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Volume 19, Issue 9
Displaying 1-18 of 18 articles from this issue
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Minoru Tanaka1955 Volume 19 Issue 9 Pages 509-513
Published: 1955
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThis is the report of some metallographical experiments in which the author found the correlations between the toughness and the microstructures of heat-treated tool steels. As shown in Table 1, steel A is a kind of die steel and steel B is a Si-Cr-V steel which has been prepared for this test. The static-bending test was used to evaluate the toughness of steel. In the toughness tests, remarkable differences appeared between steel A and steel B or in each of them, even when the Rockwell hardness values were nearly equal (Fig. 2 and Fig. 5). However, from the results obtained by other tests and the considerations in this paper, it is concluded that the above-mentioned phenomenon may be depending on the amounts of the solute atoms in the martensite or the austenite and the shapes of the decomposed products in the matrix. By micro-hardness tests, it was ascertained that the residual austenite hardened slightly by tempering up to 200° (Fig. 3 and Fig. 4). Steel B shows high hardness and toughness after quenching in oil from 850° and tempering at 200∼250° so this kind of steel may be used as shock resistance tool steel.View full abstractDownload PDF (890K) -
Kinji Yokoyama, Tsuneo Matsukura1955 Volume 19 Issue 9 Pages 513-517
Published: 1955
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSWith the specimens prepared from the 2 kinds of Cr steel containing about 2%Cr, 13%Cr as well as 1%C, 5%Cr and quenched in air from 1130° to keep much of austenite remained, 6 cycles of a treatment of cooling to −75° and tempering at 100∼600° were performed either starting with the tempering or beginning from the cooling. The change in length during the cycles and that due to the aging thereafter at room temperature were chiefly measured to investigate their stability. The results obtained were; (1) The stabilization of the residual austenite in these steels became maximum by tempering at 300° and attained to minimum by tampering at 500°. This affected the dimensional stability due to the cyclic process and due to the room-temperature aging thereafter. (2) The longitudinal change observed during aging at room temperature after the cyclic treatment was generally small. In the case of the cyclic treatment, however, at a tempering temperature at around 500°, there occurred a fairly marked increase in length owing to aging.View full abstractDownload PDF (764K) -
Sosuke Uchida1955 Volume 19 Issue 9 Pages 517-520
Published: 1955
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSBright heating of steels has been studied under various conditions. The author obtained atmospheres containing high percentages of nitrogen produced by partial or perfect combustion of city gas in air absorbing CO2 with a spray of water and reducing CO2 and H2O in these gases with a converting furnace already described before Report 1 and 2, Nippon Kinzoku Gakkai-si, 16 (1952), 468; 17 (1953), 505]. It was confirmed that these atmospheres had smaller activities against steels even at high temperatures than the converting atmosphere cotaining 96% of nitrogen the smallest activity.View full abstractDownload PDF (684K) -
Renpei Yoda1955 Volume 19 Issue 9 Pages 521-524
Published: 1955
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSCast irons having various degrees of oxidation were held under low pressure at 1200° or 1400°, and the solidification behaviors were clarified:—(1) The more the degree of oxidation of the cast iron increases, the more the advent of the structure of deoxidized iron is delayed. (2) In irons predeoxidized by vacuum-melting, the spheroidization of graphite is easily completed by addition of magnesium. (3) Vacuum-melting is useful not only for the discrimination of the quality of irons, but also has a remarkable effect for refining of molten iron.View full abstractDownload PDF (963K) -
Nobuyuki Shinohara1955 Volume 19 Issue 9 Pages 525-528
Published: 1955
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSAs the result of earlier investigations,it has been established that nodular cast-irons are more resistant to growth and scaling than are the irons containing flake graphite. Besides has been it known that irons containing from 4 to 6%Si and from 3 to 5%Al are considerably resistant to growth and scaling. The purpose of the present investigation was to obtain alloy cast irons that are superior in mechanical and high-temperature properties, by treating Si-Al alloy cast-irons so as to promote the formation of spheroidal graphite. The following results were obtained: (1) Spheroidization of graphite was promoted by alloying of about 1%Al, but impeded by alloying more than 3% of Al. (2) The growth and scaling of 3.8%Si, 5%Al nodular iron and 5.4%Si over 3%Al nodular iron, was almost inmesurably small even at 900° (3) High Si-high Al irons are so resistant to scaling and growth that an addition of Mg was not effective in improving its high temperature properties, but those of low Si-low Al irons were considerably improved by Mg treating. (4) The tensile strength of some high Si-high Al nodular cast-irons increased more than as when cast by annealing and long heating at high temperature.View full abstractDownload PDF (1063K) -
Satoru Mito1955 Volume 19 Issue 9 Pages 529-532
Published: 1955
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn this experiment the effects of pretwisting on the elastic and the fatigue strength of several cold drawn steel wire springs were examined. The specimen used for testing was a helical tension spring, 8∼9 mmφ and 7∼11 turns. It was clarified that the elastic and the fatigue limits of these springs increase 50∼100% and 20∼40% respectively by applying the pretwisting process, while the spring constant (Modulus of Rigidity) decreases several percent. The optimum blueing temperature for twisted specimens was about the same as that for not twisted ones or slightly lower.View full abstractDownload PDF (792K) -
Satoru Mito1955 Volume 19 Issue 9 Pages 533-536
Published: 1955
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn this paper the effect of pretwisting on the static and the fatigue strength of helical springs made of stainless steel, phos.-bronze, brass and duralumin wires are mentioned.The same result was obtained as with steel wire springs already reported. By the process the elastic and the fatigue limits of these springs increase about 40∼80% and 20∼40% respectively.View full abstractDownload PDF (655K) -
Sosuke Uchida1955 Volume 19 Issue 9 Pages 536-539
Published: 1955
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSBright annealing of 4:6 brass has been studied in the atmospheres produced by perfect combustion of city gas with air and freed of CO2 and H2O by various meshods. It was confirmed more zinc is expelled from the surface of brass in unoxidizing atmosphere than in air under the same heating conditions, and the formation of a fine oxidation film on the surface of brass by treating in a slightly oxidizing atmosphere prevents the expulsion of zinc from the surface of brass while the film is easily scaled off in cooling and a surface as bright as before treating was obtained.View full abstractDownload PDF (546K) -
Yûzo Nakamura, Motoi Nishisaka1955 Volume 19 Issue 9 Pages 539-542
Published: 1955
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSExperiment of electrostatic capacity has been done with single crystals of super-purity aluminium sheets (99.9%) which were etched to decrease the same weight of their unit surface area in every specimen, and on which dielectric film were electrolytically formed in ammonium borates solution. It was found that the electrostatic capacity is the lowest on {110} plane parallel to the rolled surface, and it increases toward the {111} or {100} plane to be parallel to the rolled surface. The addition of 0.02% and 0.05%Mg to super-purity aluminium (99.99%) had the effect to give a higher electrostatic capacity, and it was as certained that this effect may be due to the decrease of {110} and the increase of {100} or {111} orientation.View full abstractDownload PDF (865K) -
Hidetake Kusamichi, Yôshirô Yagi, Tôru Yukawa, Kazuo ...1955 Volume 19 Issue 9 Pages 542-545
Published: 1955
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSAs a typical titanium alloy with good heat treating property, a titanium alloy containing approximately 2% each of iron and chromium was induction-melted to enable a study in its heat treating property. The α-β transformation point of the experimental alloy is in the neighborhood of 850° and the structure quenched from the β region is the retained β. In the isothermal transformation test, hardness was found to be minimum at about 700° and increased as the temperature went down, reaching a maximum value at about 200°. In quench-aging test, the maximum hardness was shown at the aging temperatures of 300∼400°. All these results showed that precipitation took place under a low temperature. Next, the alloy of the same composition was melted by means of an arc and induction to produce specimens with and without carbon. The mechanical properties of these two specimens were compared at ambient and high temperatures.View full abstractDownload PDF (873K) -
Yûki Shirakawa, Ken’ichi Numakura1955 Volume 19 Issue 9 Pages 546-549
Published: 1955
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe Young’s modulus and the grain size have been measured with 10 kinds of polycrystalline ferromagnetic Ni-Cu alloys annealed at 700°, 800°, 900°, 1000° and 1100°. The following empirical relation between the Young’s modulus E and the average area of crystal grains S has been found: \[E=E0−BlogS\] where E0 and B are constants. The Young’s modulus vs. composition curves for alloys with the same grain size are not always similar to each other but each curve shows a minimum. The composition corresponding to the minimum shifts to the nickel side as the grain size becomes larger. With an addition of copper, the Young’s modulus of nickel with comparatively smaller grains increases, and that with comparatively larger grains decrases. These results suggest that the complexity of the so-far observed Young’s modulus vs. composition curves for Ni-Cu alloys may partly be due to the difference in the grain size of the individual alloy specimens. Finally the measured results are compared with that calculated from the formula derived by Voigt and Reuss.View full abstractDownload PDF (560K) -
Ichiji Obinata, Keizo Nishimura1955 Volume 19 Issue 9 Pages 549-552
Published: 1955
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSA characteristic deformation structure of cold-rolled titanium sheets, which has a particular relation to their recrystallization-phenomena, has been observed and discussed as to its formatoin. Titanium deforms chiefly by twinning. All the grains, however, are not the same in the degree of twinning owing to their orientations. The most disadvantageously oriented grains showed no trace of twinning even after 90%-reduction by rolling. In the structure of lightly rolled titanium, almost all the twins have been found to be those of {1012}. The {11\={2}1} twin seems to be difficult to occur when fine grained titanium is cold-rolled lightly. Definite directionalities in the twin-bands formed againts the rolling directions have been detected and they are explained crystallographically, comparing the dimentional change in the crystallites due to {10\={1}2} twinning and the strain induced by rolling.View full abstractDownload PDF (784K) -
Ichiji Obinata, Keizo Nishimura1955 Volume 19 Issue 9 Pages 552-554
Published: 1955
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSTwo types of recrystallization-processes have been found in titanium: One is the ordinary nucleation-growth type and the other is the process in which recrystallization starts and progresses by the moving grain-boundaries or the twin-boundaries without nucleation. Therefore, not only the internal strain energy but also the interfacial energy of grain-boundaries, especially, of twin-boundaries seem to play important rôle for the recrystallization of cold-rolled titanium. As the results of orientation-sensitivities in the twin-deformation. pointed out in the 1st report, the degree of progression of recrystallization differs widely with each grain: The grains which showed no twinning even after severe cold rolling recrystallize most slowly and the distribution of new grains just after the completion of recrystallization is not uniform in size, making groups according to the degree of twinning of their mother grains.View full abstractDownload PDF (869K) -
Kenjiro Okawara1955 Volume 19 Issue 9 Pages 555-558
Published: 1955
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSWhen single crystals having different orientations were heated up after rolling, the autor observed great difference in the coarsening tendency. So, the author studied (111), (110), (100) orientation single crystals of high purity aluminium (99.996%) and of the commercial aluminium (99.6%). In the case of (111) orientation single crystals, when 99.6%Al is annealed at 550° after rolling at 75% cold reduction, and 99.996%Al is annealed at 400° after rolling at 65∼90% cold reduction, the crystal grain grows up, viz., a coarsening phenomenon is observed. On the other hand, in the case of (110) and (100) orientation single crystals that phenomenon is not observed. By X-ray analysis, it is observed that a (111) single crystal recrystallizes at about 280° and at higher settled temperatures the grain grows up uncontinuously. So, the process of the grain coarsening is recognized to be as follows, (111) single crystal→(rolling and heating)→fine grains by the 1st recrystallization→(further heating)→coarsened grains.View full abstractDownload PDF (770K) -
Kenjiro Okawara1955 Volume 19 Issue 9 Pages 558-562
Published: 1955
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe author has already reported that a coarsening phenomenon was observed, when 75% rolled Al single crystals were heated up to 550°. So, in this 2nd report the author investigated the region of orientation and cold reduction in which the coarsening phenomenon was observed and then measured the change of physical properties due to the coarsening phenomenon. The investigation was carried out with Al single crystal of 99.994% purity, and the following results were obtained: (1) By increasing the cold reduction, the region of orientation where the coarsening phenomenon is observed, spreads toward (100) direction from (111) and (111)-(110) directions in a unit stereographic triangle, and becomes the greatest at 75∼80% reduction. In this region the (111) specimen has the most violent tendency of coarsening. But the coarsening phenomenon was not observed following a cold reduction under 50% or above 95%. (2) By measuring the electric resistance, the specific heat, the hardness and by X-ray, analysis there were recognized differences between (111) and (100) or (110) specimens, that is, (111) specimen sustains severer lattice distotrion rather than specimens oriented otherwise in rolling, and its hardness is the highest. In consequence, when annealed, the (111) specimen recrystalizes earlier than the others, and after recrystallization it maintains the strong preferred orientation.View full abstractDownload PDF (672K) -
Jingozaemon Matsuoka1955 Volume 19 Issue 9 Pages 562-566
Published: 1955
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSInvestigating the cause of high hardness of martensite from the views of (i) thermal and quenching stress, (ii) martensitic structure and (iii) supersaturated solid solute C atom by measuring the change of hardness and microstructure of Fe-Ni alloys due to heat treatment, (1) the degree of contribution of these three factors to the hardness of martensite was inferred and (2) some incidental conditions necessary to adopting the general principle of the relation between phase diagram and hardeness were also clarified.View full abstractDownload PDF (1468K) -
[in Japanese]1955 Volume 19 Issue 9 Pages A165-A171
Published: September 20, 1955
Released on J-STAGE: November 11, 2008
JOURNAL FREE ACCESSDownload PDF (928K) -
[in Japanese]1955 Volume 19 Issue 9 Pages A172-A186
Published: September 20, 1955
Released on J-STAGE: November 11, 2008
JOURNAL FREE ACCESSDownload PDF (11192K)
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