日本金属学会誌
Online ISSN : 1880-6880
Print ISSN : 0021-4876
ISSN-L : 0021-4876
51 巻, 3 号
選択された号の論文の15件中1~15を表示しています
  • 田頭 孝介, 住田 則行, 早川 尚, 菊地 千之
    1987 年 51 巻 3 号 p. 167-173
    発行日: 1987年
    公開日: 2008/04/04
    ジャーナル フリー
    Effect of Si on the formation of Mn-C dipoles in low carbon steels has been investigated. The changes in electrical resistivity were measured at 77 and 273 K during isothermal ageing for quenched Fe-Si-Mn-C alloys containing various Si contents (0-0.8 at%). The deviation from Matthiessen’s Rule (DMR) was given by the difference between the electrical resistivities at 77 and 273 K. In the Si-free steel the DMR decreased during the ageing when quenched from 823 and 973 K, whereas the DMR increased when quenched from 673 and 773 K. This result showed that Mn-C dipoles retained after quenching were decomposed during ageing and single Mn atoms in solution increased. The amount of Mn-C dipole or its binding energy increased with the increase of Si content up to 0.4 at%. It was suggested that the potential energies at the Fe-Mn, Fe-Fe and Fe-Si interstitial sites increased in that order by the addition of Si to the Fe-Mn-C system. Thus C atoms were trapped at the Fe-Mn interstitial sites, accelerating the formation of Mn-C dipoles. The amount and the binding energy of the Mn-C dipole became saturated with the Si content in excess of 0.4 at%. The formation of dipoles at the Fe-Mn sites was considered to be restrained by the repulsive interaction with excessive Si atoms.
  • 草開 清志, 久保 孝, 大岡 耕之, 松山 政夫, 渡辺 国昭
    1987 年 51 巻 3 号 p. 174-180
    発行日: 1987年
    公開日: 2008/04/04
    ジャーナル フリー
    The tritium thermal desorption analysis for iron was carried out in order to elucidate the trapping sites of hydrogen and to obtain the activation energy of tritium desorption from each trapping site in iron.
    The results obtained in this study are as follows;
    (1) Four desorption peaks of tritium with maxima at about 500, 620, 900 and 1100 K, which were designated as peaks 1, 2, 3 and 4, respectively, were detected in both cold-rolled and annealed irons in the thermal analyses. This result suggests that there are at least four kinds of tritium trapping site in iron.
    (2) The intensity of peak 1 which appears remarkably in the cold-rolled iron decreases by annealing the specimen.
    (3) The total amount of desorbed tritium, namely the total amount of absorbed tritium, in the cold-rolled iron is much larger than that in the annealed one.
    (4) The activation energies for desorption of tritium from the trapping sites were estimated. Peaks 1, 2 and 3 in the cold-rolled iron, they were estimated to be 56.5, 75.3 and 17.6 kJ/mol, respectively. Peaks 2 and 3 in the annealed iron, they were estimated to be 31.0 and 14.2 kJ/mol, respectively. Peaks 1 and 2 can be assigned as tritium release from dislocation and/or vacancy and iron nitride precipitate, respectively.
  • 岩 親裕, 猪飼 靖, 松田 勝
    1987 年 51 巻 3 号 p. 181-186
    発行日: 1987年
    公開日: 2008/04/04
    ジャーナル フリー
    A new procedure is demonstrated to comprehend fatigue phenomena. The internal stress and the effective stress in a material are defined to analyze the fatigue process. The internal stress is attributed to the dislocation structure developed during fatigue. From this viewpoint, fatigue tests were carried out and some characteristics such as internal stress, effective stress and hysteresis loop were measured. The internal and effective stresses were measured by means of the strain dip test.
    The main results are as follows:
    (1) The internal stress increased with the progress of fatigue.
    (2) The effective stress obtained during fatigue under a maximum stress larger than the fatigue limit (over-stress) was larger than that under or below the fatigue limit (under-stress).
    (3) During fatigue under manifold multiple-repeated stress in two stress levels (over-stress and under-stress), both the effective stress and the plastic strain range measured at the under-stress increased by the over-stress loading.
    (4) The effective stress depended on plastic strain rate.
    From those results, the concept of internal stress is anticipated to contribute not only to the understanding of fatigue mechanism but also to the establishment of a cumulative damage rule.
  • 石原 守, 安原 征治
    1987 年 51 巻 3 号 p. 187-193
    発行日: 1987年
    公開日: 2008/04/04
    ジャーナル フリー
    The fatigue crack growth behavior of roll clad steel plate, overlaying clad steel plate, and SM41B, 2\frac14Cr-1Mo steel plates was investigated by use of the surface crack specimens. The fracture surface of these plates was also analyzed quantitatively by using the fractographic method.
    The results obtained are summarized as follows.
    (1) For both roll and overlaying clad steels, the fatigue crack growth rate, db/dN, retarded slightly near the clad interface.
    (2) The intergranular facet was observed on the fracture surface of SM41B and base metals of roll clad steel and overlaying clad steel. In all cases, the shape of its observed region was half elliptical.
    (3) The stress intensity factor ranges, ΔKb and db/dN, at the location where the intergranular facet disappeared were nearly constant for SM41B and roll clad steel.
  • 浅岡 照夫, 斎藤 秀雄, 野川 憲夫, 森川 尚威, 石田 洋一
    1987 年 51 巻 3 号 p. 194-200
    発行日: 1987年
    公開日: 2008/04/04
    ジャーナル フリー
    By using electron microscopic tritium autoradiography and tritium release measurements, the hydrogen behavior in heat-treated Cr-Mo steels was analyzed.
    The optimum experimental conditions for autoradiography were first determined including the tritium charging of the sample, selection of nuclear emulsions, protective films of the sample surface, sub-zero temperature exposure and development.
    The autoradiographic observations by thin foil transmission electron microscopy, replica electron microscopy and electron microprobe analyser revealed that, prior austenite grain boundary, martensite-lath interfaces, precipitate-matrix interfaces and MnS inclusion-matrix were the trap sites for hydrogen in these steels. Tritium release measurement enabled us to separate quantitatively mobile and trapped hydrogen in these steels.
  • 溝口 数一, 前村 浩一郎, 山根 政博, 杉之原 幸夫
    1987 年 51 巻 3 号 p. 201-207
    発行日: 1987年
    公開日: 2008/04/04
    ジャーナル フリー
    The viscosities of Li2O-SiO2-Ga2O3 and BaO-SiO2-Ga2O3 melts were measured in order to clarify the behaviour of M2O3 in the composition range of molar ratio M2O3/MeO>1, and the viscosity data on each gallosilicate were arranged using the parameter Pη(1) and Pη(2) corresponding to the composition ranges of molar ratio M2O3/MeO≤1 and M2O3/MeO≥1, respectively.
    The parameter Pη(1) and Pη(2) are expressed by
    (This article is not displayable. Please see full text pdf.)
    \ oindentwhere ZMe is the electric charge of Me ion, ni is the ion fraction of i ion, XiGa is the ratio of tetrahedrally coordinated Ga3+ ions to the total Ga3+ ions and KGa is the correction factor to the XiGa on the excess Ga2O3 to MeO in the case of molar ratio Ga2O3/MeO>1.
    The viscosities measured in this study well explained by the parameters using KGa=0.56, XLiGa=0.559 and XBaGa=0.54. The viscosities of the CaO-SiO2-Al2O3 melts measured also showed a good relation to those calculated from the parameters using KAl=0.73 and XCaAl=0.63.
  • 上埜 修司, 早稲田 嘉夫
    1987 年 51 巻 3 号 p. 208-217
    発行日: 1987年
    公開日: 2008/04/04
    ジャーナル フリー
    A theoretical equation for the interaction parameters in multi-component metallic solutions has been described by the pseudopotential formalism for the free energy coupled with the free energy of the hard sphere model. The approximate equation for the pseudopotential term has also been proposed in terms of the heat of solution at infinite dilution, in order to allow simple evaluation of the interaction parameters in various multi-component systems.
    The present theory has been applied to 23 cases in non-ferrous alloys such as Pb-base and Sn-base solutions and the results of previous theoretical calculation by the hard sphere model alone, together with the further evaluation of the present work clearly suggest that the present theoretical equation by the pseudopotential formalism coupled with the hard sphere model yields a quantitatively correct prediction of the interaction parameters in multi-component metallic solutions. Numerical calculations were also made on 60 cases in Fe-base solutions closely related to steelmaking, and the agreement between calculation and experimental data appears to be at a reasonable level with the 90% reliability of agreement in sign.
  • 岩本 信也, 梅咲 則正, 平尾 一之, 曽我 直弘
    1987 年 51 巻 3 号 p. 218-227
    発行日: 1987年
    公開日: 2008/04/04
    ジャーナル フリー
    The molecular dynamics calculations assuming the ionic pair potential functions of the Born-Mayer-Huggins form have been carried out to elucidate the correlation between the atomic configuration and the properties in 2Li2O·SiO2 melt and glass. The calculated pair correlation functions were in good agreement with the radial distribution function RDF obtained from X-ray structural analysis, and the computer-simulated configuration seemed to be realistic. The Si-O stretching frequency spectra of 2Li2O·SiO2 melt and glass were analyzed through the Fourier transform of the change in distance between a Si4+ ion and its nearest-neighbor O2− ions and compared with the previously obtained Raman spectrum of this glass. As a result, the frequency spectra generated here were in satisfactory agreement with the Raman spectrum. Furthermore, it was indicated that this simulation technique can be used for estimating transport mechanism of Li+, Si4+, and O2− ions. Application of the molecular dynamics method to silicate melts and glasses would enable us to predict their structure and properties.
  • 中島 義行, 江崎 宏樹, 飛岡 正明, 時実 正治
    1987 年 51 巻 3 号 p. 228-233
    発行日: 1987年
    公開日: 2008/04/04
    ジャーナル フリー
    Diffusion bonding between hard metal (WC-Co) and tool steel (SK5) was carried out by holding at 1103 K for 3.6 ks under the applied pressure of 12 MPa in vacuum using Ni-foil as an insert metal. After such an operation, the specimens were subjected to the further heating at 1273 K (holding for various durations without loading pressure) in order to attain the advanced diffusion.
    The experimental results showed that both the decrease of the heating and cooling velocities during the bonding operation and the occurrence of martensitic transformation in the SK5 side of the bonded specimens quenched after heating at 1063 K introduce the reduction of internal stress in the inserted Ni-foil layer. These effects was a cause for an appreciable improvement of the bonding strength.
    A high value of bonding strength, 630 MPa, was obtained by the tensile test of the bonded specimens.
  • 中山 孝文
    1987 年 51 巻 3 号 p. 234-239
    発行日: 1987年
    公開日: 2008/04/04
    ジャーナル フリー
    The thermal expansion and thermomagnetization of Mn-16∼22%Ge-misch metal alloys comprising chiefly a (γ+ε) mixture phase were investigated in the temperature range from 120 to 570 K. Hardness measurements and turning and forging tests were carried out at room temperature. Compared with the experimental results and crystal structures, the relationship between machinability and structures was investigated.
    The thermal expansivity of the ternary alloys containing less than 1%misch metal is identical to that observed in the base alloys. While the magnetization of these alloys exhibits a small value, it rapidly increases with increase of misch metal content. When the Vickers hardness of these alloys is 50∼100 lower than that of the binary alloys by the addition of misch metal, the cutting capacity and forginability are improved. In the ternary alloys with misch metal, needle-like precipitates were observed in the grains and across the boundaries. It has become obvious that the higher machinability of the alloys with misch metal arises from the pinning effect of an appropriate amount of the precipitates. In particular, the Mn-19%Ge-0.5∼1.0%misch metal alloys are desirable because of their remarkable Invar characteristics, small values of magnetization and good machinability.
  • 森 信幸, 松尾 識, 大城 桂作, 松田 公扶
    1987 年 51 巻 3 号 p. 240-247
    発行日: 1987年
    公開日: 2008/04/04
    ジャーナル フリー
    The effect of Ni ion plating 0.05∼25 μm thick to graphite and of 1∼4%Ni addition to Al on the wettability of molten Al to graphite was measured by the sessile drop method in vacuum at temperatures from 973 K to 1273 K.
    The wetting angle between molten Al and graphite was hardly changed by the Ni addition to Al, and decreased with increasing temperature.
    On the contrary, Ni coating from the thickness of 0.1 μm up to graphite substrates remarkably improved the wettability of molten Al, and Ni coating thicker than 1 μm made the wetting angle below 30° at any temperature. With Ni coating of 0.1 to 1 μm thickness the wetting angle showed a tendency to increase with increasing temperature. This abnormal temperature dependence of Ni-coated substrates was considered to be due to the change in structure of the Ni coating layer with temperature. At high temperatures, Ni deposited on the substrate coagulated to produce many pores in the coating, and the wettability could be explained by Cassie’s equation for the composite surface of Ni and graphite. The wetting angle became smaller than 20° by Ni coating of 4 to 25 μm thickness and decreased with increasing temperature, which was lower than the wetting angle of molten Al to pure Ni substrate. This was explained from the viewpoint of the shape and growth rate of the reaction zone of Ni with molten Al.
  • 砥綿 真一, 生野 元, 山田 銑一
    1987 年 51 巻 3 号 p. 248-255
    発行日: 1987年
    公開日: 2008/04/04
    ジャーナル フリー
    Multifilament type silicon-carbide fiber-reinforced aluminum alloys with whiskers or particulates were prepared by the squeeze casting process. The effects of additions of whiskers or particulates on the microstructure, strength and transverse fracture behaviour of the composites were investigated.
    The results obtained are as follows:
    (1) For Al-4.5%Cu matrix composite, the large CuAl2 phase were observed around and among the fibers in the conventional fiber composite. In the whisker or particulate hybrid composites, Cu appeared to be segregated in the regions of whiskers or particulates. (2) Longitudinal flexural strength was improved by the additions of whiskers or particulates. (3) Transverse flexural strength was also improved by the additions of whiskers or particulates. Transverse flexural fracture occurred at the fiber-matrix interface for the conventional composites, but occurred in the matrix near the interface for the whisker or particulate hybrid composites. (4) Since the hybrid effect in the present study arose from the separation of continuous fibers, the matrix can easily infiltrate among the fibers. Also the growth of the brittle second phase of the Al-Cu alloy, CuAl2, is inhibited around and among the fibers by the additions of whiskers or particulates.
  • 福井 康二, 西尾 孝幸, 岩間 義郎
    1987 年 51 巻 3 号 p. 256-261
    発行日: 1987年
    公開日: 2008/04/04
    ジャーナル フリー
    Ribbons with compositions of Sm(Co0.70−xFe0.20Cu0.10Zrx)7.5, x=0∼0.06, have been prepared by melt-spinning technique, in order to examine the change of their magnetic properties and structures with Zr content. Under their optimum-aged conditions, the value of coercivity increases drasticaly with the increase of Zr content, x, when 0.02<x<0.04. When x=0.04, the maximum value of coercivity, 1.15 MA/m, is achieved. With the increase of coercivity, the two phase cellular structure composed of the 1-5 and 2-17 phases changes into the three-phase cellular structure superimposed by the 1-3 phase. And the Curie temperatures of the 1-5 and 2-17 phases change very slightly with Zr content.
  • 1987 年 51 巻 3 号 p. 261a
    発行日: 1987年
    公開日: 2008/04/04
    ジャーナル フリー
    PDFを参照. (誤)酸素量は15.6 mass%) (正)酸素量は15,6 mass%)
  • 1987 年 51 巻 3 号 p. 261b
    発行日: 1987年
    公開日: 2008/04/04
    ジャーナル フリー
    PDFを参照. (誤)s電子密度の減少を意味しており, (正)s電子密度の増加を意味しており,
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