巻号一覧
44 巻, 4 号
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李 絏, 川野 豊1980 年 44 巻 4 号 p. 339-345
発行日: 1980年
公開日: 2008/04/04
ジャーナル フリーThe object of this report is to clarify the mechanism of nodularization of graphite formed by the presence of Mg and S during annealing of white cast irons.
Fe-2.5%C-1.1%Si alloy melts containing both Mg and S were cast into metal mould (φ10 mm×100 mm). White cast iron specimens obtained in this way were annealed at 800, 950 and 1100°C. When Mg and S contents in the specimens were expressed in terms of the value of ΔMg (where ΔMg wt% denotes a stoichiometrical excess of Mg wt% to S wt%: ΔMg=Mg wt%−S wt%/1.32), the results obtained are as followes.
(1) ΔMg>0: Nodularization of graphite was promoted by the annealing at higher temperature. ΔMg<−0.02: Graphite was nodularized almost completely by annealing at comparatively low temperature (950°C), but not so at higher temperature (1100°C). 0>ΔMg>−0.02: On the other hand, nodular graphites were hardly observable in the specimens annealed at any temperature investigated.
(2) The graphite particle number decreased considerably and the graphitization time increased remarkably with decreasing ΔMg from 0 to −0.02. These results were discussed on the basis of the assumption that nodular graphites are formed by graphite precipitation into the spherical cavity defect in the solid cast iron during annealing.抄録全体を表示PDF形式でダウンロード (1996K) -
松浦 圭助1980 年 44 巻 4 号 p. 346-351
発行日: 1980年
公開日: 2008/04/04
ジャーナル フリーThe temperature dependence of work-hardening of dispersion-hardened alloy, which is due to Orowan loops formed around dispersed particles, has been calculated using a model that Orowan loops climb and annihilate through a pipe diffusion of vacancies along the loops during the deformation. Assuming a uniform distribution of Orowan loops around each particle, the rate of their annihilation was obtained by considering the total vacancy flux in a whole distribution of loops, and the amount and rate of work-hardening were finally given as a function of deformation temperature and particle size. These expressions were extended to the case in which there was a distribution of particle size.
The calculation fairly well accounted for the temperature dependence and particle-size dependence of work-hardening rate in an Al-1.2%Si alloy containing silicon particles, when reasonable values of the diffusion coefficient of pipe diffusion, that is, D0p=10−3 cm2/s, Qp=58.6 kJ/(mol·K) or D0p=10−2 cm2/s, Qp=66.9 kJ/(mol·K), were used, where D0p and Qp mean a frequency factor and an activation energy for pipe diffusion, respectively. However, the work-hardening rate calculated decreased rapidly with increasing deformation temperature in a narrow temperature range compared to the measurements on the Al-1.2%Si alloy. This discrepancy has been ascribed to the fact that although the rate of climb of the Orowan loop depends on its position lying on particle interface, the position was not taken into account in the present calculation.抄録全体を表示PDF形式でダウンロード (453K) -
中村 良三, 杉之原 幸夫1980 年 44 巻 4 号 p. 352-358
発行日: 1980年
公開日: 2008/04/04
ジャーナル フリーIn the application of the trimethylsilylation method by Götz and Masson for the analysis of the silicate anions, Masson et al. have shown that water is essential for the trimethylsilylation of anhydrous silicates. However, that a subreaction caused by the presence of water may affect the trimethylsilal reaction. In this work we used the improved solvents containing no water, (CH3)3SiCl 3 cm3, CH3OH 6 cm3 and (CH3)3SiOSi(CH3)3 9 cm3. Crystalline calcium silicates with well defined structures and lead silicate, which showed poor reaction efficiency in Masson’s method were analysed by these solvents. The results obtained are summarized as follows.
(1) The reaction efficiency of trimethylsilylation was 100% for the glasses of PbO-SiO2 and CaO-SiO2 systems.
(2) The products were obtained 100% as the derivative of Si4O1210− for the α-CaO·SiO2, 100% as the derivative of Si2O76− for the 3CaO·2SiO2 and 97% as the derivative of SiO44− for the 2CaO·SiO2.
(3) For the crystalline calcium silicate (43.3 mol%SiO2) with a mixture of different anions, the products were determined to be composed of 80.5%Si2O76− and 18.6%Si4O1210− derivatives.
As the result obtained was better than that by Masson’s method, the present method may be used for determining various silicate structures with high accuracy as their corresponding trimethylsilyl derivatives.抄録全体を表示PDF形式でダウンロード (562K) -
茂木 徹一, 大野 篤美1980 年 44 巻 4 号 p. 359-366
発行日: 1980年
公開日: 2008/04/04
ジャーナル フリーSeveral experiments were carried out in order to study the formation mechanism of equiaxed crystals in an ingot cooled from the top surface, using an ammonium chloride-water model and Al alloys.
Microscopic observation of the solidification phenomena of the ammonium chloride-water model revealed that the solid skin formed on the top surface undulated because of the release of a gas film at the interface between the solid and the liquid, and that many dendrite fragments of ammonium chloride crystals formed by the breaking of the solid skin by the undulation were scattered into the bulk liquid. Visible free dendrites growing from those fragments appeared in the liquid just below the columnar dendrites, which grew from the top. No dendrite remelting was observed during the columnar growth from the top.
Experiments performed with 99.8%Al, Al-Cu, and Al-Ti alloys suggested that the breaking of an unstable solid skin at the top surface in the initial stage of solidification was the primary source of showering crystals when the molten surface was cooled by gas blowing. Beside the cooling of the top surface, when the heat of the molten metal was extracted through the side wall of the mold as well, a U-shaped equiaxed zone was obtained in alloy ingots, showing that crystals were mostly separated at the edge of the mold and the molten surface. Showering of crystals from the top surface of molten metal occurred only when the solid skin was mechanically broken.抄録全体を表示PDF形式でダウンロード (1621K) -
高橋 恒夫, 小島 陽, 里 達雄, 大平 宏1980 年 44 巻 4 号 p. 366-370
発行日: 1980年
公開日: 2008/04/04
ジャーナル フリーThe oriented precipitation formed during the stress-aging of Al-3%Cu alloy were investigated by means of the X-ray oscillating crystal method. The compressive stress along the [001] direction induced the preferential formation of G.P. zones and θ″ phases perpendicular to the [001] axis. The degree of the orientation is increased by lowering the quenching temperature, i.e. by lowering the nucleation rate. It indicates that the stress orienting effect is determined in the stage of nuclei-formation. The stress oriented G.P. zones and θ″ phases were grown to θ″ and θ′ phases respectively in the additional free-aging, and it was clarified that the orientation of G.P. zones and θ″ phases are handed down to θ″ and θ′ phases, respectively. The finding leads to the conclusion that G.P. zones, θ″ and θ′ phases transform in regular sequence.抄録全体を表示PDF形式でダウンロード (783K) -
里 達雄, 小島 陽, 高橋 恒夫1980 年 44 巻 4 号 p. 371-377
発行日: 1980年
公開日: 2008/04/04
ジャーナル フリーX-ray diffuse scattering intensities were measured on a stress-aged Al-3%Cu alloy to investigate the structure model of G.P. zones. It has been known that G.P. zones are formed preferentially on the (001) plane if compressive stress is applied along the [001] axis. Hence the X-ray diffuse scattering intensities from those unidirectionally oriented G.P. zones were measured. The diffuse scattering intensity profile of the stress-aged specimen was much sharper than that of the free-aged specimen.
The measured scattering intensity was explained well if the strain field around G.P. zones was assumed to be the same as that proposed by Kroupa on dislocation loops. It was clarified that a consideration on the solute concentration in the vicinity of the G.P. zone will lead to a more precise explanation of the scattering intensity. In the case of the specimen stress-aged at 373 K for 18 ks, the displacement of (200) lattices from the center of the G.P. zone was fairly large up to the 12∼14 lattice spacings and decreased gradually thereafter. The average solute concentration of the G.P. zone was estimated to be 25∼30 at%Cu.抄録全体を表示PDF形式でダウンロード (703K) -
五十嵐 廉, 柴田 雅裕, 小玉 祐二郎1980 年 44 巻 4 号 p. 378-386
発行日: 1980年
公開日: 2008/04/04
ジャーナル フリーAg-In-Sn alloys with various compositions containing total solute elements of 8 at% were oxidized at 873 to 1133 K in air and 973 K in oxygen of 1.0×105 Pa in order to investigate the precipitation behavior of oxides during internal oxidation. Microstructures, oxidation tendency of solute elements, and distribution of In and Sn in oxides were observed, and oxide phases were identified by electron probe microanalysis and X-ray diffraction. Oxidation tendency of solute elements were determined from the oxide enrichment produced at the oxidation front by EPMA when oxidation conditions were changed to a higher temperature and/or a lower oxygen pressure.
The results obtained are as follows:
(1) In the composition range of 0.14≤CSn≤0.4 (CSn means the ratio of an amount of Sn to total solute elements), In was oxidized previous to Sn. The shape of oxide changed from a spherical one to a needle-like one and its size became larger simultaneously with increasing CSn. Almost all oxides were identified as In2O3 dissolving Sn as Sn4+ uniformly.
(2) In the composition range of 0.4<CSn≤0.65, In and Sn were oxidized almost simultaneously. The shape of the oxide changed from a needle-like to a wedge-shaped one through a dendritic type with increasing CSn. Both of fine spherical and wedge-shaped oxides were dispersed in the alloy with the composition of CSn=0.65. The Sn concentration was higher at the surface area than at the inner region of needle-like or dendritic oxides.
(3) In the composition range of CSn>0.65, Sn was oxidized previous to In. The shape of oxide was finely spherical and similar to that precipitated in the internally oxidized Ag-Sn alloy.抄録全体を表示PDF形式でダウンロード (1994K) -
三沢 俊平, 菊池 正明, 菅原 英夫1980 年 44 巻 4 号 p. 387-394
発行日: 1980年
公開日: 2008/04/04
ジャーナル フリーFor a better understanding of the metal-hydride cracking process resulting in the active surface for hydriding, a study has been made on a bulk sample of LaNi4Fe which readily forms metal hydride under an atmospheric pressure of hydrogen at ambient temperature. The process of cracking and powdering of LaNi4Fe during hydriding under a flowing hydrogen of 0.1 MPa at room temperature was observed. Acoustic emission during hydriding was also measured in a wide frequency band (2 kHz–1 MHz) over a period of 4.02 ks.
Various stages of the disintegration process in LaNi4Fe were photographed and AE signals were observed. The hydrogen absorption cracking fracture-surfaces of the metallic compound LaNi4Fe showed a brittle fracture surface with many microcracks. The screen classification of powdered sample indicated that an arc-melted bulk sample was partially disintegrated into a small powder below 37 μm in diameter during hydrogen absorption for 4.02 ks. AE events and energy-level histogram during hydriding were associated with the process of hydrogen absorption cracking and this process should be schematically divided into four stages on the basis of the acoustic emission characteristics. AE signals of higher energy-level corresponded to the appearence of macrocrack, and the emission source causing AE signals of lower energy-level was discussed.抄録全体を表示PDF形式でダウンロード (1930K) -
栗下 裕明, 吉永 日出男, 高尾 文雄, 後藤 正治1980 年 44 巻 4 号 p. 395-403
発行日: 1980年
公開日: 2008/04/04
ジャーナル フリーMechanical properties of Mo-TiC lamellar eutectic composite have been investigated in compression at temperatures from room temperature to 2073 K and at strain rates from 4×10−5 s−1 to 5×10−3 s−1. It is found that this material shows excellent high-temperature strength as well as appreciable room-temperature toughness, suggesting that the material is a good candidate for high-temperature application as structure material. From the observed high temperature deformation behavior, it is argued that the excellent high-temperature strength is due to the constraining of deformation in the Mo phase by thin TiC lamellars which are considerably stronger than bulk TiC. It is also concluded that the appreciable room-temperature toughness is ascribed to the frequent branching of crack paths as well as to the plastic deformation of the Mo phase.抄録全体を表示PDF形式でダウンロード (1369K) -
花井 義泰, 須藤 一1980 年 44 巻 4 号 p. 404-411
発行日: 1980年
公開日: 2008/04/04
ジャーナル フリーExtraction carbon replica technique was used to investigate the precipitation behaviour of sulphides at grain boundaries in 0.6%C-1%Ni-3%Cr steels on cooling after over-heating. The over-heating embrittlement (the loss in ductility on cooling) was also investigated by the Gleeble tensile test.
The number of precipitates per unit area and their growth rate were decreased by the addition of manganese or calcium, and the over-heating embrittlement was restricted. Especially, the addition of a small amount of calcium has a great effect. The addition of phosphorus less than its solbility limit in γ-Fe suppressed the over-heating embrittlement in some degree.
The sulphide precipitated in the manganese bearing steel has a spinel structure (a=1.00 nm) in the early stage of precipitation, and then transforms to α-MnS (NaCl type). The precipitation of FeS was observed in the calcium treated steels.
The change in hot workability on cooling after over-heating was qualitatively interpreted by the grain boundary precipitation of sulphides, the dynamic recrystallization, and the change in fracture mode.抄録全体を表示PDF形式でダウンロード (2030K) -
武津 典彦, 向井 久, 幸 善作1980 年 44 巻 4 号 p. 412-419
発行日: 1980年
公開日: 2008/04/04
ジャーナル フリーAn E.M.F. method using oxide solid electrolyte was applied to determine the sulfur activities in the liquid solution of bismuth and sulfur.
The oxygen partial pressures over the melts equilibriated with nearly one atmospheric pressure of SO2 were measured by the following galvanic cell:
(This article is not displayable. Please see full text pdf.)
\ oindentFrom the measured oxygen partial pressures and the total pressure, the equilibrium sulfur pressures were calculated by using the published data on molar Gibbs energy of coexisting gas species.
The sulfur activities of the melts were determined by this method for compositions up to 50 mol per cent of S over the temperature range 773 to 1073 K. The results were in good agreement with those reported by other authors based on the different methods.
From these results the thermodynamic behaviors of the liquid solution of bismuth and sulfur were discussed. The standard molar Gibbs energy of formation of solid Bi2S3 was calculated from these thermodynamic functions over the temperature range 793 to 993 K as follows:
(This article is not displayable. Please see full text pdf.)抄録全体を表示PDF形式でダウンロード (594K) -
黒木 克郎, 佐藤 駿, 和田 敏哉1980 年 44 巻 4 号 p. 419-424
発行日: 1980年
公開日: 2008/04/04
ジャーナル フリーAs a method for making highly oriented (110)[001] textured silicon steel, AlN and MnS are used as an inhibitor which retards the primary grain growth and induces the secondary recrystallization on high temperature annealing.
In the process, precipitation annealing prior to cold rolling is needed to achieve stable secondary recrystallization.
Here, the mechanism of precipitation stabilizing the secondary recrystallization was studied.
On precipitation annealing, the numbers and average diameters of the precipitates increased, but they were held in a dispersion with a little change during final isothermal annealing as a result of retarded Ostwald ripening. During isothermal annealing, the growth of the primary grains was drastically inhibited, and the (110)[001] secondary recrystallization was induced on high temperature annealing.
It was concluded that the stabilization of the precipitates up to a high temperature played an important role in the precipitation annealing.抄録全体を表示PDF形式でダウンロード (1342K) -
山脇 道夫, 五十嵐 孝雄, 米岡 俊明, 菅野 昌義1980 年 44 巻 4 号 p. 425-430
発行日: 1980年
公開日: 2008/04/04
ジャーナル フリーOxidation of pure vanadium has been investigated at temperatures of 702∼1087 K and oxygen pressures of 13.3 and 133 Pa by means of a thermo-electrobalance, X-ray diffraction analysis and metallographic technique. Except a few specimens oxidized at higher temperatures, the oxidation proceeded according to parabolic rate law. The obtained parabolic rate constants exhibited no pressure dependence at each temperature. The Arrhenius plot of the parabolic rate constants showed an obvious discontinuity at around 800 K. The cause of this discontinuity was attributed to the change of the substrate composition that occurred in the vicinity of that temperature. The activation energy for the parabolic oxidation process was evaluated to be 104 kJ/mol in the temperature range of 800∼993 K. Scale of columner crystallines of VO2 was found to grow on most specimens and a considerably large amount of oxygen was dissolved into the substrate metal with a strong temperature dependence.抄録全体を表示PDF形式でダウンロード (662K) -
津田 大, 伊藤 太一郎, 中山 豊1980 年 44 巻 4 号 p. 431-435
発行日: 1980年
公開日: 2008/04/04
ジャーナル フリーThe deformation behavior was studied on the age hardened Cu-5 at%Ni-2.5 at%Al alloy single crystals, initially quenched from 1173 K and aged at 623∼773 K up to 3600 ks. The results obtained are as follows.
(1) The critical resolved shear stresses (CRSS) had maximum by ageing at 773 K for 2160 ks. By ageing at lower temperatures, CRSS continued to increase, though much lower than the values at 773 K.
(2) By ageing at 773 K, spherical precipitates grew, distributed uniformly and were coherent with the matrix. The electron diffraction pattern showed that precipitates were Ni3Al with L12 type ordered structure.
(3) Single crystals exhibited three stage hardening. In stage I Lüders type deformation occurred. Slip bands became more and more localized and concentrated as the ageing proceeded.
(4) Piled-up arrays of dislocations were typical structure in the aged crystals. In both the polycrystalline specimens and single crystals, however, dislocation pairs on the same slip plane, that is, superlattice dislocations, were observed sometimes.
(5) The above-mentioned results suggest that the interaction of dislocations with the strain field of precipitates and the cutting of ordered precipitates by superlattice dislocations are the main mechanisms that govern the strength of the age-hardened Cu-5 at%Ni-2.5 at%Al alloys.抄録全体を表示PDF形式でダウンロード (1341K) -
飛田 守孝, 助台 栄一, 横張 幸男, 長川 明弘1980 年 44 巻 4 号 p. 436-442
発行日: 1980年
公開日: 2008/04/04
ジャーナル フリーThe relationship between the mechanical properties and the thermal instability of β Ti-Mo alloys was studied by hardness testing, the detailed observations of the surfaces and microstructures and the investigation of the behaviour of tensile deformation on Ti-5, 14 and 20 wt%Mo alloys. The results botained are as follows.
(1) It is shown from the dependence of hardness changes upon isochronal ageing temperature that the thermal instability is largest and the ω phase is readily formed in Ti-14 wt%Mo alloy.
(2) By cold rolling, the formation of the ω phase in Ti-14 wt%Mo alloy is apparently promoted. However, such a phenomenon cannot be detected in Ti-20 wt%Mo alloy.
(3) In tensile testing at 77 to 300 K, it appears that Ti-14 wt%Mo alloy has excellent mechanical properties having homogeneous deformation with remarkable elongation and linear work hardening rate, and Ti-20 wt%Mo alloy shows local deformation with small elongation.
(4) Ti-14 wt%Mo alloy in tension is mainly deformed by {332}β twinning and in the twin bands, an athermal ω phase as stress induced product is formed. Ti-20 wt%Mo alloy in tension is mainly deformed by slipping, and dislocation bundles and stacking faults are observed though twins are not detected.
(5) In such a thermally instable β phase such as in Ti-14 wt%Mo alloy, it seems that there is a definite relation between the formation of the ω phase and twinning, and that the remarkable elongation correlates to the formation of twins.抄録全体を表示PDF形式でダウンロード (1170K) -
飯田 孝道, 佐藤 明夫, 石裏 眞治, 石黒 進, 森田 善一郎1980 年 44 巻 4 号 p. 443-452
発行日: 1980年
公開日: 2008/04/04
ジャーナル フリーIn order to determine the viscosity of liquid by the oscillating vessel method with high accuracy, an investigation was made on the relationship between the logarithmic decrement of the oscillations of a suspended system and the viscosity of liquid.
First, improvements were made on the viscosity apparatus such as the balance weight in order to obtain the precise values of measurement on the logarithmic decrement.
In the equation proposed by Roscoe, which has frequently been used to calculate the absolute and accurate viscosity of liquid from the measured logarithmic decrement, corrections for the end, slipping and meniscus effects are not sufficiently discussed. Therefore, Roscoe’s formula was examined by experiment using the viscometer calibrating liquids such as Hg, In, Sn, Bi and Pb whose viscosities had been measured by a theoretically established capillary method. The results showed that Roscoe’s equation did not necessarily provide reliable viscosity values. A correction for Roscoe’s equation was made so as to derive reasonable values of viscosity. The corrected Roscoe’s formula appears to give precise values of viscosity of liquid.
Based on the above investigation, the logarithmic decrement of liquid zinc was measured precisely in the temperature range from 700 to 913 K by the oscillating vessel method, and its viscosity was determined by the corrected Roscoe’s formula that connects the logarithmic decrement with the viscosity of liquid.
The variation of the viscosity η (in Pa·s) with absolute temperature T is expressed by the following relationship:
(This article is not displayable. Please see full text pdf.)
The value of the melting-point viscosity of 3.50×10−3 Pa·s for liquid zinc was obtained from the above equation.
The viscosity data of zinc determined in this work are thought to be accurate within the absolute error of about ±4%.抄録全体を表示PDF形式でダウンロード (898K) -
梅本 実, 渡井 康之, 田村 今男1980 年 44 巻 4 号 p. 453-458
発行日: 1980年
公開日: 2008/04/04
ジャーナル フリーThe transition temperature of martensite morphology in Fe-Ni-C alloys from butterfly to lenticular as a function of carbon content was studied. To specify the formation temperature, the martensites were formed either by cooling just below Ms or induced by deformation at above Ms. The effect of Cr addition to the Fe-Ni-C alloys on the transition temperature of martensite morphology from butterfly to lenticular was also studied.
\ oindentThe main results obtained are as follows.
(1) The transition temperature of martensite morphology from butterfly to lenticular in Fe-Ni-C alloys does not depend on the carbon content. From room temperature to 270 K, only butterfly martensite forms, between 270 K and 210 K both butterfly and lenticular martensites form and below 210 K only lenticular martensite forms.
(2) There are two processes to form the mixed structure of butterfly and lenticular martensites. One is butterfly forms first and then lenticular martensite forms independently. Another is lenticular martensite forms first and which induces butterfly martensite around it.
(3) By the addition of Cr to Fe-Ni-C alloys, the transition temperature from butterfly to lenticular decreases 40 K per 1%Cr.抄録全体を表示PDF形式でダウンロード (1620K) -
木村 宏1980 年 44 巻 4 号 p. 459-460
発行日: 1980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 (220K)
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