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. 72 (1986), No. 2

  • The Application of Induction Heating to Iron and Steel Industry

    pp. 173-181

    Bookmark

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

    Log in / Sign Up
  • Physical Chemistry of Hydrogen Storage Alloys

    pp. 182-188

    Bookmark

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

    Log in / Sign Up
  • Fundamental Study on Thermal Degradation of Coke During Rapid Heating

    pp. 189-194

    Bookmark

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

    Log in / Sign Up
    The thermal degradation behavior of coke in the blast furnace is investigated by experiments with rapid heating and model analysis considering the intraparticle temperature and stress distributions.
    It is presumed that the thermal stress is closely related to the expansion and contraction of coke during heating and there exist two types of crack in coke in the blast furnace. One is breakage with exfoliating spherical husk and the other is split from surface to inside.
  • Investigation of Coke Degradation Behavior in Blast Furnace

    pp. 195-202

    Bookmark

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

    Log in / Sign Up
    In order to establish the evaluation method of coke quality in the blast furnace, it is important to investigate the coke degradation behavior in the furnace.
    From this point, the sampling of coke was done during the shut-down at three levels-lower shaft, bosh and tuyere. The degradation behavior of coke and the mutual correlation between the coke properties and operational conditions were investigated. From the operational results of the blast furnace, the degradation behavior of coke at the lower part of the blast furnace and the relation between the blast conditions and degradation degree of coke were discussed.
  • Investigation of Sinter Degradation in Blast Furnace Using the In Situ Reaction Vertical Probe

    pp. 203-209

    Bookmark

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

    Log in / Sign Up
    In situ Reaction Vertical Probe which is able to estimate the both effects of mechanical force and reducibility in the blast furnace has developed.
    Several types of sinter with different RDI were charged into an operating blast furnace. After the recovery of the sinter, degradation was observed.
    It was ascertained from the investigation that as the RDI value of the sinter increased, its in-furnace degradation ratio became higher, and that the RDI value was almost equal to the degradation ratio when the sinter was kept in a low temperature reserve zone (about 60 minutes in this test).
  • Prediction of Remaining Life of the Steel Shell of a Blast Furnace

    pp. 210-217

    Bookmark

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

    Log in / Sign Up
    Thermal fatigue life evaluation is conducted for the steel shell of a blast furnace where hot spots have occurred repeatedly. Thermal elasto-plastic FEM analysis is used and, as a method of thermal fatigue life evaluation, the strain-range partitioning creep-fatigue analysis is adopted. It is proved to be possible to predict the remaining life of the steel shell successfully based on the following results:
    (1) It is the center of a hot spot on the inner surface of the steel shell that undergoes the largest cyclic deformation during a cycle of a hot spot.
    (2) Thermal fatigue damages, which are accumulated by repetition of hot spots, consist of those resulted from both the plastic strain range and the ratchetting strain.
    (3) A higher hot-spot temperature, a thicker steel shell and a larger hot-spot diameter reduce thermal fatigue life of the steel shell.
    (4) Total value of thermal fatigue damages at the notched part of the steel shell can be detected by measuring the increase in shell thickness of its smooth part independent of a hot-spot temperature.
  • Equilibrium between Molten Iron and Al2O3-SiO2 Oxides

    pp. 218-224

    Bookmark

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

    Log in / Sign Up
    Experimental study and thermodynamic consideration studies have been conducted on the equilibrium relationships in Fe-Al-Si-O system. The quantitative relations between the compositions of molten iron alloys and the oxide phases were determined experimentally. The equilibrium constants for the deoxidation by silicon and aluminum and for the formation of mullite (3Al2O3· 2SiO2) from its constituent oxides were determined.
  • Phosphorus Distribution between Molten Iron and Slags of the System CaO-MgO-FetO-SiO2

    pp. 225-232

    Bookmark

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

    Log in / Sign Up
    Experiments were made to obtain phosphorus distribution ratio between molten iron and CaO-MgO-FetO-SiO2 slag in a magnesia crucible at the temperatures of 1550°C and 1600°C. The results showed that the phosphorus transfer between iron and slag was so fast that the phosphorus equilibrium was maintained with the dissolution of magnesia from the crucible into the slag. The equations for phosphorus partitions obtained in this study are as follows.
    log[(%P2O5)/[%P]2·(%FetO)5]=0.143[%CaO)+0.55(%MgO)]+13980/T+16.08
    log[(%P)/[%P]·(%T.Fe)5/2]=0.065[%CaO)+0.55(%MgO)]+12230/T-10.08
    These equations could be applied to CaO-MgO-FetO-SiO2 slags which were not saturated with magnesia as well as those saturated. The variation of the activity coefficients of FetO and P2O5 with the theoretical optical basicity of slags was also discussed.
  • On the Toughness of Boron Treated Cr-Mo Steels Tempered at High Temperature

    pp. 233-240

    Bookmark

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

    Log in / Sign Up
    Boron treatment for Cr-Mo steels has been performed to obtain the higher strength with heavy thickness. But in these steels, even under the quenched microstructure, microalloying elements affect the toughness on tempering treatment at high temperature. So, the effect of Ti, B and N on the toughness and microstructures has been investigated in B-treated Cr-Mo steels tempered at high temperature. The results are as follows:
    (1) In the case of Ti/N ≥ 3.42, the excess dissolved B ([B]) causes the precipitation of coarse M23(C, B)6 type boro-carbides and the formation of denuded zone along grain boundaries on tempering treatment at the temperatures higher than 600°C, and therefore the toughness decreases. But proper [B] causes no coarse boro-carbides precipitates along grain boundaries.
    (2) In the case of Ti/N<3.42, the precipitation of BN occurs after hot rolling. However such non-equilibrium BN precipitates partially transform to AIN at the austenitizing treatment and [B] occurs. If [B] content is excess, then M23(C, B)6 precipitates and coagulates on grain boundaries during tempering treatment at high temperature, and consequently the toughness decreases. If [B] content is proper, then microstructures are fine and BN precipitates take no effect on the toughness.
  • Low Temperature Toughness of 6%Mn Steels

    pp. 241-248

    Bookmark

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

    Log in / Sign Up
    Fe-Mn alloys have similar microstructure to Fe-Ni alloys in iron rich region, therefore they have promising potential as structural materials at cryogenic temperatures. Fe-Mn alloys, however, lose their toughness by catastrophic intergranular failure when tested at low temperatures. This is attributed to the segregation of impurities to grain boundaries. The segregation can take place at higher temperatures than 600°C, in both austenite(γ) and two phase(χ+γ) region.
    An addition of molybdenum has been found to be effective in reducing the segregation of phosphorus in the two phase region and enhances toughness. However, no perceivable difference was observed in the segregation in the γ field.
    Double temper has been also identified as a beneficial treatment for improving toughness, which promoted the reversion of austenite along grain boundaries and reduced the susceptibility to intergranular failure.
    As a result it was shown that fairly good toughness could be achieved in Fe-6Mn-0.2Mo-0.05C alloy with QLT(800°C/1h/W.Q./700°C/1h/W.Q./600°C/1h.W.Q.) treatment.
  • Effects of Ti and Si on Precipitation Behavior of Martensitic Stainless Steel

    pp. 249-256

    Bookmark

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

    Log in / Sign Up
    The effects of Si and Ti on the precipitation behavior of 14Cr-7Ni martensitic stainless steels during aging treatment have been investigated. Precipitates are examined by transmission electron microscopy, X-ray diffraction analysis and so on.
    In the steels containing Ti only, the shape of precipitates in the matrix changes from fine particles to rodshaped as the aging stage proceeded from peak hardness to over-aging. The precipitates are iderntified as Ni3Ti, η phase. At an early stage of aging, predominant precipitations take place at grain boundaries.
    On the other hand, in the steels containing Si and Ti in combination, fine spherical precipitates are formed uniformly in the matrix. They are identified as Ni16Ti6Si7(G-phase) and coherent to the matrix. It is suggested that the coherent strain induced by the precipitates hardens the steel remarkably.
  • Detection of Hydrogen in a Steel at Elevated Temperatures by an Electrochemical Method

    pp. 257-263

    Bookmark

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

    Log in / Sign Up
    An electrochemical permeation method using molten sodium hydroxide is presented to detect hydrogen in a steel at elevated temperatures (673-773 K) in the range of practical interest for hydrogen attack.
    The results are as follows:
    (1) The most suitable potential range to detect hydrogen is from -0.8 to -0.6 V vs Air/O2- (ZrO2).
    (2) The experimental permeation curves for specimens with thickness above 4 mm agree fairly well with the theoretical ones.
    (3) Diffusivities of hydrogen in the steel 6.5 mm thick in this study are in good agreement with the values obtained from a usual gaseous method.
    (4) The detection limit of hydrogen content in the steel in this study is less than 0.1 ppm.
    (5) Therefore, this electrochemical method will be useful to predict the hydrogen attack of steels.
  • State Analysis of M2C in Cr-Mo Steel by Controlled-potential Secondary Electrolysis Method by use of Porous-graphite Electrode

    pp. 264-270

    Bookmark

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

    Log in / Sign Up
    Based on the studies of electrochemical stability of Mo carbides, a new method for state analysis of M2C in Cr-Mo steel was established. By use of this method, the precipitation behavior of carbides during creep rupture test was examined.
    Results obtained are as follows:
    1) M2C in Cr-Mo steel was electrochemically less stable than carbides of M3C, M7C3 and M23C6, but almost as stable as M6C. The electrochemical stability of carbides in Cr-Mo steel is in the following order M2C≅M6C<M3C<M7C3≅M23C6.
    2) M2C can be selectively decomposed by the secondary electrolysis of primary electrolytic residues, prepared in the porous-graphite electrode, at the anode potential of +0.65 V vs. SCE in 4% methyl salicylate-1% salicylic acid-2% LiCl-methanol. M6C is also decomposed at the same condition.
    3) The amount of M2C can be determined by the dissolved amount of Mo after the secondary electrolysis. When M6C is present in primary electrolytic residues, the amount of M2C is calculated by subtracting the amount of Mo as M6C, amount of which is calculated from the dissolved amount of Fe (Fe as M6C) after the secondary electrolysis, from the dissolved amount of Mo by the same treatment.
    4) The amount of M2C precipitated during the creep rupture test is found to roughly correspond to the change in the master rupture strength of the specimens. The creep rupture strength is increased with increasing the precipitation amount of M2C in these specimens.
  • High-Temperature Deformation Characteristics of Titanium

    pp. 271-275

    Bookmark

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

    Log in / Sign Up
  • The Effect of Volume Fractions of α and β Phases in Ti-Al-V Alloys on the Superplastic Behavior

    pp. 276-283

    Bookmark

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

    Log in / Sign Up
    The effect of volume fractions of α and β phases on the superplasticity was investigated for the five Ti--Al-V alloys, of which chemical compositions being on the tie line including the Ti-6Al-4V at 900°C. The testing temperature was 900°C and the initial strain rate range was from 6.67 × 10-5 to 2.50 × 10-2/s.
    In spite of wide distribution of the volume fraction of the α phase in the alloys, all showed a good superplasticity under certain strain rate conditions. The superplastic elongation became the maximum at about equal volume fractions of α and phases, and decreased with deviation from that fraction. The initial average grain size of the alloys was dependent on the volume fraction ratio of the phases and found to become the minimum at equal volume fractions.
    At a strain rate of 6.67 × 10-4/s, the average grain size of alloys after fracture was independent of the initial average grain size and the volume fraction ratio of the phases of the alloys. The average grain size after fracture was 8 μm. At the same strain rate, the strain induced grain growth rate of alloys increased with decreasing initial average grain size.
  • The Effect of β-stabilizer Content on Tensile Properties of α-β Titanium Alloys

    pp. 284-291

    Bookmark

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

    Log in / Sign Up
    Effects of β-stabilizer content in β phase at solution treatment temperature on microstructures after quenching from solution temperature. aging characteristics, and tensile properties were investigated by using 9 α-β titanium alloys(Ti-Al-V-Sn-Zr-Mo-Cr-Fe system). The main results obtained are as follows:
    (1) Partitioning of each element to α and β phases at solution treatment temperature could be well estimated from each Ti-j (j=Al, V, etc.) binary phase diagram.
    (2) Phase stability of β phase was considered to relate well with electron-atom ratio(e/aβ). Phase transformations in the alloys during quenching could be classified by e/aβ. From changes of electrical resistivity during heating, it was considered that athermal and isothermal ω phase were formed in the alloys GT-33, 45, and 46(e/aβ=4.06-4.16).
    (3) Effects of microstructural and compositional factors Volume fraction(Vα), grain diameter(dα), and degree of solid-solution strengthening(dDEα) for primary α phase, e/aβ for prior β phase, and aging temperature(Tag) on tensile properties at 300°C were examined by using multiple regression analysis. Following regerssion equations were obtained.
    σu(kgf/mm2)=207.72-318.29Vα+119.43Vα·dDEα+178(1-Vα)·(e/aβ-4)-19(1-VαTag/100
    El.(%)=-19.86-39.28Vα+13.08dDEα+2.95Tag/100
  • Repassivation Method to Determine Critical Conditions in terms of Electrode Potential, Temperature and NaCl Concentration to Predict Crevice Corrosion Resistance of C. P. Titanium in NaCl Solutions

    pp. 292-299

    Bookmark

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

    Log in / Sign Up
    A concept of repassivation potential, ER, for crevice corrosion had been developed for stainless steels. Applicability of the ER concept to C. P. Ti was confirmed through the corrosion test in 25% NaCl solution at 100°C. ER for growing crevice with penetration depth deeper than a critical depth, h* (≅12 μm), was found to be a well reproducible electrochemical parameter which coincides with the critical potential, VCREV, below which the growing crevice does not initiate.
    The repassivation method was also applied to determine critical conditions in terms of NaCl concentration and temperature for crevice corrosion of specimens kept at -0.2V, SCE which was more noble than ER and was included in the spontaneous potential range of passivated Ti in deaerated NaCl solutions measured previously. Crevice corrosion which had been initiated in 25% NaCl solution at 100°C continued to grow in successively diluted NaCl solutions not lower than 0.75% in NaCl concentration and to grow at successively lowered temperatures not lower than 50, 70, and 90°C in 25, 3, and 1% NaC1 solutions, respectively. Critical conditions in terms of temperature and NaCl concentration determined as above were confirmed to agree with the reported results obtained by immersion tests for crevice corrosion resistance of C. P. Ti.
  • Improvement of Corrosion Resistance of Titanium by Anodizing, Thermal Oxidation and PdO/TiO2 Coating

    pp. 300-307

    Bookmark

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

    Log in / Sign Up
    It has already been made clear that corrosion resistance of titanium is improved by change of passive film composition from TiO and Ti2O3 to TiO2. Therefore, in this paper, the effect of TiO2 coating on corrosion resistance of titanium was investigated Anodized, thermally oxidized and PdO/TiO2 coated titanium specimens were used. Anodized titanium showed the same corrosion resistance as polished titanium did. This is due to the fact that anodized film was consisted of hydrated TiO2 which dissolved in an HCl solution for short time. Corrosion resistance of titanium was significantly improved by thermally oxidation because of formation of TiO2 which was stable even in a highly acidic solution. PdO/TiO2 coated titanium showed an excellent corrosion resistance in HCl solutions. Moreover, crevive corrosion was suppressed by the coating. Many cracks were observed in PdO/TiO2 films and titanium substrate was exposed at the crack. However, titanium substrate is polarized anodically to passive potential region by PdO/TiO2 film because the coating film has high corrosion potential. This is a reason why PdO/TiO2 coated titanuim shows an excellent corrosion resistance.
  • Hydrogen Absorption of Commercially Pure Titanium in the Solution System NaCl-HCl

    pp. 308-313

    Bookmark

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

    Log in / Sign Up
    Hydrogen absorption behavior of commercially pure titanium in the solution system NaCl-HCl has been studied in relation to corrosion by means of Glow Discharge Spectroscopy (GDS).
    Results obtained are as follows.
    (1) The hydrogen absorption layer on titanium formed by corrosion can be analyzed by means of GDS.
    (2) When the passive film on titanium begins to break down in NaCl-HCl, hydrogen absorption can occur.
    (3) The rate of hydrogen absorption is parabolic, indicating that hydrogen diffusion through the hydrogen absorption layer is rate controlling. The diffusion coefficient of hydrogen in titanium is 2.75-3.68 × 10-12 cm2/s.
    (4) X-ray diffraction patterns of the surface of hydrogen absorption layer show the presence of TiH2.
  • Texture of Titanium

    pp. 314-320

    Bookmark

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

    Log in / Sign Up
  • Deformation Resistance and Recrystallization of Commercially Pure Titanium in the High Strain Rate Hot Deformation

    pp. 321-328

    Bookmark

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

    Log in / Sign Up
    In this paper, the deformation resistance and recrystallization behavior in high temperature working (600-850°C) with high strain rates (2-150 l/s) which covers the most hot rolling conditions have been investigated.
    In the usual hot rolling condition the dynamic recrystallization does not occur and the resistance to hot deformation is determined by the balance between strain hardening and dynamic recovery. The flow stress sharply increases with increase in the impurity content at higher purity condition while the hardening rate due to the increase in the impurity content becomes smaller if the range exceeds a certain value. The recrystallization and grain growth behavior of commercially pure titanium is similar to that of plain carbon steels in austenite phase. In commercially pure titanium deformation bands, which act as nucleation site for recrystallization, are more easily formed than in plain carbon steels.
    The activation energy for hot deformation and recrystallization lies in a range between 220-260 kJ/ mol which is nearly the same for low strain rate deformation.
    x

    Readers Who Read This Article Also Read

    1. Superplastic Behaviour of Powder-Consolidated and Rolled Mod.IN-100 Sheet Tetsu-to-Hagané Vol.72(1986), No.10
    2. 21世紀の頭脳労働の坦手 Tetsu-to-Hagané Vol.71(1985), No.7
    3. Strength and Toughness of 9Ni-Cr Steels in the Temperature Range from 77 to 4.2K Tetsu-to-Hagané Vol.72(1986), No.10
  • 新しい経営戦略「CI」/プレートテクトニクスと海底鉱床の誕生/良い英文を書くために-論文を英語で書くこつ(2)

    pp. 329-341

    Bookmark

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

    Log in / Sign Up
  • 分析雑感

    pp. 332-332

    Bookmark

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

    Log in / Sign Up
  • 抄録

    pp. 344-345

    Bookmark

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

    Log in / Sign Up

Article Access Ranking

20 Jul. (Last 30 Days)

  1. Production and Technology of Iron and Steel in Japan during 2018 ISIJ International Vol.59(2019), No.6
  2. Perspective toward Long-term Global Goal for Carbon Dioxide Mitigation in Steel Industry Tetsu-to-Hagané Vol.105(2019), No.6
  3. Preface to the Special Issue “Fundamentals and Application Technologies for High-performance Hot-dip Galvanized Coatings” Tetsu-to-Hagané Vol.105(2019), No.7
  4. Influence of Annealing Temperature and Dew Point on Kinetics of Mn External Oxidation Tetsu-to-Hagané Vol.105(2019), No.7
  5. Microstructure and Phase of Carbon Brick and Protective Layer of a 2800 m3 Industrial Blast Furnace Hearth ISIJ International Advance Publication
  6. Insights into Accumulation Behavior of Harmful Elements in Cohesive Zone with Reference to Its Influence on Coke ISIJ International Advance Publication
  7. Recycling of Blast Furnace Sludge to the Blast Furnace via Cold-Bonded Briquettes: Evaluation of Feasibility and Influence on Operation ISIJ International Advance Publication
  8. Understanding the Structure and Structural Effects on the Properties of Blast Furnace Slag (BFS) ISIJ International Vol.59(2019), No.7
  9. Properties-to-microstructure-to-processing Inverse Analysis for Steels via Machine Learning ISIJ International Advance Publication
  10. Quantitative Analyses of Chemical Structural Change and Gas Generation Profile of Coal upon Heating toward Gaining New Insights for Coal Pyrolysis Chemistry ISIJ International Advance Publication

Search Phrase Ranking

20 Jul. (Last 30 Days)

  1. blast furnace
  2. blast furnace productivity
  3. 龍角散
  4. chinese academy of science
  5. blast furnace permeability
  6. continuous casting
  7. corrosion
  8. ladle furnace
  9. balling index
  10. cao-sio2-feo