of steels in the liquid NH3-NH4CO2NH2.
(4) The hydrogen permeability into the steel is increased by the addition of NH4CO2NH2 to liquid NH3, and the susceptibility to SCC of each steel in the liquid NH3-NH4CO2NH2 is similar to that to H2S cracking. Therefore, the propagation of cracks in the steel seems to be due partly to hydrogen emblitlement in the liquid NH3.抄録全体を表示PDF形式でダウンロード (1301K) -
吉原 秀雄, 木内 幹保, 青木 武, 梅村 茂1977 年 41 巻 10 号 p. 999-1006
発行日: 1977年
公開日: 2008/04/04
ジャーナル フリーFor the application of ion-plating to components for telecommunication and semiconductor devices, it is essential for ion-plated films to have high purity and proper adherence to substrates. To satisfy these requirements, silver films were ion-plated on copper, permalloy, and vicalloy substrates under an Ar gas pressure which was an order of magnitude lower than that used for the conventional ion-plating. The chemical composition, morphology, microstructure, and internal stress in ion-plated and RF ion-plated films were investigated by Auger electron spectroscopy, scanning electron microscopy and X-ray diffraction, in comparison with those in the vacuum evaporated ones. Auger electron spectoscopy revealed that both ion-plated and RF ion-plated films were of high purity. The cross-sectional morphology and microstructure became more coaxial and smaller with increasing impinging ions; that is, coaxial grains were observed in the RF ion-plated films, and columnar ones in the vacuum-evaporated films. X-ray diffraction analysis indicated that both the internal stress in the ion-plated and RF ion-plated films were greater than those in the vacuum-evaporated ones.
The internal stresses nearly correspond to the Vickers hardness values of the ion-plated films. Furthermore, the adhesion charasteristics for the sliding motion were investigated by the apparatus designed for this purpose. Silver films ion-plated on vicalloy were smaller in adhesion cofficient than the cold worked bulk materials and elctro-plated films.抄録全体を表示PDF形式でダウンロード (865K) -
上田 修三, 藤田 広志1977 年 41 巻 10 号 p. 1007-1013
発行日: 1977年
公開日: 2008/04/04
ジャーナル フリーRelations between the strain-induced γ→α′ transformation and active slip systems have been studied by optical and transmission electron microscopy on Fe-18%Cr-14%Ni single crystals and 18-8 type stainless steel polycrystals. The results obtained are summarized as follows: (1) The minimum strain to induce the γ→α′ transformation is larger in a crystal oriented for single slip than in the one for double slip. (2) α′-plates in a crystal oriented for single slip are wide and long needle-like, and those in the one for double or cross slip are small and lenticular. All of them are formed in banded structures on the well-developed slip bands. (3) Many slip bands are emitted on the primary slip bands from interfaces between a newly-formed α′-plate and γ-matrix. In this case, the slip band emitted from a larger α′-plate is longer and wider. (4) Stacking faults that randomly occur on primary slip planes from interfaces of both sides or one side of an α′-plate are frequently observed. (5) Many dislocations run parallel with the primary slip plane of γ-matrix inside and in the surrounding area of an α′-plate. Furthermore, in the latter area, overlapping stacking faults and ε′-plates are similarly formed. (6) Thin α′-plates are generally formed in the regions where secondary slip bands terminate on primary slip bands. Even though secondary slip bands in this case belong to two different kinds of systems, most of α′-plates formed in the regions are of the same variant. (7) A nucleation side edge of an α′-plate is straight on the well-developed slip bands.
On the basis of the above phenomena, stress relief by α′-phase formation is mainly discussed.抄録全体を表示PDF形式でダウンロード (1082K) -
増本 量, 村上 雄悦, 中村 直司1977 年 41 巻 10 号 p. 1014-1018
発行日: 1977年
公開日: 2008/04/04
ジャーナル フリーMagnetic properties, electrical resistivity, hardness and microstructure have been studied on Fe-Nb alloys (Recalloy) containing less than 4%Nb. The alloys are water-quenched from various temperatures over the α-γ transformation point, cold-drawn by more than 50% reduction, and then reheated at 400∼1000°C for less than 5 h.
The magnetic properties of those alloys depend remarkably on the reduction rate, the reheating temperature and time. An Fe-3.1%Nb alloy reheated at 650°C for 30 min after water-quenching from 1050°C and cold-drawing by 97.2% reduction exhibits very superior properties as follows: magnetic induction at 8 kA/m B8=1.74 T, residual induction Br=1.62 T, coercive force Hc=1.62 kA/m, squareness ratio Br/B8, and squareness \sqrt(BH)max⁄BrHc=0.90. The electrical resistivity and Vickers hardness of this alloy are 0.126 μΩ·m and 353, respectively.抄録全体を表示PDF形式でダウンロード (706K) -
張 博, 山本 悟, 川野 豊, 尾崎 良平1977 年 41 巻 10 号 p. 1019-1025
発行日: 1977年
公開日: 2008/04/04
ジャーナル フリーThe fading behaviour in magnesium-treated cast irons has been investigated. The main results are:
(1) The fading behaviour hardly depends on the melting atmosphere (air, Ar-gas).
(2) The amount of magnesium-consumption through reactions with oxygen, sulphur, or nitrogen in melts does not exceed 20∼30% of the total consumption.
(3) The covering of magnesium-treated cast irons with MgO decreases the fading rate of magnesium a little, while the covering with BaF2, CaF2 and MgF2 increases it considerably in the order.
(4) It has been clarified that these results are satisfactorily explained if the escape of magnesium from the melt is mainly due to the floating-up of magnesium gas bubbles.抄録全体を表示PDF形式でダウンロード (936K) -
張 博, 山本 悟, 川野 豊, 尾崎 良平1977 年 41 巻 10 号 p. 1025-1032
発行日: 1977年
公開日: 2008/04/04
ジャーナル フリーIn the present work, the austenite envelope and the solidification process of nodular cast irons have been investigated. The main results are summarized as follows:
(1) During the solidification of nodular cast irons, nodular graphites are at first formed in melts and grow to some extent in direct contact with melts and then envelopes of austenite are formed through preferential growth of austenite around graphite nodules.
(2) The number of graphite nodules increases rapidly in the initial stage of solidification and it hardly changes in the subsequent solidification. The number of graphite nodules may be specified by the amount of magnesium gas bubbles in melts.
(3) Austenite envelopes are a polycrystalline structure and the regions near grain boundaries remain as liquid state during solidification as a result of segregation of elements with low-melting points.
(4) The existence of grain boundaries in austenite envelopes causes the denodularization of pre-existing graphite nodules through the preferential growth of graphite along boundaries.
(5) The diffusion of iron through channels in austenite envelopes may be the rate determining process of growth of nodular graphite.抄録全体を表示PDF形式でダウンロード (1483K) -
常磐井 守泰, 諸住 正太郎1977 年 41 巻 10 号 p. 1033-1040
発行日: 1977年
公開日: 2008/04/04
ジャーナル フリーFundamental experiments on the internal oxidation process of vanadium alloys, were carried out for the improvement of high temperature strength of the alloys, and the following results were obtained:
(1) Zirconium and silicon were alloyed to vanadium, respectively, as an internally-oxidizing element. The former element was more favorable than the latter from the point of view of high temperature strength.
(2) Excess of oxygen, supplied by decomposition of NiO, increased the amount of oxygen dissolved in solid-solution in the internally-oxidized alloys, which caused strengthening of the alloys not at high temperature but at low temperature, accompanied by brittlement.
(3) Optimum zirconium contents of internally-oxidized V-Zr alloys was in the range of 0.3 and 1.0 wt%.
(4) Strength of V-Zr alloys internally oxidized at a temperature above 980°C was greater than those internally oxidized below this temperature. This fact was attributed to the volume expansion of ZrO2 due to the β-α transformation when the alloy was cooled down through the transformation points of 980 to 1100°C.
(5) Zirconium oxide particles formed by internal oxidation were appreciably stable at temperatures around 1000°C, but they grew obeying Seybolt’s law at 1300°C and then dissolved into the matrix above 1500°C.抄録全体を表示PDF形式でダウンロード (1070K) -
江島 辰彦, 山村 力, 内田 直人1977 年 41 巻 10 号 p. 1041-1047
発行日: 1977年
公開日: 2008/04/04
ジャーナル フリーIn order to clarify the relative importance of various factors for the solute diffusion in liquid metals as reference data for a theoretical prediction of solute diffusion coefficients the diffusion coefficients of the fifth period solutes (Ru, In, Sn and Sb) in liquid copper have been measured in the temperature range 1100 to 1300°C by the capillary reservoir method. The results obtained are summarized as follows:
(1) The solutes belonging to the fifth period in molten copper diffuse faster than the solvent atom. The diffusion coefficients obtained are in the order of DSn>DRu>DAg>DSb>DIn.
(2) The temperature dependence of diffusion coefficients obtained can be represented by the Arrhenius type equation. The apparent activation energy for diffusion of the solute in molten copper increases with increasing valence of the solute.
(3) There is some correlation between the thermodynamic property and diffusion in these systems. The larger the activity coefficient of the solute, the faster diffuses the solute.
(4) The diffusion coefficients of solutes in molten copper were estimated on the basis of the hard sphere theory originally derived by Enskog. Although the calculated and the observed diffusion coefficients agree well at 1200°C, the apparent activation energies calculated show somewhat poor agreement with the calculated ones.抄録全体を表示PDF形式でダウンロード (630K) -
河原 正泰, 森永 健次, 柳ヶ瀬 勉1977 年 41 巻 10 号 p. 1047-1052
発行日: 1977年
公開日: 2008/04/04
ジャーナル フリーThe viscosity measurements in the system Na2O-SiO2-MgO have been conducted to find out the behavior of the MgO in this system.
When MgO was added to the melt having the composition of Na2O/SiO2=1⁄4, the viscosity was almost constant up to about 10 mol%MgO content, but thereafter it decreased wih increasing MgO content. In the case of the melt having the composition of Na2O/SiO2=3⁄2, the viscosity increased with increasing MgO content. This may be considered that the MgO will act as a network former like SiO2 in this system.
The viscosity coefficient gave a linear relationship with a parameter of SiO2+0.33MgO, where 0.33 is the ratio of ion-oxygen attraction MgO in the tetrahedral site and SiO2.
The infrared and far-infrared absorption spectra were observed to investigate the structure of quenched glass. The absorption bands of Mg-O for both (MgO4) and (MgO6) were observed in the region of far-infrared absorption spectra.抄録全体を表示PDF形式でダウンロード (479K) -
石田 文彦, 土井 俊雄1977 年 41 巻 10 号 p. 1053-1060
発行日: 1977年
公開日: 2008/04/04
ジャーナル フリーThe effect of heat-treatment on the critical current density, Jc, was investigated in heavily cold-worked Nb-Ti alloys. The specimens containing 55 to 70 at%Ti and the balance Nb were reduced 75.00 to 99.99% in area by cold-working and then aged at temperatures from 350 to 550°C. The results are summarized as follows:
(1) When the specimens are aged, Jc increases initially, reaches a maximum value and then decreases. The maximum value of Jc becomes higher at a less cold-reduction prior to aging, at a lower aging temperature or with a higher Ti content.
(2) When the cold-drawn wires are heat-treated, the α phase precipitates preferentially at the fiber boundaries. The precipitates at the fiber boundaries grow coarser than those within the fibers and the amount of the former increases with increasing cold-reduction prior to the heat treatment.
(3) In precipitation of a α phase from a β supersaturated solid solution, precipitates become finer and more numerous at a lower precipitate temperature or with a higher solute Ti content in the β phase.
(4) The increase of Jc in specimens heat-treated after cold-working is mainly attributed to the precipitation of the α phase and Jc is found to be inversely proportional to a precipitate spacing. The highest Jc is obtained by the heat-treatment which produces a fine dispersion of precipitates.
(5) A Nb-65.0 at%Ti alloy is the most suitable composition for a superconducting magnet coil material. For this alloy cold-worked by 98.44% reduction and then heat-treated at 350°C for 340 h, the values of Jc at 4.2 K were 2×107 A/m2 at 3.2 MA/m, 1×107 A/m2 at 4.8 MA/m and 5×106 A/m2 at 6.4 MA/m, respectively.抄録全体を表示PDF形式でダウンロード (1111K) -
金児 紘征, 加藤 義春1977 年 41 巻 10 号 p. 1061-1067
発行日: 1977年
公開日: 2008/04/04
ジャーナル フリーThe anodic behavior of pure iron in 1 mol/dm3 sulfuric acid solution was studied with special reference to the oscillation of current and potential in a range between the active and passive states of the metal. A method using two Luggin capillaries, one for potentiostatic polarization and the other for local potential measurements, were used to study the oscillatory behavior, and the factors determining reproducibility of polarization curves were investigated. The results are summarized as follows:
(1) Periodic oscillations of current and potential are observed when the electrode process is controlled by diffusion. This phenomenon is related to the formation of a poorly conductive layer of ferrous sulfate.
(2) Although the potential is controlled at a constant value by a potentiostat, a sudden change in current occurs at the potentials corresponding to the pre-passive state. In this case, the potential distribution on the metal surface is not uniform, which indicates that the formation and destruction of the passive film are repeated irregularly with respect to location and time.
(3) Modified Degn-Franck mechanism is proposed in order to explain the oscillatory behavior.抄録全体を表示PDF形式でダウンロード (628K) -
早稲田 嘉夫, 水渡 英昭, 白石 裕1977 年 41 巻 10 号 p. 1068-1073
発行日: 1977年
公開日: 2008/04/04
ジャーナル フリーX-ray diffraction measurements have been made on the binary silicate system CaO-SiO2 in the molten and glassy states. From these results, the followings were quantitatively confirmed; Molten silicates mainly consist of SiO4 tetrahedral units up to the present experimental composition range, i.e., 50 mol%CaO. Namely the structural change in the fundamental units due to the addition of CaO is not severe. These SiO4 tetrahedral units, however, are distributed more loosely with increasing addition of CaO. If discrete anions exist, the number of oxygens surrounding a silicon as nearest neighbours is expected to be 4, which corresponds to the arrangement of SiO4 tetrahedral units observed in this work. Therefore, the results of this work give no definite answer to the discrete anion model, but it is found that the behaviour is related to the breaking of Si-O-Si bonds. The number of oxygens which surround Ca atoms at the disilicate and metasilicate compositions are 6 and 7, respectively. The structure of molten silicates is insensitive to temperature within the present experimental temperature range. However, there is a difference in the root-mean square displacements of the correlation in the near neighbour distance due to the increase of temperature. X-ray diffraction patterns of CaO-SiO2 in the molten state are similar to those in the glassy state. The results obtained by X-ray diffraction were also supported by neutron diffraction measurements in the glassy state.抄録全体を表示PDF形式でダウンロード (560K) -
天野 忠昭, 矢島 聖使, 斎藤 安俊1977 年 41 巻 10 号 p. 1074-1082
発行日: 1977年
公開日: 2008/04/04
ジャーナル フリーThe oxidation behavior of Fe-20Cr-4Al alloys, some containing 0.01, 0.04 and 0.37%Ce, was studied in air at temperatures between 1273 and 1523 K by weight-change measurements, X-ray diffraction, electron probe microanalysis and scanning electron microscopy. The surface oxide predominantly formed on all the alloys was α-Al2O3. The marker and kinetic studies suggested the α-Al2O3 scale grew into the alloys by inward diffusion of oxygen along the oxide grain boundaries. In the alloys without Ce and with 0.01%Ce, the α-Al2O3 scale spalled during cooling from the oxidation temperature. Spalling of the surface oxide, probably caused by the formation of voids at the oxide-alloy interface, initially occurred at the intersection of the alloy grain boundaries, and subsequently extended to the interior of the grains. No spalling was observed on the surfaces of the alloys with 0.04 and 0.37%Ce. In both alloys, cerium primarily existed as a Ce-Fe intermetallic compound throughout the alloy matrix, which mostly precipitated at the grain boundaries. Higher cerium additions resulted in good adherence of surface oxide due to the prevention of voids formation at the oxide-alloy interface, and pegging of intergranular oxides preferentially formed at the alloy grain boundaries.抄録全体を表示PDF形式でダウンロード (943K) -
有田 稔1977 年 41 巻 10 号 p. 1083-1084
発行日: 1977年
公開日: 2008/04/04
ジャーナル フリーPDF形式でダウンロード (135K) -
中澤 重厚1977 年 41 巻 10 号 p. 1085-1086
発行日: 1977年
公開日: 2008/04/04
ジャーナル フリーPDF形式でダウンロード (176K)
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