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Volume 24, Issue 3
Displaying 1-16 of 16 articles from this issue
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Susumu Miyata, Noboru Makino1960 Volume 24 Issue 3 Pages 135-138
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe results of fundamental researches on MT magnet (C 2.0%, Al 8.15% and Fe bal.) were already reported. In this report, the most appropriate condition for heat treatment was investigated in the course of industrialization for commercial production. The optimum temperature of quenching for magnetic properties and yielding rate of heat treatment is between 1210 and 1250°. Coating with charcoal and cementing materials is effective in preventing decarburization at requenching. The soundness of casting as well as their size and alloying elements constitute an important factor in relation with hardening cracks. With interrupted quenching, hardening cracks are smaller than in the case of the usual quenching process, but derogation of magnetic properties is more remarkable. MT magnet steel reduces its hardness so much as to become machinable by means of annealing at 800°C.View full abstractDownload PDF (668K) -
Susumu Miyata, Noboru Makino1960 Volume 24 Issue 3 Pages 139-142
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe magnetic behaviors are important for manufacturers as well as for users when any magnet available is put to use. With this in view, this paper discusses the uniformity of magnetic flux, the magnetic stability, the leakage factor in magnetic circuits, etc. With commercial magnets, the variation rate (σ⁄\barX) of the magnetic flux is about 3 percent. The temperature of tempering or aging affects the temperature coefficient. The degree of stabilization in MT magnet is usually controlled so as to give a flux drop of 7∼10%. The leakage factor in similar serial circuits depends on the reluctance of air gap and the arrangement of permanent magnets.View full abstractDownload PDF (566K) -
Shigetoshi Takayanagi1960 Volume 24 Issue 3 Pages 142-146
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSBy the simplified gas adsorption procedure previously reported by the author, an investigation was made of the surface states of tungsten powder prepared by hydrogen reduction. It was found that, while the surfaces of particles of pure tungsten powder were smooth, those of doped tungsten were roughened and covered with a layer of the alkaline components of dopes. The surface area of doped powder was remarkably affected by pure water washing as well as by pickling in dilute alkaline or acidic solutions. The surface area was also changed by oxidation or reduction of the powder. In atmospheric air at room temperature, tungsten powder is oxidized. In such oxidation process, the surface area considerably changed in relation with the transition of oxidation rate. An explanation of these phenomena was proposed with the help of electron-microscopic observations.View full abstractDownload PDF (863K) -
Nakaaki Oda, Sadayuki Tsunoo1960 Volume 24 Issue 3 Pages 146-150
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSA Spectrochemical addition method capable of alalysing the trace impurities in the order of 10−5% was studied, that is: (1) The width of “A” range, in which the light exposure on photographic emulsion is proportional to the opacity of developed plate, was examined from 2250 Å to 3500 Å, at very low intensity of incident light. (2) A foundamental theory of spectrochemical addition method in this range, including background correction,was derived. (3) The analytical procedures, applicable to industrial routine analysis, with attention to the precision and its control, were studied. The proposed method enables analyses of Cd, Fe,Sn and Pb in Zinc down to 0.0001%, with variation coefficient of 15%.View full abstractDownload PDF (714K) -
Nakaaki Oda, Sadayuki Tsunoo1960 Volume 24 Issue 3 Pages 150-154
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe authors pointed out, in the 6th report, that the various physical properties of carbon electrode affect the sensitivity and precision of this spectrochemical method for trace impurities in zinc. In this report, the authors describe the physical properties of carbon electrodes purchased from domestic producers, since 1950. From these results and repeated routine spectrochemical analysis, the influence of the physical properties on the analytical sensitivity and precision was determined and a sampling inspection system was established to find out the optimum lot of carbon electrodes (absorption of sample solution\doteqdot170 mg, Shore hardness\doteqdot30) for spectrochemical analysis of zinc.View full abstractDownload PDF (873K) -
Tôru Yoshida1960 Volume 24 Issue 3 Pages 154-157
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn wire strain gauges constantan filaments (dia. 0.025 mm) have been used as the resistant wire grid. Ordinary paper-base gauges may be used at room temperature. If the application involves the use of strain gauges at higher temperatures, a change of the electric resistance takes place during the strain measurement by the fluctuation of the measuring temperature. Even at room temperature a considerable difference between the resistance of the active gauge and that of the dummy gauge occurs due to the difference in the temperature characteristics of the gauges in no-load condition leading to zero-shift errors. Generally the temperature characteristics of gauges depend upon the thermal coefficient of resistance and the thermal expansion coefficient of the wire grid and the thermal expansion coefficient of the material to be tested. The purpose of this paper is to show the relationships between these factors and the temperature range in which strain gauges made of constantan wire grid can be used.View full abstractDownload PDF (516K) -
Kaizô Monma, Hajime Sutô1960 Volume 24 Issue 3 Pages 158-162
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThis paper describes the testing results of Cr3C2-TiC-Ni cermet prepared by the infiltration method. The cermet was prepared by mixing and compacting carbide powders and subsequently infiltrating with Ni alloy containing 35%Cr3C2 at 1,280°C for 20 min in vacuum. The best of cermets is TiC(10∼20%)-Cr3C2-Ni alloy, which has a 100-hr transverse rupture strength of 89 kg/mm2 at 850°C, and this value exceeds that of TiC-Ni cermet (67 kg/mm2). In respect of oxidation resistance also, this material is very superior.View full abstractDownload PDF (801K) -
Kaizô Monma, Hajime Sutô1960 Volume 24 Issue 3 Pages 163-167
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSFollowing the first report in which we told about the surface tension of pure metals, this paper informs the experimental results on the surface tension of copper-, iron-, nickel- and cobalt-base alloys containing molybdenum, tungsten, silicon and chromium, as follows: (1) A change of surface tension in a binary alloy system occurs in coincidence with the liquidus line of the melting point diagram. (2) Just upon the melting point, the dissociation of the intermetallic compound seems to be imperfect. (3) The surface tension of alloys containing impure chromium perceptibly decreases with the chromium concentration. This may depend on sulphur and oxygen slightly contained in the samples.View full abstractDownload PDF (550K) -
Kaizô Monma, Hajime Sutô1960 Volume 24 Issue 3 Pages 167-170
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe surface tension of pure Fe, Co, Ni, (Fe, Co, Ni)-C alloys and (Fe, Co, Ni)-(Mo2C, WC) alloys was investigated. In all the alloys investigated, the effect of carbon addition on the surface tension is not remarkable. This result is explained qualitatively by negative adsorption of carbon on the liquid surface, or by the change of surface tension factor reflected in our semi-theoretical equation proposed in our 1st report.View full abstractDownload PDF (543K) -
Akira Tokuda1960 Volume 24 Issue 3 Pages 171-175
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe fatigue fracture surfaces of some carbon steels were observed by electron microscope and their distinctive features were made clear, as follows. Experimental method: The so-called “Microfractography” with carbon replica by direct evaporation was applied. The carbon replica was stripped off the specimen surface by electrolysing or by immersing in alcoholic acid solution. Specimens: The specimens were made from steel bars with carbon content 0.3% or less and fractured with a rotating beam-fatigue tester at stress levels ranging from 44.8 to 16.3 kg/mm2. Result obtained: (1) The “river” or the “tangue” pattern which appears commonly on tensile or impact fracture surface was not observed on the fatigue surfaces. (2) Patterns observed on the fatigue fracture surface can be classified into five types, i.e. “parallel”, “cliff”, “cleavage”, “caterpillar” and “spine” patterns. (3) The fine parallel patterns with a pitch of 100∼300 Å were found in specimens fractured at the stress near the fatigue limit, while the coarse ones with intervals of 1000∼3000 Å were produced at higher stress levels, (4) Every pitch of parallel patterns nearly corresponds to the stress repeats of about ten cycles. (5) Both the caterpillar and spine patterns appeared on the specimens fractured at the repeats of the order of 106, and they were found in a line perpendicular to the direction of crack propagation. (6) The “pit” of spine patterns and the “ridge” of caterpillar patterns were regularly arranged. If we take a pit or ridge in a row of these patterns and denote the distance to the kth pit or ridge in the direction of broading intervals, with xk then xk=k2⁄C2, where C is a constant.View full abstractDownload PDF (1371K) -
Masao Izumiyama1960 Volume 24 Issue 3 Pages 175-178
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe stabilization of austenite was investigated using the steel sample containing 1%C and 5%Ni. The results obtained were as follows:—(1) The degree of stabilization in terms of the temperature lag before martensite transformation is resumed was expressed as a function of aging time. (2) The Arrhenius’s equation was applicable to express the relationship between the reaction-velocity constant of stabilization and the aging temperature. (3) The reaction-velocity constant of stabilization increased with the increase in prior martensite and the activation energy of stabilization decreased from about 30,000 to about 20,000 cal/mol with the increase in prior martensite from zero to 100%. From these results, as the most probable mechanism of the stabilization, it has been suggested that the stabilization is caused by reducing the mobilities of dislocations during aging at comparatively low temperature such as room-temperature or still lower temperature, because the interstitial solute atoms such as carbon or nitrogen will lock dislocations. On the other hand, stabilization will also be caused by the mechanical blocking of the motion of dislocation lines that can be produced most directly by the precipitation of tiny particles of a secondphase such as carbide or nitride in austenite during comparatively high temperature aging.View full abstractDownload PDF (618K) -
Go Okamoto, Norio Sato1960 Volume 24 Issue 3 Pages 179-183
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSChanges of the chemical and the electrochemical potential of electrons and of ions at the phase boundaries and in each phases were discussed in the electrode of Ni/NiO/H2O. The equilibrium Galvani-potential g(Ni⁄NiO) at the phase boundary of Ni/NiO is given by g(Ni⁄NiO)=−[(Ni)μNi2+−(NiO)μNi2+]⁄2F since in equilibrium the electrochemical potentials of Ni2+ are equal in both phases of Ni and NiO. In the same way, g(NiO⁄H2O) is given by g(NiO⁄H2O)=−[(H2O)μH2O−(NiO)μO2−−2(H2O)μH+]⁄2F. Then, the Galvani-potential of Ni/NiO/H2O electrode can be written in the form of g(Ni⁄NiO)+g(NiO⁄H2O)=−[(Ni)μNi2++(H2O)μH2O−(NiO)μNiO−2(H2O)μH+]⁄2F which is represented by the equilibrium potential Ea of the redox reaction (a) Ni+H2O=NiO+2H++2θ, when refered to the normal hydrogen electrode. When the concentration of nickel ions in solution is lower than that corresponding to the solubility product of NiO, the spontaneous potential of a nickel electrode covered with pore-free NiO is slightly less noble than Ea because the Galvani-potential of g(NiO⁄H2O) changes to the less noble direction so as to keep a mixed potential of both cathodic and anodic reactions of O2−(NiO)+2H+(aq)→H2O and Ni2+(NiO)→Ni2+(aq). If the surface film of NiO is porous, the spontaneous petential changes to the less noble direction to a greater extent with increase of the area of active holes. When a constant anodic current i is supplied to the electrode of Ni/compact NiO/H2O, the potential difference EII should appear between the phase boundary of Ni/NiO and NiO/H2O to drive the nickel ions Ni2+(NiO) through the film.View full abstractDownload PDF (692K) -
Go Okamoto, Norio Sato1960 Volume 24 Issue 3 Pages 183-187
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSA theoretical investigation was made on the anodic formation of the higher-valence oxides on nickel from the standpoint of the electrochemical thermodynamics. On the electrode of Ni|compact NiO|H2O polarized with a constant anodic current the potential difference in NiO increases in proportion to the film thickness. This potential difference can be expressed in the form on EII=(Ni⁄NiO)μ\ominus−(NiO⁄H2O)μ\ominus, and the chemical potential of the dissolved nickel atom in NiO is given by (NiO⁄H2O)μNi=(Ni)μNi−2FEII at the phase boundary of NiO|H2O. (NiO⁄H2O)μNi decreases with the increase of EII until it reaches the critical value of (NiO⁄H2O)μNi≤(Ni)μNi+4Ac, where Ac is the affinity of the disproportionation reaction (c): NiO→\dfrac14Ni3O4+\dfrac14Ni. This reaction can proceed only when (NiO⁄H2O)μNi becomes less than the critical value shown above. Therefore, beyond the critical electrode potential which is given by E(NiO⁄Ni3O4)=Ea+4Ac⁄2F, the surface film becomes a double oxide film composed of NiO and Ni3O4.The equilibrium potential of Ni|NiO|Ni3O4|H2O electrode can be given by the equilibrium potential for the redox reaction of (f): 3NiO+H2O→Ni3O4+2H++2e, which is also equal to E(NiO⁄Ni3O4). When the potential difference in Ni3O4 exceeds the critical value at which the disproportionation reaction (d): Ni3O4→\dfrac43Ni2O3+\dfrac13Ni occurs, the surface film changes again to a triple oxide film of NiO|Ni3O4|Ni2O3.View full abstractDownload PDF (630K) -
Sakae Takeuchi, Kazuo Furukawa, Kôki Gunji1960 Volume 24 Issue 3 Pages 187-191
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIt is known that Mn-Wüstite (Fe, Mn)O takes the form of solid solution over all the proportions of Fe-and Mn-atoms, and its oxygen content varies with oxygen pressure in the thermal equilibrium and with temperature. So we examined the quantitative relation between the solid and gas phases in the above mentioned system. Taking into consideration the previous papers in which Wüstite and Magnetite solid solutions were discussed, a configurational model for the Mn-Wüstite is assumed as follows: (1) O−− and metal ions are arranged on the lattice of NaCl-type, (2) in the negative ion lattice-sites O−− ions are perfectly packed, (3) in the positive ion sites Fe++, Mn++ and vacancies are randomly distributed, and (4) the electron-defects are trapped on some of Fe++ ions producing Fe+++ so that the total electrical charge of the crystal is neutralized. Considering such a model the partition function of Mn-Wüstite was formulated on the base of statistical thermodynamics, and the equilibrium relation between the solid composition and oxygen pressure in the gas phase was calculated. The calculated result is in agreement with the experimental values by MATOBA and GUNJI (1954) and our reexamination data obtained by the measurement of weight change using a spring balance.View full abstractDownload PDF (604K) -
Tadashi Ichiyama1960 Volume 24 Issue 3 Pages 191-195
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe internal friction in a high-purity nickel was measured as a function of temperature, using a torsion pendulum at a low frequency of vibration. The internal-friction curve consists of a background damping which increases as the temperature increases, and a peak at 510°C (0.44 cps) due to grain-boundary stress relaxation with an associated activation energy of 63,500 cal/mol. The limited data reviewed lead to the conclusion that neither the lattice self-diffusion nor the grain-boundary self-diffusion is the rate-determining process for grain-boundary stress relaxation, although this value for the activation energy associated with grain-boundary stress relaxation in nickel is consistent with that for lattice self-diffusion, and with the value for creep. The coefficient of viscosity of the grain boundary at the melting point, estimated from internal-friction measurements, using a modified Ke’s equation, is much smaller than (all the experimentally) determined values for many other liquid metals. Oxygen in nickel reduces the peak due to grain-boundary stress relaxation substantially.View full abstractDownload PDF (740K) -
Ryoichi Nozato1960 Volume 24 Issue 3 Pages 196-199
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe precipitation of cadmium from lead-cadmium solid solution was studied by microscopic observation, micro-hardness measurement, and specific heat measurement,with various alloys containing 1, 2, and 3 wt%Cd. (1) The precipitation of cadmium from lead takes place in two distinct stages. In the 1st stage, a cellular precipitation proceeds rapidly from grain boundary to grain center. In the 2nd stage, another cellular precipitation proceeds slowly from the grain boundary to the grain center. The lamellar spacing of cadmium in the cell of the 1st stage was considerably smaller than that of the 2nd stage. The alloy was age-hardened in the 1st stage and then softened in the 2nd stage. (2) The kinetic law for the 1st stage seems to be represented by Johnson-Mehl’s equation; f=1−exp(−btn), where f is the precipitation fraction and n is a constant independent of alloy composition and has the value of 2.9±0.2. The kinetic law for the 2nd stage seems to be represented as follows; f=K\sqrtt+C, where K and C are constants. (3) The activation energy for the 1st stage was obtained by microscopic observation as about 9 kcal/mol.View full abstractDownload PDF (786K)
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