Tetsu-to-Hagané
New Arrival Alert : OFF

You can use this feature after you logged into the site.
Please click the button below.

Log in / Sign up
ONLINE ISSN: 1883-2954
PRINT ISSN: 0021-1575

Tetsu-to-Hagané Vol. 62 (1976), No. 8

  • 新技術開発のアイデア

    pp. 951-952

    Bookmark

    You can use this feature after you logged into the site.
    Please click the button below.

    Log in / Sign Up
  • Effect of Raceway, Tuyere Diameter and Scab on Gas Flow in Blast Furnace

    pp. 953-961

    Bookmark

    You can use this feature after you logged into the site.
    Please click the button below.

    Log in / Sign Up
    Some mathematical methods had been presented for the investigation of two dimensional gas flow distribution in a packed column. These methods, however, were not enough to be applied to the gas flow analysis in blast furnaces yet. In this paper, a modification has been made on the calculation method of pressure distribution and a gas flow model has been developed for blast furnace with nonuniform distributions of void ratio, grain diameter and temperature.
    In addition, using both two dimensional experimental results and the mathematical gas flow model which corresponds to its experimental cold model, gas flow pattern and velocity profile around raceway are presented.
    Using the mathematical gas flow model, gas flow distribution in the blast furnace with different tuyere diameters or with scab on its wall is also qualitatively studied.
  • On the Circulation Flow Rate and the Desulphurization of Molten Pig Iron on the Gas-Lift Mixing Reactor Process Used for an External Desulphurization

    pp. 962-970

    Bookmark

    You can use this feature after you logged into the site.
    Please click the button below.

    Log in / Sign Up
    Measurements of the circulation flow rate of molten pig iron on the Gas-lift Mixing Reactor process (GMR process) were carried out and the relationship between the circulation flow rate and the desulphurization efficiency by the GMR process was examined. The results are summerized as follows;
    (1) The water model tests in industrial scale on measurement of the circulation flow rate were carried out and the circulation flow rate Vlm3/min can be represented by the equation
    at 5<vgvg°, Vl= { (-2.75Hd+6.35) √vg-15Hd-7} VP
    and
    at vg° ≤vg<210, Vl= (-10Hd+44) VP
    where vg: apparent gas velocity m/min, vg°: critical gas velocity m/min (= {-1.82+22.75/ (2.31-Hd) } 2), Hd: Lifting height m, VP: effective volume of the lifting tube of GMR m3 (=Hs. S), Hs: submerged depth m, and S: cross-sectional area of the lifting tube m2.
    (2) The results of the volume circulation flow rate of molten pig iron measured at the industrial test plant agree very well with these of water model test. The circulation flow rate of the 200 t commercial plant constructed at Kobe Steel's Kakogawa Works is about 100t/min.
    (3) The strong dependence is observed between the desulphurization efficiency and the circulation flow rate on the process.
  • The Mechanism and Removal of the Accumulation of Large Inclusions in the Sedimental Zone of Al-Killed Ingots

    pp. 971-980

    Bookmark

    You can use this feature after you logged into the site.
    Please click the button below.

    Log in / Sign Up
    The mechanism of the accumulation of large non-metallic inclusions in the bottom portion of 23 ton Al-killed ingots has been investigated by changing the superheat in the vicinity of the meniscus of the melt in the ingots during the early period of solidification. The change has been made by applying either slow-burning conventional exothermic or newly developed quick-igniting highly exothermic hot-topping powder under a favorable condition that downward convectional metal flow along the solidifying front is not influenced by the change of the superheating.
    With the conventional exothermic powder, marked development of the mushy-zone in the beginning of solidification is observed. The development is found to be due more than 70% to the showering of iron globulites from the vicinity of the meniscus, the balance to that from the solidifying fronts on the side walls. The showering of the globulites in cluster-like agglomerates is quantitatively shown to entrap floating large inclusions, pulling them down onto the mushy-zone.
    Application of the quick-igniting powder is shown to retard the initiation of the showering from the meniscus, allowing the inclusions to float up, hence resulting in virtually no accumulation of inclusions in the mushy-zone.
  • The Microstructural Change during High Temperature Aging in a 25%Cr-20%Ni Austenitic Steel Containing 0.41% Nitrogen

    pp. 981-990

    Bookmark

    You can use this feature after you logged into the site.
    Please click the button below.

    Log in / Sign Up
    The microstructural change in a 25% Cr-20% Ni 0.41% N steel during aging at 700°, 800° and 900°C for up to 10 000 hr was investigated through optical microscopy and measurements of lattice parameters of both austenitic matrix and precipitated nitrides.
    A dichromium nitride, Cr2N, precipitated both as a cellular precipitation and as a precipitation on grain boundaries. When nitrogen content in the austenitic matrix reached at certain lower concentration due to the precipitation of Cr2N after long aging, π. phase (a nitride with the structure of β-manganese type) began to precipitate. The rate of decrease in the lattice parameter of the austenitic matrix of the steel in the present investigation was an order of magnitude faster at earlier stages of aging (e. g. up to 100 hr at 800°C) than that of a 25% Cr-28% Ni-2% Mo-0.31% N steel where only a precipitation on grain boundaries was observed. This implies that the rate of nitrogen precipitation from the austenitic matrix is enhanced by the cellular precipitation. The lattice parameters, a and c, of precipitated Cr2N decreased with time of aging. A correlation of the decrease in the lattice parameter of the austenitic matrix with that in the lattice parameters of precipitated Cr2N was discussed.
  • Effects of Shape and Distribution of Retained Austenite on Toughness of Two Ni-Cr-Mo Steels Containing Medium Carbon

    pp. 991-999

    Bookmark

    You can use this feature after you logged into the site.
    Please click the button below.

    Log in / Sign Up
    A study has been made of effects of the shape and distribution of retained austenite on toughness of two Ni-Cr-Mo steels containing 0.4 and 0.6 per cent. Results obtained are as follows;
    (1) Retained austenite remained acicularly and lenticularly along martensite lath boundaries yielded desirable effects on toughness, but retained austenite remained massively along prior austenite grain boundaries did not necessarily yield desirable effects on toughness in the steel containing 0.4 per cent carbon.
    (2) Retained austenite remained lenticularly along martensite plate boundaries did not necessarily yield desirable effects on toughness, but retained austenite remained massively along prior austenite grain boundaries yielded desirable effects on toughness in the steel containing 0.6 per cent carbon.
    (3) In both steels, retained austenite was stable in the process of deformation.
    (4) From these results, it is assumed that toughness is closely associated with coherency between retained austenite and the matrix when retained austenite remains in the matrix containing a less twin martensite and toughness is closely associated with relaxation of stress concentration against internal defects in the matrix when it remains in the matrix containing more twin martensite.
    x

    Readers Who Read This Article Also Read

    1. Stress Corrosion Cracking of Low Carbon Steel in Methanol Solutions Tetsu-to-Hagané Vol.62(1976), No.8
  • Formation of {111} Recrystallization Textures in Polycrystalline Iron

    pp. 1000-1008

    Bookmark

    You can use this feature after you logged into the site.
    Please click the button below.

    Log in / Sign Up
    Since the remarkable development of {111} recrystallization textures in polycrystalline iron has not successfully been explained by the results obtained so far on single crystals, it was tried to clarify the original these textures by studying rolling and recrystallization textures of polycrystalline specimens having sharp initial textures and by observing their microstructures.
    It was found that interactions between differently oriented neighbouring grains during cold rolling were so anisotropic that non-random grain boundary nucleation of recrystallized grains could be expected.
    Furthermore, it was suggested that, if the stable end orientations of two neighbouring grains were common, their boundary regions might be forced during cold rolling to rotate in these orientations, so that stress and strain compatibilities could be satisfied concurrently, creating highly strained regions, which could provide recrystallization nuclei.
    Although such interactions are considered to occur among the members of <111>//ND fiber textures, whose common end orientation is {111} <110>, grain boundary regions of {111} <112> grains adjascent to {111} <110> suffer from the severest strain, rotating in {111} <110> orientation. These regions seem to be the origins of {111} <110> recrystallization textures typically found in Al-killed steel.
  • Effect of Solution Treatment Temperature on the Tensile Properties of 18%Ni Maraging Steels

    pp. 1009-1016

    Bookmark

    You can use this feature after you logged into the site.
    Please click the button below.

    Log in / Sign Up
    The effect of solution treatment temperature on the tensile properties of aged 210 kg/mm2 and 245 kg/mm2 grade 18% Ni maraging steels has been investigated.
    To obtain fine austenite grains, solution treatment is carried out after cold rolling. Temperatures of solution treatment are 750°, 775°, 820°, and 850°C. Time of solution treatment is 1 hr. The strength of the maraging steels is increased as the solution treatment temperature is lowered. An improvement of notch toughness is observed after aging the fine grained maraging steels. However, the notch trough ness of the 210 kg/mm2 grade maraging steel tends to decrease remarkably with the solution treatment at 775°or 750°C. A decrease in the notch toughness of the 245 kg/mm2 grade maraging steel is also observed in the solution treatment at 750°C. Because no undissolved precipitate remains even in the solution at 750°C for 1 hr, it is considered that the rapid decrease in notch toughness is related to the micro-segregation of solute atoms.
    The temperature range of the γ-to-αM transformation is lowered when the solution temperature is decreased. The lowering of the transformation temperature is considered to be caused by the micro-segregation of solute atoms and the strength increase in fine-grained austenite.
  • Brittle Fracture Initiation and Propagation-Arrest Characteristics in Ferritic-Pearlitic Steels

    pp. 1017-1024

    Bookmark

    You can use this feature after you logged into the site.
    Please click the button below.

    Log in / Sign Up
    The effects of the microstructure and alloying elements on the initiation and propagation-arrest properties of brittle fracture in ferritic-pearlitic steels have been investigated by means of COD (Crack Opening Displacement) and tapered DCB (Double Cantilever Beam) tests.
    It was observed that in both cases the temperature at which brittle fracture was initiated or arrested at a given toughness was linearly related to the square root inverse of the mean pearlite colony diameter.
    This implies that the pearlite colony which lay in the plastic zone in the vicinity of the fatigue crack tip or the propagating main crack tip was cleaved by the applied stress, and that the critical condition whether this pearlite crack cleaved the adjacent ferrite as a Griffith's flaw dominated the initiation or the propagation-arrest properties of the brittle fracture.
    The difference between the result of the static COD and that of the tapered DCB test might mainly exist in the strain rate, the strain rate at the tip of the advancing cleavage crack for the DCB test being much larger than that of the fatigue crack tip for the COD test.
    It was also confirmed that the addition of nickel greately improved the low temperature toughness for the tests with high strain rates.
  • Stress Corrosion Cracking of Low Carbon Steel in Methanol Solutions

    pp. 1025-1034

    Bookmark

    You can use this feature after you logged into the site.
    Please click the button below.

    Log in / Sign Up
    Steel drums made of low carbon hot rolled steel sheet (1.2mm thick) filled with a methanol solution of vinyl resin sustained cracking at the beaded regions of drums after two months storage in the summer season when drums were stacked on their sides. The cracks first initiated at the inside surface of drums and propagated intergranually toward the thickness direction. A constant strain test and constant strain rate test were carried out in methanol solutions of vinyl resin to clarify the causes of drum fracture.
    It was found that methanol and its derivatives together with the concentration of tensile stress at beads caused stress corrosion cracking of low carbon steel.
    The effect of impurities, formic acid, water, and formaldehyde in methanol on the stress corrosion susceptibility of low carbon steel sheet was investigated by the constant strain rate test. Bent specimens of low carbon steel showed high susceptibility to stress corrosion in methanol containing 0.01-0.02 wt% formic acid and 0.05-0.2 wt% water. In this case, over 1.0wt% water inhibited the stress corrosion whereas 0.05-0.2 wt% water worked as an accelerator; formaldehyde worked as an inhibitor in methanol.
    Effects of cathodic or anodic polarization and the test temperature on the time to failure were investigated, and it was confirmed that the cracking was active path corrosion and not hydrogen embrittlement.
    x

    Readers Who Read This Article Also Read

    1. Effects of Shape and Distribution of Retained Austenite on Toughness of Two Ni-Cr-Mo Steels Containing Medium Carbon Tetsu-to-Hagané Vol.62(1976), No.8
  • Ferric Oxide Produced by Spray Roasting of HCl Pickling Liquor

    pp. 1035-1044

    Bookmark

    You can use this feature after you logged into the site.
    Please click the button below.

    Log in / Sign Up
    Some physical and chemical properties of ferric oxide (a-Fe2O3, hematite) produced by spray roasting of HCl pickling liquor were examined in order to elucidate following subjects.
    (1) The effect of FeCl2 concentration in sprayed liquor and roasting temperature on mean particle size of fine hematite.
    (2) Forming process of hematite granules (agglomerated particles), thermal decomposition process from FeCl2 to iron oxide and dechlorination process of hematite.
    The results are summarized as follows:
    (1) The mean particle size of hematite is almost determined by FeCl2 concentration and roasting temperature.
    (2) The thermal decomposition of FeCl2 is an exothermal reaction. When the roasting temperature is below the melting point of FeCl2, the reaction product mainly consists of a-Fe2O3. At higher temperatures, the Fe3O4 content increases.
    (3) The weight change of hematite by firing in air coincides with the sum of the decrement of H2O and chlorides through desorption and decomposition and the increment of combined oxygen through oxidation of Fe (II) to Fe (III). The desorption of H2O and HCl on hematite is completed at about 250°C. Other chlorides in hematite are recognized as FeCl2 and FeCl3.
  • The Indirect Determination of Fluorine in Coating of Low Hydrogen Type of Arc Welding Electrode and Its Raw Materials by Separating Precipitated CeF3 and Flame Emission Spectrometry

    pp. 1045-1051

    Bookmark

    You can use this feature after you logged into the site.
    Please click the button below.

    Log in / Sign Up
    An indirect determination of F by flame emission spectrometry was studied. After a sample was fused with Na2CO3, F was precipitated as CeF3, and Ce in CeF3 which was separated by filtering was determined by flame emission spectrometry in a nitrous oxide-acetylene flame.
    The intensity of Ce in the concentration range of 0 to 1 200 ppm was measured at 520nm, and was increased by adding Sr.
    When the minimum of CH3COONH4 which was necessary to precipitate CeF3 rapidly was added to the solution, co-precipitated cerous acetate could be dissolved by washing with NH4NO3 solution when filtering the precipitate.
    The recovery of 5 mg or over F was 98-102%.
    This method was successfully applied to the determination of F in the coating of the low hydrogen type of electrode, fluorides of alkaline earth metals, and cryolite. The reproducibility (coefficient of variation) of the results was 1.46-3.48%.
  • Corrosion of Iron and Steels in Flue Gas

    pp. 1052-1065

    Bookmark

    You can use this feature after you logged into the site.
    Please click the button below.

    Log in / Sign Up
  • Report of the Section and Wire Rods Committee of the Joint Research Society of ISIJ

    pp. 1061-1071

    Bookmark

    You can use this feature after you logged into the site.
    Please click the button below.

    Log in / Sign Up
    [in Japanese]
  • Report of the Medium and Small Sections Subcommittee of the Section and Wire Rods Committee of Joint Research Society

    pp. 1071-1077

    Bookmark

    You can use this feature after you logged into the site.
    Please click the button below.

    Log in / Sign Up
  • Report of the Wire Rods Subcommittee of the Section and Wire Rods Committee of Joint Research Society

    pp. 1077-1083

    Bookmark

    You can use this feature after you logged into the site.
    Please click the button below.

    Log in / Sign Up
  • 抄録

    pp. 1084-1093

    Bookmark

    You can use this feature after you logged into the site.
    Please click the button below.

    Log in / Sign Up
  • Report of the Large Sections Subcommittee of the Section and Wire Rods Committee of Joint Research Society

    pp. 1061a-1071

    Bookmark

    You can use this feature after you logged into the site.
    Please click the button below.

    Log in / Sign Up

Article Access Ranking

16 Jan. (Last 30 Days)

  1. A Review of the Chemistry, Structure and Formation Conditions of Silico-Ferrite of Calcium and Aluminum (‘SFCA’) Phases ISIJ International Vol.58(2018), No.12
  2. Improving Blast Furnace Raceway Blockage Detection. Part 1: Classification of Blockage Events and Processing Framework ISIJ International Advance Publication
  3. Phase Transformation Behavior of Oxide Scale on Plain Carbon Steel Containing 0.4 wt.% Cr during Continuous Cooling ISIJ International Vol.58(2018), No.12
  4. Hydrogen Embrittlement Susceptibility Evaluation of Tempered Martensitic Steels Showing Different Fracture Surface Morphologies Tetsu-to-Hagané Vol.105(2019), No.1
  5. Improvement of Sinter Productivity by Control of Magnetite Ore Segregation in Sintering Bed ISIJ International Vol.58(2018), No.12
  6. Gasification and Migration of Phosphorus from High-phosphorus Iron Ore during Carbothermal Reduction ISIJ International Vol.58(2018), No.12
  7. Effect of TiO2 and MnO on Viscosity of Blast Furnace Slag and Thermodynamic Analysis ISIJ International Vol.58(2018), No.12
  8. Effect of Coke Size on Reducing Agent Ratio (RAR) in Blast Furnace ISIJ International Vol.58(2018), No.12
  9. High Temperature Thermal Diffusivity Measurement for FeO Scale by Electrical-Optical Hybrid Pulse-Heating Method ISIJ International Vol.58(2018), No.12
  10. Improving Blast Furnace Raceway Blockage Detection. Part 3: Visual Detection Based on Tuyere Camera Images ISIJ International Advance Publication

Search Phrase Ranking

16 Jan. (Last 30 Days)

  1. blast furnace
  2. blast furnace permeability
  3. blast furnace productivity
  4. 鉄と鋼
  5. continous annealing
  6. laser welder
  7. titanium
  8. a
  9. activity feo
  10. argon steel