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 Vol. 51 (2011), No. 6

  • Production and Technology of Iron and Steel in Japan during 2010

    pp. 857-869

    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.51.857

    x

    Readers Who Read This Article Also Read

    1. Production and Technology of Iron and Steel in Japan during 2012 ISIJ International Vol.53(2013), No.6
    2. Production and Technology of Iron and Steel in Japan during 1989 ISIJ International Vol.30(1990), No.4
    3. Production and Technology of Iron and Steel in Japan during 2014 ISIJ International Vol.55(2015), No.5
  • Low-temperature Synthesis of Aluminium Carbide

    pp. 870-877

    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.51.870

    The Hall-Héroult process, the only commercial technology for aluminum production requires high energy and is a major origin of perfluorocarbons and green house gases. A promising alternative process, carbothermal reduction of alumina to metallic aluminum has advantages of lower capital cost, less energy consumption, and lower emission of green house gases. Carbothermal reduction processes under development are based on formation of aluminum carbide-alumina melts at high temperatures. Solid state carbothermal reduction of alumina is possible at reduced CO partial pressure. This paper presents results of experimental study of carbothermal reduction of alumina into aluminum carbide in argon, helium and hydrogen atmospheres at 1500–1700°C. The reduction rate of alumina increased with increasing temperature, and was significantly faster in helium and hydrogen than in argon. Increasing gas flow rate and pellet porosity, and decreasing pressure favour the reduction.
  • Dehydration Behavior of Goethite Blended with Graphite by Microwave Heating

    pp. 878-883

    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.51.878

    In ironmaking and steelmaking processes, dehydration of wet substances and minerals combined by H2O are often recognized to be a key to stable practices. This study aims at understanding dehydration behavior of goethite blended with graphite by microwave treatment simulating drying wet sludge and poor iron ore with combined water.
    Firstly blend specimens with various conditions, powdery or pelletized, were heated by microwave apparatus. Dehydration rate of goethite increased with increasing temperature. Denser specimen of pelletized was confirmed to be less effective to heat up the whole part. It was found that surplus addition of graphite decreased efficiency in dehydration rate. Thus, it was estimated that a specimen with smaller amount of graphite, whose blend ratio of FeO(OH):C was 1:1, had sufficiently larger distance between graphite particles, through which microwaves could adequately penetrate into the core of the specimen. To prove this hypothesis, Network Analyzer helped evaluate penetration depth of microwave by the measurement of permittivity. The measured results showed that penetration depth decreased with increasing apparent density consistently with the heating behavior by microwave treatment. At the blend ratio of 1:2 of FeO(OH):C, however, the specimen was estimated to behave as if it was under percolation.
  • Numerical Simulation of Heat Transfer during Microwave Heating of Magnetite

    pp. 884-888

    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.51.884

    Numerical simulation of heat transfer during the microwave heating process of a one-dimensional (1-D) magnetite slab subjected to convective, radiative boundary conditions was performed. The governing equations representing the heating process in the slab were discretized using an explicit finite-difference approach, and a computer code was developed to predict the temperature distributions inside the slab. The heat generation from microwave irradiation dominates the initial temperature rise in the heating and the heat radiation heavily affects the temperature distribution, giving rise to a temperature peak in the predicted temperature profile. As heating continues, the temperature peak migrates inward. The microwave power level is crucial to obtain a high temperature increase rate in the initial heating period (i.e. < 60 s for magnetite). Microwave heating at 915 MHz exhibits better heating homogeneity than 2450 MHz due to larger microwave penetration depth. To minimize/avoid temperature non-uniformity during the microwave heating the optimization of the object dimension should be considered.
  • Hydrogen Dissolution in the TiO2–SiO2–FeO and TiO2–SiO2–MnO Based Welding-Type Fluxes

    pp. 889-894

    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.51.889

    The hydrogen solubility of TiO2–SiO2–FeO and the TiO2–SiO2–MnO welding-type flux systems have been studied to identify and compare the hydrogen dissolution behavior in molten welding fluxes at high temperatures of 1823 K in a wide range of compositions. The dependence of the water vapor pressure and the hydrogen solubility showed a slope of 1/2 suggesting thermodynamic equilibrium was obtained. For an acidic slag composition, the hydrogen was found to be incorporated within the silicate network structure and decreased with higher TiO2 additions due to the dilution effect of SiO2 and subsequent decrease in incorporation sites. The additions of FeO and MnO, which acts as a basic component to the slag system, provided free oxygen ions, and decreased the incorporation sites for hydrogen dissolution. FTIR analysis of as quenched molten flux samples showed more pronounced bands for Si–OH bending vibrations when hydrogen solubility increased. For a basic slag composition, the hydrogen existed as a free hydroxyl and the addition of basic components such as FeO and MnO to the slag system increased the hydrogen solubility in the molten slag. Furthermore, it was observed that the hydrogen solubility was slightly lower for FeO than MnO containing fluxes.
  • Magnesium Deoxidation Equilibrium of Molten Fe–Cr–Ni Alloy Expressed by Quadratic Formalism and Redlich-Kister Type Polynomial

    pp. 895-900

    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.51.895

    Magnesium deoxidation equilibrium of molten Fe–Cr–Ni alloy was determined by a chemical equilibrium method at temperature of 1873 to 1973 K. Extreme care was taken of oxygen analysis of the samples. Numerical analysis on Mg deoxidation of molten Fe–Cr–Ni alloy has been carried out by utilizing the model based on Darken's quadratic formalism and Redlich-Kister type polynomial. Magnesium deoxidation equilibrium can be expressed in wide composition region of the Fe–Cr–Ni alloy.
    x

    Readers Who Read This Article Also Read

    1. The Extraction of Sm from Sm-Co alloys by the Glass Slag Method MATERIALS TRANSACTIONS Vol.44(2003), No.4
    2. Composition Dependence on Compressive Magnetostriction of Fe–Sm Binary Alloy Thin Films MATERIALS TRANSACTIONS Vol.46(2005), No.12
    3. Deoxidation Equilibrium of Vanadium in the Iron–Nickel Melts ISIJ International Vol.49(2009), No.2
  • Recovery of Calcium from BF Slag and Synthesis of Zeolite A Using Its Residue

    pp. 901-905

    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.51.901

    The elution and recovery of Ca from blast furnace slag and the alkali hydrothermal synthesis of zeolite A using the residue from the elution treatment were investigated using a ball-milling-type reaction vessel. The superior elution was obtained by using citric and formic acid solutions from which Ca could be selectively eluted from the slag. Whereas hydrochloric acid solution and ion-exchanged water were ineffective for Ca elution. Ca ions eluted in the solution were recovered as calcium formate by evaporation of water. From the formic acid eluted slag residue after three elution treatment cycles of the slag for 7.2 ks, zeolite A was synthesized in 1 mol/L NaOH solution with a reaction time of 86.3 ks at 343 K, without the addition of any other materials.
  • Effects of Firing and Reduction Conditions on Swelling and Iron Whisker Formation during the Reduction of Iron Oxide Compact

    pp. 906-912

    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.51.906

    The effects of firing and reduction conditions on swelling and iron whisker growth were investigated. The iron oxide compacts sintered in air were reduced in the tubular high temperature reactor by carbon monoxide or hydrogen. The experimental results showed that catastrophic swelling was suppresed by increasing the firing temperature or the firing time at moderate firing temperatures. The severest swelling happened in the reduction temperature of 900–1000°C with carbon monoxide. No catastrophic swelling was observed when hydrogen was used as the reducing gas. The SEM micrographs showed that catastrophic swelling was caused by a large amount of long whiskers formed during the reduction. The number of nucleation sites of whisker growth was limited when the firing temperature was increased above 1000°C, which also suppressed catastrophic swelling. On the basis of exprimental data and SEM results, a conceptual diagram was formulated to describe the effects of firing and reduction conditions on iron whisker growth and swelling.
  • Development of Secondary-fuel Injection Technology for Energy Reduction in the Iron Ore Sintering Process

    pp. 913-921

    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.51.913

    JFE Steel Corporation developed the hydrogen-based gas fuel injection technology for sintering machines to improve sinter quality without increasing coke breeze ratio. With the technology, it is possible to extend the temperature zone between 1200°C and 1400°C by injecting the gaseous fuel from the top surface of the sintering machine as a partial substitute for coke breeze. Theoretical and experimental studies were carried out to verify the effect of the gaseous-fuel injection technology on pore structure in the sinter cake with the X-ray CT scanner and sintering pot test.
    It is important to hold the temperature between 1200°C and 1400°C in order to produce high strength and high reducibility sinter. The liquid phase ratio can be increased with extending the proper temperature zone by applying the gaseous fuel injection technology. The increase in liquid phase ratio promotes the combination of pores (1–5 mm) and sinter strength is improved. At the same time, the pores over 5 mm growth are promoted and the permeability is improved in the sintering bed. Moreover, the low-temperature sintering process depresses the iron ore self-densification. Micro pores under 1 μm remain in unmelted ores and improve sinter reducibility. As a result, the technology enables to improve the pore structure in the sinter cake and sinter quality.
    The technology was put into commercial operation at Keihin No. 1 sinter plant in January 2009 and stable operation has continued up to the present. As a result, the energy efficiency in the sintering process is greatly improved, and it has been achieved to reduce CO2 emissions by a maximum of approximately 60000 t/year at Keihin No. 1 sinter plant.
  • Influence of Iron Ore Fines Feed Size on Microstructure, Productivity and Quality of Iron Ore Sinter

    pp. 922-929

    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.51.922

    The sinter structure and its characteristics mainly depend on the raw material chemistry, size, size distribution and the sintering process parameters. In sintering process heat is supplied by coke breeze in the sinter mix to raise the bed temperature to achieve partial fusion and diffusion bonding. Airflow rate and flame front speed in sintering process has been found to guide the performance of the sinter plant and these parameters mainly depends on the sinter bed permeability. The flame front speed (bed permeability) has been considered as one of the important operating parameter and it depends on several factors; the feed size of the sinter being one of the most important parameter among them. Since iron ore proportion is at higher side in the sinter mix, its size fraction is very important. JSW Steel sinter plant receives iron ore fines of –10 mm size from Bellary – Hospet region which consist of 3 to 9% bigger than 10 mm and 30 to 35% smaller than 0.15 mm size fraction. It is well known that larger particles favour diffusion bonding and smaller particles favour slag bonding in sintering process. Accordingly, the study of the assimilation characteristics of different size range iron ore has an important role to control the reactions in the sinter bed and to obtain the target mineral structure. Too much variation in coarser and finer particle size range in sinter mix, the behavior of these +10 mm and –0.15 mm particles have been a subject of investigation and it is necessary to understand the role of iron ore particle size on sinter microstructure, sinter strength, sinter RDI, and productivity. In present work pot grate sintering experiments have been carried out in laboratory with different level iron ore size (mean particle size from 1.22 to 3.95 mm) to understand the influence of iron ore mean particle size on mineralogy, productivity, physical and metallurgical properties of the sinter. Sinter productivity increased with increase in iron ore mean particle size due to increased flame front speed (FFS) and improved bed permeability with lower sintering time. Sinter with iron ore mean particle size of 2.59 mm (Classifier fines) yielded better sinter strength with lower fines (–5 mm) and lower RDI. Higher sinter strength is due to effective distribution of acicular silico ferrites of calcium and alumina (SFCA) phases. The improvement in sinter RDI is due to the change in proportion of magnetite and hematite phase with flame front speed.
  • Lump Ore and Sinter Behaviour during Softening and Melting

    pp. 930-938

    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.51.930

    The softening and melting test is widely used to assess the behaviour of ferrous materials in the cohesive zone of a blast furnace. It is generally agreed that the performance of lump ores is inferior to sinter in the test. To understand the factors determining material behaviour, tests were terminated by quenching samples at different temperatures. The samples were then studied under an optical microscope. The formation of a low temperature liquid fayalite caused beds of lump ores to rearrange and contract earlier. Beds of fluxed sinter remained essentially intact with reduction until higher temperatures. The study also showed that results obtained for a mixed burden of 80% sinter and 20% lump ore – a ratio used in many blast furnaces – are not different to results obtained from tests using only sinter. This difference increases as the lump ore level is increased. These findings indicate that there is significant interaction between the material types in the test and that results from single material tests should not be used in isolation assess material performance in a blast furnace. Any prejudice against lump ores as a blast furnace feed material based on softening and melting test results for single materials is clearly incorrect.
  • Effect of Chemical Composition on the Microstructure of Carbide Reinforced Indefinite Chilled Rolls

    pp. 939-944

    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.51.939

    In the present work, effects of elements such as V, Nb, Si and Cr on the microstructures of the conventional indefinite chilled rolls made by small vertical centrifugal caster were investigated, using optical microscopy, Scanning Electron Microscopy (SEM, Jeol 6400), Energy Dispersive X-ray Spectroscopy (EDXS, Cu-Kα radiation) to identify the type, morphology, and to measure the volume fraction and the distribution of carbides and graphites formed during solidification. Microstructural analysis indicates that, the amount of graphite is dramatically reduced by adding V element. The volume fraction of the square-like carbides NbC increases with the Nb content increasing. However, if Nb content is over a critical point, large amount of the square-like NbC carbide can be seriously segregated in the out part of the section. The test also shows that, by increasing Si and reducing Cr content, the volume fraction of the graphite increases accordingly, whereas much of its shape turns to be finely flake-like. In addition, it can be found from the microstructures observed by optical microscopy that, the volume percentage of the rod-like NbC carbides increases as the examining position is near the inner portion of the section, and that of the cubic-like NbC carbides decreases contrarily.
  • A New Approach to Modeling the Flow Curve of Hot Deformed Austenite

    pp. 945-950

    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.51.945

    A new, more physically realistic and practically useful model is presented for the simulation of high temperature austenite flow curves. It is an extension of our earlier empirical model based on the Avrami kinetics of dynamic recrystallization. In the new approach, the normalization parameter is expressed in terms of the fractional recrystallization and not the amount of softening. Compression experiments carried out on a Nb-modified plain carbon steel enable the simulated flow curves and progress of recrystallization predicted by the two models to be compared.
  • Recrystallization Texture of Cold-rolled Oxide Dispersion Strengthened Ferritic Steel

    pp. 951-957

    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.51.951

    The recrystallization behavior of a 88% cold-rolled 15Cr–ODS ferritic steel was investigated. Specimens annealed at low and high temperatures show two different recrystallization modes. Annealing at 1000°C generates a structure consisting of coarse grains with {110}<112> texture, while annealing at 1150°C and 1300°C produce fine grains with {111}<112> texture. This phenomenon is ascribed to that the mobility of boundaries between {110}<112> nuclei and {001}<110> deformed matrix are higher than between {111}<112> nuclei and {001}<110> deformed matrix. Also it is found that a recovery annealing at 900°C prior to recrystallization annealing will retard recrystallization, which results in a structure of coarse grains with {110}<112> texture even after the following annealing at 1300°C.
  • Formation of Ultrafine Grained Dual Phase Steels through Rapid Heating

    pp. 958-964

    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.51.958

    In this study, ultrafine grained dual phase structures have been developed in a plain low carbon steel, 0.17C and 0.74Mn (wt pct). The approach is based on rapid heating of a very fine ferrite-carbide aggregate into the intercritical annealing region followed by water quenching. This rapid heat treatment results in an ultrafine grained dual phase steel with improved properties. The effect of thermomechanical processing parameters such as heating rate and intercritical annealing time on the microstructure and mechanical properties have been examined. The key factors contributing to the grain refinement are uniform distribution of nanosize cementite particles acting as potential sites for austenite nucleation as well as the limited time available for coarsening of the microstructure. The mechanical properties of the present ultrafine grained dual phase steel show an excellent combination of strength and uniform elongation because of considerable work hardening.
  • Evaluation of Sensitization and Self-Healing in Austenitic Stainless Steels Based on Simulations of Cr-Depleted Zones

    pp. 965-968

    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.51.965

    A simulation of the grain boundary precipitation of the Cr-rich carbide, M23C6, in austenitic stainless steels has been carried out using the DICTRA software package employing kinetic and thermodynamic databases. Our calculations reproduced the evolution of the Cr-depleted zone close to M23C6 carbide and the disappearance of the zone after a long annealing time. In addition, the calculated time-temperature-sensitization diagrams were in line with the experimental results of typical corrosion trends with annealing time. According to our results, despite the simple treatment used, a reasonable approximation for the simulations was to set the initial width of the austenite region from which the carbon was drawn as a sixth of the grain size. We also confirmed that the onset of sensitization for a steel with 0.1 mass%C shifted to shorter times and to higher temperatures compared with a steel with 0.06 mass%C.
  • Influence of Critical Carbide Dissolution Temperature during Intercritical Annealing on Hardenability of Austenite and Mechanical Properties of DP-980 Steels

    pp. 969-974

    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.51.969

    The hardenability of intercritically formed austenite and the mechanical properties of DP-980 steels were found to be strongly influenced by the state of the dissolution reaction of carbides during intercritical annealing. The carbide dissolution behavior of 0.15C–Nb–Cr–Mo–V steels was investigated.
  • Evolution of Goss Orientation during Rapid Heating for Primary Recrystallization in Grain-oriented Electrical Steel

    pp. 975-981

    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.51.975

    To obtain ideal Goss-oriented Fe-3.1%Si electrical steel, we studied the Goss orientation and microstructure during the various processes from hot-band annealing to the primary recrystallization. In particular, we examined the effect of the heating rate (20°C/s and 150°C/s) on the primary recrystallization behavior. In the annealed hot-band, the surface and middle layers have different textures. In the surface layer, a weak Goss texture developed, while in the inner layer, very strong α-fiber and weak γ-fiber texture were formed. The cold-rolled sheet had a relatively strong α-fiber and weak γ-fiber texture. In the cold-rolled sheet, the Goss oriented grains with an average size of 0.15 μm were more in the surface layer than in the middle layer. One part of the Goss-oriented grains originated from the annealed hot-band, while the other was formed during the cold rolling. During recrystallization, the size of the Goss-oriented grains was not influenced by the heating rate. However, the fraction and distribution of the grains depended on the heating rate. For high heating rates, the fraction of Goss grains is larger, and these grains had similar distributions in both the surface and middle layers.
  • Grain Boundary Deformation at High Temperature Tensile Tests in ODS Ferritic Steel

    pp. 982-986

    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.51.982

    The tensile test of the recrystallized ODS ferritic steels was performed in the loading direction for the longitudinal and 45° inclined with respect to the grains alignment. The testing temperature was 800°C and the strain rate was 10–4 s–1. A clear serration structure was observed at near the grain boundaries at the surface of 45° specimen ruptured. This is a clear evidence of the occurrence of the grain boundary sliding in 45° direction. For the total strain of 12% in 45° direction, grain boundary deformation induced by sliding was estimated about 9%, whereas the amounts of the transgranular strains was 2% measured by EBSD analysis. The grain-subdivision was also identified near grain boundaries by FIB analysis, which could be caused by a dynamic recrystallization during the localized grain boundary deformation.
  • Effects of Anti-phase Boundary on the Iron Loss of Grain Oriented Silicon Steel

    pp. 987-990

    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.51.987

    We present a systematic analysis of the iron loss behavior of grain oriented silicon steels containing different Si contents using transmission electron microscopy. When the silicon content changed in the range of 3–6.5 wt%, the iron loss showed a convex profile and the maximum iron loss was observed in 5.2 wt% silicon steel. This maximum iron loss should be ascribed to the formation of antiphase boundaries that acted as pinning centers in the magnetic domain wall.
  • Effect of V, Nb and Ti Addition and Annealing Temperature on Microstructure and Tensile Properties of AISI 301L Stainless Steel

    pp. 991-998

    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.51.991

    The effects of V, Nb and Ti additions and the annealing temperatures on the microstructure and tensile properties of AISI 301L stainless steel have been investigated. The grain size of 0.9 μm was obtained by adding 0.5 mass% V with the annealing at 850°C for 30 s, while those of original 301L annealed at 850 and 1000°C were 2.7 and 9.8 μm, respectively. The grain size decreased as V and Nb increased up to 0.5 and 0.1 mass%, respectively, with the increase in the number density of the precipitate particles. The additions of V over 0.5 mass%, Nb over 0.1 mass% and Ti did not affect the grain size because these additions hardly contributed to the increase in the particle number density. The grain size also decreased with the decrease in the annealing temperature from 1000 to 850°C. These grain refinements were achieved mainly by the pinning effect of the precipitates and the decrease in the mobility of the grain boundary itself with the decrease in the annealing temperature. The difference of the pinning effect by V, Nb and Ti was explained by the gap of the solubility limit of these elements between the temperatures of the solution treatment and annealing. 0.2% proof stress increased from 400 to 750 N/mm2 as the amount of V and Nb increased and as the annealing temperature decreased. These strengthenings were explained mainly by the grain refinement in accordance with the Hall-Petch relationship and the influences of other strengthening mechanisms were estimated as quite small.
  • The Increase in a Brittle-to-ductile Transition Temperature in Fe–Al Single Crystals

    pp. 999-1004

    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.51.999

    The effect of aluminium concentration on a brittle-to-ductile transition (BDT) has been investigated in Fe–Al single crystals. The BDT temperatures in Fe-4mass%Al and Fe-8mass%Al crystals with <100> specimen axis were measured by an instrumental falling weight impact tester, indicating that the BDT temperature in Fe-8%Al is higher than that in Fe-4%Al. Twin-twin intersections were seen on fracture surfaces in Fe-8%Al tested at low temperatures, which shows that the intersection was the origin of a brittle fracture. In order to highlight the effect of deformation twinning on the BDT behaviour, specimens with the <110> axis were also employed to suppress the onset of deformation twinning during the impact tests. The BDT temperature in Fe-8%Al was found to be decreased by suppressing deformation twinning, which indicates that deformation twinning is a key mechanism behind increasing the BDT temperature in Fe–Al single crystals. A model to explain the increase in the BDT temperature with aluminium content is also presented.
  • Property and Cost Optimisation of Novel UHS Stainless Steels via a Genetic Alloy Design Approach

    pp. 1005-1010

    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.51.1005

    A computational alloy design approach for precipitation harden Ultra High Strength (UHS) stainless steels is presented. The design methodology is based on thermodynamic and kinetic principles, employing genetic algorithm for optimization. Alloy compositions covering 14 elements are optimized simultaneously together with key heat treatment parameters, i.e., austenitization temperature and ageing temperature, so as to achieve the desired microstructures: strong lath martensite matrix, fine precipitates of particular species for strengthening, adequate Cr concentration in the matrix for corrosion resistance and controlled amounts of undesirable phases throughout the entire heat treatment. Two alloys utilizing MC carbides and Ni3Ti intermetallics, respectively, are designed employing the genetic approach. For the alloys designed, the cost effects of each single element are investigated and both the most and the least cost effective elements are identified. Subsequently the alloy design model was extended to take into account alloying costs by employing the ratio of strengthening contribution to alloying costs as the new optimization factor. Redesigned alloys display significant cost reductions without significantly sacrificing the strength. The extended model is shown to provide valuable guidelines in the industrial practice to design/modify alloy compositions, and optimize strength and cost in an integrated manner.
  • Numerical Simulation on Penetration Stage of a Rising Bubble through an Oil/Water Interface

    pp. 1011-1013

    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.51.1011

  • Pressure Drop in the Blast Furnace Hearth with a Sitting Deadman

    pp. 1014-1016

    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.51.1014

  • Joining of Al2O3 to 316SS Using Braze-infiltrated Ni Net

    pp. 1017-1019

    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.51.1017

Article Access Ranking

19 Jun. (Last 30 Days)

  1. Perspective toward Long-term Global Goal for Carbon Dioxide Mitigation in Steel Industry Tetsu-to-Hagané Vol.105(2019), No.6
  2. A Kinetic Model of Mass Transfer and Chemical Reactions at a Steel/Slag Interface under Effect of Interfacial Tensions ISIJ International Vol.59(2019), No.5
  3. Improvement of Sinter Strength and Reducibility through Promotion of Magnetite Ore Oxidation by Use of Separate Granulating Method ISIJ International Vol.59(2019), No.5
  4. Evaluation of the Structure and Strength of Coke with HPC Binder under Various Preparation Conditions ISIJ International Advance Publication
  5. Effect of a Zn Interlayer on the Adhesion Strength and Corrosion Resistance of Zn–Mg Coated TRIP Steel ISIJ International Vol.59(2019), No.6
  6. Numerical Investigation of Applying High-carbon Metallic Briquette in Blast Furnace Ironmaking ISIJ International Vol.59(2019), No.5
  7. Effects of Surface Microstructure on Selective Oxidation Morphology and Kinetics in N2 + 5%H2 Atmosphere with Variable Dew Point Temperature ISIJ International Vol.59(2019), No.5
  8. Evolution Mechanism of Inclusions in H13 Steel with Rare Earth Magnesium Alloy Addition ISIJ International Advance Publication
  9. Formation of Non-Metallic Inclusion and Acicular Ferrite in Ti–Zr Deoxidized Steel ISIJ International Advance Publication
  10. Effect of Nut Coke Addition on Physicochemical Behaviour of Pellet Bed in Ironmaking Blast Furnace ISIJ International Vol.59(2019), No.5

Search Phrase Ranking

19 Jun. (Last 30 Days)

  1. blast furnace
  2. blast furnace productivity
  3. blast furnace permeability
  4. deadman coke
  5. inclusions
  6. bubbling ladle
  7. isij xafs
  8. joo hyun park
  9. mold flux, b2o3
  10. phosphatability