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Volume 23, Issue 8
Displaying 1-16 of 16 articles from this issue
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Shigeo Muromachi, Shigenori Hori1959 Volume 23 Issue 8 Pages 433-437
Published: 1959
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe deformation process of two-phase alloys by rolling differs from that of alloys with homogeneous structure. We studied the volume dependence of the 2nd phase on the deformation process. The experiments have been carried out by statistical methods using a microscope. The results obtained are summarized as follows: The following equation which had been obtained in the previous report have been confirmed also in this experiment: Δh⁄h⁄ΔH⁄H=a1−Vi⁄Vm where Δh⁄h is the deformation degree of the 2nd phase, ΔH⁄H the average percentage reduction of the test-piece, Vi⁄Vm the relative hardness of both the phases and the value of a depends on the amount, shape and distribution of the 2nd particle in the material. The deformation of the 2nd phase due to rolling increases with a decreasing of the amount of the 2nd phase in the test-piece and when rounded 2nd phase particles are uniformly distributed throughout the section, the following relation between n and a is satisfied: a=1.8n−0.8. If the hard and brittle 2nd particles are in the form of needle-shaped crystals, this phase expresses greater relative deformation than that of the rounded particles caused by their rotation or breaking in the matrix, and this tendency is affected by the total volume of the 2nd phase in the test-piece.View full abstractDownload PDF (775K) -
Masao Ikeda1959 Volume 23 Issue 8 Pages 437-441
Published: 1959
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSStudying the effects of chloride and fluoride addition and the calcining temperature on the yield of magnesium in the process of reducing dolomite, the following results were obtained: (1) Addition of NaF, NaCl, 3NaF·AlF3 and CaCl2 decreases the yield of magnesium, but addition of CaF2, fluorite, MgF2 increases it. (2) CaF2 is more effective than MgF2 for increasing the yield, but, as a binder of dolomite briquette, MgF2 is superior. (3) The decomposition temperature of MgCO3 is higher by 200∼300°C than that in dolomite, but that of CaCO3, matches the latter. (4) The relation between the calcining temperature and the yield of magnesium shows a maximum near the temperature of 1000°C, and this tendency corresponds well that of the insoluble residue of calcined dolomite leached with 5% acetic acid solution in methyl-alcohol.View full abstractDownload PDF (624K) -
Nakaaki Oda, Sadayuki Tsunoo, Toshio Hashimoto1959 Volume 23 Issue 8 Pages 441-444
Published: 1959
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn connection with our 1st and 2nd report of “Quantitative Spectrochemical Analysis of Silicon and Vanadium in Titanium Tetrachloride”, the spectral line pairs for determination of magnesium, iron, manganese and silicon in titanium sponge were studied by 5×5 Graeco-Latin square experiments, bifactorial experiment and standard deviation, calculated from 50 repeated analysis. The titanium sponge sample was dissolved without boiling in dilute hydrochloric acid (5 g Ti/50 cc HCl (1:1)) on a hot plate. Besides of sample preparation, all of the analytical conditions and procedures were identical to those described in our 1st report. The variation coefficient and the limits of these analytical line pairs are shown in Table 5.View full abstractDownload PDF (716K) -
Yoshio Kubota1959 Volume 23 Issue 8 Pages 445-448
Published: 1959
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThis paper presents the results of replica studies on the effect of electrolysing conditions and after-treatments on the particle shape of E-Zn, by optical and electron microscope. The electrolysing conditions affect the particle shape such as its number of branching,thickness and the interstice of layers. Among such conditions the temperature and the stirring in electrolysing bath are effective. But E-Zn grows always dendrites with 60°C branching angles.View full abstractDownload PDF (1271K) -
Yoshio Kubota1959 Volume 23 Issue 8 Pages 448-452
Published: 1959
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe relationship between the chemical reactivity and the crystal structure of Zn particles was studied by using an X-ray diffractometer and a microfocus X-ray camera. The results indicate that particles of caustic electrolytic Zn powders (E-Zn) are dendrites with branches grown in three directions perpendicular to the C-axis and with well-developed {001} faces which determine the particle size. The broadening of X-ray reflections, especially of {103}, which was the most significant characteristics of E-Zn, was shown not to be due to the fineness of the crystal size but to be due to the crystal imperfections, such as lattice strain, lattice mistakes, which greatly affect the chemical reactivity.View full abstractDownload PDF (810K) -
Akira Adachi, Kazumi Ogino, Hironobu Toritani1959 Volume 23 Issue 8 Pages 453-456
Published: 1959
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe surface tension of the sodium silicate-metal oxide system was measured by a sessile drop method in nitrogen flow. The sodium silicate consisted of 44.5 mol%Na2O and 55.5 mol%SiO2, and metal oxide (CaO, MgO, MnO, and Al2O3) was added by 5 mol%, 10 mol%, 15 mol% to sodium silicate. Generally, the surface tension of sodium silicate increases with the content of additional metal oxide. When sulfur was added to the sodium silicate, its surface tension decreased. The temperature coefficient of the surface tension of sodium silicate was negative, while that of the silicate containing Al2O3 was positive. The density of liquid sodium silicate was calculated based on the dimensions of the sessile drops of silicate.View full abstractDownload PDF (581K) -
Tomo-o Sato, Yen-Chien Huang, Yutaka Kondo1959 Volume 23 Issue 8 Pages 456-460
Published: 1959
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe Titanium-rich side phase diagram of the system Ti-Al has been re-examined. Electrical resistance measurement and microscopical and X-ray analyses were carried out to determine the equilibrium relations between the inter-solid phases. The partial phase diagram up to 50 wt%Al was constructed as shown in Fig. 8. The saturated α-Ti solid solution exists conjugated with α2 in the temperature range under 1,020°, at which temperature a peritectoid reaction, β-Ti+α2\ ightleftarrowsα-Ti, takes place. The α2 phase extends at 19∼25 25%Al and it corresponds to Ti2Al. One new phase named δ has been assumed to exist in the composition range from 26∼34% at high temperature.
The non-variant reactions in solid alloys of this system were determined as follows:
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Shin’ichi Nagashima1959 Volume 23 Issue 8 Pages 460-464
Published: 1959
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn the previous paper it was shown that two kinds of G.P. zones were formed in the aged Mg-Ag alloys containing 12.6 wt%Ag; one was an ordinary zone having a platelike form and the other was a new one of an oblate ellipsoid. In the present experiment the structure of the latter G.P. zone has been studied by X-ray diffraction using monochromatic radiation, with the result that this zone has an ordered arrangement of silver atoms in it. This type of G.P. zone can be called G.P.[2] after the denomination of the ordered G.P. zone in Al-Cu alloys. In the oscillation photographs about the [0001] axis of the matrix, the diffuse diffraction spots from the G.P.[2] are seen forming a set of layer lines superposing those of the matrix. The distribution of diffraction spots on the (000l) layer lines can be satisfactorily interpreted as due to the stacking of the two-dimensional superlattice which has the value of lattice parameter a\sqrt7 times as large as that of the matrix, and the angle between the a axis of the superlattice and that of the matrix is tan−1(\sqrt3⁄5)=19°6.4′. The lattice parameters of the G.P.[2] obtained from this model of superstructure are a=3.14×\sqrt7=8.31 kX and c=5.36 kX.View full abstractDownload PDF (755K) -
Shin’ichi Nagashima1959 Volume 23 Issue 8 Pages 465-468
Published: 1959
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSAn X-ray study has been made of the structures formed during the aging of Mg-12 wt%Ag, with the following results: G.P.[1] is formed by room temperature aging for a long time (more than 600 days), and it disperses at the aging temperature higher than 60°C, while, G.P.[2] is formed by aging at room temperature, 60°C, and 100°C, and this may have some effect on the formation of the following precipitates. At the aging temperature higher than 150°, the intermediate state, γ′ phase, is firstly formed, followed by the precipitation of a stable γ phase. With the prolonged aging, the γ′ phase vanishes and yet the γ phase grows continually. The early precipitates of γ′ phase are considered to be platelike and parallel to (0001) as well as to {11\bar20} planes of the matrix.View full abstractDownload PDF (830K) -
Genjiro Mima, Michio Mizuta1959 Volume 23 Issue 8 Pages 469-473
Published: 1959
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe internal friction of several kinds of carbon steels were measured at room temperature by the transversal vibration of about 1.85 kc/s. The main results obtained were as follows: (1) The internal friction of martensitic specimens is proportional to the carbon content (after the completion of recovery at room temperature) and this internal friction is caused by the stress induced by diffusion of carbon atoms in the iron lattices. (2) A two-staged change of room-temperature internal friction was observed during the tempering process of martensitic specimens. This may be interpreted by the decrease of carbon atoms in the lattice,which precipitate into the forms of ε-carbide and cementite. (3) The internal friction of annealed specimens containing coarse free ferrite was proportional to the amplitude in our measuring range (maximum strain ca. 1.2×10−5) and this behavior was not affected by the presence of Ni, Cr or a large amount of hydrogen in the specimens. It indicates that the amplitude-dependent internal friction is caused by the magneto-mechanical hysteresis.View full abstractDownload PDF (707K) -
Tsuneo Matsukura, Akira Nagai, Etsuo Matsumoto1959 Volume 23 Issue 8 Pages 473-477
Published: 1959
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSApplying “the direct-vision equipment of magnetization curve” possessing the simple integrating circuit, we are able to observe the magnetization curves of materials instantaneously on the screen of cathode-ray oscilloscope. So, we succeeded in making continuous observation of the changes in magnetization curves of steel during the process of heat treatment by using this equipment. In this paper self-hardening high-C and high-Cr steels were used as specimens, and the variations of their various magnetic elements with Ar″ transformation by quenching and tempering were observed, as follows: (1) The tendency of increase of coercive force during the course of Ar″ transformation differs from the tendency of increase of saturation and residual induction, in that the increase of coercive force is great at the commencement of the transformation and its value becomes quickly constant. (2) The relation between residual induction Br and coercive force Hc with Ar″ transformation by quenching is given in the following experimental formula: Hc=a[1−exp(−bBr)], but in this formula a and b are constant values which are determined by the kinds of steel. (3) The main reason for the increase of coercive force during Ar″ transformation lies in the fineness of martensite particles, and cannot be considered as being attributable to the precipitation of carbides and the increase of internal stresses.View full abstractDownload PDF (727K) -
Toshio Doi1959 Volume 23 Issue 8 Pages 477-481
Published: 1959
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe structure changes were studied microscopically on a Cu-0.54%Cr-3.06%Ti alloy, which was solution-treated and aged at various temperatures from 550°C to 700°C. The grain boundary reaction was observed in the specimens aged at 550°C and 600°C. Together with the structure of pearlite type, the structure of Widmanstätten type was observed in the specimens which were aged at 600°C. However, when aged at 700°C, only the structure of Widmanstätten type was found without any trace of a pearlitic region. The crystal structure of the precipitates which were extracted with 50% nitric acid from specimens aged for 100 minutes at 550°C and for 480 minutes at 700°C respectively was studied by means of X-ray analysis. It was shown that the precipitates from both were β′-Cu3Ti and γ-TiCr2. The crystal planes upon which the precipitation of Widmanstätten type takes place were determined by three methods. The results obtained by use of these methods were in good agreement, that is, the precipitates of Widmanstätten type were parallel to (111) planes of the matrix crystal.View full abstractDownload PDF (1601K) -
Toshio Doi1959 Volume 23 Issue 8 Pages 482-485
Published: 1959
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIdentification of the precipitates was made by means of extraction-replica technique and extra-high voltage (300 kV) electronmicroscopy for Cu-0.54%Cr-3.06%Ti alloy, which was solution-treated and aged at various temperatures from 550°C to 700°C. The results obtained by micro diffraction method were as follows; The particles of insoluble plase, the precipitates of pearlite type and of Widmanstätten type were β′-Cu3Ti and the precipitates of box type were γ-TiCr2. On the basis of the results on the identification of the precipitates, the author discussed the precipitation process of this alloy.View full abstractDownload PDF (790K) -
Tadao Sano, Shosuke Imoto, Mungyu Kang, Yasuo Hashimoto1959 Volume 23 Issue 8 Pages 486-489
Published: 1959
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThis study was conducted to develope a new oxidation-resistant zirconium alloy. As the oxidation proceeds by anion migration via vacancies through the oxide film, some factors contributing to the concentration and the mobility of vacancies were examined, such as the valency of the alloying ion, ionic radius, ionization potential, etc. As a result of the examination, sulfur selenium and tellurium were expected to have a beneficial effect on the oxidation resistance of zirconium. The oxidation test of some zirconium-tellurium alloys in oxygen or air was carried out with a silica spring thermobalance. The test showed that the breakaway time for oxidation was much delayed by adding some amount of tellurium to zirconium and thus proved the beneficial action of tellurium for enhancing oxidation resistance. For example, the breakaway times of pure zirconium, 0.2%Te-Zr and 0.059%Te-Zr alloys for oxidation in air at 750° were respectively 1300 min, 2000 min, and 3600 min, while with 0.016%Te-Zr specimen no breakaway was observed to occur before 5500 min.View full abstractDownload PDF (600K) -
Reiichi Ohno1959 Volume 23 Issue 8 Pages 489-493
Published: 1959
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThis investigation has been made to ascertain the desulfurization process of cast iron in vacuum-melting. The results of Fe-S and Fe-C-S alloys are summarized as follows: (1) In vacuum-melting at 1600°C, an Fe-S alloy containing 0.075%S is slightly desulfurized and in five minutes a minimum sulfur concentration is obtained. And then the sulfur concentration increases with increasing time. In the case of melting of Fe-C-S alloys in graphite crucibles, considerable desulfurization occurs and after certain times finite sulfur concentrations are obtained. When an alumina crucible is used, although the initial rate of desulfurization of the Fe-C-S alloy containing 3.34%C is much slower than that of melting in a graphite crucible, this rate increases with increasing time and finally the sulfur concentration becomes lower than that of the Fe-C-S alloy melted in a graphite crucible. (2) It may be considered that a slight desulfurization of the Fe-S alloy should occur by oxygen-sulfur reaction and that the increase of sulfur concentration should be due to vaporization of iron. If the desulfurization reactions are approximately in equilibrium during vacuum-melting, it may be said that the Fe-C-S alloy which contains 0.01 to 0.5%S should be most strongly desulfurized by the reactions C+S=CS (g), S=S (g) and C+2S=CS2 (g) in the range of lower sulfur concentration, and by the reaction C+2S=CS2 (g) in the range of higher concentration. The increased rate of desulfurization in the melting of the Fe-C-S alloy in the alumina crucible is considered to be due to entrance of silicon into the melt from the crucible. It may be considered from the thermodynamic equilibrium condition that as far as the carbon concentration is fixed during vacuum-melting the obtainable minimum sulfur concentration should be decreased with increasing carbon concentration of the Fe-C-S alloy used. (3) The sulfur concentration obtained in vacuum-melting of an Fe-C-S-alloy in a graphite crucible for 1/2 hr decreases with increasing emperature, which result consists with the thermodynamic considerations.View full abstractDownload PDF (748K) -
Reiichi Ohno1959 Volume 23 Issue 8 Pages 493-497
Published: 1959
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe experimenal results and considerations on the desulfurization of Fe-Si-S and Fe-C-Si-S alloys in vacuum-melting are summarized as follows: (1) The desulfurization velocity of Fe-Si-S and Fe-C-Si-S alloys is more rapid compared with that of the Fe-C-S alloys. And the minimum sulfur concentration obtained in vacuum melting of the Fe-Si-S and Fe-C-Si-S alloys is lower than that of the Fe-C-S alloys. In the case of vacuum melting of Fe-Si-S alloys, both a desulfurization and a decrease of silicon concentration occur at the same time, and the sulfur concentration obtained decreases with increased silicon concentration; the sulfur concentration obtained in melting at 1700°C is lower compared with that obtained in melting at 1600°C. In the case of vacuum-melting of Fe-Si-S alloys which contain approximately the same amount of Si and S, the ratio of the decrease of sulfur to the decrease of silicon closely approximates the weight ratio of sulfur to silicon which is required to form the silicon monosulfide SiS. (2) From the experimental result made by Oelsen-Maetz and the author’s thermocynamic consideration, it may be considered that if a chemical reaction, i.e., Si+S=SiS (g) is approximately in equilibrium during the vacuum melting, the desulfurization of Fe-Si-S and Fe-C-Si-S alloys should be almost carried out by the reaction which forms SiS, and that the strong desulfurization of Fe-Si-S and Fe-C-Si-S alloys should be due to a very high equilibrium partial pressure of SiS.View full abstractDownload PDF (781K)
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