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. 104 (2018), No. 2

  • Evaluation of Porosity Closure during Hot Compression of Steel by Synchrotron X-ray Laminography and FEM Analysis

    pp. 65-71

    Bookmark

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

    Log in / Sign Up

    DOI:10.2355/tetsutohagane.TETSU-2017-057

    The shape change due to hot compression of the porosities formed in center of the steel ingot of carbon steel S25C and stainless steel SUS316L was sequentially, nondestructively and three-dimensionally observed by synchrotron X-ray laminography. As a result, it was revealed that closure of porosities was easier in SUS316L than in S25C. In addition, when the compression ratio increased, originally high aspect ratio porosities (length/width ratio, ℓ/w > 2.5) became decoupled. Larger porosities were more readily closed with smaller compression ratio. As a result of verifying the difference in closure behavior between S25C and SUS316L by Finite Element Method (FEM), it was demonstrated that the hydrostatic integration was larger for SUS 316L of which work hardening coefficient was smaller. This result was consistent with the experiment as results that porosities of SUS 316L tended to close easily.
  • Evaluation of Heat Flux Extracted from Steel Surface with Oxide Scale Utilizing Evaporation Rate of Water Droplet

    pp. 72-80

    Bookmark

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

    Log in / Sign Up

    DOI:10.2355/tetsutohagane.TETSU-2017-070

    The present work has proposed a new method to evaluate heat flux extracted from steel surface with iron oxide scale using the mass change of a water droplet and the standard enthalpy of evaporation for water at 100ºC. The apparatus was composed of a furnace, an electronic balance, a water droplet supplying device, a combination of a thermocouple and a digital multi-meter, in addition to a video camera. Ultra-low carbon steel plate samples were oxidised in air at 850ºC in the furnace so as to have iron oxide scale (mainly FeO) with desired thicknesses, and then moved onto the electronic balance. About 3 g of water was supplied onto the sample, and the mass change of water and temperature inside the sample were measured by the balance and the thermocouple, respectively. In addition, boiling behaviour of water was also recorded by the video camera. The mass and temperature changes well corresponded to the video images which recorded film boiling and nucleate boiling of water. The quench temperatures obtained in experiments using the samples with scales 40, 58, 77 and 103 μm thick were 131, 167, 121 and 182ºC, respectively, and the respective heat fluxes just before quench were estimated to be 31, 35, 33 and 43 kWm–2. Assuming that the present system is at a quasi-steady state, Fourier’s law has been applied to estimate the thickness of water vapour film during film boiling; resultantly, the thickness decreases from ca 100 μm to ca 20 μm with cooling of steel.
  • Strengthening Mechanism in Nitrogen Diffusion Layer of Nitrocarburized Fe-C-Mn Steel

    pp. 81-87

    Bookmark

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

    Log in / Sign Up

    DOI:10.2355/tetsutohagane.TETSU-2017-061

    Steels containing 0.3mass%C and various amount of Mn were nitrocarburized at 873 K for 2 h to investigate behavior of N and Mn in a nitrocarburized layer. Transmission electron microscopy observation showed that a part of Mn precipitated as nitrides η-Mn3N2 in the ferrite matrix. To fix the state of N in the nitrocarburized layer, solution and aging treatments were carried out sequentially. Most N was presumed to exist as dissolved N or Mn nitrides in the solution treated specimen and as iron or Mn nitrides in the aged specimen. Amount of the precipitation hardening with η-Mn3N2 increased with the increasing Mn content, whereas amount of solid solution hardening in the steel with high Mn content was smaller than that with low Mn content. On the basis of measuring N concentration and thermodynamical calculation, it was estimated that the precipitation hardening ability of Mn nitrides was smaller than that of Cr, Al, Ti and V nitrides.
    x

    Readers Who Read This Article Also Read

    1. Fatigue Behavior of Fe-Cr-Ni-based Metastable Austenitic Steels with an Identical Tensile Strength and Different Solute Carbon Contents Tetsu-to-Hagané Vol.104(2018), No.2
    2. Influence of Induction Heating Condition on Mechanical Properties of JIS-SUJ2 Steel Tetsu-to-Hagané Vol.104(2018), No.2
    3. Contents Tetsu-to-Hagané Vol.104(2018), No.2
  • Fatigue Behavior of Fe-Cr-Ni-based Metastable Austenitic Steels with an Identical Tensile Strength and Different Solute Carbon Contents

    pp. 88-97

    Bookmark

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

    Log in / Sign Up

    DOI:10.2355/tetsutohagane.TETSU-2017-058

    Fatigue properties of Fe-19Cr-8Ni-0.05C and Fe-19Cr-8Ni-0.14C steels were investigated using a rotating bending fatigue test machine. Fatigue limit of both of the steels were dominated by critical stress amplitude for crack initiation. Because of the austenite stability, the fatigue limit of the Fe-19Cr-8Ni-0.05C steel was 200 MPa higher than that of the Fe-19Cr-8Ni-0.14C steel. Although occurrence of dynamic strain aging in the Fe-19Cr-8Ni-0.14C was expected to improve fatigue limit, the effect did not appear due to the remarkable increase of phase stability that deteriorates positive effects of transformation-induced plasticity and transformation-induced crack closure.
  • Influence of Induction Heating Condition on Mechanical Properties of JIS-SUJ2 Steel

    pp. 98-106

    Bookmark

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

    Log in / Sign Up

    DOI:10.2355/tetsutohagane.TETSU-2017-059

    In our previous report (Tetsu-to-Hagané, 103(2017), 194), we investigated the microstructure of induction-heated SUJ2 steel. The austenitization was carried out at much higher temperatures (900-1000°C) than those typically being used at present in furnace heat treatment. It is worth noting that the fraction of retained austenite tended to be relatively high in induction-heated steels, which seem to be disadvantageous for the components of rolling bearing. In this study, the mechanical properties, in particular static and dynamic load capacities, were evaluated for the induction-heated steels containing 4 to 12 vol% undissolved carbide and austenitized at from 900 to 1000°C in order to establish the conditions for which the mechanical properties of SUJ2 steel are equal to or better than those of furnace heated SUJ2 steels.Dimensional change over time, static load capacity and torsion fatigue life were evaluated. From the results, the conditions 900°C with 8 vol%, 900°C with 10 vol%, 950°C with 8 vol% and 950 with 12 vol% were found to be promising. Using these conditions, deep groove ball bearings were further fabricated, and rolling contact fatigue tests were conducted. Data obtained from these tests were statistically processed and the fatigue life of these bearings was found to be more than three times the predicted fatigue life. The performance can be closely related to the amount of each constituent such as tempered martensite, retained austenite and undissolved carbide.
  • Complete Melting of Steelmaking Slag and Behavior of Alkali Dissolution

    pp. 107-116

    Bookmark

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

    Log in / Sign Up

    DOI:10.2355/tetsutohagane.TETSU-2017-073

    The problems on the alkali dissolution from steelmaking slag sometime occurred in the location of slag recycling. It is important to clarify the alkali dissolution mechanism and develop the method to inhibit an alkali dissolution. There might be many approaches for decreasing the alkali dissolution, the decrease of basicity (CaO/SiO2) is best and easy way for complete melting and inhibition of the alkali dissolution.In this study, dephosphorization slag was modified by addition of reagent, fly ash (FA) and brown bottle (BB). Basicity was changed from 2.0 to 0.53. Dissolution experiments were carried out according to the condition developed by Kitamura, et al. based on JIS method.Ca content in dissolution experiment, which analyzed by ICP, was highest compare to Al, Si, Mg, Fe and P. It was found that the relationship between the content of Ca dissolved and modified basicity (C/(S+F)=CaO/(SiO2+FeOx)) showed good correlation.On the other hand, the pH value was excellent correlation with the content of Ca, although the value of pH saturated around 11 over 20 ppm of Ca. Then, using the relationship of ion product, Kw=[H+][OH], the equation between Ca and [OH-] was derived. Finally, the following equation successfully calculates the calcium content [Ca2+] ppm dissolved using pH value. [Ca2+] = 3.0 × 10(pH–10)
  • Theoretical Discussion of Dislocation Strengthening in Cold Rolled Iron

    pp. 117-120

    Bookmark

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

    Log in / Sign Up

    DOI:10.2355/tetsutohagane.TETSU-2017-053

    In work hardened metals, it is known that the strength of metals is heightened with increasing dislocation density. In the case of cold worked iron, dislocation is introduced heterogeneously and forms dislocation cell structure. Yield stress increases with an increase of volume fraction of cell wall where dislocation density ρ is much higher than the matrix. Applying the composite model to cold worked iron with dislocation cell structure, it was theoretically explained that linear relationship is realized between √ρ and the increment of strength Δσ, so called Bailey-Hirsch relation. On the other hand, the Bailey-Hirsch equation; Δσ[GPa]=18√ρ/109 was constructed from the experimental data which were already reported for cold worked iron. In previous papers, dislocation density was measured directly by transmission electron microscopy. As a result, it was confirmed that experimental data agree well with the result which was theoretically introduced based on the composite model and that the above Bailey-Hirsch equation can be applied for cold worked iron in which dislocation density is below 4×1014/m2 at least.
    x

    Readers Who Read This Article Also Read

    1. Contents Tetsu-to-Hagané Vol.104(2018), No.2
    2. Cover Tetsu-to-Hagané Vol.104(2018), No.2
    3. Editorial Board and Copyright Page Tetsu-to-Hagané Vol.104(2018), No.2
  • Contents

    p. Contents

    Bookmark

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

    Log in / Sign Up
    x

    Readers Who Read This Article Also Read

    1. Cover Tetsu-to-Hagané Vol.104(2018), No.2
    2. Editorial Board and Copyright Page Tetsu-to-Hagané Vol.104(2018), No.2
    3. Theoretical Discussion of Dislocation Strengthening in Cold Rolled Iron Tetsu-to-Hagané Vol.104(2018), No.2
  • Cover

    p. Cover

    Bookmark

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

    Log in / Sign Up
    x

    Readers Who Read This Article Also Read

    1. Contents Tetsu-to-Hagané Vol.104(2018), No.2
    2. Editorial Board and Copyright Page Tetsu-to-Hagané Vol.104(2018), No.2
    3. Theoretical Discussion of Dislocation Strengthening in Cold Rolled Iron Tetsu-to-Hagané Vol.104(2018), No.2
  • Editorial Board and Copyright Page

    p. Editorial

    Bookmark

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

    Log in / Sign Up
    x

    Readers Who Read This Article Also Read

    1. Contents Tetsu-to-Hagané Vol.104(2018), No.2
    2. Cover Tetsu-to-Hagané Vol.104(2018), No.2
    3. Theoretical Discussion of Dislocation Strengthening in Cold Rolled Iron Tetsu-to-Hagané Vol.104(2018), No.2

Article Access Ranking

26 May. (Last 30 Days)

  1. Iron Powders from Steel Industry by-products: A Review ISIJ International Advance Publication
  2. In Situ Temperature Measurement of Sinter Beds at High Spatial and Time Resolution ISIJ International Vol.58(2018), No.5
  3. Measurement for Contact Angle of Iron Ore Particles and Water ISIJ International Vol.58(2018), No.3
  4. Quantitative Analysis of Mineral Phases in Iron-ore Sinter by the Rietveld Method of X-ray Diffraction Patterns ISIJ International Advance Publication
  5. Effect of Natural Gas Injection Point on Combustion and Gasification Efficiency of Pulverized Coal under Blast Furnace Condition Tetsu-to-Hagané Vol.104(2018), No.5
  6. Recovery of Phosphorus from Modified Steelmaking Slag with High P2O5 Content via Leaching and Precipitation ISIJ International Vol.58(2018), No.5
  7. Dissolution Mechanism of Carbon Brick into Molten Iron ISIJ International Vol.58(2018), No.5
  8. Amenability of Reduced Iron Ore Pellets to Mechanical Degradation ISIJ International Advance Publication
  9. Agglomeration of Return Fines of Sinter for Blast Furnace Raw Materials Tetsu-to-Hagané Vol.104(2018), No.5
  10. Effect of Annealing Temperature on the Selective Oxidation and Reactive Wetting of a 0.1C-6Mn-2Si Advanced High Strength Steel During Continuous Galvanizing Heat Treatments ISIJ International Advance Publication

Search Phrase Ranking

26 May. (Last 30 Days)

  1. blast furnace
  2. blast furnace productivity
  3. blast furnace permeability
  4. reduction behavior of iron oxides in hydrogen and carbon monoxide atmospheres
  5. 鉄と鋼
  6. gehlenite
  7. steel
  8. gehlenite mold flux
  9. isij
  10. isij international