Tetsu-to-Hagane
Online ISSN : 1883-2954
Print ISSN : 0021-1575
ISSN-L : 0021-1575
Volume 46 , Issue 9
Showing 1-15 articles out of 15 articles from the selected issue
  • [in Japanese]
    1960 Volume 46 Issue 9 Pages 953-954
    Published: August 01, 1960
    Released: February 22, 2010
    JOURNALS FREE ACCESS
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  • Keiji Tsujiahta, Koretaka Kodama, Noboru Tsuboi, Kôgo Katô ...
    1960 Volume 46 Issue 9 Pages 955-961
    Published: August 01, 1960
    Released: February 22, 2010
    JOURNALS FREE ACCESS
    At the end of June 1958, pure oxygen was, for the first time, successfully injected into the hot blast pipe of Higashida No. 5 blast furnace. In summer 1959 the furnace was run again with oxygen-enriched blast, and the operating data were analysed. The results then obtained were briefly reviewed in this paper.
    The test run was started on May 26th 1956 and was terminated on July 11th. In the coures of the test period, O2-content, as well as humidity, of blast was increased step by step; iron production increased correspondingly, untill, at the beginning of July, the furnace, with its volume of 646m3, produced a maximum of 805 t/d.
    (Production rate: 1·25t/m3/d., “throughgut” rate: 16·7t/mm2/d)
    The coke rate, ranging between 600 and 630 kg/t, was not affected by an O2-enrichment of blast, nor by a strong humidification.
    It was found that the increased iron production could be preliminarily calculated on the basis of a stoichiometric equation. The following equation was given for the calculation, which showed that 1% of O2-enrichrnent was equivalent to an increase in blast rate of 4·76%.
    Where; P: Praductio……t/d
    L: Blast valume……Nm3/mn
    S: O2 flow-rate……Nm3/mn
    w: Humidity of blast……g/m3
    K1: A constant characteristic of the furnace
    C. R. : Coke rate……t/t
    A set of material balances and heat balances was worked out. They were compared with each other, and the following conclusions were drawn: (1) O2-enrichment and humidification of blast decreased solution losses and correspondingly increased the calorific value of coke in the furnace. (2) Decrease in the sensible heat of blast, which was due to decreased volume of N2, could well be compensated by the corresponding decrease in the heat carried out by top gas. (3) When blast was strongly humidified (e. g. 40g/m3), major fraction of H2, which was evolved at tuyere-combustion-zones, could be effectively used to reduce the iron ores charged. (4) The volumes of blast, bosh gas and top gas per ton of pig iron were proportionately decreased by O2-enrichment.
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  • Masazo Okamoto, Ryohei Tanaka, Rokuro Ito
    1960 Volume 46 Issue 9 Pages 961-967
    Published: August 01, 1960
    Released: February 22, 2010
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    The effect of various alloying elements such as Si, Ni, Mn, Cr, Mo in copper-bearing low carbon steels on the age hardening phenomena was investigated and discussed. The results obtained were as follows:
    (1) Only a hardening due to the C precipitation from ferrite was found to take place with the steels solution-quenched from 680°C. after the usual annealing, and the hardening due to the Cu precipitation was not observed to occur except with the steel containing Mo.
    (2) With the steels furnace-cooled from 930°C. to 680°C. by 13·3°C. /mn. and subsequently quenched from the latter temperature, both of these precipitation hardenings were found to occur, the quenched state being supersaturated with copper as well as with carbon. The hardening caused by the C precipitation was found at the range from room temperature to 100°C., and the hardening by the Cu precipitation was found at above 350°C. In the stage of the C precipitation, the carbide-forming elements such as Mn, Cr, Mo retarded the hardening and reduced the maximum hardness. While, in the stage of the Cu precipitation, only Mo retarded the hardening and increased the hardness.
    (3) With the steels water-quenched directly from 930°C., as a whole, the hardening due to the Cu precipitation was not clearly found, because of the increased resistance to softening on tempering by addition of the alloying elements. With the steels oil-quenched directly from 930°C., nearly the same precipitation hardening behavior was observed as that described in (2), except with one containing Mo, in which especially high hardness due to the Cu precipitation was attained.
    (4) With the cold worked steels super-saturated with Cu, the recrystallization softening was found to be superposed with the precipitation hardening, and the softening temperature was raised by the Cu precipitation and the existence of carbide-forming elements, particularly of Mo.
    (5) It was also certified that the addition of Ni reduced the red-shortness of the steel containing Cu.
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  • Morio Nakajima
    1960 Volume 46 Issue 9 Pages 967-972
    Published: August 01, 1960
    Released: February 22, 2010
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    High temperature bending tests and high temperature tensile tests of the mild steels in contact with various liquid Cu-Pb alloys were examined, and the dihedral angles of γ iron/ Cu-Pb liquids in equilibrium condition at high temperature were measured.
    As copper percentage in the liquid Cu-Pb alloys increased, the steels in contact with the liquid alloys became more brittle, that is, the surface cracking of the steels by high temperature bending became severe, and tensile strength & elongation of the steels in high-temperature tensile tests decreased. The dihedral angles of γ iron/liquid fell down to 20°C. These relation was investigated. And the fracture streses estimated roughly from dihedral angles were compared with the stresses obtained from tensile tests.
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  • Shizuya Maekawa, Yoshitaka Nakagawa
    1960 Volume 46 Issue 9 Pages 972-976
    Published: August 01, 1960
    Released: February 22, 2010
    JOURNALS FREE ACCESS
    The solubilities of nitrogen in liquid Fe-Ni, Fe-Co, Fe-Mo, Fe-Cr, and Fe-V alloys were measured at 1600-1750°C under 760mmHg pressure by the same method as in the report-I (ib., Tetsu-to-Hagané, Vol. 46 (1960), 748).
    The results obtained were as follows;
    (1) The solubility of nitrogen in the liquid iron was decreased with increasing nickel and cobalt content. But the solubility was increased with increasing molybdenum, chromium and vanadium content.
    (2) The effect of alloying elements on the activity coefficient of nitrogen in liquid iron was summarized as follows:
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  • Kozo Seto
    1960 Volume 46 Issue 9 Pages 976-981
    Published: August 01, 1960
    Released: February 22, 2010
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    As the fundamental concept to get the uniform martensite that was effective to the life of ball bearing, the author considered the behavior of cementite during various heat-treatment processes to arrive at the spherodizing annealed structure on the manufacturing process.
    The primary-eutectoid net-work cementite was sharp and the Cr content in it decreased with the rise of cooling velocity. The diffusion constant was more important factor than the affinity of Cr for C.
    When the specimen, of which the matrix was fine sorbitic pearlite, was heated at a temperature between A1 and Acm transformation point, the non-dissolved cementite changed as follows. At the side of higher temperature of the range it was coarser somewhat and Cr% in it decreased with the rise of temperature and holding time. At the other side Cr% was increased with the holding time. The former the diffusion constant of cementite was effective, the latter the affinity of constructive elements in it.
    In case of the specimen with globular cementite was heated at the same temperature, Cr content in the non-dissolved cementite was increased with the temperature, because the cementite with the poor Cr content was dissolved more rapidly.
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  • Ryuichi Nakagawa, Yasuo Otoguro
    1960 Volume 46 Issue 9 Pages 982-987
    Published: August 01, 1960
    Released: February 22, 2010
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    In the study of materials served at high temperature, the experimental value in creep test and creep rupture test spread in wide range, so it was very important to consider the deviation of the experimental result in engineering for constructions and installations used at elevated temperature.
    With 18Cr-8Ni stainless steel, studies mere made with deviation of creep rupture properties such as creep rupture time, elongation and creep rate under stress of 10, 13kg/mm2 at 650°C, and the effect of quenching temperature on creep rupture strength, and size effect of test piece.
    The followieg results were obtained:
    i) Both creep rupture time and elongation were decreased with increasing quenching temperature, but were almost invariable at above 1100°C.
    It seemed that these phenomena were due to precipitation of Cr23C6 on grain boundaries.
    ii) Compared to the results in short time testing, the deviation of creep rupture time was smaller and those of elongation and creep rate were larger in long time testing.
    iii) Size effect was not recognized between test pieces with 6 and 8mm in dia., however in the results obtained from test piece with 10mm in dia., the deviation or the mean was larger than that in test pieces with 6mm in dia.
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  • Kozo Momoki, Shizo Hirano, Takeji Koizumi, Fumio Sawai
    1960 Volume 46 Issue 9 Pages 988-994
    Published: August 01, 1960
    Released: February 22, 2010
    JOURNALS FREE ACCESS
    Fluorescent X-ray spectrometry was successfully applied to the determination of alloying elements in special steels, including super-heat-resistant alloys, as follows:
    Tungsten, 2 to 19% in high speed steel, 3 to 5% in super-heat-resistant alloy, and 2 to 9% a in a low-alloy steel, were determined with standard deviation of 0·34%, 0·16%, 0·083% tungsten, respectively. Molybdenum, 1 to 8% in high speed steel, 3 to 5% in super-heatresistant alloy, and 0·2 to 0·7% in low-alloy steel, was determined with standard deviation of 0·15%, 0·11%, 0·018% molybdenum, each. Cobalt, 2 to 12% in high speed steel, was determined with standard deviation of 0·15% cobalt. Vanadium, 1 to 5% in high speed steel, was determined with standard deviation of 0·053% vanadium. Nickel, 7 to 14% in stainless steel, 18 to 22 in super-heat-resistant alloy, and 0·2 to 3% in low-alloy steel, was determined with standard deviation of 0·074%, 0·096%, 0·056% nickel, respectively. Chromium, 13 to 22% in stainless steel, 18 to 22% in super-heat-resistant alloy, and 0·2 to 5% in low-alloy steel, was determined with standard deviation of 0·081%, 0·087%, 0·056% chromium, each. Niobium, 0·5 to 5% in super-heat-resistant alloy, was determined with standard deviation of 0·060% niobium.
    The method was found to be very simple, rapid, and accurate, enough to be applicable for a routine analysis of these alloying elements in many types of special steel samples.
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  • 1960 Volume 46 Issue 9 Pages 994
    Published: 1960
    Released: February 22, 2010
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  • Morito Nakazawa
    1960 Volume 46 Issue 9 Pages 995-1009
    Published: August 01, 1960
    Released: February 22, 2010
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  • Tsuguo Miné
    1960 Volume 46 Issue 9 Pages 1010-1023
    Published: August 01, 1960
    Released: February 22, 2010
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  • Makoto Mizuno
    1960 Volume 46 Issue 9 Pages 1024-1035
    Published: August 01, 1960
    Released: February 22, 2010
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  • [in Japanese], [in Japanese], [in Japanese], [in Japanese], [in Japane ...
    1960 Volume 46 Issue 9 Pages 1036-1038
    Published: August 01, 1960
    Released: February 22, 2010
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  • 1960 Volume 46 Issue 9 Pages 1039-1040
    Published: August 01, 1960
    Released: February 22, 2010
    JOURNALS FREE ACCESS
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  • 1960 Volume 46 Issue 9 Pages 1043-1044
    Published: August 01, 1960
    Released: February 22, 2010
    JOURNALS FREE ACCESS
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