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Volume 19, Issue 3
Displaying 1-15 of 15 articles from this issue
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Tooru Furukawa1955 Volume 19 Issue 3 Pages 205-208
Published: 1955
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThis study is concerned with the method of the Jominy test, and aims at discussing the relation between the Jominy hardness curve and the conditions of the surface grinding which is a process between the end quenching and the hardness measurement along the length of the test piece. In this report, of the grinding conditions, all the elements of the surface grinding were kept constant, except the depths of cut per stroke of grinding machine. The depths of cut per stroke adopted were 10 μ, 25 μ, 50 μ per stroke. By this cutting depth two flats 180 degrees apart were grounded the depth of 0.015 in. deep along the entire length of test pieces. According to the results of test, the influence of the grinding conditions was unexpectedly large so that if merely the cutting depth was considered, it was very strong indecd at the quenching end, and the difference of the hardness number was about 7 Rc at the maximum. The auther also took photographs of the microscopic structure along the length and near the grinding surface at the section of the test piece, and compared these photographs with the difference of the hardness number. It seems that the phenomena as stated above are caused by the metamorphosed layer formed by the cutting heat and the distortion during the grinding.View full abstractDownload PDF (848K) -
Saburo Shimodaira, Yoshinobu Sawada, Namio Ootani1955 Volume 19 Issue 3 Pages 209-212
Published: 1955
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe damage to carbon steels by cavitation in acid aqueous solutions was studied. Cavitation was produced by the ultrasonics. The experimental results showed that the damage by cavitation was due to electrochemical reaction and the direct blow of water. Both these actions were always coexisting, and the former was rather more powerful than the latter in oxydizing acid solutions. The resistance to cavitation increased both with corrosion resistance and hardness.View full abstractDownload PDF (1048K) -
Hikozô Endô, Saburo Shimodaira, Yoshinobu Sawada1955 Volume 19 Issue 3 Pages 213-216
Published: 1955
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe corrodibility of aluminium and aluminium alloys in acid river water has been studied. 3S and 61S are as corrosion resistant as gun-metal. Pure aluminium is also excellently resistant, but it is apt to suffer pitting corrosion. The perforation by pitting on pure aluminium is eliminated by additions of manganese or magnesium as alloy element. Corrosion of aluminium and aluminium alloys in acid river water is cathodic controlled and is of depolarization type.View full abstractDownload PDF (645K) -
Yoshizo Takeda, Yutaka Fujita1955 Volume 19 Issue 3 Pages 217-219
Published: 1955
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe characteristics of rectification by cuprous oxide rectifiers consisting of copper plates containing oxygen from 0.054 to 0.0006% have been studied. (1) When tough pitch copper containing about 0.05% of oxygen was remelted and cast in vacuum or in nitrogen atmosphere, the oxygen content of copper decreased. These copper plates had good forward characteristics for rectification. (2) When cathodic copper was melted in vacuum, the rectification characteristics became good on the forward direction, but not on the reverse side. (3) After cathodic copper was melted in the air bublling oxygen or air, and cast in vacuum, these copper plates had good character in the reverse direction. (4) The results showed that S, Se and As in cathodic copper, which are very injurious to the reverse character, were decreased by oxygen, and that oxygen-free copper exhibited good characteristics on the forward and reverse directions. Oxygen in copper, left after having decreased the contents of S, Se and As in copper, was injurious in the forward direction. (5) Deoxidised copper oxygen freed copper by means of adding some elements such as P, Si or Mg which have affinity to oxygen in copper, exhibited very bad characteristics in both directions.View full abstractDownload PDF (536K) -
Harujiro Sekiguchi, Michio Inagaki1955 Volume 19 Issue 3 Pages 220-223
Published: 1955
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESS“The same direction change of dimension due to annealing after plastic deformation,” that is the dimensional changes due to the low temperature annealing of plastically cold-worked low carbon steel bars appearing in the same direction as the deformation due to working before annealing, was also observed in the cases of drawn, rolled or bent as well as elongated or compressed specimens. Residual macrostresses in the cold-worked specimen are not considered to be the fundamental origin which causes the same direction change of dimension.View full abstractDownload PDF (638K) -
Masao Ibaragi, Toshikuni Okumura1955 Volume 19 Issue 3 Pages 223-226
Published: 1955
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn order to study the effect of silicon on the tempering of martensite, hardness measurement and differential dilatometric measurement were used. It was demonstrated in these experiments that the starting temperatures of the first stage and the second stage of tempering were not affected by the silicon contents of steels, while the starting temperature of the third stage was raised by silicon contents.
On tempering of steels containing silicon, there appears a retardation of softening at the temperature between 200° and 300° and the cause of this phenomenon was discussed.View full abstractDownload PDF (541K) -
Masao Ibaragi, Toshikuni Okumura1955 Volume 19 Issue 3 Pages 226-229
Published: 1955
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn order to study the effect of silicon on the tempering of martensite, magnetic analyses were performed. It was demonstrated in these analyses that the starting temperature of the second stage of the tempering was not affected by the silicon contents of steels, but the decomposition of the retained austenite at low temperature became smaller by the addition in steels. Moreover, it was found that the temperature at which the second stage progressed at the maximum velocity in high silicon steels was higher than that in low silicon steels, and, also that the carbides which were precipitated at each tempering stage in high silicon steels were equivalent to the carbides precipitated at the same tempering stages in low silicon steels.View full abstractDownload PDF (453K) -
Goro Shimaoka1955 Volume 19 Issue 3 Pages 229-232
Published: 1955
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe crystal texture of thin, single graphite flakes extracted from molten pig iron has been studied by electron diffraction and a reflecting optical microscope. It has been found that each flake consists of two arrangements of single crystals having definite orientations on both sides of the flake surface, and the twinning plane varies for each flake, being (12\={3}0), (134\={0}), (156\={0}), (167\={0}) or a more complicated indexed plane. It was impossible to explain the mechanism of the formation of these twins from the stable graphite structure only. On the other hand, the existence of β-SiO2 crystal as an inclusion in such graphite flakes has been detected by electron diffraction. Further experiments have shown that the β-SiO2 crystal yields a “parallel growth” with the graphite crystal and forms a nucleus of growth of the latter. From these data, it is concluded that the nucleation of flake graphite may occur at the vacant sites in the β-SiO2 crystal.View full abstractDownload PDF (891K) -
Mikio Yamamoto, Jirô Watanabé1955 Volume 19 Issue 3 Pages 233-237
Published: 1955
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe solution-body phenomenon and anisotropy of solution rate have been investigated on tetragonal tin crystals, of circular rod and sphere forms, as etched with concentrated hydrochloric acid and with aqua regia plus water. The solution body was produced only with an originally spherical crystal etched with concentrated hydrochloric acid. The relation between the form and dimension of solution-body produced and crystal directions indicates that the series of solution rates of tetragonal tin crystals in concentrated hydrochloric acid is in the order of
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\ oindentthe mean solution rates for main crystal directions being in a ratio V⟨110⟩:V⟨001⟩:V{101}:V⟨100⟩=1.13:1.08:1.05;1.00. It has also been found that this series of solutioon rate is valid for the case of etching with aqua regia plus water, though any solution body is not produced.View full abstractDownload PDF (808K) -
Yûgorô Ishii, Noboru Furuta1955 Volume 19 Issue 3 Pages 237-241
Published: 1955
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIt has been observed from the patterns of electron diffration that 4 or 5 kinds of the crystal deformation exist beneath the cut surface in polycrystalline copper as shown in Fig. 3. The axis of the fibrous structure obtained in the present experiment, [110], is the same as that observed in compressed copper. Consequently, the direction of the fibrous axis is considered to coincide with the direction of the compressing force and of the cutting resistance in the cutting process. Therefore, we have compared the shear angles calculated from the cutting ratio with those obtained from several analytical solutions which have hitherto been used in metal cutting.View full abstractDownload PDF (781K) -
Yoshitsugu Mishima1955 Volume 19 Issue 3 Pages 241-245
Published: 1955
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSFurther study has been carried out to examine the behavior of alpha-brass after cold-work and three results have been obtained; (1) The secular change at room temperature after cold-work was found to occur in pure Ag, Cu, Al and Ni, as well as in 24S type super-duralumin and 5 or 7%Mg hydronalium, and thus can not be considered to be particular to anomalous hardenable alloys. (2) Cross-rolled 70/30 brass shows greater amount of anomalous hardening and secular change after cold-work but lower hardness than usually rolled sheets. (3) The process of anomalous softening, found and discussed in the 2nd report, was observed more closely; the behavior somewhat resembles the softening during secular change after low-temperature annealing, but the amount of softening was found to be far greater. Three types of anomalies were summarized and compared with each other in conclusion, based upon the informations hitherto obtained.View full abstractDownload PDF (806K) -
Kazuo Hori1955 Volume 19 Issue 3 Pages 245-249
Published: 1955
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe discontinuous change of density due to solidification of metals and alloys is well known but a complete explanation of this phenomenon has not been given. The theory that the solidifying volume change depends on the range of solidifying temperature was not complete to explain some facts indicated by the author and further experiments were carried out to solve this problem. This phenomenon may be considering the atomic movements in metals and alloys. The experimental results carried out with the adove consideration proved an interesting facts. These were as follows: (1) The solidifying volume change by different additional elements to Aluminium proved to change depending on the melting temperature of the added element. (2) Quite the same phenomenon was seen in thermal expansion metals of solid state. (3) Then, it was recognized that the essence of change of density based on the thermal vibration of each atom and the intervention of other atoms proved to be the disturbance to the thermal vibration of the solvent atoms.View full abstractDownload PDF (655K) -
Shiro Terai1955 Volume 19 Issue 3 Pages 249-254
Published: 1955
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSOn this first report, the mechanism of grain refinement of Al by a small addition of Ti was investigated. That is: (a) the effects of Ti contents on the grain size (b) the effects of casting and the melting condition on the grain size (c) the analysis of the precipitates extracted from the slowly cooled ingot and the casting solidified under centrifugal force were studied. The results obtained are as follows:—(1) The Ti content which refined the grain size markedly coincides with the contents at the periptectic point of the Al side diagram of Al-Ti system (0.15%Ti). (2) The range of Ti content effective for grain refining of the castings solidified under centrifugal force and slowly cooled ingots is above 0.15%Ti and the large amount of the precipitates extracted from this range is TiAl3, though TiC increased when the melt was treated by CCl4. (3) The grain size depends upon the super-heating temperature, especially in the case the melt is treated by CCl4, even if the casting temperature is constant. (4) According to (2) and (3), this effect seems to be based on the formation of TiC, and TiC is stable up to about 30° above the liquidus, because the grain size of the specimen cast up to this temperature is refined markerdly. (5) As above mentioned, in the case of grain refining of super pure Al by small addition of Ti, both TiAl3 and TiC may act as the nuclei during solidification.View full abstractDownload PDF (919K) -
[in Japanese]1955 Volume 19 Issue 3 Pages A37-A41
Published: March 20, 1955
Released on J-STAGE: November 11, 2008
JOURNAL FREE ACCESSDownload PDF (1687K) -
[in Japanese], [in Japanese]1955 Volume 19 Issue 3 Pages A42-A48
Published: March 20, 1955
Released on J-STAGE: November 11, 2008
JOURNAL FREE ACCESSDownload PDF (787K)
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