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Volume 24, Issue 10
Displaying 1-19 of 19 articles from this issue
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Tetsutarô Mitsuhashi, Renpei Yoda, Masao Yakushiji1960 Volume 24 Issue 10 Pages 615-618
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe effects of Ti and Al on the high temperature property of 60%Cr-25%Fe-15%Mo-type alloys prepared by rapid melting in a Tamman furnace were investigated in the same manner as described in the previous report. The results obtained are summarized as follows: (1) The high-temperature properties of 60%Cr-25%Fe-15%Mo-alloys were exceedingly deteriorated by 2%Al addition. (2) The properties of the alloys were considerably improved excepting the deterioration in oxidation resistance by 2%Ti addition. (3) The high-temperature properties of the alloy with addition of 2%Ti plus 1%Al were inferior to that of the alloy with addition of only 2%Ti. (4) The creep strength remarkably increased in the case of the alloy, in which Fe was partly replaced with Co and besides 2%Ti was added.View full abstractDownload PDF (674K) -
Masataka Sugiyama, Hisashi Suzuki1960 Volume 24 Issue 10 Pages 618-622
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe mechanical properties, the density and the microstructure of TiC-Co cermets containing 20 to 60 wt% of Co, hot-pressed at temperature ranging from 1550° to 1750°, and at pressure of 20 to 140 kg/cm2 for 2 to 15 min were investigated and the relationship between the properties of cermets and the hot-pressing conditions, and also the applicability of this sintering process, were described. The main results obtained were as follows: (1) For example, powders mixed with 30 to 40 wt% of Co could be hot-pressed under condition of 1700°×(20∼50) kg/cm2×5 min. (2) The values of transverse rupture strength, hardness, density and mean grain size of carbide were 120∼130 kg/mm2, 85∼87 RA, 5.4∼5.5 g/cc and about 3 μ respectively. (3) But even under such favorable conditions, squeezing out of binder was so extreme that the maximum metal binder content of cermets successfully hot-pressed was thought to be below about 30 wt%.View full abstractDownload PDF (749K) -
Masataka Sugiyama, Hisashi Suzuki1960 Volume 24 Issue 10 Pages 622-625
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn our previous report concerning TiC-Co alloy, the main points in the hot-pressing technique were described. As continuation thereof, experiments on other TiC-base cermets containing about 30 wt% binder such as Ni, Nimonic 90, Ni-Cr-Co alloy, X-40, Fe, 18-8 stain-less steel were carried out. The main results obtained were as follows: (1) The relation between the properties of cermets and the pressing conditions was almost similar to the case of TiC-Co alloy. (2) The low values of transverse-rupture strength and high hardness, etc. in alloy binder cermets were, probably due to oxidation of binder and also to chrome-carbide formation caused by carbon transfer from graphite die during the process. (3) Therefore, the process was found perhaps not suitable for sintering these cermets. (4) Some properties of TiC-Ni·Cr·Co cermets were examined in connection with Cr content.View full abstractDownload PDF (810K) -
Kazuo Tsuya1960 Volume 24 Issue 10 Pages 625-629
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSConsumable-electrode vacuum-arc melting of molybdenum has been studied. The operating conditions of the plant was as follows:
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It has been observed by fractographic examination that the ingots melted without deoxidizer contain molybdenum oxide on grain surfaces. So, the conditions of carbon deoxidation were investigated.View full abstractDownload PDF (764K) -
Kazuo Tsuya, Hideyuki Sasaki1960 Volume 24 Issue 10 Pages 629-633
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe recrystallization brittleness of arc-cast molybdenum and sintered molybdenum was studied by metallographic and microfractographic techniques. The ductility of molybdenum was evaluated by bend testing at lower temperatures. In general, it is suggested that in fracturing of commercial purity molybdenum at low temperatures, cracks at first nucleate along the grain boundaries and subsequently propagate through the grains.View full abstractDownload PDF (882K) -
Masazô Okamoto, Takeshi Naitô1960 Volume 24 Issue 10 Pages 633-637
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe effect of nitrogen-addition on the properties of 13Cr-stainless steels was investigated by microscopic, dilatometric, hardness, tensile and corrosion tests. The results obtained were as follows: (1) Maximum amount of nitrogen addition which insures the soundness of small cast ingots was about 0.14% and 0.18% at a carbon level of 0.03% and 0.14%, respectively. (2) With increasing content of nitrogen, both the temperature of transformation during heating and the Ms temperature were lowered. (3) When air-cooled from austenitizing temperatures of 880∼1050°C, only a martensitic γ→α transformation was found to occur at temperatures below 350°C in all the steels used except for steel No. 1 containing the lowest carbon and the lowest nitrogen, in which diffusion transformation at high temperatures as well as martensitic transformation at low temperatures were observed. (4) The incubation period of the steels during the isothermal holding at 700°C became longer with increase of nitrogen content of the steels causing increased hardenability. (5) The hardness of air-cooled steels from the austenitizing temperatures was raised by tempering at above 560°C due to the decomposition of retained austenite, the amount of which increased by addition of nitrogen. (6) The tensile strength of 13Cr-stainless steel was slightly increased by nitrogen addition, but the effect was considerably smaller than that following carbon addition. (7) The corrosion resistance of the steels against boiling 1%HCl and 5%H2SO4 solutions was appreciably deteriorated by nitrogen addition as well as by carbon addition.View full abstractDownload PDF (838K) -
Takemichi Ôtsu, Shirô Satô1960 Volume 24 Issue 10 Pages 637-641
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSA corrosion test has been made on Cu-5∼40%Zn alloys in saturated water and steam at 300°, 86 kg/cm2, for 250 hours using autoclave. Specimens were prepared as cold-rolled and annealed strips. All specimens, except those of low-zinc alloys exposed to saturated water, increased in weight with increase of zinc content forming the dark red corrosion product. The effect of corrosion on the tensile strength and the elongation of specimens were remarkable with increase of zinc content of the alloys. From microscopical examination, alloys of low zinc content (Zn=5∼20%) suffered preferred whisker-like corrosion penetrating along and in the grains, under the layer of corrosion product. On the other hand, the alloys of high zinc content (Zn=25∼40%) suffered layer type corrosion. The depth of penetration and thickness of the layer of corrosion increased with increase of zinc content. From X-ray powder diffraction and chemical analysis, corrosion products formed on the surface of the specimens were identified as a mixture of metallic copper and zinc oxide (hexagonal). Annealing treatment of the specimens tried has no perceptible effect on corrosion. As the results of these tests, it is considered that the zinc atoms near the surface of Cu-Zn alloy are selectively oxidized by high temperature water and steam forming the metallic copper and the zinc oxide as the corrosion product.View full abstractDownload PDF (811K) -
Hisashi Mori, Hirokazu Umezawa1960 Volume 24 Issue 10 Pages 641-645
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSTrace amounts of manganese in steel was determined nondestructively by neutron activation analysis using JRR-1 reactor (neutron flux: 1011 n/cm2·sec). The induced radioactivity of 56Mn was measured with a well type scintillation counter and a γ-ray spectrometer. The results were as follows: (1) The agreement between neutron activation analysis and chemical analysis were within 10%, and the reproducibility of activation analysis were within ±10%. (2) The relative error due to counting fluctuation was 2% for 0.01γ of manganese (2 hrs irradiation). (3) In order to eliminate the influence due to the activity of 64Cu, manganese activity should be counted from 1 to 5 hours after the irradiation for two hours.View full abstractDownload PDF (688K) -
Gunji Shinoda, Tadakazu Sakurai, Tadao Sano, Tadashi Kawasaki, Hisashi ...1960 Volume 24 Issue 10 Pages 645-649
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe present work was undertaken to examine the fatigue strength of stainless steel at elevated temperatures, since little work had been done in this field. The specimens used are samples of several austenitic stainless steels such as AISI Type 304, 316, 347, 321 and also iron-base high-Cr high-Ni alloys. Rotating cantilever fatigue tests were made with plain and notched specimens at temperatures 460°C to 700°C, and the results obtained were as follows: (1) The higher the carbon content, the higher was found the fatigue strength in 18%Cr-8%Ni steels, irrespective of their Cr or Ni contents. (2) Whenever the specimens had not fractured after the first 105∼106 times of repetitions of loading, fatigue failure would not occur even if repetition of loading was continued further; therefore a definite endurance limit was obtained which was higher than the yield point of the specimen. (3) The fatigue strength of stainless steels at elevated temperatures was increased by under-stressing, and a significant coaxing effect was observed. It may be concluded that the fatigue strength of austenitic stainless steel at elevated temperatures is affected remarkably by precipitation of chromium carbide and other precipitates.View full abstractDownload PDF (738K) -
Gunji Shinoda, Tadao Sano, Tadakazu Sakurai, Tadashi Kawasaki, Hisashi ...1960 Volume 24 Issue 10 Pages 650-654
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe tensile strength of austenitic stainless steels decreased with rising temperature up to about 300°C, but it remained almost constant at 300∼600°C. This may be explained as follows: The decrease in tensile strength with rise of temperature is suppressed by precipitation of chromium carbide and other precipitates along the slip bands which takes place during the tensile test at this temperature range. This was confirmed by microscopic examination. If the precipitation is prevented by some devices, the tensile strength of stainless steels would be decreased continuously with rise of temperature, as pure metals do. This assumption was confirmed by a tensile test on sharp-notched specimen. It may be reasonable to conclude that the strength of austenitic stainless steels at elevated temperatures is significantly affected by structural changes which occur during the tensile test, and then cold or hot-working at a suitable temperature makes it possible to improve the high temperature strength of this alloy.View full abstractDownload PDF (1144K) -
Masami Hasegawa1960 Volume 24 Issue 10 Pages 654-657
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe use of (C9H7N)4H4 (SiO4·12MoO3) was studied for precipitation of Si as quinoline complex by Wilson, Duval and Brabson for the first time. But the extremely attractive new method based on the precipitation is not widely applied to the routine analysis even now. Hereupon, I made studied in order to apply the method to the determination of Si in Al-alloy. Namely, Si in Al-alloy is first converted into Na2SiO3 by attacking with NaOH, and then made acidic with HCl. Practically all of the Si remains in the solution as H4SiO4, which reacts with Na2MoO4 to form a yellow H8[Si(Mo2O7)6] in pH 1.10 acid solution as follows: H4SiO4+12MoO3+3H2O=H8[Si(Mo2O7)6]·H2O. The solution, made more acidic with HCl to prevent the precipitation of quinoline molybdate, is treated with C9H7N, and the precipitate of quinoline complex (C9H7N)4H4(SiO4·12MoO3) is quantitatively determined. When this complex is dissolved in excess NaOH, it is broken down to C9H7N, H4SiO4 and H2MO4. C9H7N and H4SiO4 are too weak to react with NaOH, and so only H2MoO4 reacts with NaOH according to the following equation: (C9H7N)4H4(SiO4·12MoO3)+24NaOH=4C9H7N+H4SiO4+12H2O+12Na2MoO4. The excess of NaOH may be determined, and each equivalent of NaOH used in reaction corresponds to 1/24 of the molecular weight of Si. This method is more rapid in the procedure than JIS gravimetric method, because the whole procedure may be carried out within 70 minutes. Furthermore, it was found that the standard deviation was 0.006 to 0.02, which favorably compares that (0.016 to 0.060) in JIS gravimetric method, when the similar samples of about 0.40 to 13.0%Si were used. In the case of alloyed Al, only interference by P, As and Ge has to be considered, so it can be applied to analysis of most of Al-alloys. Therefore, this method is very suitable for industrical routine analysis.View full abstractDownload PDF (555K) -
Kenzaburo Kumada1960 Volume 24 Issue 10 Pages 658-662
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSAnnealing of iron-chromium alloys containing more than 40% chromium at and over 600°C, where the so-called 475°C brittleness is not observed, causes the shift of the magnetic transformation temperature to somewhat higher temperature. In order to clarify this phenomenon, thermomagnetic analysis, hardness, thermal expansion- and magnetization-curve measurements and microscopic observation were made on variously heat-treated Fe-Cr alloys. This phenomenon is shown to be not due to the formation of superlattice FeCr but seems to be explained by the precipitation and resolution of the chromium compound, i.e. chromium carbide (or possibly nitride).View full abstractDownload PDF (902K) -
Kenzaburo Kumada1960 Volume 24 Issue 10 Pages 662-664
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe magnetic transformation temperatures of residual Fe-Cr ferrites during sigma transformation of Fe-Cr alloys containing 35∼60% chromium were investigated by thermomagnetic analysis. It has been found that the content of the sigma phase increases with lengthening of annealing time but the magnetic transformation temperature does not change. Thus the composition of residual Fe-Cr ferrite during sigma transformation may be considered to be always the same. Based on this consideration,the content of ferrite is determined quantitatively by the measurement of the saturated intensity of magnetization since this depends on both the content and composition of Fe-Cr ferrite. When the content of the Fe-Cr ferrite is known, that of the non-magnetic sigma phase will be easily known. According to this explanation, the content of the sigma phase at each annealing time was determined in some specimens.View full abstractDownload PDF (422K) -
Akira Tokuda1960 Volume 24 Issue 10 Pages 665-668
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIt was mentioned in the first report that the fatigue fracture surfaces of low carbon steels could be classified roughly in five types according to the different patterns of their electron-microfractographs and that their characteristic features were remarkably different from those of the fracture surfaces obtained by tensile or impact tests. This report refers to the observations which we conducted on the fatigue-fracture surfaces of low-alloy steel and high carbon steel brought about by the rotating-beam fatigue tester, using the electron-microfractographs of the fatigue-fracture surfaces, as in the case of the previous report, and comparing the fatigue fracture surfaces with those of low-carbon steel. The results obtained are as follows; (1) The electron microfractographs of fatigue fracture surfaces of low alloy steel in quenched and tempered conditions were classified in five types as in the instance of low-carbon steel. (2) The fatigue fracture surfaces of hardened carbon steel (0.6% carbon) did not show the characteristics of a fatigue fracture, but the river pattern whicd usually appears in brittle fracture surfaces was noticed. (3) In the case of high-carbon steel in annealed condition, a pattern like lamellar pearlite was observed appearing in the fatigue-fracture surfaces, though the surfaces were not treated by etching. A part of the surface which corresponded to ferrite took on an appearance of fine stripes at intervals of less than 200 Å while the remaining part corresponding to cementite was smooth and no pattern of stripes was seen in it.View full abstractDownload PDF (927K) -
Kichizo Niwa, Mitsuo Shimoji, Osamu Mikuni1960 Volume 24 Issue 10 Pages 668-672
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThermodynamic studies on liquid Pb-Bi alloys have been carried out by means of the electromotive force method. Electrode concentration cells of the following type were operated at 370∼480°; Pb(liquid)/PbCl_2, KCl-LiCl/Pb-Bi (liquid). The experimental results indicate that this system shows a negative deviation from Raoult’s law and that the excess entropies are practically zero. The calculated heats of mixing are slightly less negative than those of Seltz’s e.m.f data, though less positive than those of the calorimetric data. Thus the excess free energy and excess enthalpy can be written as follows, G_m^e=H_m^e=-1,150x_Pb ·x_Bi cal/mol. The phase diagram of this system is discussed on the basis of the present results.View full abstractDownload PDF (551K) -
Hisafuji Watanabe1960 Volume 24 Issue 10 Pages 672-676
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe phase diagrams of the system Zn-Cu-Mg and Zn-Al-Mg-Cu (especially in the range of Zn side) have been studied by means of microscopic examination and inverse rate thermal analysis. The ternary diagram obtained is shown in Fig. 3. Five non-variant points in this system are observed as follows:
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The Zn-side of the quaternary system is divided into two ranges by the pseudo-ternary system of Zn-MgZn2-CuAl2 and in these ranges no ternary or quaternary intermetallic compound appears. The reactions—ternary eutictic, peritecto-eutectic, peritecto-ternary eutectic and quaternary eutectic—in the range of Zn-Al-MgZn2-CuAl2 and Zn-Cu-MgZn2-CuAl2 are observed as follows.
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Masayoshi Tagaya, Imao Tamura, Yoichi Murakami1960 Volume 24 Issue 10 Pages 676-679
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe cooling ability of liquid increases with rise of the flow rate. In this report, the relation among the cooling ability, the flow rate of oil in turbulent streams and the diameter of specimens were examined and the next equation was obtained:
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\ oindentwhere H and H0 are the severity of quench in the cases of flowing state and still state of oil, D the diameter of specimen, Re the Reynold’s No., (vD⁄ν) and Pr the Prandtl’s No., (cρν⁄λ). K, m and n are constants. V is the flow rate and ν the kinetic viscosity of oil. λ, c, and ρ the thermal conductivity, the specific heat and the specific gravity of oil respectively. This relationship quantitatively determines the effect of flaw rate on the cooling ability of oil and give basal data to design a quenching tank and its agitating device.View full abstractDownload PDF (489K) -
Akimi Umezono, Susumu Morioka1960 Volume 24 Issue 10 Pages 680-684
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe effect of halide ions on the anodic passivation of zirconium in acid, neutral and alkaline solutions was studied. In the presence of F− ions, dissolution of zirconium was observed in acid solution and pitting corrosion in neutral solution, but in alkaline solution zirconium was not attacked. In the presence of Cl− or Br− ion, pitting corrosion of zirconium was observed in solutions of any pH value, but pitting by Cl− ion and that by Br− ion was prevented comparatively by presence of NO3− or NO2− ion and OH− ion, respectively. Neutral iodide solution, without other oxyanions, can pit zirconium, but the solution containing other oxyanion caused no pitting. Oxidizing agents promote the start of pitting, but general anions (e.g. SO4=, SO3=, NO3−, NO2−, OH−) prevent corrosive action of halide ions. The pitting corrosion potential, 0.20∼0.23 V (vs. S.C.E) for Cl− 0.1 mol/L, 0.45∼0.50 V for Br−, and 0.82∼0.86 V for I−, did not vary with current density. A linear relation exists between the pitting corrosion potential and the logarithm of the halide ion concentration. Halide ions cause a greater number of smaller pits in the order of Cl−<Br−<I−.View full abstractDownload PDF (667K) -
Harue Wada, Yasuji Kawai, Tunezo Saito1960 Volume 24 Issue 10 Pages 684-688
Published: 1960
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe activities of chromium in the liquid systems of iron-chromium and iron-chromium saturated with carbon were determined by a vaporization method using radioactive Cr51. The experiments were carried out at 1630°C up to about 40 at. pct chromium. It was found that iron-chromium system is a regular solution, showing negative deviation from the Raoult’s law. The interchange energy w was found to be about −10 kcal/mole. The value of w calculated from the phase diagram is also negative, but is not in good agreement with the above. It is theoretically inferred that the deviation from the Raoult’s law is larger in iron-chromium system than in iron-nickel system. The addition of carbon lowers the activities of chromium and the interaction parameter εCrC in carbon-saturated system is −12∼−16 over the composition range 0∼10 at. pct chromium.View full abstractDownload PDF (625K)
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