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Volume 23, Issue 7
Displaying 1-19 of 19 articles from this issue
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Yukio Ohba1959 Volume 23 Issue 7 Pages 363-366
Published: 1959
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThis paper presents data of age-hardening of Cr-Ni-Mo alloys containing 35 to 60%Cr at 600° to 1000°C. The raw materials used were Cr produced by electrolysis of chromic acid and high grade Ni and Mo. All specimens were prepared in water-cooled Cu crucible under argon atomosphere by means of arc-melting. The results were as follows: Most of the 35 to 50%Cr alloys show marked age-hardening caused by the precipitation of Cr α and σ phase, but the 60%Cr alloys exhibit age-softening which is due to the decomposition of β or α′ phase. (2) This age-hardening is effective for the rise of hardness at high temperature, while the existence of or α′ phase seems to lead to the decrease of hardness at high temperature, in spite of its extreme hard structure at room temperature. (3) The hardness at high temperature increases with increase of Mo and Cr contents after 500 hr aging.View full abstractDownload PDF (725K) -
Hirosi Amano1959 Volume 23 Issue 7 Pages 367-370
Published: 1959
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSA method for determination of hafnium in zirconium metal was studied. Hafnium was concentrated from hydrochloric acid solution of zirconium sample through four steps of thiocyanate-hexone extraction-stripping method. After several steps of extraction, pure hafnium fraction was obtained by passing the solution through a cation-exchange resin column and eluting with 0.45 M nitric acid+0.095 M citric acid eluent. Combining the isotope dilution method and the above mentioned method hafnium which existed from 0.01 to 0.1 per cent in zirconium was determined.View full abstractDownload PDF (662K) -
Kichinosuke Hirokawa1959 Volume 23 Issue 7 Pages 371-373
Published: 1959
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe differential spectrophotometric method was applied to the determination of chromium in ferrochromium and high chromium alloys. Chromium was determined by reading the absorbance of chromium (VI) in 1 N-HClO4 at 350 mμ against the reference solution which contained 16.0 mg chromium per 100 mL. The common alloying elements iron, nickel and manganese did not interfere up to about 50 per cent concentration. However, when samples contained over 50 per cent of iron, it was removed by solvent extraction from hydrochloric acid solution. Similarly titanium and cobalt in concentration up to 20 per cent did not interfere.View full abstractDownload PDF (427K) -
Mitsuru Nagakura, Tetsuro Yamaguchi1959 Volume 23 Issue 7 Pages 373-376
Published: 1959
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn the study of producing oriented barium ferrite magnets, the manufacturing procedures of dry pressing and the influence of addition of unfired powders and of oxides such as CuO, Al2O3 and Cr2O3 were examined. Water included in fine particles to be pressed has harmful effects on the degree of orientation. This effect is the greatest when the weight ratio of water to powder is about 0.1. On the contrary, in fully dried powders and powders suspended in water high degree of orientation is obtained by the pressing in orienting fields. We have studied dry pressing in particular, and have found the best conditions in the preliminary pressing under which we could orient the powders and make the binding solution permeate into the powders. Also good effects on magnetic properties of the specimens pressed in orienting fields and fired were obtained by addition of unfired powders of barium ferrite up to 10%, and the reason for it is discussed. Further, the influence of addition of oxides such as CuO, Al2O3 and Cr2O3 on the magnetic properties and the density is reported.View full abstractDownload PDF (432K) -
Kichinosuke Hirokawa1959 Volume 23 Issue 7 Pages 376-380
Published: 1959
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe fluorescent X-ray spectroscopy was applied to the analysis of total iron and total manganese in slag, in order to provide a rapid method for the determination of both these elements. It was recognized that the standard addition method was suitable for the determination of iron and manganese in slag which contained various coexisting elements.View full abstractDownload PDF (674K) -
Shin’ichi Nagashima1959 Volume 23 Issue 7 Pages 381-384
Published: 1959
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn order to obtain some informations about G.P. zones which are formed in the matrix of the hexagonal lattice, single crystals of Mg-Ag alloy containing 12.6%Ag were aged at room temperature for a long time, and were investigated by the method of X-ray diffraction. In the Laue photographs as well as in the small angle scattering photographs, diffuse scatterings were observed showing the presence of two kinds of G.P. zones: one of them is platelike and parallel to one of {1\bar101} planes of the matrix, and the other is of an oblate ellipsoid, its major axis being parallel to the basal plane. From the difference in shape and orientation between these two kinds of G.P. zones, it may be possible to conclude that they are formed independently by different mechanisms.View full abstractDownload PDF (744K) -
Tatsuo Maekawa, Takuya Hata1959 Volume 23 Issue 7 Pages 385-388
Published: 1959
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe post-breakaway oxidation rate of reactor grade pure zirconium, 2.5% tin-zirconium and 0.24% iron-zirconium alloy in dry oxygen and air were measured over the temperature range of 500∼850°C and pressure range of 15∼760 mmHg. The results were as follows: (1) A lower oxidation rate and its pressure dependence were found in the oxidation of pure zirconium and 0.24% iron-zirconium alloy in oxygen. (2) A higher oxidation rate and its pressure dependence were found in the oxidation of 2.5% tin-zirconium alloy in oxygen and air. (3) In the case of air oxidation of pure zirconium and 0.24% iron-zirconium alloy the oxidation rate and its pressure dependence increased remarkably with temperature. (4) Thus, a correspondence between oxidation rate and its pressure dependence were found.View full abstractDownload PDF (688K) -
Shôsuke Imoto, Genjiro Mima1959 Volume 23 Issue 7 Pages 389-392
Published: 1959
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSCold-rolled tough pitch copper and oxygen free copper were annealed for 1 hr at each of the following temperatures successively, namely, 20°, 100°, 158° (165°), 210°, 250°, 300° (308°), 367°, 443°, 518°, 600°, 700°C (temperatures in parentheses refer to oxygen free copper). Then the internal friction and its amplitude dependence were measured after each annealing at room temperature by the transversely vibrating bar method. The results were as following. (1) Before recrystallization, the internal friction was decreased with the annealing temperature and was independent of amplitude. (2) As recrystallization proceeded, a maximum developed in the internal friction-amplitude curve and the internal friction itself was much increased. These facts were inferred to be associated with birth of dislocations liberated from firm pins in the course of the recrystallization. (3) After annealing at higher temperatures than recrystallization completion temperature, both the internal friction and its amplitude dependence of oxygen-free copper were again decreased. This was looked upon as due to the concentration of impurities to the new-born dislocations.View full abstractDownload PDF (739K) -
Sakae Takeuchi, Sukeji Kachi, Tsuneo Satow1959 Volume 23 Issue 7 Pages 393-397
Published: 1959
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn order to see the separation efficiency of the high temperature electrorefining of thorium, mixtures of thorium and other metals were electrorefined in a fused salt bath containing sodium and potassium chlorides. In these experiment, radioactive tracers were used to estimate the micro-quantities of these elements. Cobalt and lead, which have lower reversible decomposition voltage, can be thoroughly eliminated as anode slime. And the contents of these elements in the cathode deposites were about 10−10%. Titanium, zirconium and uranium, which have only a few tenth volt of difference, were also separated fairly well. Rare earth elements, which have high absorption cross section for thermal neutron, can also be removed in this process, because the electrode potentials of these elements are rather high. Activation analysis by neutron irradiation showed that the refined thorium contained less than 5 ppm of Dy and Sm.View full abstractDownload PDF (779K) -
Yoshio Kubota1959 Volume 23 Issue 7 Pages 397-400
Published: 1959
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThis paper presents the results of studies on the reactivity of Zn powder in relation to particle shape and specific surface area. The specific surface area was determined by different methods and used to discuss the surface structure. The methods used are the “equivalent circle method”, the liquid phase adsorption method using crystal violet in methanol and B.E.T method using N2, CO2 and n-C4H10. The shape of D-Zn particles is nearly spherical or polyhedral, but that of E-Zn is dendritic with layer growth. The specific surface area of E-Zn is twice to three times as large as that of D-Zn. But this does not account for the high reactivity of E-Zn about ten times as large as that of D-Zn. E-Zn products, nearly equal in purity but prepared under different electrolysing conditions do not show the activity as expected from their surface area. These facts and the ineffectiveness of the trace impurities strongly suggest some unknown factors responsible for the very high reactivity of E-Zn (E-Zn: electrolytic Zn powder, D-Zn: distilled Zn powder).View full abstractDownload PDF (690K) -
Yoshio Kubota1959 Volume 23 Issue 7 Pages 401-403
Published: 1959
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThis paper presents the results of studying the surface structure of Zn particles by optical and electron microscopes, using replica technique. Particles of distilled Zn powder (D-Zn) prepared in vacuum by rapidly distilling onto a cold surface except J-2, are nearly spheres consisting of layers, the extremities of which are made visible under high magnification as sprouts or wrinkles. The thickness of each layer and the interstice between two adjacent layers seems to be less than 100 Å. But J-2 is rather like electrolytic Zn powder (E-Zn). E-Zn grows to into dendrites with 60° branching angles. The interstice between the layers is large enough to let a polystyrene solution easily penetrate into it. The dendrites consists of thin layers (0001 plane) whose hexagonal terminations form a terrace.View full abstractDownload PDF (810K) -
Tomo-o Sato, Taiji Nishizawa, Jô Ishiwara1959 Volume 23 Issue 7 Pages 403-407
Published: 1959
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSMicrohardness tests were carried out on carbides in samples of alloyed cast irons and of some tool steels, using a 136-degree Vickers pyramid indenter with a 50 gram load. The indentations were between 4 and 9 microns in diagonal length, as measured under a 400×microscope equipped with a ocular micrometer. The V.H.N obtained were as follows;
(This article is not displayable. Please see full text pdf.)View full abstractDownload PDF (806K) -
Mitsuru Nagakura, Tetsuro Yamaguchi1959 Volume 23 Issue 7 Pages 407-409
Published: 1959
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSDomain patterns on large crystals of anisotropic barium ferrites were observed microscopically with a colloidal solution of fine iron oxide particles. The domain patterns on the hexagonal plane have such a complicated configuration as maze pattern, flower pattern, etc. The distances between the domain walls observed on the hexagonal plane are few microns, and the domains are assumed to be superficial. On both the face and side planes, the behaviour of the powder patterns was observed by applying magnetizing field in the direction of the hexagonal axis.View full abstractDownload PDF (582K) -
Yô Takeuchi, Rokurô Kawanishi, Yasuhiro Morooka, Denjir&oc ...1959 Volume 23 Issue 7 Pages 410-413
Published: 1959
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe nitriding process of Ti in N2 stream has been studied through weight-increase, hardness-increase and change of microstructure, and the surface films formed have been examined by electron diffraction. The weight-increase at 800∼1000°C has shown the nitriding to follow the parabolic law in accordance with many previous works, and the activation energy has been determined to be 45,500 cal/mol·deg.Diffraction tests have revealed surface films to consist of TiN above 800°C but of the oxide at 700°C. While the formation of the hardened surface layer is not remarkable at 800°C, the increased diffusion of N2 causes the hardened layer to be thickened progressively with increase in time above 900°C. The most suitable temperature for the surface hardening of Ti has been found from the present study to be 850∼900°C.View full abstractDownload PDF (803K) -
Fumitaka Yoshikawa1959 Volume 23 Issue 7 Pages 414-418
Published: 1959
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSApplying the outer-differential thermal dilatation method which was detailed in the preceding report concerning a cyanided specimen, a carbonitriding diagram—corresponding to sectional diagram—was drawn. First, the chemical and phase compositions for the diagram were determined and next, it was experimentally demonstrated that there is a correlation of the carbonitriding diagram with the micro-structure, the micro-Vicker’s hardness distribution and the thermal changes of the specimen.View full abstractDownload PDF (1076K) -
Tadashi Ichiyama, Masayuki Kawasaki, Kikuo Takashina, Shinzaburo Saika ...1959 Volume 23 Issue 7 Pages 418-422
Published: 1959
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe internal friction in iron and steels was measured as a function of temperature, using a torsion pendulum at about 1.9 cps. Vacuum-melted electrolytic iron with low nitrogen content (0.004%) exhibits, in addition to a Snoek damping peak, a stress-relaxation peak at about 500°C and 550°C respectively. However,the vacuum-melted electrolytic iron treated with wet hydrogen exhibits a stress-relaxation peak at about 500°C. The first peak manifested at about 500°C is a grain-boundary stress-relaxation peak, and the second peak at 550°C is the solid-solution peak accompanying the presence of nitrogen in solid solution in α-iron. Armco iron recrystallized at 650°C after cold drawing exhibits a pronounced solid-solution peak at about 570°C. The activation energy of the solid-solution peak in Armco iron is 64,000 cal/mol. The peak is characterized by a distribution of relaxation times. The peak decreases markedly by the precipitation of cementite at the grain interfaces. The peak is considered to be a grain-boundary peak for the solid-solution of carbon in α-iron. In annealed states, the Snoek damping peak in medium and high carbon steels cannot be detected, and a material recrystallized at 650°C after cold-drawing exhibits a smaller Snoek damping peak than the same material annealed at above A3−1. The Snoek damping peak in iron is markedly affected by A3 transformatiom.View full abstractDownload PDF (765K) -
Ryuzo Ueda1959 Volume 23 Issue 7 Pages 422-426
Published: 1959
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSColloidal particles of tungsten trioxide having boat-like and rectangular shapes were prepared from aqueous solution of tungstic acid. These crystals were single-crystalline (Photo. 1), and they were mounted on a carbon film placed on a perforated thin gold plate, and were reduced by hydrogen at one atmospheric pressure in the specimen-treating adaptor to the electron microscope, previously devised by the present author, and the morphological and the chemical changes of a certain chosen region of the specimen were followed by taking micrographs and selected-area diffraction patterns (Photo. 2). By reduction at 500°C, the entire uniform surface of the particle becomes finely granular and the patterns of β-W and α-W appeared, but by further reduction at 600°C, β-W was completely transformed into α-W, and the granular surface became coarser and finally at 700°C broke into separate particles, later becoming somewhat rounded. Even at the highest temperature these tungsten particles filled uniformly the unshrunk contours of the original oxide crystals. Above 700°C the tungsten particles reacted with carbon film to form carbide. Nickel oxide particles prepared by heating nickel nitrate hexahydrate were mounted on the sharply pointed end of a tungsten wire, and the progress of reduction was examined. Fine nickel particles produced by reduction grew to larger ones and coalesced together at higher temperatures (Photo. 3). On the contrary, fine nickel particles produced by reduction of the oxide prepared by heating kieselguhr and asbestos fibers impregnated with nickel nitrate solution did not show any sign of coalescence even at high temperatures (Photo. 4, 5). Based on these observations the mechanism of formation of nickel particles and the role of support for catalysts have been discussed.View full abstractDownload PDF (1020K) -
Ryuzo Ueda1959 Volume 23 Issue 7 Pages 426-429
Published: 1959
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSFused magnetite for ammonia synthesis, with and without promoter, was finely pulverized in an agate mortar. These particles were mounted on the sharply pointed end of a tungsten wire, and exposed to heated hydrogen gas at about one atmospheric pressure in the specimen-treating adaptor for electron microscope previously devised by the presenet author, and the morphological and the chemical changes of a certain chosen region of the specimen were followed by taking micrographs and selected-area diffraction patterns. The progress of formation of iron particles from the magnetite granule without promoter (Photo. 1) differed very markedly from that with the promoter (Photo. 2, 3). The oxidation and the reduction processes of reduced catalysts were also examined (Photo. 4). Almost perfectly spherical iron particles were observed, when the weakly magnetic part of fused magnetite with alumina and potassium promoters was reduced (Photo. 5).View full abstractDownload PDF (746K) -
Toranosuke Kawaguchi, Mitsuru Nagakura, Tetsuro Yamaguchi, Isao Tanabe1959 Volume 23 Issue 7 Pages 429-432
Published: 1959
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSFine iron powders were prepared by electrodeposition into a mercury cathode, and both their particle-size distributions and their dimension ratios (length/diameter) were examined directly by electron micrographs. As the result of our experiments, it has been verified that the concentration of ferrous sulphate and hydrogen ion in electrolytic solutions and the heat-treatment of electrodeposited iron powders have a marked effect on the magnetic properties of ESD (elongated single-domain) iron magnets. Of course, these magnetic properties depend on the packing factor of fine iron powders. The heat-treatment makes the diameters of electrodeposited iron powders large and increases the ratio of the metallic part to the oxidized part, making the packing operation of powders more easy. In the packed state of fine powders oriented at random and ranging from 150 to 300 Å, the relation between the average dimension-ratio and the intrinsic coercive force are consistent with the Jacobs and Bean\'{s} model, and also with Pain, Mendelsohn, and Luborsky’s experimental results.View full abstractDownload PDF (525K)
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