Journal of the Japan Institute of Metals and Materials
Online ISSN : 1880-6880
Print ISSN : 0021-4876
ISSN-L : 0021-4876
Volume 37 , Issue 9
Showing 1-18 articles out of 18 articles from the selected issue
  • Kazuo Nagakura
    1973 Volume 37 Issue 9 Pages 933-937
    Published: 1973
    Released: April 04, 2008
    High purity gold wires were recovered and recrystallized after cold-working of 10∼88%, and the changes in electrical resistivity (Δρ) and thermo-electric power (ΔS) with the structural change were compared by using the Nordheim-Golter relationship at −30°C.
    The characteristic value of ΔSΔρ for the vacancies was calculated to be −0.65±0.2 V/deg Ω cm from the result of the recovery in the vicinity of room temperature.
    The ΔSΔρ value for the dislocations was +0.74±0.07 V/deg Ω cm as obtained from the results of the work-hardening and recrystallization in the lower deformation range up to 60%.
    Moreover, the ΔSΔρ value in the early stage of recrystallization in the higher deformation range over 60% decreased to a value of +0.45±0.06 V/deg Ω cm which was lower than that for the dislocations.
    From the above facts, it seems most probable that the formation of stacking faults results in the decrease of the ΔSΔρ value.
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  • Ry\={u}ta Onodera, Seiz\={o} Teshima
    1973 Volume 37 Issue 9 Pages 938-944
    Published: 1973
    Released: April 04, 2008
    Ductile fracture and lattice rotation in the necked region was studied in a Fe single crystal deformed in tension at room temperature. The crystal whose initial orientation was nearly parallel to [011] underwent necking by two slip bands crossing each other, and in the necked region the [011] direction tilted toward the center of the narrowest section.
    In the necked region of the crystal necked by only one slip band, the direction of lattice rotation was opposite to that occurring during uniform elongation. The lattice rotation in the necked region could be explained by the formation of tilt boundaries at the edges of main slip band by the secondary slip.
    The crystal having two slip bands either raptured at the chisel edge or fractured in a double wedge manner through the formation of an internal cavity. The crystal having only one slip band fractured always in the double wedge manner, and the contraction of area by fracture is smaller than that in the case of the two slip bands. This could be due to the difference in the number of voids which contribute to the formation of the internal cavity and also in the degree of inclination of the elongated voids to the tensile axis.
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  • Yoshiyuki Miwa, Nobuhiro Iguchi
    1973 Volume 37 Issue 9 Pages 945-950
    Published: 1973
    Released: April 04, 2008
    The formation of austenite by rapid heating has influence on the transformation characteristics on cooling and offers substantial problems concerning the hardenability of steels. And the transformation on rapid heating has been keeping deserving its importance in the field of strengthening of steels. However, it has not been established so far whether the α→γ transformation occurs in a diffusion or diffusionless mode.
    In the present study the test specimen (thickness of 0.1 mm) was heated by 85 kVA electric power of spot welder, and Ac3 points by various heating rates up to the order of 107°C/sec were measured by a PbS cell heat radiater.
    The main results obtained are as follows:
    (1) The heating cycle under the speed of 107°C/sec was recorded by the PbS cell heat radiater.
    (2) The PbS cell heat radiater was sufficient to detect the α→γ transformation temperature on super-rapid heating.
    (3) The increments of transformation temperature from the equilibrium point (Ac3) in pure iron with increasing heating rate (0∼107°C/sec) were determined. As one of the results, Ac3f was around 1100°C at the heating rate of 107°C/sec. This means that the α→γ transformation is not intercepted by super-rapid heating.
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  • Tetsuji Noda, Kiyokatsu Kudo, Norio Sato
    1973 Volume 37 Issue 9 Pages 951-957
    Published: 1973
    Released: April 04, 2008
    The anodic passivation film formed on iron in neutral borate-buffer solution has been studied by using ellipsometric, electrochemical, and gravimetrical techniques. The film can be dissolved from its outer surface by applying a cathodic current in borate-buffer solution at pH 6.35 in which the reductive dissolution,
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    \ oindentproceeds at 100 per cent current efficiency. Ellipsometric measurements carried out during the galvanostatic-cathodic reduction of the film in this solution reveals that the film consists of two layers, an inner layer with the optical constant 3.0−0.5i and an outer layer with the constant 1.8−0.1i. It is also shown that the density of the inner layer is in agreement with that of γ-Fe2O3.
    The inner layer thickness increases linearly with the passivating potential, and the potential extrapolated at zero thickness of the inner layer corresponds to the equilibrium potential of the anodic formation of γ-Fe2O3,
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    \ oindentThe outer layer, however, is not directly related to the anode potential.
    Thermo-gravimetrical measurements indicate that the film contains some amount of water which is concentrated in the outer layer. The average composition of the outer layer is estimated as Fe(OH)3.
    A film model is proposed in which the inner layer of anhydrous γ-Fe2O3 is the cause of the potential drop in the film producing a field intensity of 5.6×106 V/cm and the outer layer of hydrous ferric oxide depends on the solution environment and passivation process.
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  • Mikio Inoue, Isamu Yoshii, Reiichi Ohno
    1973 Volume 37 Issue 9 Pages 958-963
    Published: 1973
    Released: April 04, 2008
    In order to determine the rates of evaporation of silver from liquid Cu-Ag alloys under vacuum, copper, silver and Cu-Ag alloys are melted in vacuum at temperatures from 1100 to 1400°C by use of a high-frequency induction furnace. The rates of evaporation of copper at 1200 and 1300°C are much higher than those in previous studies, some of which are considered to show the maximum rate of its evaporation. This can be explained by the idea that the temperature of the surface of the liquid copper is higher than that in the bulk. The rates of evaporation of silver from liquid Cu-Ag alloys follow first-order kinetics and the rate constants at the measuring temperatures of 1200, 1280 and 1400°C range from 2.2×10−3 to 5.2×10−3 cm·sec−1. Most observed values of the evaporation coefficient defined by Olette on the basis of the Hertz-Langmuir-Knudsen equation are in the range of 23 to 55. The calculated ratios of the concentration of silver at the surface of the liquid alloy to that in the bulk (CsCb) at 1200 and 1280°C are greater than unity in disagreement with the experimental results.
    This disagreement can be explained by the idea that the temperature of the surface of the liquid alloy is higher than that in the bulk as in the case of pure liquid copper. The surface temperatures calculated on the basis of an equation explaining the relation between the observed and calculated evaporation coefficients in iron alloys are 1340, 1350∼1380 and 1400°C at the measuring temperatures of 1200, 1280 and 1400°C, respectively. It is considered that the observed rate constants and evaporation coefficients show their values at these surface temperatures. Evaporation coefficients calculated at the surface temperatures are 60 to 70, being generally greater than the observed ones. Values of CsCb at the surface temperatures, which were calculated from the values of evaporation coefficients on the basis of the above equation, are 0.5 to 0.7. This shows that the rates of evaporation of silver are mixed controlled.
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  • Yoshiaki Umehara, Shigeyasu Koda, Sosuke Uchida
    1973 Volume 37 Issue 9 Pages 964-968
    Published: 1973
    Released: April 04, 2008
    An eutectic alloy of InSb-MnSb has been unidirectionally solidified at various rates of solidification in order to investigate the structure change due to the solidification condition.
    The results obtained are as follows:
    (1) The spacing λ between the MnSb rods was expressed to be linear to R−1⁄2, where R is the rate of solidification, and λ2R was 1.50×10−10 em3/sec.
    (2) The alloy specimens consisted of polycrystalline columnar grains which elongated to the solidification direction. The crystallographic orientation relationship between the InSb and MnSb phases was determined by X-ray diffraction. A preferred relationship observed can be stated approximately:
    Growth direction: ⟨110⟩InSb\varparallel⟨0001⟩MnSb
    Coherent interface: {110}InSb\varparallel{10\bar10} or {11\bar20}MnSb
    (3) The phase interface energy between the InSb and MnSb phases was determined from a dislocation model considering the mismatch at the interface and equal to 1.18×103 erg/cm2. Assuming that the crystal growth followed Jackson’s model, and also using this phase boundary energy, the diffusion coefficient was evaluated as D=1.5×10−5 cm2/sec.
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  • Masaru Okuyama, Shiro Haruyama
    1973 Volume 37 Issue 9 Pages 969-977
    Published: 1973
    Released: April 04, 2008
    The thickness and chemical composition of passive films formed on Fe-Ni alloys with various Ni contents were estimated by means of coulometry at potentiostatic-anodic oxidation and galvanostatic-cathodic reduction. The amounts of Fe2+ and Ni2+ dissolved during the oxidation and reduction were determined by colorimetric analysis. The passive films were found to consist of a mixture of Fe3O4, γ-Fe2O3, NiO and Ni3O4. At the potentials over 800 mV, NiO2 was formed from Ni3O4. The thickness of the passive films increased almost linearly with the anodic potential and was estimated to be 15∼81 Å. The film thickness was also found to increase with increasing Ni content, showing a critical value at 30 Ni wt%. This tendency is similar to the dependence of corrosion resistivity on Ni content. The Ni content in surface oxide films enriched during the passivation in lower pH solutions, while no enrichment occurred in higher pH solutions.
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  • Yoshinobu Motohashi, Syuichi Otake
    1973 Volume 37 Issue 9 Pages 978-985
    Published: 1973
    Released: April 04, 2008
    Bismuth single crystals with various orientations for which the Schmid factor of the (111)⟨1\bar10⟩ glide system has a small value are deformed in tension. The stress-strain curves, slip bands and dislocation etch-pit distribution for the observed {001}⟨\bar1\bar10⟩ glide systems are investigated.
    Principal results obtained are as follows:
    (1) The active slip plane is {001} and the slip direction is ⟨\bar1\bar10⟩ or ⟨110⟩ among all the orientations tested. The slip plane {001} contains the most close-packed direction ⟨1\bar10⟩, but slip to the ⟨1\bar10⟩ direction is not observed. (2) Resolved shear stress vs. resolved shear strain curves show a fairly long transition stage in the process of yielding from elastic proportionally limit (microscopic yielding) to the flow (easy glide) region. (3) Yield and flow stresses of the crystals are greatly influenced by the strain rate, and at a high strain rate the crystals are deformed by twinning with a little ductility. (4) Slip band patterns of the crystal surfaces are fine and are rather wavy as compared with those observed on the (111)⟨1\bar10⟩ glide. This means the difference in dislocation behaviour between the (111)⟨1\bar10⟩ and {001}⟨\bar1\bar10⟩ glide systems. (5) Dislocation etch-pit distribution is at random in the transition region from microscopic to macroscopic yielding.
    In the easy glide region the etch-pits initiate their distribution parallel to the slip plane, and the distribution develops with increasing strain.
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  • Masaki Kobayashi, Fumio Noguchi, Yasuaki Ueda
    1973 Volume 37 Issue 9 Pages 986-992
    Published: 1973
    Released: April 04, 2008
    The kinetics and mechanism of the chloride volatilization of CuO by HCL-Ar mixture gas were investigated using thermogravimetric analysis under the various chloridizing conditions. The results obtained are summarized as follows.
    (1) The overall reaction products were gaseous and liquid cuprous chloride within the temperature range of 600 to 900°C. The rate of chlorination was controlled by the two processes; one is the diffusion of HCL gas through the gas film boundary layer and the other is the vaporization of Cu2Cl2(l) at the surface of the sample, and it was found that they play a major role in controlling the reaction of chlorination.
    (2) In the diffusion-controlled zone, the rate of chlorination was affected significantly by the partial pressure of HCL and the gas flow rate. However, it was scarcely affected in the vaporization-controlled zone.
    (3) The activation energy obtained from the relation between the rate of chlorination and temperature was found to be 3.0 kcal per mol for the diffusion-controlled zone and 20.6 kcal per mol for the vaporization-controlled zone, respectively.
    (4) The phenomena of weight increase and parabolic weight loss were observed in the initial reaction stage of the vaporization-controlled zone under the various chloridizing conditions. These phenomena may be explained by the rate equation which considered the mechanism of nuclear formation and growth of Cu2Cl2(l).
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  • Yoshiaki Umetsu, Tatsuhiko Ejima
    1973 Volume 37 Issue 9 Pages 993-997
    Published: 1973
    Released: April 04, 2008
    Phase diagram of the PbCl2-ZnCl2 binary system has been determined and compared to the previous ones. In addition, the density of the PbCl2-ZnCl2 binary melt has been measured as accurately as possible by the Archimedean method with two spherical sinkers made of platinum of different sizes. The results obtained are summarized as follows: Phase diagram of the PbCl2-ZnCl2 binary system shows an eutectic at 23 mol% PbCl2, 286°C and an inflection of the liquidus in the composition range of 40∼50 mol% PbCl2.
    Density shows an approximately linear decrement with rising temperature. Molar volume deviates negatively from the additivity over the entire system. There are inflection points at about 50 mol% PbCl2 for the plots of thermal expansion coefficient and temperature coefficient of density vs. composition. This may indicate some structural change in the PbCl2-ZnCl2 melt.
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  • Yoshiaki Umetsu, Yoshikazu Ishii, Takahisa Sawada, Tatsuhiko Ejima
    1973 Volume 37 Issue 9 Pages 997-1004
    Published: 1973
    Released: April 04, 2008
    Electric conductivities of the PbCl2-ZnCl2 binary melts have been measured by the use of a U-shaped cell having a relatively high cell constant. Viscosities of these melts have also been determined by using the oscillating vessel method for the low viscosity melts and the falling body method for the higher viscosity melts.
    Changes in the liquid structure or the constituent ionic species have been estimated on the basis of the results obtained. The results are summarized as follows:
    (1) Molten ZnCl2 exhibits much lower electric conductivity and very high viscosity as compared with other chlorides. This seems to indicate the associating property as previously suggested by others workers.
    (2) Electric conductance does not obey the Rasch-Heinrichsen equation, κ=Aκexp(−EκRT), at any composition due mainly to the thermal decomposition of large structure units.
    (3) Specific conductivity increases and viscosity markedly decreases as the content of PbCl2 mcreases.
    (4) Apparent activation energies for electric conductance and viscous flow drastically decrease by the addition of PbCl2 to ZnCl2 but they become nearly constant values which are similar to the values for pure PbCl2 in the range of 50∼100 mol% PbCl2.
    (5) It is estimated from the results that the associating property of ZnCl2 is weakened by the addition of PbCl2 which is considered as a salt with a relatively high ionic dissociation tendency and also that single ions become predominant ionic species in the PbCl2 rich side.
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  • Hakaru Masumoto, Shôhachi Sawaya, Michio Kikuchi
    1973 Volume 37 Issue 9 Pages 1005-1010
    Published: 1973
    Released: April 04, 2008
    Measurements of Young’s modulus at −150∼400°C and of rigidity modulus, thermal expansion and hardness at room temperature have been carried out with Mn-Ni-W and Mn-Ni-W-Mo alloys subjected to various heat treatments and cold working. Young’s modulus vs temperature curves of the ternary and quarternary alloys slowly cooled after heating for 1 hr at 950°C showed distinct anomalous changes associated with antiferromagnetic\ ightleftarrowsparamagnetic transformation. Young’s modulus at room temperature does not show any great difference by the states of cold working and heat treatment, but it tends to increase with increasing manganese, tungsten or molybdenum content. The temperature coefficient of Young’s modulus is greatly affected not only by annealing, water quenching, cold working and reheating after water quenching or cold working but also by alloy composition. The positive temperature coefficient of Young’s modulus exist in a wide composition range, showing the appearance of the Elinvar property. The variation of rigidity modulus and its temperature coefficient with heat treatment, cold reduction rate and composition is quite similar to that of Young’s modulus and its temperature coefficient. The hardness shows a very complicatd change about 100 to 600 within the range of in Vickers hardness by the aforementioned treatments. The ternary and quarternary alloys have fairly good corrosion resistivity.
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  • Sakae Takeuchi, Kenji Suzuki, Masakatsu Misawa, Fumitake Ito, Katsuhik ...
    1973 Volume 37 Issue 9 Pages 1011-1018
    Published: 1973
    Released: April 04, 2008
    The magnetic susceptibilities and electric resistivities of liquid copper alloys of Cu-Bi, Cu-Sn and Cu-In were measured as functions of compositions at temperatures in the neighborhood of 1000°C.
    In the liquid Cu-Bi alloy, the observed magnetic susceptibility and electric resistivity were well explained under the assumption of a random distribution of Cu and Bi ions in an electron gas atmosphere consisting of their valence electrons.
    In the liquid Cu-Sn and Cu-In alloys, an anomalous behaviour of magnetic susceptibility and electric resistivity was observed. It was shown that the observed deep valleys of diamagnetism in the magnetic susceptibility curves of both liquid alloys corresponded to the peaks of heat evolution in the heat of mixing curves for the same alloys observed in our previous report. From the comparison of the observed curves of magnetic susceptibility with theoretical curves calculated by taking account of a contribution from nR pseudo-molecules, it was found that about two electrons were localized in the pseudo-molecule for both liquid alloys near 1100°C and the observed deep valley of diamagnetism corresponded to the distribution curve nR of pseudo-molecules.
    Electric resistivities for both liquid alloys are given by the sum of contributions from scattering by randomly distributed free ions and pseudo-molecules. The former contribution ρ1 can be calculated using a hard sphere model with the Ashcroft potentials, and the latter contribution ρ2 can be assumed to be in proportion to the distribution function nR of the pseudo-molecule in the liquid alloy on the basis of its flexible structure.
    For both alloys, such a proportional relationship was shown to be reasonable by comparing the nR curve with a curve of (ρ−ρ1) which was obtained by subtracting ρ1 from the observed total resistivity.
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  • Noriyuki Kuwano, Chiken Kinoshita, Yoshitsugu Tomokiyo, Tetsuo Eguchi
    1973 Volume 37 Issue 9 Pages 1019-1025
    Published: 1973
    Released: April 04, 2008
    The annealing behavior of Cu-14.2 at% Al alloys was investigated by means of X-ray diffraction, supplemented with micro-Vickers hardness and specific heat measurements. Samples filed at room temperature were step-annealed from room temperature up to 500°C. Effective domain sizes and rms microstrains were determined from diffraction line profiles by Fourier analysis. Stacking fault probabilities and lattice parameters were calculated from shifts in the peak maximum position by the least squares analysis.
    The experimental results are interpreted as follows:
    (1) The increase of the lattice parameter on deformation of αCu-Al alloys might be due to the destruction of short range order (SRO).
    (2) Filing is more efficient in producing a disordered state in αCu-Al alloys at room temperature than quenching from a high temperature.
    (3) Step-annealing treatment shows that the recovery of SRO, the annihilation of stacking faults and the growth of domains take place in turn with increasing temperature.
    (4) The increase of the asymmetry of the diffraction line profile in filed αCu-Al alloys on annealing might involve the effect of the local ordered segregation of solute atoms which is considered as the origin of anneal-hardening.
    (5) Kinetic study shows that the effective order and activation energy for the reaction which describe the variation in stacking fault probability in the second stage of annealing process are approximately 2 and 43 kcal/g·atom, respectively.
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  • Hideo Umezawa, Tsutomu Mori, Tadahisa Nakamura
    1973 Volume 37 Issue 9 Pages 1026-1030
    Published: 1973
    Released: April 04, 2008
    Single crystals of copper with a volume fraction of 0.004 of spherical SiO2 particles were deformed at −196, 18 and 100°C in tensile tests. Thin foils were prepared from each specimen and examined under an electron microscope in order to observe the void formation at the interface between the SiO2 particles and the matrix. It was found that there existed a critical strain for the void formation. The magnitude of the critical strain decreased as the temperature was lowered and as the size of the SiO2 particles increased. This temperature dependece of the critical strain for the decohesion of the particles was attributed mainly to the annealing effect through diffusion during deformation at higher temperatures. The dependence of the critical strain for the decohesion on the size of the SiO2 particles at −196°C was disscussed in conjunction with existing theories and it was concluded that the theory based on the energy consideration reasonably explained the observed size dependence of the decohesion strain.
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  • Osamu Okuno, Ishi Miura
    1973 Volume 37 Issue 9 Pages 1031-1037
    Published: 1973
    Released: April 04, 2008
    The effects of elasticity, strength and work hardening of matrices on micro-mechanics of discontinuous fiber composite alloys were investigated by means of the Moiré pattern technique. Pb-5% Sn alloy containing a short stainless steel fiber and pure Ni containing a short W fiber were studied as the two-dimentional models of the discontinuous fiber composite alloys. Uniaxial tensile loading which was parallel to the fiber was considered. The following results were obtained:
    (1) The shear strains in the matrix along the fiber-matrix interface of stainless steel/Pb-5% Sn were larger than that of W/Ni under almost the same maximum value of fiber strain. And, in both cases, the maximum shear strains in the matrix along the fiber-matrix interface were over the yield shear strains of the each matrix even at a little loading to the composite.
    (2) Stress distribution in a discontinuous fiber almost agreed with Kelly-Tyson’s equaition and Piggott’s equation. But, it did not agree with Piggott’s assumptions, because the maximum shear strain in the matrix was over the yield shear strain of the matrix in the entire region.
    (3) The larger the maximum value of fiber strain ef max, the higher the shear strain concentration factor τm maxef max at the fiber-matrix interfaces. The concentration factor of stainless steel/Pb-5% Sn was larger than that of W/Ni in the entire region.
    (4) Because of the high strain concentration in the matrix at the end of the fiber, the failure of stainless steel/Pb-5%Sn originated in fracture of the matrix around the end of the fiber and pulling-out of the fiber from the matrix. On the other hand, W/Ni having a relatively low strain concentration failed due to fracture of the matrix which was adjacent to W fiber fracture points.
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  • Zensaku Kozuka, Yoshito Hirato, Kenzo Kuroda
    1973 Volume 37 Issue 9 Pages 1038-1044
    Published: 1973
    Released: April 04, 2008
    The equilibium distribution of antimony in the liquid Pb and the PbO-SiO2 system was investigated by using the EMF method employing a solid electrolyte.
    The oxygen pressure in an equibrium state was determined from the e.m.f. of the following cell:
    (This article is not displayable. Please see full text pdf.)
    Slag composition ranged NPbONSiO2=2∼1 and Sb2O3=2∼10 wt% and the experimental temperature was 900°C. From the present experimental results it was found that antimony in such slag was almost always trivalent ion, and the distribution coefficient (1/2 NSb2O3NSb) increased with increase in oxygen pressure and NPbONSiO2 and with decrease in NSb2O3. Based on the experimental results on the distribution of antimony, the activity of Sb2O3 in the molten PbO-Sb2O3-SiO2 system was determined. The activity of Sb2O3 was found to have a considerably negative deviation from Raoult’s law, but it increased with decrease in NPbONSiO2.
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  • Tadayuki Nakayama, Akihiko Kitada
    1973 Volume 37 Issue 9 Pages 1044-1048
    Published: 1973
    Released: April 04, 2008
    Effects of surface polishing on the structures and chemical compositions of oxide films formed on 18-8 stainless steel at 300°C in high temperature water were investigated.
    Main results obtained are as follows:
    The oxide films produced on the mechanically polished surface were composed, under the electron microscope, of two different parts, that is, one consisting of a continuous film and the other of a massive body. The former was composed mainly of corundum type oxides and a small fraction of spinel type oxides, while the latter consisted of only spinel type oxides. The former contained mainly Fe and Cr besides Mn, while the latter was composed of large amount of Mn.
    On the other hand, on the chemically polished surface grew the oxide films having the following tow parts. One part consisting of a continuous film was composed of spinel-type oxides which contained Ni in addition to Fe and a small amount of Cr, while the other part consisting of a massive body was also composed of spinel type oxides which contained Mn in the main.
    It was made clear by ion microanalysis that the cause of the difference, according to the way of surface polishing, in structure and composition of the oxide film was based on the variation of the composition of each polished surface. That is, the variation of quantitative ratios of Fe, Cr and Mn to Ni from the mechanically polished surface to the inside of the alloy was hardly recognized. In the vicinity of the chemically polished surface, however, the area in which the quantitative ratios of Cr and Mn to Ni decreased was clearly detected.
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