ISIJ International
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: 1347-5460
PRINT ISSN: 0915-1559

ISIJ International Advance Publication

  • Reconstruction of Three-dimensional Temperature Distribution with Radiative Image by Monte Carlo Method in Blast Furnace Raceway

    Bookmark

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

    Log in / Sign Up

    DOI:10.2355/isijinternational.ISIJINT-2017-317

    This paper presented reconstruction of three-dimensional temperature distribution of raceway from radiative images based on Monte Carlo method and image processing techniques in the blast furnace. The Monte Carlo method was introduced to describe radiative heat transfer of raceway for its efficiency. Color CCD camera was used to obtain radiative information in visible spectrum of raceway. An efficient numerical inverse reconstruction model was established by the relationship between three-dimensional thermal radiation and two-dimensional radiative image. Because the reconstruction was an ill-posed inverse problem, a hybrid Tikhonov regularization method was used to determine the meaningful reconstruction. The numerical simulations were utilized for checking the validity of inverse reconstruction model before each experimental reconstruction. Experiment was done to reconstruct three-dimensional temperature distribution of 2500 m3 blast furnace raceway. Ultimately, this method could restore temperature distribution of the raceway effectively. Moreover, computational fluid dynamics (CFD) technology was applied to simulate combustion process and obtain temperature distribution of blast furnace raceway, which was compared with the reconstructed temperature distribution. All results show that the temperature distribution of raceway can be reconstructed reasonably using Monte Carlo method and image processing techniques.
  • Visualization and Analysis of Groove Residual Magnetism for Narrow Gap Arc Welding

    Bookmark

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

    Log in / Sign Up

    DOI:10.2355/isijinternational.ISIJINT-2017-067

    Residual magnetism obviously exists in welding groove of high strength steel and thus influences narrow gap arc welding quality. The present work investigates the characteristics of residual magnetism for U-shape welding groove, and reveals its formation mechanism by physically modeling the residual magnetism. An experimental data based visualization approach is then proposed to characterize dominant distributions of residual magnetism. It is shown that residual magnetism is much stronger in groove width and at groove bottom respectively than in groove length and at groove top, as well as of bar magnet features for each groove sidewall. Two-dimensional visualization of residual magnetism vector is realized by plane and curved surface cloud maps of equivalent color bars, while three-dimensional visualization is expressed by assembling six outermost plane cloud maps of residual magnetism in groove measuring space. The built models and digital visualizations well contribute to understand the phenomena of residual magnetism.
  • Recovery of Soluble Potassium from Electric Arc Furnace Dust of Manganese Alloy Production: Characterization and Water Leaching Kinetics

    Bookmark

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

    Log in / Sign Up

    DOI:10.2355/isijinternational.ISIJINT-2017-421

    As an environmentally hazardous waste, electric arc furnace (EAF) dust had a potential to provide a wider resource of potassium if recycled due to high potassium content. In this study, the chemical and mineralogical characteristics of the EAF dust, especially the existing state of potassium, were analyzed. The results showed that the dust consisted dominantly of manganese oxides (Mn3O4, MnO, MnO2) and manganese silicate (MnSiO3). The K element existed in the dust was in the form of potassium permanganate (K2Mn4O8, insoluble) and potassium sulfate/sulfite (soluble). Then the soluble potassium salts in the dust were recovered by water leaching and crystallization. The recovery ratio of K reached 88.2%, and the products K2SO4 and KCl with the K2O content of 65.25% were obtained. During leaching, the Mn3+ and Mn4+ components were reduced to Mn2+ by sulfide (S2-) or sulfite (SO32-), and the S2- and SO32- components were oxidized to SO42-. The leaching kinetics was studied by the specific electrical conductivity method. The apparent activation energy was 7.76±0.65 kJ/mol, suggesting that the rate controlling step of leaching process was the diffusion of K+ through the diffusion layer.
  • Effect of Solidification Pressure on Interfacial Heat Transfer and Solidification Structure of 19Cr14Mn0.9N High Nitrogen Steel

    Bookmark

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

    Log in / Sign Up

    DOI:10.2355/isijinternational.ISIJINT-2017-356

    The effect of solidification pressure (0.5, 0.85 and 1.2 MPa) on heat transfer between ingot and mould was investigated with the measurement of cooling curves and calculation of heat transfer coefficient. Combined with cooling rate, temperature gradient and local solidification time (LST), the influence of pressure on solidification structure of 19Cr14Mn0.9N was revealed by macrostructure observation. The calculation results of heat transfer coefficient, obtained by the Beck-Nonlinear estimation technique, indicate that increasing solidification pressure obviously enhances heat transfer at the ingot/mould interface. And higher solidification pressure is benefit to increase cooling rate and temperature gradient of ingot. Meanwhile, increasing solidification pressure considerably suppresses nitrogen gas pore, and reduces the whole area of dispersing porosity and shrinkage, which is favorable to obtain a sound ingot. With the solidification pressure increasing from 0.5 to 1.2 MPa, the columnar zone is lengthened, the columnar-to-equiaxed transition (CET) position gradually moves to the ingot center, and both dendritic arm spacing (λ1 and λ2) and local solidification time (LST) gradually decrease. The solidification structure is significantly refined and compressed under higher solidification pressure.
  • Viscosity-structure-crystallization of the Ce2O3-bearing Calcium-aluminate-based Melts with Different Contents of B2O3

    Bookmark

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

    Log in / Sign Up

    DOI:10.2355/isijinternational.ISIJINT-2017-252

    In order to restrain the slag-metal interface reaction in the process of heat resistant steel continuous casting, the aluminate-based mold flux was devised. The effect of B2O3 on the viscosity, structure and crystallization property of the aluminate-based melts was studied. Appropriately adding B2O3 could decrease the viscosity of the melts. However, the viscosity could remain relatively constant when the addition of B2O3 exceeded 5 mass%. The structures of the melts, which were correlated to the viscosity, were confirmed through Fourier transformed infrared spectroscopy. The main network former of the melts was AlO4-tetrahedral unit. With adding B2O3, B2O3 formed 2D BO3-triangular unit, the bridging oxygen of the network combined by AlO4-units was broken, the polymerization of the melts decreased, and the viscosity, the apparent activation energy decreased consequently. With no B2O3 addition, the main crystalline phase was CaO. Because of Ca–O have the strongest interaction force and the weakest irregular thermal motion. The crystallization of CaO could be restrained by adding B2O3, the crystalline phase transferred from CaO to LiAlO2 and CaCeAlO4. CaCeAlO4 precipitated later than LiAlO2 because of the different interactions and the irregular motion ability of different structure units.
  • A Simple Method for Observing ω-Fe Electron Diffraction Spots from <112>α-Fe Directions of Quenched Fe–C Twinned Martensite

    Bookmark

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

    Log in / Sign Up

    DOI:10.2355/isijinternational.ISIJINT-2017-270

    In twinned martensite, a metastable hexagonal ω-Fe phase always exists in the twin boundary region of the body-centered cubic (bcc) {112}<111>-type twin. The ω-Fe electron diffraction spots at the 1/3{112}α-Fe and 2/3{112}α-Fe positions have been treated as the twinning double diffraction effect previously. The ω-Fe spots fully cover the spots of the bcc matrix, twin and their double diffraction. Due to this, it is difficult to practically distinguish the ω-Fe diffraction spots from the sum of matrix + twin + double diffraction. Here, a simple method for observing the ω-Fe spots is introduced based on the twinning crystallographic analysis.In this method, at first a [011] zone axis is found in twinned martensite, containing the diffraction spots of twin and ω-Fe (previously double diffraction spots). It is then confirmed that the twin plane is inclined to the incident electron beam by means of the dark field observation. The reciprocal <222>* direction (containing spots at 1/3{222} and 2/3{222} positions), is noted. A tilting is then performed keeping this direction un-tilted, i.e., tilting about this direction, to <112> zone axis. This requires about 30° tilting. If the ω-Fe spots are absent at the 1/3{222} and 2/3{222} positions when the zone axis reaches <112>, then an opposite tilt is performed (since there are two tilting directions: clockwise and counter-clockwise), then, the ω-Fe diffraction spots can be seen at the 1/3{222} and 2/3{222} positions. A large twinned martensite at the TEM specimen edge is better for tilting to avoid any overlapping.
  • Heterogeneous Nucleation of Graphite on Rare Earth Compounds during Solidification of Cast Iron

    Bookmark

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

    Log in / Sign Up

    DOI:10.2355/isijinternational.ISIJINT-2017-398

    To investigate the heterogeneous nucleation of graphite on rare earth non-metallic inclusions during the solidification of cast iron, Fe-4.1mass%C-2.5mass%Si and S-added Fe-4.1mass%C-2.5mass%Si-0.01mass%S alloys are contact-melted and solidified on RE2O3 (RE; La, Yb) substrates. Regarding the Fe-4.1mass%C-2.5mass%Si alloy, XRD analysis and SEM observation results show that graphite, with an overall orientation in the [0001] direction, precipitates at the alloy/substrate interface. In addition, formation of nodular graphite with rare earth sulfides as the heterogeneous nuclei is observed in the bulk alloy. In the 0.01%S-added specimens, precipitation of graphite at the alloy/substrate interface is observed to be significantly weakened compared to reference specimens. Such precipitation behavior is considered to be due to the increased formation of nodular graphite in the bulk as a result of S addition. Based on these results, the precipitation behavior of graphite on rare earth compounds is discussed.
  • Effect of Carbon Content on Bainite Transformation Start Temperature in Middle–High Carbon Fe–9Ni–C Alloys

    Bookmark

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

    Log in / Sign Up

    DOI:10.2355/isijinternational.ISIJINT-2017-387

    Bainite in steel is an industrially useful structure. However, the controlling factor of its transformation start point is not clearly known. In this study, we measured the bainite transformation start temperature (Bs) in Fe–9Ni–C alloys containing 0.3–0.9 mass%C via microstructure observation of the specimens held isothermally between 600 K and 798 K. Bs existed between 758 K and 773 K in all alloys used, and was independent of carbon content. Especially, Bs was higher than T0, at which fcc and bcc of the same composition have the same free energy, at more than 0.3 mass%C. This result was completely different from that of our previous study on low carbon Fe–9Ni–C alloys, in which Bs decreased with the increase in carbon and kept the certain driving force of partitionless transformation from fcc to bcc. Bs in middle–high carbon alloys corresponded to the temperature of the intersection point between T0′, at which the driving force is 400 J/mol, and the γ/(γ + θ) phase boundary. This suggests that the nucleation and growth of bainitic ferrite in austenite containing solute carbon higher than T0′ is promoted by the precipitation of cementite in austenite.
  • Effect of Argon Injection in Meniscus Flow and Turbulence Intensity Distribution in Continuous Slab Casting Mold Under the Influence of Double Ruler Magnetic Field

    Bookmark

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

    Log in / Sign Up

    DOI:10.2355/isijinternational.ISIJINT-2017-448

    In the present investigation, an experimentally validated coupled two phase Magnetohydrodynamics (MHD) flow and turbulence model has been developed to analyse the combined implications of Argon injection and double ruler electromagnetic breaking (EMBr) in continuous casting flow control (FC) mold of the Tata Steel plant. The numerical model essentially solves transient Euler–Euler two-phase model, turbulence, and MHD Maxwell equations for prescribed experimentally plant measurement of magnetic field boundary conditions data at various Argon flow rates, casting speeds, and submerged entry nozzle (SEN) depths. The numerical model primarily validated with the plant experimental measurement data and found to be in good agreement. The computational results demonstrate that the application of magnetic field suppresses turbulence and meniscus velocity decrement. However, increasing Argon flow rate is found to magnify meniscus velocity and turbulence intensity at the mold. The Argon gas injected from the ports clusters nearer to the SEN and a local chunk of it gradually escapes from the meniscus by short-circuiting its path. Effect of EMBr is not found to be prominent at the higher Argon gas flow rate values. Maximum meniscus level disturbance is noticed at an Argon flow rate of 10 L/min.
  • Micro-bubble Formation under Non-wetting Conditions in a Full-scale Water Model of a Ladle Shroud/Tundish System

    Bookmark

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

    Log in / Sign Up

    DOI:10.2355/isijinternational.ISIJINT-2017-390

    The effect of interfacial wettability on the size of gas bubbles releasing from orifices submerged in high velocity cross flow coupled with strong turbulence, was investigated in a full-scale water model of a commercial ladle/tundish/mold system, located at the McGill Metals Processing Centre. The present work attempted to simulate bubble formation in liquid steel passing through a ceramic (non-wetting) ladle shroud, with a high velocity and strong turbulence. This was accomplished by using a hydrophobic coating, sprayed onto the inner surface of the vertical acrylic ladle shroud, forming a contact angle of 150° at the three-phase line of contact, versus an angle of ~45° on the bare plexiglas surface.As such, the poor wettability of the treated acrylic surface of the ladle shroud led to slight increases in the diameters of micro-bubbles of 8.0%–22.4%, vs wetting systems, depending on gas flow rate and gas injection position. The present results indicate that the cross flows of liquid and their associated kinetic energy of turbulence within a ladle shroud flow can effectively refine bubbles into the micron size range, and prevent bubble growth caused by the poor wettability of liquid steel. Thus, argon gas injection through a ladle shroud could be an effective approach of producing small bubbles in liquid steel, even under the non-wetting conditions associated with such flows, which cannot be achieved by conventional gas curtain technique.
  • Kinetic Analysis of Aluminum and Oxygen Variation of G20CrNi2Mo Bearing Steel during Industrial Electroslag Remelting Process

    Bookmark

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

    Log in / Sign Up

    DOI:10.2355/isijinternational.ISIJINT-2017-227

    Kinetics of slag-metal reactions was investigated in order to elucidate the mechanism of Al-oxidation and oxygen increase during industrial electroslag remelting (ESR) process. G20CrNi2Mo bearing steel was utilized as the consumable electrode and remelted using a 2400-kg industrial ESR furnace. It was found that with the content of FeO in the slag increasing from 0.20 wt% to 0.45 wt%, the content of oxygen increased from 12 ppm in electrode to 16 ppm, 21 ppm in the ingot while Al decreased from 0.040 wt% in the electrode to 0.031 wt%, 0.019 wt% in the ingot. Based on penetration and film theories, a kinetic model has been developed. The model indicates that Al in the electrode is mainly oxidized by FeO at the metal film. Increase of soluble oxygen mainly occurs during the time of droplet formation and falling. The content of soluble oxygen occupies about fifty percent of the total oxygen. The rate-determining step of Al-oxidation is the mass transfer of Al at metal side, whereas oxygen increase lies in the mass transfer of FeO at slag side. With the content of FeO increasing from 0.20 wt% to 0.45 wt%, the mass transfer resistance of FeO decreases obviously, thus would result in an increase of Al-oxidation and total oxygen. In order to improve the cleanliness of refined ingot, it is more effective to decrease the oxygen potential of slag pool to a minimum level, or decrease the time of droplet formation and the temperature of slag pool to some extent, rather than improve the Al content in the electrode.
  • Effects of Welding Procedures on Resistance Projection Welding of Nuts to Sheets

    Bookmark

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

    Log in / Sign Up

    DOI:10.2355/isijinternational.ISIJINT-2017-219

    In this study, experiments were conducted to investigate the effects of welding current, welding time, electrode force and types of nuts on resistance projection welding of nuts to sheets. The microstructures and welded joint size of welded joints in different welding procedures have been analyzed. The failure mode of welded joints was also discussed. It is found the microhardness distribution of the fusion zone gradually becomes homogeneous with the increase of the welding current or the welding time. Lower electrode force causes the occurrence of splash and large fluctuations of the microhardness in fusion zone. Different types of nuts lead to different heat distribution in the projection welding process. The welded joint in nut is deeper than that in base metal for welding nut with higher electrical resistivity. Button pull fracture, partial thickness fracture and interfacial fracture are the three failure modes of nut projection welded joints. The interfacial fracture is brittle rupture and the partial thickness fracture is ductile rupture.
    x

    Readers Who Read This Article Also Read

    1. Revisit of Rule-Deletion Strategy for XCSAM Classifier System on Classification Transactions of the Institute of Systems, Control and Information Engineers Vol.30(2017), No.7
    2. One-Pot Fabrication of Hydrophobic Nanocellulose-Silica Film for Water Resistant Packaging Application Journal of the Japan Institute of Energy Vol.96(2017), No.8
    3. Mixed Meal Model in Type 1 Diabetes Transactions of the Institute of Systems, Control and Information Engineers Vol.30(2017), No.7
  • Influences of the Transverse Static Magnetic Field on the Droplet Evolution Behaviors during the Low Frequency Electroslag Remelting Process

    Bookmark

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

    Log in / Sign Up

    DOI:10.2355/isijinternational.ISIJINT-2017-267

    To visualize the electroslag remelting (ESR) process, a transparent experimental model was adopted. The droplet evolution process at the consumable electrode tip was recorded by a high-speed camera. Different intensities of the transverse static magnetic field (TSMF) were imposed during the ESR process with a low frequency current of 5 Hz. The representative processes of formation and detachment of the droplets under different conditions were given. The results showed that when the intensities of the TSMF were equal or greater than 0.3 T, the droplet evolution processes would be influenced remarkably. When the TSMF reached 0.5 T, the liquid neck would be broken up into two arrays of smaller droplets. The mechanism of the breakup phenomenon appearing on the droplet neck was discussed. Statistical analysis of the videos captured by the high-speed camera under different conditions had been done. The results showed that the separation degree of the droplet necks and the remelting rate could be increased to a certain extent as the increase of the TSMF. The features of the collected droplets with the TSMF of 0.7 T showed a smaller average size and more tiny droplets comparing with what were obtained without the external magnetic field. The decrease of the droplet size and the generation of numerous tiny droplets enlarged the interfacial area between metal and slag tremendously.
  • Influence of Metallic Powder Contents on Corrosion Resistance of Galvanized Steel with Metal Powder-containing Organic Coatings for Automobile Fuel Tanks

    Bookmark

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

    Log in / Sign Up

    DOI:10.2355/isijinternational.ISIJINT-2017-244

    Pb- and Cr(VI)-free galvanized steel sheets for fuel tanks are coated with epoxy-resin films (thickness: approx. 3 µm) containing particulate Ni powder and flaky Al powder to provide a combination of weldability and degraded gasoline resistance (sour gasoline resistance). The corrosion behavior of galvanized steel specimens coated with epoxy resin containing different amounts of the two types of metal powders was investigated in a solution containing acetic acid, formic acid and NaCl at pH 3.2 and 40°C to elucidate the mechanism of corrosion protection by the coatings. The oxygen gas permeability and water vapor permeability of the coatings were also examined. The results indicated that the addition of particulate Ni powder promoted galvanic corrosion between the Ni and the Zn coating. Voids generated around the embedded Ni powder particles also appeared to accelerate the penetration of the corrosive solution through the coating. On the other hand, the addition of the flaky Al powder improved corrosion resistance. This improved corrosion resistance is associated with the suppression of direct contact between the Ni powder and the Zn coating and also with increased barrier properties, which could be confirmed from oxygen gas and water vapor permeation measurements.
  • Effect of Operating Conditions on Inclusion of Die Steel during Electroslag Remelting

    Bookmark

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

    Log in / Sign Up

    DOI:10.2355/isijinternational.ISIJINT-2017-429

    The current paper focuses on the effect of different operating conditions on the content of inclusions and cleanliness of remelting ingots. For these investigations, eight ingots were remelted with two slag amount and with two current intensity under otherwise comparable remelting conditions. A two-dimensional (2D) coupled mathematical model was employed to simulate the velocity field, solidification and inclusion motion for a system of electrode, slag and ingot in electroslag remelting (ESR) processes, to reveal the inclusion removal mechanism. The results showed that the content of large-sized inclusions in ESR ingot was decreased by approximately 66.18% when the slag amount was increased from 17.85 kg to 20.50 kg. Because of the increase of slag amount, the metal and slag flow faster and the maximal velocity increases by 10.3%, thus there is an increasing trend in trajectories of inclusions (i.e., inclusion motion) in slag pool resulted from the stronger natural convective flow, which is beneficial for the inclusion removal. When the average current was increased from 4 kA to 5 kA, the content of large-sized inclusions in ESR ingot was decreased by approximately 51.38%. Because of the increasing of current, the flow in the middle of the slag pool becomes stronger and the maximal downward velocity increases by 2.7%, thus there is an increasing trend in the renewal rate of the metal film surface due to the stronger washing by slag flow, which can promote the inclusion removal.
  • Slag/Metal Separation from H2-Reduced High Phosphorus Oolitic Hematite

    Bookmark

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

    Log in / Sign Up

    DOI:10.2355/isijinternational.ISIJINT-2017-304

    A process of H2 reduction followed by the slag/metal separation for the utilization of high-phosphorus oolitic hematite has been proposed. The H2 reduction was conducted at 1073 K in a horizontal rotary electric resistance furnace, which significantly promotes the metallization ratio of reduced ore fines. Thermodynamic calculation of H2 reduction for apatite and XRD analysis of ore samples before and after H2 reduction confirmed that gangue minerals containing P, Al and Si in oolitic hematite hardly be reduced. The slag/metal separation was carried out in an induction furnace at 1873 K. After separation, metal block and slag were obtained, and most of gangue minerals combined with lime and calcium fluoride formed the slag, but some impurities remained in the form of slag inclusions in the metal. Based on the SEM-EDS examination of P-containing slag inclusions and ternary phase diagram of Fe–P–O system computed by FactSageTM 6.4 at 1873 K, phosphorus in the metal product can be precipitated as iron phosphate or iron phosphide, and the evolution of P-containing slag inclusions is Fe2P(l) + Fe3(PO4)2(l)→Fe3(PO4)2(l)→FeO(l) along with the increase of slag basicity, melt separation time and additive CaF2. A satisfactory metal product with 99.80 wt% T. Fe, 0.027 wt% P, 0.0013 wt% Si, 0.004 wt% Al and 0.05 wt% O was achieved by the slag/metal separation under the optimum conditions: slag basicity of 2, melt separation time of 10 min, CaF2 mixing ratio of 4 wt% and metallization ratio of reduced fines of 85.9%.
  • Effect of Niobium on Precipitates and Texture Evolution of Fe-3% Si Grain-oriented Electrical Steel Annealed Hot Band

    Bookmark

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

    Log in / Sign Up

    DOI:10.2355/isijinternational.ISIJINT-2017-335

    Precipitation behavior of inhibitors, microstructure and texture evolution in annealed hot band of grain-oriented Fe-3%Si electrical steel with niobium addition were analyzed, and compared with that of common grain-oriented electrical steel. Stoichiometric ratio of C and N in Nb(C, N) was determined by their lattice parameters. Inhibitors precipitated in the hot rolled band with niobium addition are mainly Nb(C, N). Their average size was 34.1 nm and number density was 3.80×107/mm2, with stronger inhibition effect than inhibitors in common grain oriented electrical steel. Stoichiometric ratio of C and N in Nb(C, N) changed from Nb(C0.85, N0.15) to Nb(C0.71, N0.29) which means NbC is dominant in Nb(C, N) of current study. After niobium addition, recrystallization of annealed hot band was incomplete while more Goss texture is preserved. Addition of niobium is proved helpful to obtain precipitates with higher inhibition effect during hot rolling, instead of adopting hot band annealing.
  • Numerical Study on the Capture of Large Inclusion in Slab Continuous Casting with the Effect of In-mold Electromagnetic Stirring

    Bookmark

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

    Log in / Sign Up

    DOI:10.2355/isijinternational.ISIJINT-2017-347

    Large inclusions captured by the solidifying shell deteriorate the surface quality of interstitial free steel. To investigate the capture of large inclusion in slab continuous casting, a three-dimensional model coupling flow field, solidification and inclusion motion has been developed. Additionally, to study the effect of in-mold electromagnetic stirring (M-EMS) on large inclusion capture, the electromagnetic field has been also coupled in the model. The results of electromagnetic field indicates its centrally symmetrical distribution on the cross-section, and the electromagnetic force swirls on the cross-section. The effects of M-EMS on flow pattern, solidification and inclusion capture have been discussed. The M-EMS significantly changes the flow pattern and solidifying shell thickness. The inhomogeneous distribution of large inclusions existing in the slab surface in the slab surface are different between the cases with and without M-EMS. Furthermore, the number of captured inclusions increases at 0–0.02 m beneath the wide surface and decreases at 0.02–0.04 m beneath the wide surface in response to the application of M-EMS. Large inclusions in steel were quantitatively analyzed by the galvanostatic electrolysis method. The experimental results are in agreement with the simulation results, suggesting that the model is valid.
    x

    Readers Who Read This Article Also Read

    1. Micro-bubble Formation under Non-wetting Conditions in a Full-scale Water Model of a Ladle Shroud/Tundish System ISIJ International Advance Publication
  • Effect of Super-gravity Field on Grain Refinement and Tensile Properties of Cu–Sn Alloys

    Bookmark

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

    Log in / Sign Up

    DOI:10.2355/isijinternational.ISIJINT-2017-233

    In this paper, the effect of super-gravity field on the grain refinement and tensile properties of as-cast Cu–Sn alloys were investigated systematically. The experimental results revealed that the as-cast grains of Cu–Sn alloys can be significantly refined in super-gravity field. In normal gravity field, the average grain size is 2.13 mm, while in super-gravity fields of G=100, 300 and 600, they are 0.35 mm, 0.173 mm and 0.074 mm, respectively. Accordingly, both the tensile strength and the plasticity are enhanced with the increasing gravity coefficient. The ultimate tensile strength of Cu-11wt%Sn sample in normal gravity field is 265 MPa, while in super-gravity fields of G=100, 300 and 600, they are 449 MPa, 487 MPa and 521 MPa, respectively. The fracture morphology transforms from fragility to plasticity with the increasing gravity coefficient. The mechanism for the grain refinement is that super-gravity promotes the falling of crystal nuclei within the solidifying melt only at the early solidification period, which can be called the "Crystal Rain". As a result, the crystal nuclei multiply within the solidifying melt and a refined grain structure was obtained. Besides, the refining effect by super-gravity increases with the increasing solute Sn concentration because of the increased nucleation rates and a decrease in crystal growth.

Article Access Ranking

23 Nov. (Last 30 Days)

  1. Factors to Determine Inclusion Compositions in Molten Steel during the Secondary Refining Process of Case-Hardening Steel ISIJ International Vol.56(2016), No.11
  2. Convergent-Divergent Injection Lance for the Enhancement of Combustion Efficiency of Pulverized Coal at Blast Furnace Tetsu-to-Hagané Vol.103(2017), No.11
  3. Dissolution Behavior of Lime into Steelmaking Slag ISIJ International Vol.57(2017), No.10
  4. Improvement of Strength–Elongation Balance of Al–Mg–Si Sheet Alloy by Utilising Mg–Si Cluster and Its Proposed Mechanism MATERIALS TRANSACTIONS Vol.58(2017), No.5
  5. Relationship between Amount of Retained Austenite and Mechanical Properties in Martensitic Precipitation Hardening Stainless Steel Tetsu-to-Hagané Vol.103(2017), No.11
  6. Effect of Phosphorus on Solidification Characteristics in Austenitic Stainless Steels QUARTERLY JOURNAL OF THE JAPAN WELDING SOCIETY Vol.35(2017), No.4
  7. Applicability of Nonaqueous Electrolytes for Electrolytic Extraction of Inclusion Particles Containing Zr, Ti, and Ce ISIJ International Vol.53(2013), No.11
  8. Prevention of Hydrogen Embrittlement in Steels ISIJ International Vol.56(2016), No.1
  9. Study on Information Transmission Structure of Environmental Terms by Graphical Modeling Analysis Journal of the Japan Institute of Energy Vol.94(2015), No.4
  10. A Review of Slag Splashing ISIJ International Vol.45(2005), No.5

Search Phrase Ranking

23 Nov. (Last 30 Days)

  1. blast furnace
  2. blast furnace productivity
  3. blast furnace permeability
  4. 鉄と鋼
  5. arvedi esp
  6. breakout continuous casting
  7. breakout prediction, continuous casting
  8. camp-isij
  9. cold reduction recrystallization
  10. cold reduction recrystallization steel