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Volume 29, Issue 11
Displaying 1-20 of 20 articles from this issue
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Kyuya Nagasaki, Mayumi Someno, Chomei Chin1965 Volume 29 Issue 11 Pages 1015-1019
Published: 1965
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe anodic polarization behaviour of iron was investigated in deaerated sulfuric acid, and ferric sulfate solutions by means of a potentiostatic method. Two peaks were obtained in the anodic polarization curve prior to passivation potential, these two peaks containing the first and second stages of passivation.
The first stage of passivation is in the range of −300∼−400 mV (S.C.E.), and the second stage of passivation is in the range of +280∼+500 mV (S.C.E.), corresponding to the conventional “passivation potential”.
The first stage of passivation was discussed to be due to an interaction between Fe and SO4−− ion.View full abstractDownload PDF (559K) -
Kenji Tamura, Akira Moriyama, Iwao Muchi1965 Volume 29 Issue 11 Pages 1020-1026
Published: 1965
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThis paper deals with the numerical calculus of temperature distribution in the blast-furnace shaft, which will serve to clarify the operation principle and predicting the condition of the performance of this unit.
Practically, it is very difficult to experimentally determine the temperature distribution in the blast-furnace. Making use of a parameter of effective thermal conductivity, ke, a theoretical analysis of temperature distribution has been developed.
On the basis of the temperature distribution observed at the top of the shaft, the temperature at arbitrary positions in the shaft can be estimated by means of the numerical calculus proposed.
Regarding the shaft as a moving-bed reactor, the heat balance for a differential element in the shaft leads to the fundamental equation (1), which is transformed into a difference equation (10).
Substituting the data of the temperature distribution at the top of the shaft and the distributions of ke into the difference equation, the successive calculations have been conducted to determine the downward distribution of temperature in the shaft. Table 4 is shown in order to compare the results of theoretically calculated values with the experimental ones and it has been found that the calculated temperatures agree satisfactorily with the measured temperatures.View full abstractDownload PDF (845K) -
Hiroshi Itô, Mitsuhiko Furukawa, Kôki Uwafune1965 Volume 29 Issue 11 Pages 1027-1031
Published: 1965
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe oxidation of tungsten contacts at room temperature was examined by means of electron diffraction, contact resistance measurement, arc duration measurement.
The examination was performed at 35°C in 80% moisture. The surface of tungsten contacts was treated by emery paper, electrolytic polishing, barrel finishing and anticorrosion reagents for various tungsten materials.
In all samples, tungstic (V,VI) acid Ho5Wo3 was formed on the surface of tungsten contacts after the lapse of thirteen months.
The effect of the anticorrosion reagent could in some measure be observed when moisture was 80%, but in effective in the saturated vapour.
In the saturated vapour, H2Wo4 or Wo3 was formed after the lapes of twenty days.
The contact resistance and the arc duration showed a tendency to increase with the lapse of time, and effects of the surface roughness and the grain size of tungsten material were not observed in these examinations.
No oxide film which brought about poor counductivity at contact pressures of 100∼1000 g was observed.View full abstractDownload PDF (709K) -
Hideo Kaneko, Taiji Nishizawa, To-oru Oka1965 Volume 29 Issue 11 Pages 1032-1035
Published: 1965
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSFundamental conditions for the growth of granular and columnar crystals in an alloy were studied in the present investigation by measuring the rate of solidification and the temperature gradient of melt near the solid-liquid interface.
In order to make a theoretical treatment of the growth conditions, the critical degree of supercooling Sc and the maximum degree of supercooling Sm were obtained. The value of Sc was calculated from the equation proposed by Turnbull et al. On the other hand, the equation for Sm was derived from the equation suggested by Tiller et al. as follows:
(This article is not displayable. Please see full text pdf.)
\ oindentin where m: slope of the liquidus line, k: distribution coefficient, C0: initial concentration of the melt, D: diffusion coefficient of the solute, G: temperature gradient of melt near the interface, R: rate of solidification.
It has been estimated that granular crystals were formed when Sm is larger than Sc (Sm≥Sc), and columnar crystals were formed in the case of Sm<Sc. To determine the growth conditions, G and R were experimentally measured by making the unidirectional solidification of the samples. Macrostructures of the ingots were also observed. The experimental results agree fairly well with the theory presented by the authors.View full abstractDownload PDF (687K) -
Isao Gokyu, Hirokazu Tanabe, Keijiro Suzuki1965 Volume 29 Issue 11 Pages 1035-1040
Published: 1965
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSA survey of earlier work has suggested that the average strain ratio \barr does not sufficiently represent deep drawability, both theoretically and experimentally. Therefore, the authors investigated to recognize the direct relationship between deep drawability and sheet texture.
Circular blanks were cut off from single crystal sheets of aluminium by the spark method and drawn through a conical die with a round bottomed punch. The orientation dependence of drawability was found remarkable; i.e., the sheets with their normals near, [111] or [110] had higher drawability than those near [100].
Further more, a simple theoretical calculation of the r-values using the maximum resolved shear stress criterion was made for the slip on the {111}⟨110⟩ systems, the calculated values of which agreed fairly with the experimental ones. Then, the r-values of various sheet textures with different components were calculated, in order to predict their distributions in the textured sheets of aluminium.
The role of the strain ratio and the work-hardening exponent in the deep drawing were also discussed. In a strongly textured sheet, the strain hardening as well as the yield stress seems to considerably depend on the boundary condition for stress and strain, which are different from those under uniaxial stress Therefore, these two effects are considered to exert influence on the deep drawability of the textured sheets.View full abstractDownload PDF (1066K) -
Yoshinori Onodera, Takeshi Ishihara1965 Volume 29 Issue 11 Pages 1040-1046
Published: 1965
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSBi2Te3, Sb2Te3, Bi2Se3, and their solid solution alloys were prepared by application of ultrasonic vibration in order to improve their thermoelectric properties. The ultrasonically prepared sample showed thermal conductivity 3∼23% smaller and electric resistivity 3∼16% larger than those of the normally prepared one and consequently the thermoelectric figure of merit exceeded 3.2×10−3/°C.
Measurements of the thermal conductivity and the Hall coefficient at a low temperature showed that the thermoelectric properties were improved by the effect of fine grained crystals and internal defects. Further, X-ray diffractometric analysis qualitatively verifies this effect.
The electric current which gives the maximum cooling efficiency for this material can be reduced by about 20% because of the high electric resistivity. The thermoelectric modules composed of these materials can be applied to cooling parts which require a high temperature difference because of the low thermal conductivity.View full abstractDownload PDF (1371K) -
Yûnoshin Imai, Masao Izumiyama, Masayuki Tsuchiya1965 Volume 29 Issue 11 Pages 1047-1052
Published: 1965
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSAfter preparing iron-nitrogen binary alloys by nitriding a pure iron plate 0.15 mm in thickness in an atmosphere consisting of a mixture of ammonia and hydrogen, its quenched and tempered structures were investigated. The martensite of the iron-high nitrogen alloy appears in a lenticular form having a mid-rib, and its habit plane is an approximately {124}γ or {259}γ plane. By means of transmission electron microscopy, a great many of micro-stripes are observed in the martensite. These results are all alike to those obtained in iron-high carbon alloy.
When the martensite of the iron-nitrogen alloy is tempered at various temperatures for 1 hour, Fe16N2 (α″ phase) precipitates at 150°C and it is replaced with Fe4N (γ″ phase) beyond 200°C. On the other hand, no precipitation is detected below 200°C in the tempering of the austenite of the iron-nitrogen alloy and Fe4N is detected above this temperature.View full abstractDownload PDF (1386K) -
Yûnoshin Imai, Takeo Murata1965 Volume 29 Issue 11 Pages 1053-1058
Published: 1965
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSCreep tests have been carried out in the temperature range from 600° to 800°C on a commercial 25% chromium steel and a fairly high-purity iron-25% chromium alloy with grain sizes controlled by annealing treatment. Attention is paid to the difference in the mode of precipitation arising from annealing treatments, which will cause to mask the grain size effect. Comparative tests have also been made on the tensile properties and the hardness at elevated temperatures. The results obtained are as follows:
(1) Uniformly distributed precipitates are most effective to raise the creep strength. Grain boundary precipitates also exhibit a strengthening effect which increases with the rise of temperature, but are not so effective as the uniformly distributed ones.
(2) The creep strength of coarse grained material is lower than that of the fine grained one above about 650°C.
(3) The temperature dependence of the steady-state creep rate above 640°C can be explained by Dorn’s expression. A breaking point on the log\dotε v.s. 1⁄T curve appears at 620°∼630°C, probably due to the magnetic transformation.View full abstractDownload PDF (924K) -
Shigeo Muromachi, Shigeo Zaima, Shizuo Tada1965 Volume 29 Issue 11 Pages 1059-1066
Published: 1965
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIt is predicted that the machinability of brass differs by the hysteresis of heat treatment or working regardless of the chemical composition. In this paper, the turning test and the drilling test are experimented by regulating the grain size of 65/35 brass for examining the machinability in relation to the cutting resistance, surface roughness and chip formation.
The results are as follows: The turning resistance of the specimens with a large grain size decreases a little with a rise of the annealing temperature. In the constant feed drilling, the thrust and the torque decrease with the increase of the grain size, whereas in the constant load drilling, the torque increases and the drilling time decreases. The above differences by the drilling method agree well with the results of the previous experiment. Moreover, it appears that the grain size effect on the machinability in the drilling test is greater than that in the turning test.View full abstractDownload PDF (1144K) -
Akira Isaka, Yasushi Matsumoto, Makoto Sugihara1965 Volume 29 Issue 11 Pages 1066-1070
Published: 1965
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSAn appropriate method to control the oxygen content in the sintering and cooling atmospheres for the preparation of ferrites has been reported previously. In this paper the magnetic properties of Mn-Zn ferrites prepared by this method with various cooling atmospheres are discussed. The temperature dependence of permeability, quality factor Q and disaccommodation are dependent on the oxygen content in the atmosphere for the cooling process. When the secondary peak of permeability exists in the neighbourhood of room temperature, the permeability is influenced substantially by the cooling atmosphere. Quality factor Q and disaccommodation increase with the oxygen content in the cooling atmosphere.View full abstractDownload PDF (640K) -
Shozo Yoshioka, Yutaka Nakayama, Taichiro Ito1965 Volume 29 Issue 11 Pages 1071-1075
Published: 1965
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSSuitable etchants were investigated to produce etch pits, whose dislocation sites arise from the low index crystallographic surface of Cu-Al α solid solutions. Modified solutions of Livingston’s composition were found to give excellent results. Moreover, it was confirmed by various experiments that a majority of these etch pits corresponded fairly well to dislocations arising from the {111} surface of Cu-Al α solid solutions. Preliminary observations suggest that this technique may be useful in studying the formation and development of slip bands and the dynamical behaviour of dislocations in Cu-Al α solid solutions.View full abstractDownload PDF (882K) -
Yoshio Baba1965 Volume 29 Issue 11 Pages 1075-1080
Published: 1965
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe influence of addition of Fe (0.02∼0.4 wt%) and Si (0.04∼0.5 wt%) to Al-6 wt%Zn alloy upon the pre-precipitation or clustering phenomenon has been investigated mainly by means of the resistivity measurements at the liquid nitrogen temperature.
The results are as follows:
(1) The rate of clustering of Zn atoms is influenced by the addition of Fe and Si, but general features of the pre-precipitation in these ternary alloys are not different from those in Al-6 wt%Zn binary alloy since the third elements do not interact with Zn atoms.
(2) As to the influence of addition of Fe, it has been observed that the rate of clustering of Zn atoms is substantially reduced by the presence of Fe more than the solubility limit in Al. It may be considered that the increase in the area of the boundaries by grain refining and in dislocation density which would act as sinks result in the decrease in the concentration of quenched-in vacancies.
(3) The addition of Si also decreases the rate of clustering of Zn atoms. The influence is not observed clearly for Si less than 0.04 wt%, but remarkably with a higher content of Si atoms in the super-saturated solid solution of the alloy.
This effect could be interpreted from the fact that the binding energy between Si atom and vacancy is greater than that between Zn atom and vacancy. However, alike the influence of the addition of Fe, it is probable that a number of dislocation loops stabilized by the addition of Si act as sinks to eliminate quenched-in vacancies.
(4) It seems to be premature to explain the effects of third elements on the pre-precipitation of Al-Zn alloy in the light of the atmoic radius or binding energy alone, and a more detailed inverstigations are required.View full abstractDownload PDF (824K) -
Sadatoshi Inada, Koichi Uesaki1965 Volume 29 Issue 11 Pages 1081-1086
Published: 1965
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe behaviors of precipitates around inclusions and grain boundaries on the free surface of phosphor-deoxidized copper compressed at elevated temperatures between 650° and 770°C, were studied. The specimens, furnace cooled, water quenched and dry ice quenched, were prepared.
The results obtained were as follows:
(1) Precipitates around inclusions were observed in all the specimens when uncompressed and compressed constantly or rapidly.
(2) Precipitates along grain boundaries were not observed under the uncompressed condition, but when compressed constantly, the precipitation took place not parallel with the direction of compression and caused the formation of cracks. The silicon content was found in very small quantities by the chemical analysis, segregated from the matrix into the grain boundaries and precipitates. It appeared that the silicon had an effect on the formation of cracks. In the furnace cooled specimens, there was some difference in cracking behaviors when compressed constantly and when compressed rapidly.View full abstractDownload PDF (1329K) -
Masanobu Ohmori, Yoshitoyo Yoshinaga, Hideo Takei1965 Volume 29 Issue 11 Pages 1087-1093
Published: 1965
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe effect of the strain rate on the blue brittleness temperature, lower yield stress and tensile strength of a killed steel containing 0.14%C was investigated under various strain rates: 1×10−3, 1.2×10−2, 1×10−1, 1.2 and 1.1×102 l/sec. Main results in the present paper are summarized as follows:
(1) The blue brittleness temperature increases linearly with the logarithm of the strain rate in the range from 1×10−3 to about 1 l/sec. Namely, a ten-fold increase of the strain rate induces a rise of the brittleness temperature by 50°C. However, the increase of the temperature is steeper with the rate beyond 1 l/sec.
(2) The yield stress and tensile strength have two strain rate sensitivities, respectively; i.e., smaller sensitivities below the rate of 10−1 l/sec and much larger ones beyond it. Both yield stress and tensile strength at 300°∼−78°C in the range of the rate larger than 10−1 l/sec, and yield stress at −78°C in the smaller range are described quite well as increasing linear functions with log (strain rate). The rate sensitivities for both yield and tensile strength increase with lowering of temperature. This phenomenon is attributed to the sensitivity for “friction stress” (resistance against the motion of free dislocations). It was also discussed that the yield stress was more sensitive to the strain rate than the tensile strength.
(3) In the range of lower strain rates, strain ageing (blue brittleness) can give an account for the abnormal or negative strain rate sensitivities for yield and tensile strength at the temperatures higher than 200°C, but not for the absence or the slightness of sensitivity and slight one at room temperature and −78°C.View full abstractDownload PDF (1805K) -
Meguru Nagamori, Mitsuo Kameda1965 Volume 29 Issue 11 Pages 1094-1101
Published: 1965
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe activity of iron in liquid Au-Fe alloys, which range from pure gold to the composition saturated with a gold solid solution or γ-iron solid solution, was measured in the temperature range of 1100°C to 1300°C by the application of distribution equilibria of iron between wüstite and the molten alloys. The data reported by Darken and Gurry were used for the relation between the gas composition of CO2/CO over wüstite and the activity of iron in wüstite. The starting materials, pure gold plus Fe2O3 and Au-Fe alloys rich in iron, were exposed to the controlled gaseous atmosphere for 20 hr. The quenched samples were hammered to a plate and polished with emery papers. Iron contents of samples were determined at the surfaces by means of an X-ray fluorescent spectrometer. The activity data are summerized with the modified α functions;
(This article is not displayable. Please see full text pdf.)
The following equations were also derived as functions representing the partial or integral heats of mixing at 1200°C:
(This article is not displayable. Please see full text pdf.)
The changes of entropy due to the mixing at 1200°C are expressed as follows:
(This article is not displayable. Please see full text pdf.)View full abstractDownload PDF (1477K) -
Hakaru Masumoto, Takeo Kobayashi, Yûetsu Murakami1965 Volume 29 Issue 11 Pages 1101-1105
Published: 1965
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThree years ago the present investigators studied the relation between the magnetic permeability and the order-disorder transformation (Ni3Mn) in the ferromagnetic Ni-Mn alloys and found a new magnetic alloy “Nimalloy” having a high permeability.
A further investigation on the influence of the addition of iron on the magnetic properties of Nimalloy has revealed that the initial and maximum permeabilities of the alloys are increased generally by the addition of iron: The alloys containing 19.37% manganese and 4.36% iron, and 19.33% manganese and 4.55% iron show an initial permeability of 39,200 and a maximum permeability of 213,000, respectively, when they are cooled at the rate of 26°C/sec from 600°C. And in the former alloy the magnetic hysteresis loss is 5.40 erg/cm3/cycle, the coercive force 0.0042 Oe for the maximum induction of 2000 G, and the specific electric resistance 68.5 μΩ-cm at 20°C.View full abstractDownload PDF (579K) -
Susumu Morioka, Yoshinobu Sawada, Katsuhisa Sugimoto1965 Volume 29 Issue 11 Pages 1105-1111
Published: 1965
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe corrosion resistance of SAP in acid, basic and neutral aqueous solutions has been investigated in comparison with that of pure aluminum. Specimens used were SAP 32 (3.5%Al2O3), SAP 51 (6.8%Al2O3), SAP 71 (9.8%Al2O3), SAP 92 (15.5%Al2O3), 99.99%Al and 99.49%Al. The results obtained by means of the electrochemical measurement and the immersion test are summarized as follows:
(1) The corrosion potentials of the SAPs with varying amounts of Al2O3 were not affected by the Al2O3 content, but the order of magnitude of the corrosion current densities obtained from the cathodic polarization curves by the overvoltage intercept method corresponded to that of the corrosion loss in the same solution.
(2) In acid and basic aqueous solutions, SAP was not so stable as pure aluminum. The weight loss by corrosion increased with the increasing content of Al2O3 in SAP.
(3) In a neutral NaCl aqueous solution saturated with air, the corrosion resitance of SAP was greater that of 99.49%Al, but less than that of 99.99%Al and increased with the increasing content of Al2O3 in SAP.
(4) Improvement of purity of the matrix aluminum increases the corrosion resistance of SAP.View full abstractDownload PDF (1372K) -
Kozo Furukawa, Jin-ichi Takamura, Shuji Nagata1965 Volume 29 Issue 11 Pages 1112-1120
Published: 1965
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe change in the vacancy concentration during the quench of noble metals such as gold, with particular reference to the sink density and the cooling rate, has been computed semi-analytically by taking into account the annihilation of divacancies to sinks, which has not been treated before. For the convenience of integrating the nonlinear differential equation for the reaction kinetics, the cooling curve is divided into a number of steps, each of which consists of the instantaneous temperature-drop ΔT and the subsequent isothermal aging for a short time ts=ΔT⁄β, where β is the cooling rate. In this calculation, point sinks uniformly dispersed are assumed, which could be converted into line sinks such as dislocations. Main results obtained are as follows:
(1) The vacancy loss is dominant in the early stage of quenching above 500°C. The loss is mostly attributed to the annihilation of mono-vacancies to sinks but not to that of divacancies, since the divacancy concentration itself is very small in the high-temperature range. Thus, the total vacancy concentration retained in a specimen can be reasonably expressed by the equation C=C0exp(−ACs⁄β), where A is a constant, C0 the total vacancy concentration at the quench temperature, and Cs the sink concentration. The above relationship is valid for the effective density of line sinks of the order of 107 cm/cm3 or less. (2) Below 350°C, for example in gold, the vacancy loss to sinks during the quench becomes negligibly small (<10−9), thereby the total vacancy concentration being almost conserved. Even below this temperature, the concentration of divacancies continues to increase in expense of monovacancies during the quench down to the critical temperature T*, below which the rate of reaction V1+V1\ ightleftharpoonsV2 extremely slows down. (3) The divacancy abundance in the total vacancy concentration, 2C2⁄C, is affected by the sink density, the quench temperature and the cooling rate.View full abstractDownload PDF (1257K) -
Masao Ibaraki, Hirofumi Yoshimura1965 Volume 29 Issue 11 Pages 1120-1124
Published: 1965
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe deformation modes in martensite and austenite of Cr-Ni steel were investigated by means of optical and transmission electron microscopy, and the micro-hardness test.
(1) The deformation in martensite occurred by slip at any degree of deformation.
(2) The deformation in austenite occurred by deformation twinning, and the formation of ε phase and stacking faults. These deformations were accompanied by slip of dislocation.
(3) The micro-hardness test showed that the martensite was not hardened so much, but the austenite was remarkably hardened. It appeared that martensite was hardened by the interaction of dislocations only, while the hardening of austenite was due to the interaction of dislocations and also due to other faults: deformation twins, ε phase and stacking faults.View full abstractDownload PDF (698K) -
Kyôji Tachikawa, Satoshi Fukuda1965 Volume 29 Issue 11 Pages 1125-1130
Published: 1965
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe multilayer Nb-Sn wire containing a continuous intermediate phase lengthwise was made by the following procedure. A small-diameter Nb tube was set concentrically in a large diameter Nb tube and Sn was molten into the empty space. This composite rod was cold drawn into a fine wire and then heated at elevated temperatures. By this heat treatment, Nb and Sn diffused each other and Nb-Sn intermediate phases were formed.
The Nb-Sn intermediate phases were distinguished by the anodizing oxidation technique and their compositions were determined by an electron probe X-ray microanalyser. Three intermediate phases, i.e., Nb4Sn, Nb3Sn2 and Nb2Sn3, were found. The Nb4Sn phase is formed above 900°C, the Nb3Sn2 phase is formed between 800°C and 925°C, and the Nb2Sn3 phase is formed below 850°C. At 950°C, the relation between the width of the Nb4Sn phase x (μ) and the diffusion time t (hr) is represented approximately as x∼7.5\sqrtt.
The highest superconducting transition temperature is obtained by the diffusion treatment between 950° and 1100°C. The superconducting to normal transition of the specimen begins at 17.8°K and finishes at 18.0°K. When the diffusion temperature is lowered below 950°C, the transition finishes at 17.5°K and the transition width of the specimen increases.View full abstractDownload PDF (931K)
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