巻号一覧
22 巻, 12 号
選択された号の論文の13件中1～13を表示しています
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作井 誠太, 折井 秀彦, 大野 明, 隅野 一雄1958 年 22 巻 12 号 p. 617-621
発行日: 1958年
公開日: 2008/04/04
ジャーナル フリーThe behaviour of die lubricant during casting in die-casting process has not been fully investigated. We added small amount of HCl solution of radioactive H3PO4 to the die lubricant (called “Die Slick”) mechanically and the radiographs of the surface and the inner part of the casting were taken after solidification. Comparatively large amount of radioactive lubricant was applied to the gates of cavities or to the points marked by X in the photo. 1∼8. Zinc alloy ZAC No. 1 was cast in the dies shown in Fig. 1 and 2. The results obtained were as follows:—(1) The lubricant travelled with the flow front of the molten metal through the die cavity and accumulated at the place where the movement of molten metal came to end or remarkable turbulent motion occurred. (2) A large amount of lubricant was entrapped in the casting and distributed comparatively uniformly. (3) The chilled layer of casting occluded hardly any particles of the lubricant. (4) The entrapping of lubricant increased with the rise of casting temperature and with the increase of gate area.抄録全体を表示PDF形式でダウンロード (781K) -
大日方 一司, 小松 登, 小林 研一1958 年 22 巻 12 号 p. 621-624
発行日: 1958年
公開日: 2008/04/04
ジャーナル フリーThe structure of phosphorus-bearing hypereutectic Al-Si alloys, bubbled by such gases as argon, nitrogen, air, steam, and chlorine, has been observed. Treatment by gas except chlorine promotes the growth of primary silicon crystallite. Among gases mentioned above, the effect of steam on crystallite growth was most conspicuous, even though there exists sufficient amount of phosphorus to retard the growth of primary silicon crystallite. In the alloys with crystallite growth caused by steam-treatment, grain-refinement may fully be observed after chlorine-treatment. The presence of hydrogen in alloy probably inhibits the role of phosphorus that contributes to the grain-refinement of primary silicon crystallite. Gas-treatment and remelting of Al-Si alloys may hardly reduce the content of phosphorus in alloys in the case of lower than 0.01% phosphorus.抄録全体を表示PDF形式でダウンロード (1045K) -
天野 恕1958 年 22 巻 12 号 p. 625-628
発行日: 1958年
公開日: 2008/04/04
ジャーナル フリーThe methods of determination and separation of Nb and Ta in steels were studied using the radioactive isotopes 95Nb and 182Ta as tracer and radioactive indicators. It was found from the experiences that the perchloric acid-hydrolysis separation method was most superior for separating Nb and Ta from Fe and that after a single s paration from Fe, Nb and Ta could be successfully titrated with cupferron solution using Ta-182 as the radioactive indicator.抄録全体を表示PDF形式でダウンロード (652K) -
多賀谷 正義, 田村 今男1958 年 22 巻 12 号 p. 629-631
発行日: 1958年
公開日: 2008/04/04
ジャーナル フリーThe influence of water contamination on the cooling curves and quenching severity (H) of rape-seed oil and 110-dynamo oil was examined. For rape-seed oil, the characteristic temperature at which vapor film breaks down on cooling descends, the vapor film stage elongates and the beginning temperature of convection stage obviously descends with increase in water content of oil. For 110-dynamo oil, the beginning temperature of convection stage obviously descends but the characteristic temperature does not descends and the cooling rate in the whole range especially in lower temperature range, increases with water content. It seems that there is a difference between the influence of water on rape-seed oil (fatty oil) and that on 110-dynamo oil (mineral oil). Such a difference depends on the boundary activity of oil. Mineral oil usually has so small a boundary activity that stable emulsion is not formed in water. Below the solubility limit of water the influence of water is relatively small, in the range forming emulsion it is large and in mixed state with oil and water over the range of emulsion formation it is reratively small. The remarkable character of its influence is that the cooling rate at temperature range below 300°C at which martensite is formed rose much and does not vary much at higher temperature range. It may be considered that water is not so much effective on the hardening response of steel but extremely effective on the quenching distortion or crack.抄録全体を表示PDF形式でダウンロード (430K) -
多賀谷 正義, 田村 今男1958 年 22 巻 12 号 p. 631-636
発行日: 1958年
公開日: 2008/04/04
ジャーナル フリーThe effect of flow rate on the cooling ability of water and three sorts of oil were quantitatively examined. All of streams of liquid in this research were turbulent. The cooling ability of liquid increases with Reynolds No. as shown Fig. 9. But oils with high viscosity have an upper limit of its cooling ability because it is difficult to make the flow rate increase above some extent. The cooling ability of mineral oil becomes easily higher than that of rape-seed oil of still state when it flows, but it seems that its cooling ability cannot reach that of water of still state even with violent circulation. The smaller the viscosity of liquid the larger the effect of flow rate. It would be desirable to design the quenching tank so that the Reynolds No. might be over 1600 or v⁄ν (Where v is the flow rate, cm/sec, and ν the kinematic viscosity, cm2/sec) might be over 1000. In the case of oil having large viscosity, since it is difficult to get such a flow rate, we must try to get as large flow rate as possible and to use lighter oil, It would be advisable to choose mineral oil having long life and make up for cooling ability with by faster circulation.抄録全体を表示PDF形式でダウンロード (802K) -
中谷 義三, 清水 恭治, 大谷 雅博1958 年 22 巻 12 号 p. 636-640
発行日: 1958年
公開日: 2008/04/04
ジャーナル フリーThere are many investigations on the grain growth of α-Brass, but few on primary recrystallization of this alloy. Recently, Channon and co-workers studied this primary recrystallization isothermally by hardness measurement. The present authors also investigated primary recrystallization of a commercial α-Brass bearing 30%Zn by direct microscopic observation. The results obtained were as follows: (1) The activation energies of recrystallization QR was 48.2 kcal/mol with 30% reduction, and 46.2 kcal/mol with 50% reduction sheet with 50∼80% recrystallized fraction X, and decreased with decrease of X down to 50%. (2) Applying the Channon’s results, QR increased with an increase of the initial grain size, approaching a constant value. (3) Micro-Vicker’s hardness with unrecrystallized and recrystallized matrix decreased with an increase of annealing time, in the former case perhaps owing to recovery and in the latter case owing to grain growth. (4) The as-recrystallized grain size became finer with increasing reduction independ of temperature. (5) Under microscopic observation, the recrystallization nuclei appeared at the highly strained region, such as the grain boundary, the twin boundary and the slip band, preferentially.抄録全体を表示PDF形式でダウンロード (934K) -
大竹 正, 石崎 敬三, 江口 直記1958 年 22 巻 12 号 p. 640-644
発行日: 1958年
公開日: 2008/04/04
ジャーナル フリーThe distribution of tramp elements in the enriched layer and the scales produced by oxidization while heating was minutely investigated by spectrographic and chemical analyses. The results obtained were as follows:—(1) When steel is heated in oxidizing atmosphere, Cu, Sn, Ni, As and S contained in steel are enriched on the surface of steel. (2) A linear relationship is observed to exist between the depth from the surface of steel and the logarithm of the concentration of each enriched element contained in the layer. (3) In the case the scaling loss of steel is constant, the surface concentration of enriched Cu and Sn is decreased while that of S is increased with rising h ating temperature, and the surface enrichment of each element is also affected by the oxidizing velocity and the coexisting elements. (4) The diffusion constants of Cu and Sn in steel are determined by measurement of the enriched depth at various temperatures, and the following were the values obtained: & D_Cu^- 12700 exp(-48700/RT) cm^2/day
& D_Sn^- 4570 exp(-45600/RT) cm^2/day(5) The concentrations of Cu and Sn in scales are less than those in the steel matrix, and usually depend on the degree of scaling loss.抄録全体を表示PDF形式でダウンロード (614K) -
三好 栄次1958 年 22 巻 12 号 p. 644-648
発行日: 1958年
公開日: 2008/04/04
ジャーナル フリーIn the previous report it is shown that the wear at high temperature is closely related to oxidation. The results of wear tests of carbon steel in air and in vacuum were compared with each other. The effects of frictional speed and surface load on the wear in vacuum are examined. At room temperature, wear loss in vacuum is smaller than in air, but at high temperature this relation is reversed. The hard layer on the surface of the test pieces in vacuum test is believed to reduce the wear loss. The hardness of this hard layer is about 900∼1000 of Micro-Vickers hardness. The cause of this hard-layer formation will be reported later. The effect of speed on wear loss in vacuum is ascribed to the temperature rise at the surface. Wear loss decreases with increasing speed. Increase of the surface load yields the hard layer at an earlier stage. So the load-wear loss curve shows one maximum and one minimum. The former is due to the thickening of the hard layer and the latter to the rise of surface temperature.抄録全体を表示PDF形式でダウンロード (932K) -
末永 勝郎, 岡本 正三1958 年 22 巻 12 号 p. 648-651
発行日: 1958年
公開日: 2008/04/04
ジャーナル フリーThis investigation was conducted to evaluate the high-temperature strength of Ni-Cr binary alloys ranging from 20%Cr to 40%Cr in homogenized state after casting or rolling of about 30% at 750°C, by measuring the high-temperature hardness, testing the bending-cre p behavior, etc. It was found that rolled specimens are hard r in high-temperature-hardness and strong r in b n-ding-cr p-tests than sp cim ns without rolling. The deflection in bending-creep-tests at 700°C of 35%Cr-Ni alloy was found to be minimum in specimens homogenized without rolling, and that of 25%Cr-Ni alloy was minimum in roll d and homog nized specimens. With heating of specimens ranging from 30%Cr to 40%Cr at 700°C for 100 hrs, troostic decomposition was found to take place at the grain boundaries and spread into the grains. This was conspicuous in rolled 40%Cr alloy. One of the causes for weakness in bending-creep-strength of the rolled 40%Cr alloy will be due to the finer grains and the more decomposition. 20%Cr-Ni alloys were found to show Widmanstätten structure and subgrains after 100 hr-heat at 700°C. This phenomenon might have more or less relation with the so-called anomaly of the γ solid solution at low temperature.抄録全体を表示PDF形式でダウンロード (547K) -
八百 輝彦, 寺田 実男1958 年 22 巻 12 号 p. 652-655
発行日: 1958年
公開日: 2008/04/04
ジャーナル フリーThe effect of fine particles in tungsten powder at sintering observable by a Geiger counter X-ray diffractometer was investigated by measurements of specific gravity, X-ray, microscopy and air-flow method for sintered materials. The X-ray method is better than the others. The fine particles below 1 μ affect the sintering rate,the specific gravity and the structure of the sintered body at all temperature range of sintering until it melts down. The structure of the sintered body and the mechanism of sintering was investigated by specific surface areas, average pore diameters, pore population densities, average particle diameters and particles population densities as calculated by gas-flow method. An interesting effect at the beginning of the recrystallization and after it has been achieved.抄録全体を表示PDF形式でダウンロード (758K) -
吉田 秋登1958 年 22 巻 12 号 p. 656-660
発行日: 1958年
公開日: 2008/04/04
ジャーナル フリーStatistical thermodynamics was applied to the quantitative interpretation of the immiscibility of the binary silicate systems. The author has established the model of molten MO-SiO2 systems composed of c mol MO and (1−c) mol SiO2, as follows: (1) When c mol MO dissolves into (1−c) mol SiO2, Nc in the 2(1−c)N Si-O-Si chains decompose into Si-O* *O-Si by the following reaction: MO+Si-O-Si→Si-O* MO*-Si. (2) The binding energies of Si-O, Si-O*, M-O and M-O*. vary in proportion to the Si-O-Si decomposition ratio c⁄2(1−c). From this model, the Gibbs’ free energy of the molten system Gl can be written, as follows: G_l=(1-c)G_Sio_2^l+Ac+Bc^2/1-c+Cc^3/(1-c)^2+RT{c lnc+(2-3c) ln(2-3c)-2(1-c) ln2(1-c)}where GSio2l is the Gibbs’ free energy of SiO2 liquid and A, B and C are constants. From this formula, the immiscibility of MO-SiO2 systems can be explained systematically and the activities of SiO2 in molten binary silicate systems have been calculated.抄録全体を表示PDF形式でダウンロード (720K) -
足立 彰, 荻野 和巳1958 年 22 巻 12 号 p. 660-663
発行日: 1958年
公開日: 2008/04/04
ジャーナル フリーThe electrical conductivity of slags containing iron oxide was measured in air, in order to clarify the behavior of ferric oxide in liquid slag. In the slags of Fe2O3-CaO-SiO2 and Fe2O3-CaO systems, the specific conductance increases with the content of Fe2O3 and with the temperature. The order of the magnitudes of the specific conductance of both systems was about from 0.1 to 0.5 and from 1.0 to 4.0 Ω−1 cm−1 at 1400°C, respectively. It seems to be probable that the electric conductance in these slags is predominantly ionic. The relation between κ and 1⁄T is generally linear. In certain kinds of slags, there is a sudden decrease in specific conductance below the solidification temperature. However, an anomalous variation of the specific conductance near the solidification temperature was observed in slags of certain compositions.抄録全体を表示PDF形式でダウンロード (453K) -
高村 仁一, 佐々木 靖男1958 年 22 巻 12 号 p. 663-667
発行日: 1958年
公開日: 2008/04/04
ジャーナル フリーThis study was undertaken in an effort to provide a clearer picture of the oxidation mechanism where by nitrogen reduces the heat resistance of zirconium and also to develop a new heat-resistant zirconium alloy containing a small amount of phosphorus. The oxidation test was carried out in dry oxygen and in air at temperatures of 700∼900°C using the weight-gain method. Since the oxidation process of zirconium has been explained by the diffusion of negative ion vacancies through the oxide, the factors determining the concentration and the mobility of the vacancies require further examination; Theye are the valency, the ionic radius and the ionization potential of the alloying element and the electroneutrality in the oxide lattice. Under such considerations, phosphorus was chosen for the alloying element. The results obtained are as follows: (1) Addition of a small amount of phosphorus counteracts the harmful effect of nitrogen in zirconium and exceedingly prolongs the breakaway period. It is noted that there is an optimum content of phosphorus. The amount ranges from 0.03 to 0.06 wt% according to the purity of zirconium. The beneficial effect may be attributed tothe solution of phosphorus in ZrO2 lattice as P+5, with consequent reduction of the concentration and the mobility of negative ion vacancies. An excess amount of phosphorus is harmful. (2) The exponent n for the equation of oxidation process was obtained in pure zirconium and phosphor zirconium alloys, as listed in Table 3. The activation energies of 38,000 and 34,000 cal/mol were determined for pure zirconium in dry oxygen and air, respectively.抄録全体を表示PDF形式でダウンロード (689K)
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