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Volume 22, Issue 11
Displaying 1-16 of 16 articles from this issue
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Hideo Kaneko, Katashi Masumoto1958 Volume 22 Issue 11 Pages 553-556
Published: 1958
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSWith a view to preparing high purity Si from crude Si, Mg or Cu alloying process was studied as an improvement of the Al-alloying process(1) proposed by I. Obinata and N. Komatsu. In Mg-alloying method, Mg-Al-Si alloy has been used to prepare the anode in the electrolysis because of the difficulty of preparing Mg and Si alloy. In Cu alloying method, besides the electrolytic treatment, an acid-leaching dissolution method has been also studied. The results of spectroscopic analysis of various Si purified by these alloying methods are shown in Table 1. Purified Si obtained by Cu-alloying process shows higher purity than those by Al or Mg alloying process. We consider that in the purification process, Al or Mg remains as oxides in purified Si, while Cu oxide is removed easily by acid treatment.View full abstractDownload PDF (644K) -
Kôkichi Hashiura, Mitsuru Watanabe1958 Volume 22 Issue 11 Pages 557-560
Published: 1958
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe present authors studied the changes of structure and hardness of austenitic manganese steel isothermally transformed at various temperatures between 400°C and 900°C, under different conditions. The results obtained were as follows: (1) The formation of carbide primarily occurred at the grain boundaries, and then as needles or plates within the austenite grains. It is largely affected by the quenching strain, and the acicular carbides are formed when the specimens are much strained, and are delayed, or not at all formed when they are only slightly strained. (2) When the specimens are quenched to 300°C from 1050°C (showing the minimum hardness) and reheated to 500°C, carbide was formed only at the grain boundaries by heating for 1 hour. (3) In a series of isothermal treatments of austenitic manganese steel between 400°C and 900°C under different conditions, the beginning of transformation (carbide and troostite) is most early in the water quenched state, and the smaller the quenching strain, more is it delayed, and the narrower becomes its temperature range, especially on the low temperature side. (4) The troostite transformation of austenitic manganese steel (at isothermal treatment) is very much affected by carbide formation mainly depending on the quenching strain.View full abstractDownload PDF (876K) -
Masao Ikeda1958 Volume 22 Issue 11 Pages 560-564
Published: 1958
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSUpon studying the production of metallic magnesium by means of Fe-Si reduction process, the following results were obtained. (1) Metallic iron in Fe-Si has no connection with the reduction of MgO, and this is also ascertained from a chemical-thermodynamic view-point. (2) The yield, and the amount of magnesium per unit charge, increase with the rise of Si% in Fe-Si. (3) A considerable amount of MgO remains unreacted, due to the formation of Mg2SiO4, the main product in the residue, based on MgO—Fe-Si reaction. (4) Excess in Si% over the theoretical content in MgO/Si (mole ratio) increases the yield for MgO, but MgO% in excess decreases the effectiveness of Si. (5) Both Al2O3 and Fe2O3 decrease the yield of metallic magnesium.View full abstractDownload PDF (593K) -
Tokunosuke Nakazima, Masao Takahashi, Hiroshi Kawaguchi1958 Volume 22 Issue 11 Pages 564-568
Published: 1958
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSA method has been developed for the determination of rare earth elements including yttrium in uranium and its compounds. The greater portion of the uranium is separated from the rare earths by ether extraction. The rare earths are then precipitated as fluorides and subsequently purified as hydroxides. Lanthanum was used as the carrier. The efficiency of the above separation procedures was studied by means of the radioactive tracer Eu152+154. The final determination was carried out spectrographically by the copper-spark method. Five rare earth elements which showed extremely high neutron absorption were investigated, and their limits of detection (sensitivity) and recoveries from U3O8 are reported.View full abstractDownload PDF (572K) -
Masao Terasawa1958 Volume 22 Issue 11 Pages 568-572
Published: 1958
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn this paper, the author describes the change of performance of lead alloys for bearing due to silicon content. The specimens were of a generally used bearing alloy (specimen No. 1: Sn 22%, Sb 14%) and other lead alloys (specimen No. 2: Sn 0.15%, Si 0.017%, Sb 3%, No. 3: Sn 3%, Si 0.017%, Sb 6%, No. 4: Si 0.017%, Sb 6%, No. 5: Sb 6%). The diameter of the testing shaft was 19.8 mm, the running load 30 kg, and the revolution of the shaft 780, 910, 1130, 1380, or 1650 rpm. The obtained results were as follow: (1) In compressive stress and hardness tests specimen No. 1 and No. 3 showed better results than the others. (2) In the tests for the coefficient of friction, No. 1 showed better results than the others at lower revolution range, but No. 3 and No. 1 showed the same value at higher revolutions range. (3) In the bearing temperature after 300 mins running, No. 1 showed a lower value than the others in general, but No. 3 showed the lowest at 1650 rpm. (4) In the abrasion weight, No. 1 and No. 3 showed the lowest value at lower revolution range, and No. 1, No. 2, No. 3, all showed the same value at higher revolutions range. By all accounts, the quality of bearing performances of specimen No. 1, and No. 3, were of the same rank. Therefore, if lead alloys for bearing metal contain silicon, tin will be remarkably saved by addition of silicon.View full abstractDownload PDF (705K) -
Masao Kuroda, Isao Gokyu, Kakunosuke Yamamori, Tatsuo Watanabe1958 Volume 22 Issue 11 Pages 572-576
Published: 1958
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn order to investigate the effect of rolling conditions on spread in wire flattening, Al, Cu and steel wires of various sizes were rolled on a two-high mill having rolls of 257 mm and 69 mm diameter, respectively. The results were as follows: (1) When the reduction was small, the deformation of wire was heterogeneous and localized upon the regions near the contacting surfaces with the rolls, therefore the specific spread was small in this stage. The greatest amount of specific spread was obtained by 15∼30% reduction in thickness. (2) The spread increased with increasing reduction in thickness per pass. (3) The relation between the strength of the material and the amount of spread was not clear. (4) The most important factor influencing the spread was the ratio of the roll to the wire diameter. Increase of this ratio increased the spread. (5) From the experimental results an experimental formula for spread including the total reduction in thickness, the reduction per pass, the roll and the wire diameter, and the properties of wire was introduced.View full abstractDownload PDF (724K) -
Masao Kuroda, Isao Gokyu, Kakunosuke Yamamori1958 Volume 22 Issue 11 Pages 576-580
Published: 1958
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn order to explain the experimental results reported in the 1st report, the flow of material was investigated by the plug-method, hardness distribution in the cross section of rolled wire was measured by a micro-vickers hardness tester, and the elastic stress distribution in the round and the flat materials under compression was obtained by the photoelastic method. The results were as follows: (1) The maximum shearing stress took the greatest value at the regions near the contact surfaces with rolls in a round material, but in a flat material at the center of the cross section. From a maximum shearing stress line, the direction of material flow was deduced. (2) The flow of material obtained experimentally agreed with that deduced from the photo-elastic method. (3) The maximum hardness occured at the center of the cross section by medium reduction but the higher the reduction the distribution of hardness became more the homogeneous.View full abstractDownload PDF (590K) -
Hiroshi Kitagawa, Norio Shibata1958 Volume 22 Issue 11 Pages 580-583
Published: 1958
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSWe found that, in spectrophotometric determination of vanadium in iron and steel by phosphotungstic acid method, addition of hydrofluoric acid was useful for masking of iron, molybdenum, titanium and etc, and the optimum conditions of spectrophotometric determination were determined. Based on the above results, the following procedure has been proposed. 0.5 g of the sample is dissolved in 5 mL of nitric acid (1:1) and 15 mL of perchloric acid and made to fume. Add concentrated hydrochloric acid dropwise and chromium (VI) is volatilized. Then add 50 mL of distilled water, boil and add 20 mL of hydrofluoric acid (1:10) and 5 mL of phosphoric acid (1:2) and dilute up to 80 mL. Add 10 mL of 0.5 M sodium tungstate solution at 100°C and keep 5 minutes at the same temperature, cool with tap water and dilute to 100 mL. The absorption at 440 mμ is measured.View full abstractDownload PDF (494K) -
Shôsuke Imoto, Genjiro Mima1958 Volume 22 Issue 11 Pages 584-587
Published: 1958
Released on J-STAGE: April 04, 2008
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Shôsuke Imoto, Genjiro Mima1958 Volume 22 Issue 11 Pages 588-592
Published: 1958
Released on J-STAGE: April 04, 2008
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Gunji Shinoda, Tadao Sano, Tadashi Kawasaki1958 Volume 22 Issue 11 Pages 592-596
Published: 1958
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSApplying surface radioactivity measurement, auto-radiographic method and weightless method, the corrosion resistance of some austenitic Cr-Ni steels against uranyl salt solution has been investigated. It was concluded that the count number and the auto-radiographic method are useful to study the initial stage of corrosion mechanism. An X-ray diffractometer study was also made on welded specimens to examine the carbide precipitation and the ferrite formation, and the Nb-carbide precipitated in the matrix was easily detected by an X-ray diffractometer study. The relative abundance of Nb-carbide is less in the welded portion than in the other portion of base metal, and in the welded specimens, there is no ferrite phase. Niobium-stabilized steels always show good corrosion resistance against uranyl salt solution. Some of the specimens were neutron-irradiated (1012 cm2/sec, 8 MeV) at about room temperature, and the irradiated specimens showed no change in the structure and the corrosion characteristics.View full abstractDownload PDF (688K) -
Goro Ohira, Katsuya Ikawa1958 Volume 22 Issue 11 Pages 596-600
Published: 1958
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn our preceding investigation(1)(4) on the solidification process of cast iron, it was found that the eutectic solidification of flake graphite is neucleated by primary austenite in hypo-eutectic composition or by primary graphite in hyper-eutectic alloys. Then, the solidification process would be abnormal in iron of eutectic composition. The process might be influenced by the inoculation such as with calcium-silicide or ferrosilicon and also be correlated in some manner with the structure of undercooled graphite containing titanium. In this report the effects of saturation degree and inoculation on the chill structure of flake graphite or undercooled graphite cast iron are studied. The depth of chill decreases as the saturation degree increases, but there appears an abnormal chill in low silicon alloy and undercooled graphite in high silicon alloy when the compositions of the alloys are approximately that of the eutectic. The inoculating effect of calciumsilicide is stronger than that of ferrosilicon in hypo-eutectic flake graphite iron, but the former is less effective than the latter in hyper-eutectic iron, and in the alloy with the structure of undercooled graphite containing titanium, inoculation of ferrosilicon is always more effective than that of calcium-silicide.View full abstractDownload PDF (919K) -
Katsuya Ikawa1958 Volume 22 Issue 11 Pages 600-604
Published: 1958
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn chilled cast iron, the depth of the ledeburite layer, that of mottled structure and its coarseness of it, depend on the number of eutectic cells formed at different distances from the chill end. In the present investigation, the number of eutectic cells was counted on vertical sections of wedge castings of various compositions. It is shown that the number of eutectic cells increases as the cooling rate increases till ledeburite begins to form. The cell number is far larger in the hyper-eutectic alloys than in hypo-eutectic ones. Phosphorus to 0.4% increases the number but more phosphorus decreases it. Silicon increases the number. Manganese and chromium decrease the number and widen the mottled part and coarsen the mottled structure making the size of flake graphite uniform. Sulfur, tellurium and oxygen remove the maximum point of cell number more slowly cooled part and increase the number, accordingly increase the chilled layer without widening the mottled part and refine the structure, and change the flake graphite to fine undercooled graphite. When manganese and sulphur coexist, the effects of both the elements appear in proportion to their balance. Titanium decreases the cell number and refine the graphite structure, but the structure is peculiar because the ledeburite containing titanium decomposes rather quickly after solidification.View full abstractDownload PDF (751K) -
Tomo-o Sato, To-oru Furukawa1958 Volume 22 Issue 11 Pages 604-608
Published: 1958
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn aqueous solution of 10 wt%H2SO4 (30°) and 40 wt%HNO3 (boiling), corrosion tests were carried out on 17%Cr and 7%Ni PH stainless steel samples containing 0.73%Al cold-rolled to 50 and 70% reduction in thickness and then aged at 300∼600° for various hours. The following results were obtained; (1) Against 10%H2SO4 solution, the corrosion resistance of the samples cold-rolled 50% was almost the same as that of 18-8 stainless steel (Fig. 1). (2) Against the same solution, the corrosion resistance of this steel cold-rolled to 50 and 70% and aged at 400°×20 hr, 450°×3 hr and 500°×1 hr showed the minimum values. These aging times are somewhat shorter than that required for obtaining the maximum hardness at the respective aging temperature. (3) In 40%NO3 solution, the corrosion loss of the cold-rolled and aged samples of 17-7 steel was almost the same as that of 18-8 steel.View full abstractDownload PDF (663K) -
Taro Takeyama1958 Volume 22 Issue 11 Pages 608-612
Published: 1958
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSHardness/aging time curves have been obtained and systematic electron metallographic studies have been made on an Al-4%Cu alloy single crystal aged at 30°, 130°, and 250° for various periods. On the two-stage age-hardening curve at 130°, the initial rise in hardness is due to the formation of G.P. [1] and the second rise takes place by the growth of G.P. [2]; but softening occurs at the same time by the formation of new precipitate particles (θ′). The single-stage age-hardening curve at 250° is, however, associated with the growth of θ′ precipitate particles. Therefore the mechanism of age-hardening of 130° and 250° aging may be completely different. From a view point of the dislocation theory of age-hardening, age-hardening at 130° is explained by Mott and Nabarro’s critical dispersion theory. At the peak hardness obtained by aging at 130° for 20 days, the average distance between the nearest precipitate particles was estimated as 230 Å.View full abstractDownload PDF (955K) -
Shin-ichi Nagashima1958 Volume 22 Issue 11 Pages 613-616
Published: 1958
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSAs the first step to clarify the mechanism of precipitation from a solid solution having close-packed hexagonal structure, the age-hardening has been studied using polycrystalline specimens of the Mg-Ag alloy containing 12.6%Ag, aged at room temperature, 100°, 150°, 175°, 200°, 250° and 300°, by means of hardness measurement, microscopic examination and X-ray investigation. At high temperatures, from 150° to 300°, hardening is related to the precipitation of a new phase. At low temperature, 100°, no evidence of precipitation has been found, though hardening occurs with prolonged aging. In general cases, the number of precipitated phases is one, i.e. continuous precipitation occurs, throughout the period of aging. However, two-phase precipitation, that is, a pearlitic precipitation of the depleted matrix and a gamma phase have also been observed locally when the aging temperature is higher than 200°. The mode of growth of the two-phase precipitation in this alloy resembles that of the so-called grain boundary reaction, but its microstructure is different from that in the latter case: the precipitated particles in the pearlitic structure are smaller than in the case of the continuous precipitation. From Debye-Scherrer patterns, it has been deduced that the structure of the gamma phase (Mg3Ag) is complicated but not simply hexagonal such as proposed by Ageew and Kuznetzow.View full abstractDownload PDF (1056K)
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