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Volume 17, Issue 7
Displaying 1-13 of 13 articles from this issue
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Susumu Kawakami1953 Volume 17 Issue 7 Pages 309-312
Published: 1953
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn the previous paper, the phenomenon of thermal diffusion was applied all over the ranges of the concentrations of tin alloys and it was found that the rate of thermal diffusion depended largely upon the concentration. To find the quantitative relation between the above two, experimental and theoretical researches were carried out in this paper. At first, the experimental relations were studied and the linear relations shown in Fig. 1 were found to exsist between the value of time t and log(Δns⁄(Δns−Δn)), where Δn was the difference in concentration at the cold and hot parts and Δns that at the Soret equilibrium. From this result, the following empirical equation regarding the first order reaction was drived
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The rate constant k could be calculated by using the following equation obtained from the above one,
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The value of k was found to decrease inversely with the increase of the concentration of the solute and become minimum nearly at the middle part of the latter. The results obtained above were treated by theoretical consideration and the equation (1) could be derived concerning the case of dilute solutions.View full abstractDownload PDF (500K) -
Hakaru Masumoto, Hideo Saitô, Masao Shinozaki1953 Volume 17 Issue 7 Pages 312-314
Published: 1953
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe specific heat of 17 alloys in the range of α solid solution of iron and cobalt system has been measured. It has been found that there are 3 maximum portions on the curve of the maximum temperature of specific heat against concentration, beside the one corresponding to the transformation of FeCo superlattice; the 3 portions extend over the concentration ranges of 20 to 29, 34.6 to 66 and 66 to 78 percent of cobalt, respectively. The maximum portion in the range of 34.6 to 66 percent of cobalt has been already found by S. Kaya and H. Sato and is considered by the present investigators to be due to a lattice transformation of FeCo superlattice. The other maximum portions, in the ranges of 20 to 29 and 66 to 78 percent of cobalt, are considered to be due to the existence of superlattices of Fe3Co and FeCo3, respectively.View full abstractDownload PDF (395K) -
Mikio Yamamoto, Jirô Watanabé1953 Volume 17 Issue 7 Pages 315-318
Published: 1953
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe solution-body phenomenon and the anisotropy of solution rate of hexagonal zinc crystals have been investigated with specimens of round-bar and sphere forms etched with concentrated nitric acid and with concentrated and dilute hydrochloric acids. It was found, as was expected, that the solution rate of zinc crystal in concentrated nitric acid was isotropic and hence no solution body was formed. Round-bar crystals, of which the rod axes, lie closely parallel to the [0001], [10\bar10], [11\bar20] and an intermediate direction, respectively, were tested with 29.6 and 6.1 percent hydrochloric acids. Irrespective of the concentration of the etchant, the [0001] crystals converted into hexagonal prisms and both [10\bar10] and [11\bar20] crystals transformed into elliptical prisms, the intermediately orientated crystals changing into slightly distorted hexagonal prisms. From the correspondence of the shapes of these solution bodies with crystal orientations as determined by means of light figures it is shown that the anisotropy of solution rate of zinc crystal in hydrochloric acids is in the following order:—
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Further, this series is shown to be valid also for the solution rate of zinc crystal in dilute sulphuric acid.View full abstractDownload PDF (585K) -
Nitrogen as an Alloying Element in Steel (12th Report). Effect of Nitrogen on Quench-Aging of SteelsYunoshin Imai, Tetsuro Ishizaki1953 Volume 17 Issue 7 Pages 318-322
Published: 1953
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe present investigation was carried out to ascertain the effect of nitrogen on the quench-aging of steels containing C 0.02∼0.03% or C 0.15∼0.20%. The specimens tempered at 700° for 3 hours after quenching from 950° were quenched from 300∼700° after heating for 3 hours at this temperature and aged at 30°, 50° and 100°C. From the present investigation the authors concluded as follows:
(1) There is a clear correlation between the nitrogen in steel and the quench-aging. (2) By addition of denitrogenizer (Al or Ti) or fusion in vacuum the aging by nitrogen is reduced. (3) The specimens containing less than 0.005% of N2 revealed aging due to carbon in the steels.View full abstractDownload PDF (692K) -
Kunio Okabayashi, Yoshibumi Sunahara1953 Volume 17 Issue 7 Pages 322-325
Published: 1953
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSQuenching strain and crack have an intimate relation with internal stress originate from quenching. Experiments were carried out to investigate this relation in cast iron treated by ordinary quenching and high frequency induction heating. The specimens used were flake graphite, and spheroidal graphite cast iron, which contain the typical form of graphite in cast iron, and 0.5%C steel. This relation changes considerably according to the quenching method and the form of graphite in cast iron. Strain and residual stress in specimens treated by ordinary quenching were found passably larger than that in induction heated specimens. Nodular graphite cast iron shows a tendency similar to 0.5%C steel on the stress distribution and strain, but flake graphite cast-iron shows a different tendency from both of them. As a characteristic in stress distribution and its strain of flake graphite cast iron different from the case of nodular graphite cast iron and steel, the value of compressive stress on the tangential direction near the surface is rather small, in spite of the large value of the expansion of the outer diameter, while that of the inner diameter is small, that is, the relative difference of the two values is larger than in the case of nodular graphite cast iron and steel.View full abstractDownload PDF (825K) -
Hiroshi Imai, Kazuo Hori1953 Volume 17 Issue 7 Pages 325-328
Published: 1953
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn this paper, the authors report about the effects of a small addition of titanium to Al and its alloys. Titanium was added in ratio of 0.1, 0.2, 0.3, 0.4 and 0.5% to Al, Al-Si, Al-Cu, Al-Fe and Al-Si-Cu-Fe systems. The apparatus used was the quite the same as in the former report. The results obtained were as follows: (1) It is cleared that the decreasing tendency in solidifying shrinkages of every Al-alloy based on addition of titanium resembles to the general change in Al-Ti binary system. Accordingly, the great decrease of solidifying shrinkage in Al-alloys by addition of titanium is due to the phenomenon based on Al-Ti binary system. (2) The cause of a rapid decrease in solidifying shrinkage of Al-Ti binary system by addition of titanium is due to the properties of titanium atoms themselves and further studies about the motion of each the individual atom in liquid alloys will lead to elucidation of the more essential causes. (3) In practical operation, it will be possible to make strong and good castable Al-alloys by adding titanium just for this purpose.View full abstractDownload PDF (731K) -
Kyukichi Shimba, Sadakichi Kitajima1953 Volume 17 Issue 7 Pages 329-334
Published: 1953
Released on J-STAGE: April 04, 2008
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Kyukichi Shimba, Sadakichi Kitajima1953 Volume 17 Issue 7 Pages 335-337
Published: 1953
Released on J-STAGE: April 04, 2008
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Yoshitsugu Mishima1953 Volume 17 Issue 7 Pages 338-341
Published: 1953
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSAccording to recent studies, the retrogression phenomena seems to be caused by the re-solution of the cluster or G.P. aggregate due to a sudden increase of its solubility in aluminium above 205°C. If this is true, only the precipitation process is expected to occur without showing remarkable hardening caused by the formation of pseudo-precipitate or cluster, when Al-Cu alloy is aged above the temperature. This fact was confirmed in this report and only slight hardening effect could be observed when the alloy (3.9%Cu) was aged at 240∼270°, after being quenched from 520°C. Then the softening was observed where actual precipitation of the second phase was detected both by microscopic examination and X-ray diffraction. Therefore, the precipitation hardening process, as the author calls it alone can be observed at these temperatures. The degree of aging (p) was calculated from the hardening curves at the respective temperatures between 240 and 270° and logp⁄(1−p) vs. logt (t: time) was plotted. The relation was proved to be linear by this method as well as by calculating p from the data of G. Borelius and L. Ström(4) in their study on evolution of heat during aging. The inclination of the line (n) was 2.6 by both methods, which will again support the author’s idea on the formula of age-hardening. The relation between the type of aging process and the temperature of aging was discussed(5): At lower temperatures (T<T1), neither of the two types, pseudo-precip. and precip., can occur within the time of our observation. At the temperature above T1, there is a range (T1<T<T2), where only pseudo-precip. type can occur within the time of our observation. Then the range (T2<T<T3) comes where pseudo-precip. type occurs first, followed by precip. type afterwards. And at last, above T3 (T<T3), only precip. type can be seen. In Al-Cu alloy, for example, T1≈−30°, T2≈80° and T3≈205°. In some other alloys, these relations are not so clearly observable. The results of the two studies by other workers(6)(8) which were published after this report was read in April, 1950, were considered at the end of this report. These studies support the idea of the author described here.View full abstractDownload PDF (758K) -
Masayosi Tagaya, Masamichi Hujii, Sabro Kondo, Takashi Horibe1953 Volume 17 Issue 7 Pages 342-345
Published: 1953
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSFrom the standpoint of investigating the resistance to corrosion and tarnishing in the mouth, the dental alloys in our country have been tested by dipping them in 1% lactic acid, 0.05% HCl, 1% NaCl, and 0.1% Na2S, solutions at 37° for 3 days. The corrosion rate of the dental chromium-nickel alloys in these dilute acids was very low, and found to be affected or controlled by various factors. Now, by measuring the current between the specimen and Cu/CuSO4-electrode immersed in the test solution, we could easily and rapidly test the corrosion properties of the dental chromium-nickel alloys, 18-8 stainless steels and vitallium alloy. The results of our experiments are as follows. The loss in weight of the dental chromium-nickel alloys in dipping test in 1% lactic acid solution, was compared with the amount of current measured in microamperes. The resistance of chromium-nickel alloys to lactic acid is extremely sensitive upon some unknown factors. According to the electrochemical test, one sample of lactic acid had the property to allow the formation of protective film, another sample preventing its formation. The 18-8 stainless steels used in dentistry are perfectly passive in 1% lactic acid solution, where as a small addition of sodium-chloride changed its character. The critical concentrations of sodium chloride in 1% lactic acid solution to destroy passivity are different, some samples being activated by addition of 0.5% sodium chloride solution. In fine the electrochemical test above mentioned is particularly valuable in indicating the boundary between the active and the passive states of chromium alloys.View full abstractDownload PDF (704K) -
Yoshichika Ôtô, Takanobu Hamaguchi1953 Volume 17 Issue 7 Pages 346-349
Published: 1953
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSApplying the characteristics of the emission spectral analysis for the purpose of local analysis, qualitative, of metallic structures, as the microscopic observation, the apparatus was built for catching the spectral lines which resulted from the spark between the specimen surface and the Pt-wire put into a small hole of a transparent quartz tube, a medium quartz spectrograph a metallic microscope and a transparent quartz tube were employed for this purpose. Although the transparent quartz tube and the photographic plate allowed an accuracy of only 0.08±0.02 mm at the spark point, the apparatus was sufficient to achieve the sought result. The apparatus was applied to Mg analysis for Mg nodular cast iron that at any degree of spheroidization of nodular cast iron the Mg content in the spheroidal graphite was larger than that in the matrix and when the analysis value of Mg contained in the nodular cast iron was larger than about 0.08% (segregation not considered), the matrix was supposed to be containing Mg.View full abstractDownload PDF (726K) -
Yûkô Mitani1953 Volume 17 Issue 7 Pages 350-353
Published: 1953
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSInduction hardened steels which had large amount of residual stress show higher fatigue strength than the conventional quenched steels. However the life of ball bearings depends almost upon pitting alone. Dr. Nishihara’s experiment showed that decreasing of residual stress by tempering prolonged the pitting time. The author described in a former report, martempering was very suitable for eliminating residual stress, and tried to apply martempering on induction hardening of bearing steels, comparing the result with tempering at low temperature.View full abstractDownload PDF (553K) -
Minoru Tanaka, Sôkichi Umekawa1953 Volume 17 Issue 7 Pages 353-357
Published: 1953
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe main cables of suspension bridges are usually anchored by white metal such as A-alloy in Table 1 in our country. In this paper, the results of tests of four different kinds of white metals listed in Table 1, are reported as in Table 3, 4 and Fig. 5. From these results obtained, it is concluded that pure zinc metal and tin-rich white metal such as S-alloy are more recommendable than the other lead-rich metals, and the authors feel that better alloys will be found by their further investigations.View full abstractDownload PDF (845K)
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