Tetsu-to-Hagane
Online ISSN : 1883-2954
Print ISSN : 0021-1575
ISSN-L : 0021-1575
Volume 50 , Issue 8
Showing 1-15 articles out of 15 articles from the selected issue
  • [in Japanese]
    1964 Volume 50 Issue 8 Pages 1159-1160
    Published: July 01, 1964
    Released: October 12, 2010
    JOURNALS FREE ACCESS
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  • Koin ITO, Kokichi SANO
    1964 Volume 50 Issue 8 Pages 1161-1167
    Published: July 01, 1964
    Released: February 20, 2012
    JOURNALS FREE ACCESS
    In an experiment related with the measurements of oxidation velocity of molten iron alloys by atmosphere, we studied the change in the rate of concentration of alloying elements by evaporation.The rate equations of evaporation of alloying elements were proposed by many investigators in various forms.Here, we measured the change of Mn concentration by evaporation in molten Fe-Mn alloys, and derived rate equations on the basis of 2-film theory. Results obtained here are as follows:
    1) Under external pressures below 0.1 mmHg, the rate of concentration change is expressed by Eq.(10)_??_which is derived from the rate of evaporation in vacuum.As the external pressure increases, Eq.(10)_??_becomes meaningless because f k approaches to 0.
    2) Under external pressures above 0.1 or 1 mmHg, Eq.(12a) derived from 2-film theory, _??_seems to be more suitable as the rate equation.At atmospheric pressure, assuming KG=DmG approximately, σG, thickness of gas-side diffusion layer, was found to be 0'2 to 03 cm.Eq.(12 a) may be true independently of the external pressure and evaporative materials, and it can be transformed to a rate equation in vacuum by suitable approximations.
    3) The rate is also expressed by Eq.(12 b)_?_ which has the same form as the rate equation of degassing from molten iron.
    As the external pressure decreases, KL approaches to DL.σ/L.
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  • Kazuhiro GOTO, Yukio MATSUSHITA
    1964 Volume 50 Issue 8 Pages 1167-1175
    Published: July 01, 1964
    Released: December 22, 2010
    JOURNALS FREE ACCESS
    The standard free energies for formation of several metal oxides were determined by electromotive force measurements of reversible oxygen concentration cells. Zircorria, stabilized with calcium oxide, was used as the electrolyte, which performed as a pure anion conductor due to the movement of oxygen lattice defects at high temperature above 500°C.
    The measurement has been carried out extensively on many different structures of the cells, including the cells with four electrodes.
    The obtained results are as follows:
    (1) Fe(α)+1/2O2(G)=FeO(s)
    ΔG°f=57, 610+14.13T(°C)±300Cal
    (500°C-up to transformation point of α→γiron)
    (2) 3Fe(α)+2O2(G)=Fe3O4(s)
    ΔG°f=-236, 600+63.33T(°C)±1000Cal
    (500°C-up to transformation point of α→γiron)
    (3) Pb(l)+1/2O2(G)=PbO(S. or l)
    ΔG°f=-45, 710+23.47T(°C)±100Cal (500°C-M.P. of PbO)
    ΔG°f=-40, 840+17.82T(°C)±100Cal(M.P. of PbO-1150°C)
    (4) Sn(l)+1/2O2(G)=SaO(s)
    ΔG°f=-61, 000+23.72T(°C)±50Cal (500°C-1100°C)
    (5) Cu(s)+1/2O2(G)=CaO(s)
    ΔG°f=33, 640+23.66T(°C)±300Cal (500°C-900°C)
    (6) 2Cu(s)+1/2O2(G)=Cu2O(s)
    ΔG°f=-35, 360+16.98T(°C)±100Cal (500°C-M.P. of Cu)
    (7) 2Ta(s)+5/2O2(G)=Ta2O6(s)
    ΔG°f=-413, 800+70.66T(°C)±300Cal (800°C-1200°C)
    The accuracy of the above data was discussed in comparison with the previous data. Also, the reversibility, and polarization effects of the cells were discussed.
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  • Susumu MINOWA, Mineo KOSAKA
    1964 Volume 50 Issue 8 Pages 1175-1181
    Published: July 01, 1964
    Released: October 12, 2010
    JOURNALS FREE ACCESS
    The rates of solution of the cylindrical sintered silicon carbides by liquid iron that were melted in various furnaces (Tammann furnace and two high-frequency furnaces of different cycles) were measured at temperatures from 1400°C to 1600°C.
    It was found that the rates of solution of SiC bars in liquid iron were markedly influenced by the concentration of carbon and silicon in the metal and the stirring action of melts. The diffusion process controls the rate of solution of SiC. When the sintered SiC sample was immersed in carbon saturated liquid iron and Fe-C-Si melt (C=1.5%, Si=3.0%), the activation energy of solution was as follows, 49-86 Kcal/mol in carbon saturated liquid iron, 53-72 Kcal/mol in Fe-C-Si melt.
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  • Tomoyoshi KAWADA, Masatoshi SUZUKI, Tomoyuki TAKEUCHI, Tomoo KUMABE, S ...
    1964 Volume 50 Issue 8 Pages 1182-1188
    Published: July 01, 1964
    Released: October 12, 2010
    JOURNALS FREE ACCESS
    Hot impact direct extrusions have been carried out to test the workability of steel with high strain rate and large deformation using the high energy rate metal-working machine, Dynapak.The strain rate was up to 3.6X 103 sec-1, and the extrusion ratios were from 4 to 25.The extrusion pressure and the relative displacement of punch and die were recorded by synchroscope.
    Results obtained are summarized as follows:
    (1) Impact energy E and extrusion length x0 are approximately proportional, i. e., E=S qxo, whers S is the cross-sectional area of container and q is the mean extrusion pressure.
    (2) Mean extrusion pressure is approximately proportional to the natural logarithm of extrusion ratio γ i. e., q =B ln γ.
    (3) Extrusion pressure q is proportional to the n-th power of extrusion velocity x, i. e., q=qo xn.
    (4) When the extrusion velocity becomes higher, there appear inertia forces of the form of 1/2 Spγx2 2 and S pγxx, where p is the density of materials.
    These behaviors are discussed in comparison with those in tension-compression test and hydraulic extrusion.
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  • Yoshinori FUJIMURA, Tomo-o SATO
    1964 Volume 50 Issue 8 Pages 1188-1195
    Published: July 01, 1964
    Released: October 12, 2010
    JOURNALS FREE ACCESS
    In the present study, the following points were revealed with regard to the quenching effects of several kinds of oil mixtures:
    (1) The relation between blending proportion and degree of quenching effect of the mixture composed with mineral oil and rape seed oil is like that of the mixture composed with fatty acid ester and fatty oil.Mineral oil in the former mixture will display a similar cooling action to that of fatty acid ester in the latter mixture.
    (2) The relation between blending proportion and degree of quenching effect of the mixture composed with mineral oil and fatty acid ester resembles that of the mixture composed with fatty oil and fatty acid ester.Mineral oil in the former mixture seems to play a similar cooling role to that of fatty oil in the latter mixture.
    (3) The mixtures composed with mineral oil and the blended oil give almost the same quenching effect as one composed with the latter only, in the case of the blended oil concentration being over 20% in volume.Therefore in these mixtures, cooling depends almost on the blended oil of rape seed oil and fatty acid ester, 50: 50.
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  • Masazo OKAMOTO, Omi MIYAKAWA, Takeshi NAITO, Toshiaki TSUJINO
    1964 Volume 50 Issue 8 Pages 1195-1203
    Published: July 01, 1964
    Released: October 12, 2010
    JOURNALS FREE ACCESS
    Studies have been made on the mode of the formation of a nitrogen-bearing austenite in 18%Cr-Ni-Fe alloys containing Ni up to 6% and Mo up to 3% by the authors' nitrogen-absorption method and on the stability of the formed austenite at the plastic working.Mechanical properties and corrosive resistivities of those alloys have also been investigated, the results obtained being as follows.
    (1) Austenite containing about 0.5%N is formed to a considerable depth in the surface zone of 18%Cr-Ni-Fe alloys by nitrogen-absorption at 1250°C for 32 hours.The depth of the nitrogen-bearing austenite zone from the surface increases with an increase in the Ni content of the alloys and with a longer time of nitrogen-absorption.By nitrogen-absorption treatment at 1250°C for 32 hours, the specimens having 4.0mm thickness and containing 2%or more of Ni without Mo have been found to turn completely austenitic to the core of the plate.
    (2) When the Ni content of the alloys is 2% or less, the nitrogen-bearing austenite decomposes into martensite on cooling to room temperature, while one bearing 3% or more of Ni is retained as austenite without being decomposed by water quenching from high temperatures. However, some part of the austenite of the alloy containing 4% Ni and free from Mo decomposes into martensite on subzero-cooling in the liquid-nitrogen bath.Nitrogen-bearing austenite containing 1% Mo and 4% Ni or more of 5% Ni is not decomposed into martensite even by the cooling to the temperature of liquid-nitrogen.
    (3) When the alloys containing 4% or more of Ni are rolled at room teperature, the nitrogen-bearing austenite is considerably hardened due to the martensitic transformation of a part of the austenite, while in the alloys containing 5 to 6% Ni and 1 to 3%Mo, the nitrogen-bearing austenite is not decomposed into martensite even by the 30% rolling at room temperature.
    (4) Tensile properties of the nitrogen-absorbed alloys containing 4% or more of Ni and up to 3% Mo are δB 95-84kg/mm2, δs 68-61kg/mm2, δ45-68%.To make the alloys stronger, it is adequate to cold roll the nitrogen-absorbed alloys by 30% at room temperature, the final tensile-properties of them being δB 115-135 kg/mm2, δs 113-128 kg/mm2 and 5 21-40%.
    (5) Corrosive resistivities of the alloys to the aqueous boiling solution of 5% H2SO4 or 1% HCl are improved markedly by the nitrogen-absorption treatment; especially those alloys are characterized by the strong resistivity against HCI solution.The corrosive resistivity to boiling HC1 solution of the nitrogen-absorbed alloys containing 1% Mo and 5% Ni is conspicuously superior to that of SUS 27 stainless steel water-quenched from 1050°C after held at this temperature for 30 minutes.
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  • Yasuo OTOGURO, Yoshikuni KAWABE, Ryuichi NAKAGAWA
    1964 Volume 50 Issue 8 Pages 1204-1209
    Published: July 01, 1964
    Released: October 12, 2010
    JOURNALS FREE ACCESS
    In the study of steels used in corrosive environment, the experimental values of corrosion tests are scattered over wide range, so it is very important to know the variation of the experimental results under various test conditions in order to compare the corrosion resistance of specimens.Studies were made on type 316 stainless steel in boiling 5% H2SO4 to examine the variation of experimental results and to analyse statistically the effects of surface conditions, solution-treatment temperature and cold rolling on the corrosion resistance. An investigation was also made on the effect of σ ferrite on the intercrystalline corrosion.
    The following results were obtained.
    i) The variation of the experimental results decreased and the corrosion resistance increased as the surface texture of the specimens became finer.
    ii) The loss in weight in boiling 5% H2SO4 was minimum in the specimen as solutiontreated at 1200°C.
    iii) The loss in weight increased remarkably with an increasing reduction ratio between 10 and 30% but it was almost invariable above 30%.
    iv) The variation of the experimental results in the test for two hours in boiling 5% H2SO4 was wider than that in the test for six hours.
    v) In Huey test, the steels used in this experiment were attacked over the whole surface. But σ ferrite seemed to have a favourable effect on the corrosion resistance to boiling 65% HNO3.
    vi) In all specimens, the electric resistance did not change after Strauss test.
    vii) In this experiment, any definite conclusion about the effect of σ ferrite on the intercry-stalline corrosion was not obtained.It is necessary to select the steel and to find the optimum testing method for investigation of the effect of σ ferrite on the intercrystalline corrosion.
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  • Shigehiro INOUE, Takashi TSUCHIYA, Yosuke MATSUMOTO
    1964 Volume 50 Issue 8 Pages 1210-1216
    Published: July 01, 1964
    Released: December 22, 2010
    JOURNALS FREE ACCESS
    To investigate the effect of alloying elements on the creep rupture strength of NA22H, stress-rupture tests were carried out at stresses of 1 and 0.6 kg/mm2 and a temperature of 1200°C on the specimens of varying C, W, Si, Cr and Ni contents respectively.And also the microstructural changes associated with varying the contents of alloying elements were investigated by optical microscopy and X-ray phase identification.
    The following results were obtained:
    (1) i) Addition of 0.4 to 0.65% C improved effectively creep rupture strength. ii) The strength increased with an increased W content up to c.a.3%, above which the strength remained nearly constant.iii) The maximum creep rupture strength was obtained by the addition of c. a. 1% Si. It is deduced that excellent creep properties are obtained in the practical working range of 0.8 to 1.5% Si.iv) The specimen containing 27% Cr and 48% Ni showed a higher creep rupture strength than the others of varying Cr and Ni contents.
    3) The elongation after rupture, especially at less stress, decreased with a rise in the amount of massive carbides.It is considered that the elongation depends to a considerable degree on the amount of massive carbides.
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  • Hiroshi SAWAMURA
    1964 Volume 50 Issue 8 Pages 1217-1220
    Published: July 01, 1964
    Released: October 12, 2010
    JOURNALS FREE ACCESS
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  • Kanichiro KATURA
    1964 Volume 50 Issue 8 Pages 1221-1228
    Published: July 01, 1964
    Released: October 12, 2010
    JOURNALS FREE ACCESS
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  • 1964 Volume 50 Issue 8 Pages 1229-1265
    Published: July 01, 1964
    Released: October 12, 2010
    JOURNALS FREE ACCESS
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  • 1964 Volume 50 Issue 8 Pages 1266-1269
    Published: July 01, 1964
    Released: December 22, 2010
    JOURNALS FREE ACCESS
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  • 1964 Volume 50 Issue 8 Pages 1270-1271
    Published: July 01, 1964
    Released: December 22, 2010
    JOURNALS FREE ACCESS
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  • 1964 Volume 50 Issue 8 Pages 1276-1278
    Published: July 01, 1964
    Released: December 22, 2010
    JOURNALS FREE ACCESS
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