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Volume 24, Issue 2
Displaying 1-18 of 18 articles from this issue
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Yûki Shirakawa, Ichiro Oguma1960 Volume 24 Issue 2 Pages 63-66
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThis paper describes a method for measuring elastic constants, sound velocity and their changes,especially very small changes,newly devised by the authors. The principle of measuring method is based on the use of an electrostatic-type mechanical vibrator-controlled oscillator. The new oscillator is capable of measuring elastic constants and its small changes of the order of 10−6 or smaller precisely by comparing the oscillation frequency of the oscillator with a known accurate standard frequency (e.g., the standard frequency broadcasted by JJY). As examples, the results of measurement of Young’s modulus of some metals and of very small anomalous change of resonant frequency (or sound velocity) of specimen vibrator made of co-elinvar alloy are described.View full abstractDownload PDF (746K) -
Masao Kanamori, Shôji Ueda, Hiroshi Sakaguchi1960 Volume 24 Issue 2 Pages 67-70
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe Fluid flow in the gating systems of propeller casting with the aid of transparent models made of plastics, in which the flow of metal is simulated by that of water, is studied. The effect of sprue base and 2nd sprue on the rate and the quality of the flow, viz. whether the flow is quiet or agitated, whether entrainment of air bubbles occurs, is mainly discussed. It was summarized that the design of sprue base was important to avoid the intense agitation of the flow and the considerable aspiration, and the use of 2nd sprue was effective in decreasing the rate of flow and in washing away the trapped air.View full abstractDownload PDF (706K) -
Masao Kanamori, Shôji Ueda, Hiroshi Sakaguchi1960 Volume 24 Issue 2 Pages 71-74
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe effect of the design of the runner and the ingate on the rate and the quality of the flow is described. A comparison of flow properties in tapered, U-bent runner or runner with attached damper box and mono-hole or multiple-hole type ingate is discussed. The application of “pre-filling” method as a proposed pouring practice, by which aspiration and agitation are much rudused and the trapped air is washed away more quickly, is also outlined.View full abstractDownload PDF (658K) -
Shigetoshi Takayanagi1960 Volume 24 Issue 2 Pages 74-78
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThis article gives a description of a modification of the standard Brunaner-Emmett-Teller (BET) method for the determination of the surface area of metal powders. The modified procedure involves the use of CO2 as adsorbate, the determination of adsorption isotherm from three measured points and other simplifications. The use of CO2 for tungsten and molybdenum powders seems to give just as satisfactory results as in the case of conventional N2. It is shown that values within 2% of those by the standard method using CO2 are obtained by this simplified procedure One sample can be measured in about 1.5 hr with the result reproducible within 2%.View full abstractDownload PDF (598K) -
Tsuneo Sasahara, Mayumi Someno, Kyuya Nagasaki1960 Volume 24 Issue 2 Pages 78-82
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe conditions of formation of silicides, when chromium powder or mixed powders of chromium and silicon were reacted with silicon tetrachloride gas in hydrogen, argon and nitrogen atmospheres at 800°C to 1300°C, were examined by weight changes and X-ray analysis. In hydrogen and argon atmosphere, the chromium silicides were easily produced. On the other hand, in nitrogen atmosphere, X-ray analysis showed the formation of chromium nitrides other than chromium silicides below 1000°C, and showed alone the formation of silicon nitride higher than 1200°C. A mechanism of formation of silicon nitride, when chromium powder was reacted with silicon tetrachloride in nitrogen atmosphere, was discussed.View full abstractDownload PDF (709K) -
Kazuo Ota1960 Volume 24 Issue 2 Pages 82-85
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe fundamental conditions for photometric determination of zinc using zincon (2-carboxy-2′-hydroxy-5′-sulfoformazylbenzene) have been investigated and applied to the analysis of cast iron. Zinc-zincon complex shows high absorbancy at 615 mμ over pH 8.5∼9.5, and is stable at least for 1 hour. However the stability of absorbancy varies with the maker of zincon. It obeys Beer’s law up to 200γ of zinc in 50 mL for 1 cm cell. Preliminary separation of zinc from large amounts of iron etc. is made by extraction with dithizone in benzene from citrate solution of pH about 8.3 and following back extraction with dilute hydrochloric acid solution. The proposed method is suitable for determining 0.002∼0.04% of zinc in cast iron, when carried out without great care which is necessary in the dithizone photometric method.View full abstractDownload PDF (490K) -
Hidehiro Goto, Hiroshi Amano, Yasushi Inoue1960 Volume 24 Issue 2 Pages 85-88
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSSilver and arsenic in high-purity metallic silicon were determined by radioactivation method. The sample was irradiated in a pile by a neutron flux of 4×1011 n/cm2·sec intermittently for 3 days. Then silicon was expelled by treating with hydrofluoric acid. From the residue after the sublimation of silicon tetra fluoride, silver was separated as silver chloride and arsenic was collected on manganese dioxide. Carrying the analysis on two kinds of samples, 0.249 ppm silver and 0.0034 ppm arsenic, and 0.372 ppm silver and 0.0616 ppm arsenic were found.View full abstractDownload PDF (429K) -
Hiroshi Amano1960 Volume 24 Issue 2 Pages 88-92
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSTungsten, molybdenum and vanadium were determined simultaneously by using organic solvent extraction-spectrophotometric method. From the sample solution which contained these three elements, molybdenum and vanadium were first extracted into chloroform layer in the presence of potassium xanthate, molybdenum was determined at 550 mμ, and vanadium at 375 mμ. Then tungsten was extracted by 2 per cent oxine-chloroform solution from the remaining solution after the extraction of molybdenum and vanadium, and was measured at 400 mμ. Although many other elements, such as iron, nickel and etc., disturbed this method, they were removed by using magnetic mercury cathod electrolysis and other method.View full abstractDownload PDF (728K) -
Tadashi Ôtake, Kôichi Aoki, Toshiyuki Fujishima1960 Volume 24 Issue 2 Pages 92-96
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSFour kinds of mild steel varying in degrees of deoxidation, but constant in C% were oxidized in a small gas furnace under many different heating conditions. Heating conditions: Range of soaking temperatures 1270∼1320°C, Atmosphere μ=0.8∼1.3, Heating time plus soaking time 2 hrs plus 0.5 hrs. The increase in weight, thickness, porosity and other properties of scales, together with the structure of subscales and internal oxidation were examined in relation to the above-given heating conditions. As the result, it was clarified that the properties of scales were influenced by heating temperaure, atmosphere and Si% in specimens, and the structures of subscales and the depth of internal oxidation was affected by the Si content of the specimen.View full abstractDownload PDF (748K) -
To-oru Furukawa, Tomo-o Sato1960 Volume 24 Issue 2 Pages 96-100
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESS17%Cr-7%Ni stainless steel containing 0.93%Al was experimented for determining its mechanical properties after several treatments such as solution treatment at 1050°C, 30∼70% cold-rolling and aging at 400∼500°C for 0.5∼500 hr. The following results were obtained: (1) Super-cooled austenite in this steel hardens due to internal stress and transformation into martensite by cold-rolling. The ratio of this hardening is larger than that of 18-8 stainless steel. (2) The hardness and the yielding strength of cold-rolled 17-7 PH steel increase exceedingly by aging at 400∼500° for suitable hours. (3) The highest mechanical properties of this steel were obtained under the following aging conditions; 400°C×100 hrs, 450°C×8∼12 hrs, 470°C×5∼8 hrs.View full abstractDownload PDF (1040K) -
Tadashi Ichiyama, Kikuo Takashina1960 Volume 24 Issue 2 Pages 101-104
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe internal friction at higher temperatures before Ac1 transformation in 0.09, 0.38, and 0.85% carbon steels was measured as a function of temperature, using a torsion pendulum with a frequency of vibration of about 1.9 cycles per second. The internal friction curves in 0.85% carbon steel do not show a peak but continue to rise with the rise of measuring temperature from about 400°C. The activation energy of the process causing the anelastic behaviour was found to be 59,000 to 64,000 calories per mole. The internal friction at a given temperature increases with an increase of the amount of carbide in steel. In recrystallized and tempered steels, the internal friction curves shift toward higher temperatures with the rise of annealing temperature. In addition, the internal friction at a given temperature in fully recrystallized and tempered steels is considerably greater than that in steel annealed fully at above A3−1. Such behaviours are interpreted in terms of the concept of the coupled relaxations of an irregular network of interfaces.View full abstractDownload PDF (741K) -
Go Okamoto, Norio Sato1960 Volume 24 Issue 2 Pages 105-109
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIt has been pointed out in our previous paper that the Flade potential of nickel is the equilibrium potential of the redox reaction of 3NiO+H2O\ ightleftarrowsNi3O4+2H++2e and that the passive film is composed of these two oxides. For the purpose of clarifying the role of this double oxide film on the passivation of nickel, the transition phenomena from the active to the passive state were investigated by means of an electrochemical technique, and a generalized theory of passivity was presented from the kinetic standpoint. It can be expected that passivation would result when the metal surface is covered with a compact film which has the character of self-repairing action. The defects of the double oxide film of NiO and Ni3O4 can be repaired by the electrode reaction of Ni2++2NiO+2H2O→Ni3O4+4H++2e, because the rate of this reaction increases with increasing the concentration of nickel ion resulting from the active dissolution at the defects. Such a repairing electrode reaction cannot be kinetically expected on the single oxide film of NiO, so that no passivition results from the formation of this film. It is assumed in general for the passivation of metals in corrosive solution that the passive film should always be composed of oxides in which the valency of metal ions is higher than that of the metal ions dissolved from the active defects into the solution. The passivation of iron and chromium could also be explained by this higher-oxide-film theory.View full abstractDownload PDF (771K) -
Naoya Ito, Go Okamoto1960 Volume 24 Issue 2 Pages 109-113
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe effect of potential on the etching figure was studied for 18-12Cr-Ni-Mo-Si duplex cast steel. The specimen was heat-treated either by quench-annealing or by sigmatizing and it was etched for an appropriate length of time in 1 N H2SO4 containing 0.01% NH4SCN under constant potentials controlled by a potentiostat. It was found that a certain kind of phase can be selectively etched according to the applied potentials with appreciable rate in both active and overpassive potential ranges. In the active potential range, the optimum potential for etching shifted to the less noble direction with the increase of Cr content of structural phase. Thus, differential etching for δ, γ′ and γ can be performed at the potential range of −0.40∼−0.30, −0.30∼−0.21 and −0.25∼−0.21 V (v.s.S.C.E), respectively. The σ phase was not attacked but appeared in relief brightly in the active state. In the overpassive region, the etching rate increased with the increase of Cr content of phase. The σ phase can be well differentiated at the potential region of the so-called 2nd passivity which appeared above ca.1.4 V because of the remarkable difference between the rate of attack of this σ phase and that of the other phases.View full abstractDownload PDF (1073K) -
Kazuko Yokogawa, Takesi Sugeno1960 Volume 24 Issue 2 Pages 113-117
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSPalladium was chosen for the investigation of the effect of γ-radiation on absorption of hydrogen in metals. The amount of hydrogen in palladium can be estimated by the change in electrical resistance. No absorption of hydrogen was observed during irradiation even for a long time, when palladium wires were immersed in acidic or alkalic solutions. On the other hand, palladium with thin oxide films formed either by the anodic treatment or by γ pre-irradiation in aerated water or in hydrogen peroxide, absorbed a large amount of hydrogen in dilute sulfuric acid or in dilute hydrochloric acid. From these results, it is concluded that a thin oxide film is necessary for absorption of hydrogen by palladium in an acidic solution. But the oxide film formed by heating in air showed no such effect. Probably, such a film may be too thick and too dense to permits permeation of hydrogen ions. The results are interpreted by the photovoltaic theory of semi-conductors.View full abstractDownload PDF (684K) -
Kaizô Monma, Hajime Sutô1960 Volume 24 Issue 2 Pages 117-121
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSWe are trying to clear the fundamental mechanisms on cermet making from the view point of surface and interfacial tension. In this paper, we firstly describe the measurement of surface tension of molten metals by the sessile drop method, and then deduce a semi-theoretical equation as follows: Us=BM(LV−RT⁄2)N\frac−13V−\frac23 or γ=KMLVN−\frac13V−\frac23, where Us is the surface energy, γ the surface tension, Lv the molar heat of vaporization, N the Loschmidt’s number, V the molar volume,and BM or KM is a constant for molten metals. From our results, KM\doteqdot0.16 and BM=0.18. In general, similar equations are obtained for Van der Waals’ and ionic liquid by applying results reported by other authors. But in these cases, the constant for Van der Waals’ liquid is BV\doteqdot0.5 and for ionic liquid, BI\doteqdot0.10, KI\doteqdot0.07.View full abstractDownload PDF (683K) -
Kenzo Igaki, Shozo Tanimoto1960 Volume 24 Issue 2 Pages 121-125
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSTwenty molten zones were passed on lead and tin bars, which were vacuum-sealed in glass tubes. The refining effect and the impurity distribution were estimated from intensity measurement of the emission spectrum. It was confirmed that zone-refining was effective for Pb and Cu in Sn; Cu and Ag in Pb. But we could not observe the refining effect for Bi in Sn; therefore, another method must be found in order to remove Bi in Sn. The highest purity was usually found at nearly middle but a little closer to the top portion. Adding one per cent of 4-nine-purity lead to the zone-refined purest lead, we could observe a clear difference in microstructure of quenched specimens from molten state. It was concluded that purity was improved by two orders, from 4-nine to 6-nine, — at least in respect of those impurities which had effects on quenched structure. This improvement in purity was endorsed by the results of spectrum analysis.View full abstractDownload PDF (863K) -
Norio Sato1960 Volume 24 Issue 2 Pages 126-130
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSDissolution of copper in aqueous solution is generally much more rapid in the presence of NH3 and NH4+, when stable complex ions of copper are formed. It has been known in previous experiments that the dissolution rate i under low and high oxygen pressure can be given by i=ka[O2] and i=k[NH3]+kc[NH3], respectively. The rate also can be given by i=k[Cu(NH3)42+]0.5 at low values of the ratio [O2]/[Cu(NH3)42+]. These experimental facts are interpreted in terms of a new mechanism based on the multi-electrode kinetics. In the presence of oxygen, the dissolution of copper proceeds according to an electrochemical process involving separate anodic and cathodic steps as follows: anodic process [α:Cu+mNH4→Cu(NH3)m++e, ω: Cu+mNH4+→Cu(NH3)m++H++me], cathodic process [β: Cu(NH3)m+n2++e→Cu(NH3)m++mNH3]. In the presence of oxygen, Cu(NH3)m+ produced by the anodic and the cathodic processes is oxidized into Cu(NH3)m+n2+ by oxygen according to a coupled reaction of the anodic step of β and the cathodic step of [γ: O2+2H2O+4e→4OH−]. The dissolution rate is controlled by the diffusion rate of oxygen under low oxygen pressure. Under high oxygen pressure, on the other hand, the rate is controlled by the diffusion rate of NH3 or NH4+. Schematic polarization curves of this tri-electrode system involving α,β and γ are presented.View full abstractDownload PDF (702K) -
Go Okamoto, Norio Sato1960 Volume 24 Issue 2 Pages 130-134
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThree different methods, the galvanostatic, the potentiostatic and the rapid can be used to measure the rate of growth of the anodic oxide film on metals. By using these methods, the rate of growth of a passive oxide film on nickel was measured in ln H2SO4 at 40°C. The rate of growth i can be expressed in the form i=i0exp(β′ε), where β′=zaeα⁄kT and ε is the strength of the electric field which can be expressed as ΔE⁄d. The value of β′=40×10−3 coul./V·cm2 obtained by the galvanostatic method was considerably different from β′=416×10−3 coul./V·cm2 obtained by the rapid method. Under a certain potentiostatic condition, the value of β′ was almost equal to that measured by the galvanostatic method except in the initial period immediately after the change of the potential when β′ is larger than 250×10−3 coul/V·cm2 and rather close to the β′ obtained by the rapid method. From these results, it may be presumed that the significance of the measured values are essentially different in the galvanostatic method and in the rapid method. From the β′ of the galvanostatic method, the plausible value of a≈2.3 Å, as the thickness of the energy-barrier in the rate-process, was obtained under the assumption of α=0.5.View full abstractDownload PDF (792K)
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