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Volume 20, Issue 9
Displaying 1-16 of 16 articles from this issue
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Masayoshi Tagaya, Imao Tamura1956 Volume 20 Issue 9 Pages 477-480
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSAlthough the quantitative relation among hardenability in terms of ideal diameter, severity of quench, H, and actual critical diameter in steel quenching has been roughly established based on some significant assumptions by Grossmann and others, it seems that there is a lack in data as to H values of many coolants for quenching. In view of this, the H values were here determined for various coolants from their cooling curves with silver specimen employing the chart already presented by the present authors which enable the H values to be derived easily from cooling curves of any coolants with silver specimen.View full abstractDownload PDF (605K) -
Masayoshi Tagaya, Imao Tamura1956 Volume 20 Issue 9 Pages 480-484
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe cooling curves were measured with silver specimen as to several typical mineral oils having widely different viscosities and flash points with one another in order to correlate the properties of mineral oils with the quenching severity, H, derived from the cooling curves here obtained, and the examinations of the results presented in the 7 th report were also done with the findings in this experiment. The H values of mineral oils increase with oil temperature up to a point at which maximum value of H is reached and subsequently decrease. The maximum values of H, the temperature at which the H value rises to the maximum and the variation of H value with oil temperature are correlated with the flash points of oils. Paraffinic mineral oils have smaller values of H as compared with naphthenic ones and the H value decreases so much so that the degree of refining is elevated. It is also referred to the improving reagent of cooling ability of mineral oils.View full abstractDownload PDF (767K) -
Waichi Ota1956 Volume 20 Issue 9 Pages 485-489
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe influences of external stresses, such as tensile or compressive stress, upon some properties of cold worked Armco iron were studied. The equalization of hardness and structure, some recovery of magnetic properties and the diminution of residual stresses appeared relating to the addition of external stresses. The amount of the necessary external stress was about one half of the tensile strength, that is, within the elastic limit.View full abstractDownload PDF (917K) -
Waichi Ota1956 Volume 20 Issue 9 Pages 489-492
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe fracture in rods and plates of an Armco iron under a tensile force was studied by measuring both the hardness distribution and the structure appearing on the sheared surface of the material. The fracture starts with a crack first at the centre of the minimum section in the neck and then propagates rapidly towards the outer surfaces.View full abstractDownload PDF (858K) -
Tadakazu Sakurai, Tadashi Kawasaki, Hisashi Izumi1956 Volume 20 Issue 9 Pages 492-496
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe effects of stress-aging treatments are more remarkable in mild steel quenched from 700° and spheroidized mild steel than in annealed steel. The static strength of mild steel containing 0.22% carbon is increased by stress-aging but its toughness is decreased. In the case of spheroidized mild steel, stress-aging augments not only its hardness and static strength but also its impact value remarkably. The larger the pre-strain the more effective the strengthening, but the lower the toughness. Therefore it is advantageous to confine the pre-strain within about 4%. The improvement of mechanical properties, when spheroidized mild steel is stress-aged at 400° for one min. with 3% pre-strain, is as follows: more than 100% in proportional limit and yield point, about 40% in tensile strength and hardness, and about 7% in impact value compared with those of annealed steel without stress-aging.View full abstractDownload PDF (794K) -
Yoshikazu Hosoi1956 Volume 20 Issue 9 Pages 497-499
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe probable effect of preheating the billets to be extruded on the extrusion pressure, the distribution of hardness in the rods and the softening of the rods due to annealing was studied. From the results of the measurements of the extrusion pressure etc., it was found that a higher temperature was required for extruding as-cast billets than preheated ones.View full abstractDownload PDF (614K) -
Saburô Shimodaira, Yoshinobu Sawada1956 Volume 20 Issue 9 Pages 500-502
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe field tests of commercial pure aluminum, 3S and 61S were carried on at the electric power generation stations using acid river water in the North Eastern District of Japan. The corrosion rates of the specimens were measured by the change of the tensile strength. Three hundred specimens were used in the tests. Commercial pure aluminum is excellently proof to acid river water and it is probably fit for practical use. 3S and 61S were severely corroded within eight months.View full abstractDownload PDF (453K) -
Satoshi Taniguchi, Mikio Yamamoto1956 Volume 20 Issue 9 Pages 503-507
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn order to explain the magnetic annealing effect in ferrites, we have extended our theory of the ferromagnetic uniaxial anisotropy induced by magnetic annealing in metallic cubic solid solutions to cases of ferrites and obtained a general expression for the uniaxial anisotropy induced in ferrites. A criticism has been made on the explanation of the effect proposed recently by Williams et al. The concentration dependence of the magnetocrystalline anisotropy constant in binary ferrites composed of cobalt ferrite and other inverse ferrite has also been discussed briefly, based on the model given by Van Vleck and extended by Sugihara.View full abstractDownload PDF (786K) -
Satoshi Taniguchi, Mikio Yamamoto1956 Volume 20 Issue 9 Pages 507-510
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIt is shown that our theory of the magnetic annealing effect in ferrites as given in Part I can explain almost all of the available experimental results on the induced uniaxial anisotropy as dependent on the concentration, on the orientation of the magnetic field during annealing, and on the temperature of magnetic annealing. Thus, we conclude that the uniaxial anisotropy induced by magnetic annealing in ferrite is caused by an anisotropic distribution among cations and cation vacancies, namely, by a similar mechanism as in ferromagnetic metallic solid solutions.View full abstractDownload PDF (727K) -
Kokichi Sano, Kazuhisa Okajima, Naoki Okuda1956 Volume 20 Issue 9 Pages 511-512
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe same apparatus was used as in the previous study. In the experimental operation, we took special care to avoid the experimental error in the e.m.f. data introduced by dissolution of graphite in nickel-rich alloy. From the results obtained by experiments at the temperatures 1470° and 1510°, it has been shown that the relationship between the e.m.f. and the mole fraction of silicon at 1470° is represented by a curve with curvatures which lies below the approximately smooth curve for 1510°. Moreover, it is found that the activity curves in molten Ni-Si alloys show large negative deviation from Raoult’s law.View full abstractDownload PDF (308K) -
Kokichi Sano, Kazuhisa Okajima1956 Volume 20 Issue 9 Pages 512-514
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe activities of molten Fe-Si alloys were studied using the same technique as in molten Ni-Si alloys already described. It is shown that both negative and positive departures from Raoult’s law occur, namely, the activities of silicon are less than its atom fractions at low concentrations, but greater than its atom fractions at high concentrations. The agreement between the author’s and Chipman’s experimental data is excellent up to NSi=0.55, but beyond this composition, the author’s activity values are found to be unexpectedly high.View full abstractDownload PDF (291K) -
Yasuji Kawai1956 Volume 20 Issue 9 Pages 514-517
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe diffusion coefficient of sulfur in liquid iron has been measured at the temperature range from 1560° to 1670°. Since the concentration of sulfur was low in the present investigation, the diffusion coefficient was calculated assuming as constants independent of the concentration. The result was expressed as follows: D=4.9×10−4e−4350⁄T. The diffusion coefficient and the activation energy are nearly the same with those of carbon, cobalt and phosphorus in liquid iron. The activation energy is about one-tenth of the heat of vaporization and this shows that the holes in liquid iron are small. The theoretical values derived from the absolute reaction rate theory and the diffusion coefficient calculated by the Stokes-Einstein equation are compared with the experimental results.View full abstractDownload PDF (496K) -
Yasuji Kawai1956 Volume 20 Issue 9 Pages 517-520
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe diffusion coefficient of sulfur in liquid iron saturated with carbon has been measured at the temperature range from 1390° to 1560° by the use of radioactive sulfur, S33. It was found to be 2.9-3.6×10−5 cm2/sec and its dependency on temperature was expressed as follows: D = 2.8 ×10^-4 e^-3800/TThe values of the diffusion coefficient are lower than those of the same concentration in iron-sulfur binary solution. The decrease of the diffusion coefficient by the presence of carbon can be explained partly as due to the fact that the decrease of the activity coefficient of sulfur with concentration is larger than that in binary solution.View full abstractDownload PDF (555K) -
Mikio Yamamoto, Jirô Watanabé1956 Volume 20 Issue 9 Pages 520-524
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe light-figure phenomena have been observed with chemically etched single crystals of nickel-iron alloys containing 30∼81.5 percent nickel, and the suitability of the observed light figures for determining crystal orientations and the crystal planes developed by etching have been examined. All of the etchants tested, namely, aqua regia plus water (1:1), saturated aqueous solution of ferric chloride at boiling and room temperatures, saturated aqueous solution of ferric chloride plus concentrated hydrochloric acid (95:5), and saturated aqueous solution of ammonium persulphate at boiling temperature, produced distinct light figures, suitable for the orientation determination, for all of alloy crystals, among which boiling saturated aqueous solution of ferric chloride was found most suitable. It has been found that the most close-packed {111} faces, their vicinal faces, and high-index crystal faces inclined 10∼15° to {100} and {110} planes are developed by etching.View full abstractDownload PDF (832K) -
Hideo Nishimura, Hirozo Kimura1956 Volume 20 Issue 9 Pages 524-528
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe constitution of titanium-oxygen binary system was experimentally studied using microscopical and X-ray analysis, and measuring the melting temperature of these alloys. According to the investigation on the titanium-rich side of this system carried out by Bumps, Kessler and Hansen, it has been shown that there exist two peritectic reactions, Melt+α\leftrightharpoonsβ at 1700° and Melt+α\leftrightharpoonsTiO at 1770°, and the phase α containing about 10% oxygen shows a maximum melting temperature at about 1900° on the liquidus. The present investigation has been carried out mainly to clarify the equilibrium diagram on the more oxygen-rich part of this system. The results were as follows: The liquidus temperature of TiO (δ) phase decreases with the increase of oxygen contents, and it reaches a munimum at about 1750°, its oxygen content being 30%. On the side of Ti2O3 (ε) phase, the liquidus temperature rises again and it shows a peritectic point at 1810°, the reaction being Melt+Ti2O3 (ε)\leftrightharpoonsTiO (δ). The solid solubility of TiO (δ) phase on the oxygen-rich side decreases with the fall of temperature from 32.4% oxygen at 1800° to about 30% oxygen at room temperature. The melting temperature of Ti2O3 is 1830° and it has a perceftible solid solubility range. Between Ti2O3 (ε) phase and TiO2 (η) phase, there exists an eutectic reaction showing Melt\leftrightharpoonsε+η at 1680° and 36.5% oxygen. The TiO2 (η) phase decomposes at above its melting temperature of 1825° into a liquid containing less oxygen than 40% and a gaseous phase.View full abstractDownload PDF (765K) -
Hideo Nishimura, Hirozo Kimura1956 Volume 20 Issue 9 Pages 528-531
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIt is well known that titanium and carbon forms a titanium carbide (TiC), and the equilibrium diagram between titanium and titanium carbide was already investigated by Cadoff and Nielsen, but the equilibrium diagram on the carbon-rich side is not yet known. The present paper is an investigation carried out in the whole range of the contents of titanium and carbon. The liquidus temperature rises with the increase of carbon contents from the melting point of titanium 1660°, and to the melting point of titanium carbide 3150°. When the carbon content increases more than 20%, the liquidus temperature falls somewhat lower and reaches an eutectic temperature at about 3050°. By microscopic study, it was shown that this eutectic reaction is to be shown by Melt\ ightleftharpoonsTiC+Carbon, the concentration of carbon being 26%. With the increase of the carbon content beyond this eutectic point, the liquidus temperature rises to 3800°±200° at the concentration of 33% carbon. At this temperature the reaction Vapour+Graphite\ ightleftharpoonsLiquid take places.View full abstractDownload PDF (833K)
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