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Volume 24, Issue 9
Displaying 1-19 of 19 articles from this issue
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Hisashi Ito, Masao Ikeda1960 Volume 24 Issue 9 Pages 549-552
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSBy studying the crystal size of magnesium deposite, the temperature range in which magnesium is condensed and the distribution of impurities in the subject reduction the following results were obtained. (1) With the rise of reduction temperature and the temperature gradient in the sleeve, magnesium condenses at the higher temperature side and becomes more coarse at the position of the water jacket (b) in Fig. 1. It is desirable to set the water jacket at the position of (a) for production of fine grains of magnesium. (2) With higher vacuum, magnesium condenses at the lower temperature side in the sleeve and becomes rather fine. (3) In longitudinal direction, Mn, Cu, Al and Si are distributed poorly in the middle part and densely in both ends of the sleeve, while Zn shows high value at the lower temperature side. (4) Most of the impurity metals show high values of distribution at the first stage of reduction and then decrease in content in the radial direction.View full abstractDownload PDF (652K) -
Toshinori Kuroda, Haruki Kondo1960 Volume 24 Issue 9 Pages 553-555
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSElectrolytically hardened hack-saws (SK-3, SKS-7) are much more excellent in cutting ability than saws hardened in the ordinary furnace(1) or by high-frequency method as shown in Fig. 1. It is probable that the excellency arises from rapid heating, strong quenching, low decarbonization, or under certain circumstances, carbonization. The abrasion test on the points of various microscopic structures of SKS-7 steel hardened ordinarily or electrolytically suggested that the heating of the tips of the saw-teeth at higher temperature than in the ordinary process is a cause of high cutting ability of the electrolytically hardened saw.View full abstractDownload PDF (613K) -
Kichinosuke Hirokawa1960 Volume 24 Issue 9 Pages 555-558
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSUsing the X-ray intensity from zinc as standard, a small amount of cadmium, iron, lead and arsenic in zinc was determined by the non-destructive method. Lead and arsenic in tin were similarly analysed. In the case of iron in titanium, the X-ray intensity was measured, after the samples were dissolved in hydrofluoric acid and their salts obtained were briquetted with carbon powder. In the present experiments, the agreement between chemical and X-ray fluorescent analysis was very good.View full abstractDownload PDF (570K) -
Kichinosuke Hirokawa1960 Volume 24 Issue 9 Pages 559-562
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe calibration curves for the determination of tin, antimony and lead in tin-lead, lead-antimony, antimony-tin and tin-antimony-lead alloys were obtained. In the case of tin-antimony and tin-antimony-lead alloys, a background subtraction method was attempted, and this method was recognized to be more suitable to the rapid analysis than the integrated area method.View full abstractDownload PDF (547K) -
Kichinosuke Hirokawa1960 Volume 24 Issue 9 Pages 562-564
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe calculation method which had been proposed by Brissey, Sherman and others was applied to the determination of tin, antimony and lead in the subject binary and ternary alloys. For example the equation of determination of tin and lead in tin-lead alloys was obtained as 1.853=WSn⁄WPb(ISn⁄ISn-Pb−1), WSn+WPb=100. Then this method and the calibration curve method were applied to the actual analysis of samples.View full abstractDownload PDF (380K) -
Akira Takamura1960 Volume 24 Issue 9 Pages 565-569
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSA kinetic study of the nitriding process of titanium in nitrogen stream was carried out in order to establish a method to improve the frictional properties of titanium. The diffusion layer formed by nitriding was covered by a very thin compound layer (TiN). The maximum hardness of the diffusion layer was above Vickers 1000, but the rate of its growth was comparatively low. The rate of reaction of titanium with nitrogen was found to follow the parabolic law at 800∼900°, and the rate-controlling process was considered to be the diffusion process in both the compound layer and the diffusion layer. As the rate of growth of the diffusion layer is considered to be controlled exclusively by the solubility and the diffusion coefficients of nitrogen in α-titanium, both of which are functions of temperature only, it is necessary to operate at higher temperature and for longer time in order to make the hardened layer deeper. However, the nitriding at a temperature above the transformation point of titanium is not practical because of the formation of surface reliefs produced in the course of β→α transformation and the deformation of material nitrided at high temperature. Therefore, it is concluded that the most practical nitriding temperature is about 850°C. The diffusion coefficients of nitrogen in α-titanium and the compound layer were also determined at 850°C as follows: Dα=1.3×10−11 cm2/sec and Dγ=1.4×10−12 cm2/sec.View full abstractDownload PDF (688K) -
Masataka Sugiyama, Kunio Shida1960 Volume 24 Issue 9 Pages 569-570
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe effect of TiH2 addition to sintered permanent-magnet alloy of the MK3 type (11%Al, 18%Ni, 12.5%Co, 6%Cu, residue Fe) has been studied, particularly, in relation to their linear shrinkages, densities, magnetic properties, and pore size distributions. It has been found that the addition of TiH2 within the range of 0.2∼0.5% improves the qualities of Fe-Al-Ni-Co-Cu alloys prepared by sintering in pure hydrogen, but larger addition causes the pore growth and a detrimental effect on the magnetic properties.View full abstractDownload PDF (260K) -
Shigeo Wakamatsu1960 Volume 24 Issue 9 Pages 571-573
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSEDTA titration method for the determination of Mg in cast iron was developed. The procedure was as follows: Weigh a sample of 0.25 to 0.5 g. Add HCl and HNO3 and evaporate to dryness. Cool and take up the residue by adding 6 NHCl. Filter off SiO2 and G.C Transfer the filtrate to a separatory funnel. The solution is adjusted to an acidity of 6 N with HCl. Add methyl-isobuthyl-ketone and shake for 1 min. (iron is extracted in the solvent layer). Drain off the aqueous layer. Add HNO3 and evaporate to dryness. Add HCl and water and swirl to dissolve the salts. Add ammonium oxalate and NH4OH until the solution is alkaline. Filtered on a filter paper, Al, Ti, Cr and Ca remains on the filter paper. The filtrate is ajusted to pH 10 with NH4OH. Add KCN and Mg is titrated with EDTA using EBT as an indicator.View full abstractDownload PDF (449K) -
Masazô Okamoto, Ômi Miyakawa1960 Volume 24 Issue 9 Pages 573-577
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe effects of heating time, heating temperature, the surface condition of specimens and the purity of the gas employed on the high temperature nitrogen-absorption of the 20%Cr-Fe alloy containing 0.1% carbon and 0.2% nitrogen in extremely pure nitrogen atmosphere were studied. The results obtained were as follows: (1) More nitrogen was absorbed as the heating was longer. The rate of absorption, however, was reduced gradually as the heating time was more prolonged. (2) Nitrogen was absorbed most readily when the alloy was heated at temperatures of 1100∼1150°C at which it contained most of austenite. (3) The oxide film preformed on the alloy surface appreciably inhibited the nitrogen-absorption of the alloy, whilst the effect due to the presence of oil on the surface was not so marked. The roughness of the alloy surface had some effect on the nitrogen-absorption of the alloy, and the rougher the surface, the greater the rate at which nitrogen was absorbed. (4) When unpurified gas was employed, the rate of nitrogen-absorption of alloy was more or less retarded. The effect of unpurified gas was more pronounced at relatively lower temperatures.View full abstractDownload PDF (937K) -
Katsurô Suenaga1960 Volume 24 Issue 9 Pages 578-580
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThis investigation was made to evaluate the high temperature properties of Ni-Cr-Co austenitic alloys containing up to 40%Co with Cr fixed at 20%. The alloys were examined at both the 20% cold-rolled state after solution-quenching at 1200°C and the water-quenched state at 1200°C after the cold-rolling. The results were as follows: The alloys harden with the increase of the Co content of the alloys due to the cold-rolling. The recrystallization temperature of the alloys exists at about 800°C, and appears to be a little lowered with increase of the Co content. The bending creep ductility was measured by the deflection in the creep test, the values being smaller in the cold-rolled specimens than that of the water-quenched one at 1200°C after the cold-rolling. In the cold-rolled specimens, the deflections are very small, and the rupture times are short in alloys of low Co content. Among the water-quenched specimens at 1200°C after the cold rolling, the alloy containing about 30%Co was found to be minimum in the deflection and long in the rupture time. The weight increase due to the heating at 800°C for 100 hr in air is minimum in the 25%Co specimen. It can be said that the alloys containing 20 to 30%Co are the strongest in the high temperature strength. The addition of nitrogen hardens the alloys and raises the recrystallization temperature, and the oxidation resistivity at high temperatures is somewhat improved, although the rupture time in the bending creep test is shortened.View full abstractDownload PDF (485K) -
Tatsuo Maekawa, Junjiro Kai1960 Volume 24 Issue 9 Pages 581-584
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSRates of oxidation and hydrogen absorption of iodide-processed high purity zirconium, commercial-grade zirconium, Kroll-processed reactor-grade zirconium, its 2.5% tin alloy and 0.24% iron alloy with water vapor were measured over the temperature range of 650° to 850°C. The results were as follows; (1) There was no great difference between the oxidation rates in water vapor and in oxygen. (2) The percentage of absorbed hydrogen in the specimens oxidized with water vapor were 1% to 20% of hydrogen produced by the oxidation process and decreased as the temperature became higher. (3) The amounts of absorbed hydrogen were larger in the specimens of higher oxidation rate than in those of lower oxidation rate.View full abstractDownload PDF (597K) -
Toranosuke Kawaguchi, Mitsuru Nagakura, Tetsuro Yamaguchi, Isao Tanabe ...1960 Volume 24 Issue 9 Pages 585-588
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSElongated single domain iron-cobalt fine powders were prepared by electrodeposition onto a mercury cathode. After heat-treating at 175∼250°C for 10∼60 minutes, their average diameters and dimensional ratios were examined, using the distribution graphs obtained from their electron micrographs. Our experiments have shown that, in such surface-oxidized particles, the inner metallic part is enriched in cobalt, whereas the oxidized surface is enriched in iron because of the selective oxidization of iron. Also, on the basis of the relation between the cobalt content and the coercive force of particles of given average diameter and average dimension ratio, it was shown that these particles exhibited shape anisotropy as was pointed out by Luborsky and his colaborators. Furthere, the magnetic properties of powders pressed isotropically into a cylindrical form with various packing factors were examined, and it has been verified that specimens pressed 35∼40% have optimum magnetic properties at about 50% cobalt content.View full abstractDownload PDF (565K) -
Goro Ohira, Katsuya Ikawa1960 Volume 24 Issue 9 Pages 588-592
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe solidification process of hypo-and hyper-eutectic Fe-C alloy was investigated by thermal analysis and quenching method. The flake graphite separated from the eutectic austenite in hypo-eutectic iron, while in hyper-eutectic alloy the primary graphite separated directly from the melt and was surrounded by small austenite dendrites followed by the eutectic solidification around them. Addition of manganese to these alloy made plate-like cementite in the melt at eutectic or at primary solidification which neucleates the ledeburite colonies, and the ledeburite structure was normal and the solidification temperature was not so much supercooled. On the contrary, addition of sulphur changed the flake graphite to undercooled structure containing small amount of nodular graphite or cluster-type mesh-like graphite and then produced the inverse-chilled or massive ledeburite structure. The temperature of austenite-graphite eutectic solidification was lowered by increasing the sulphur content and that of the formation of plate-like cementite in eutectic or hyper-eutectic melt was lowered considerably. By these investigations it was considered that manganese stabilized the cementite and made its formation more easy than that of the eutectic austenite or the primary graphite, but sulphur interrupted the formation of eutectic austenite or primary graphite and supercooled the melt resulting in the formation of some abnormal graphites or massive ledeburite.View full abstractDownload PDF (1297K) -
Masahisa Sammonji1960 Volume 24 Issue 9 Pages 593-597
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSBy means of the measurement of the resistivity distribution curve and the N, P type of silicon single crystal pulled by the Czochralski’s technique, it is possible to calculate the initial concentration of impurities according to the following well-known segregation equation, C=KC_0(1-g)^k-1where C is the concentration in the solid at the liquid-solid interface, g is the fraction of the original weight which has frozen, K is the segregation constant and C0 is the initial concentration of impurity in the melt. The calculated concentration fits the experimental data fairly good. This paper describes the mathematical analysis of some resistivity-distribution curve and its application for a test of impurities in quartz-crucible.View full abstractDownload PDF (735K) -
Tatsuo Fujiwara, Tetsuo Kato1960 Volume 24 Issue 9 Pages 597-600
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSElectric resistance-temperature curves were traced with Ainico 5 magnet aged at various temperatures. The results suggest that different mechanisms of transformation may operate at about 600°C and at about 650°C. The former temperature corresponds to the aging temperature that gives the best magnetic characteristics, and the latter corresponds to anoth er aging temperature where the irreversible change in magnetic property occurs. The electric resistance-temperature curves of specimens aged at a temperatures over 650°C show a kink point meaning a precipitation, which disappears after 600°C re-aging. This re-aging also changed the inclination of the whole curve.View full abstractDownload PDF (649K) -
Hisato Hagiwara1960 Volume 24 Issue 9 Pages 601-603
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe effects of arsenic, antimony, silver and tin on the removal of copper in liquid lead by addition of sulfur have been studied in the temperature range of 500∼800°C. The content of copper retained in the liquid lead is increased by the presence of arsenic, antimony and tin, and is decreased slightly by silver. Among these, arsenic has the strongest effect. Almost the same tendency is seen in the case of sulfur in lead, but this tendency is not so appreciable as copper. The behavior of copper and sulfur might be explained by the effects of these elements on the activity of copper and the activity coefficient of sulfur in lead.View full abstractDownload PDF (481K) -
Tadao Sano, Shosuke Imoto, Mungyu Kang1960 Volume 24 Issue 9 Pages 604-607
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe beneficial effect of tellurium as an added element on the oxidation resistance of zirconium has been reported in our previous papers, where it was stated that the addition of tellurium would decrease the concentration and the mobility of oxygen ion vacancies. In the present papers, experiments by oxidation test was carried out to determine whether the vacancy concentration or the mobility is mainly affected by the presence of tellurium in the oxide. The results obtained are as follows. Tellurium addition was not so effectual at high temperatures as at rather low temperatures, but the amount of tellurium addition which resulted in the longest breakaway time (i.e. the lowest oxidation amount) was scarcely changed by the oxidation temperature and nitrogen content which was said to increase the concentration of oxygen ion vacancv. From these results a conclusion is deduced, that is, a tellurium ion in zirconium oxide does not contribute to the decrease in the vacancy concentration, but mainly to the decrease in the mobility of vacancy by taking the state of positive quadruvalency.View full abstractDownload PDF (675K) -
Tatsuo Maekawa1960 Volume 24 Issue 9 Pages 608-611
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe oxidation rate of reactor-grade pure zirconium, its 2.5% tin alloy and 0.24% iron alloy in carbon dioxide were measured over the temperature range of 650° to 850°C and pressure range of 15 to 760 mmHg using the weight gain method. The results were compared with the oxidation data in oxygen, and expressed as follows: (1) No great difference was found on the initial stage of the oxidation between the oxidation rates in carbon dioxide and in oxygen except 2.5% tin alloys. (2) In the post-breakaway period, the rate constants depended on the change of gas pressure, and the oxidation rates in carbon dioxide were lower than the oxidation rates in oxygen, and remarkably in 2.5% tin alloys. (3) No existence of carbon absorption was found during the oxidation of specimens in carbon dioxide by chemical analysis. (4) It is concluded from the present investigation that the reaction proceeds in accordance with the equation of Zr+2CO2=ZrO2+2CO, and the oxidation in carbon dioxide is similar to the oxidation in lower pressure oxygen.View full abstractDownload PDF (506K) -
Kaizo Monma, Hajime Suto1960 Volume 24 Issue 9 Pages 611-614
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe effects of dissolved sulfur on the surface tension of iron, nickel and cobalt saturated with carbon have been measured by a sessile drop method. Sulfur is surface-active in liquid iron, nickel and cobalt alloys, and the maximum surface excess of sulfur is calculated to be about 1.6×10−9 mol·cm−2 in the alloy systems above. This value corresponds to a mono-molecular layer of sulphide. This result is similar to those with Cu-S, Cu-O, Cu-Se and Cu-Te alloy systems reported in our previous papers.View full abstractDownload PDF (569K)
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