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. 64 (1978), No. 5

  • Measurements on the Densities and the Surface Tensions of Molten Alkali Metal and Alkali-Earth Metal Fluorides

    pp. 523-532

    Bookmark

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

    Log in / Sign Up
    Densities and surface tensions of molten alkali metal and alkali earth metal fluorides were measured by Archmedean method and maximum bubble pressure method, respectively. The results showed that the properties of the fluorides, such as surface tension, temperature coefficient of surface tension and coefficient of thermal expansion, depended on the Coulomb force experienced by foreign ions. Isothermal compressibility and coefficient of thermal expansion of fluorides calculated by application of the scaled particle theory, developed by H. REISS, agreed well with the experimental results. From the relation between surface tension and molar volume, it has been supposed that structure of liquid surface is similar to that of solid cleavage plane.
  • Deforming Behaviors of a Water Droplet Impinging onto Hot Metal Surfaces

    pp. 533-538

    Bookmark

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

    Log in / Sign Up
    Deformations of a water droplet impinged on the hot metal surfaces were studied. Thin film flow at the bottom part of the deformed droplet was regarded as a potential flow and theoretical velocity components and pressure distributions in it were given. The droplet is decelerated by the pressure difference at the bottom and the upper surfaces.
    From mass and energy balances of the thin film flow theoretical relations of the film thickness and the radial extent of the thin film flow were derived and compared with the experimental data which had been obtained from measurements on the photographs presented by WACHTERS et al.
    For an initial impacting velocity of v0=63 cm/s, the theory on the film thickness and the radial extent well coincided with the experimental data both in the cases taking no account of the surface tension of the droplet and taking account of it. When v0 is 139 cm/s, the radial extents theoretically predicted with taking account of the surface tension only at the spherical portion of the droplet coincide with the data. In the similar calculations under conditions of v0=220 cm/s it was found that the coincidences were within about 25%.
  • On the Structure of Chromium Oxide Film on the Surface of Tinplate

    pp. 539-547

    Bookmark

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

    Log in / Sign Up
    The structure of passivated film on electrolytic tinplate by a cathodic treatment in a dichromate solution has been investigated by anodic potential measurement and Auger-electron spectroscopy.
    According to the analysis of the peak shifts between three peaks of chromium observed in Auger-electron spectrum, the passivated film substantially consists of chromium oxide. Further, a new interpretation to estimate the hydration degree of chromium oxide by analysis of chemical effect of the spectrum was proposed.
  • On Formability Control Factors of Low-Interstitial 18 Cr-Mn Ferritic Stainless Steel

    pp. 548-557

    Bookmark

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

    Log in / Sign Up
    On the purpose of increasing the toughness of welded joint, Mn-added low-interstitial 18 Cr ferritic stainless steel has been developed.
    The present investigation has been directed to make clear the effects of Mn and Ti contents, and of rolling schedule on the formability of titanium-stabilized 18 Cr-Mn ferritic stainless steel sheet. Formability and texture development are evaluated by utilizing mainly plastic strain ratios (r value), work-hardening coefficients (n value) and X-ray pole figure analysis.
    Mn addition of less than 2% has little effect on the formability of cold-rolled annealed sheet. The {554} <225> type texture is formed by Ti addition, and composition range of Ti having the best formability depends on C and N contents and not on Mn. Two-step cold reductions produce higher r values than those produced by the one-step schedules, but Δr values also increase with two-step reductions. The sheet with the least plastic anisotropy can be produced by the processing conbination of non hot-band annealing and one-step cold rolling.
  • Acoustic Emission Study on Hydrogen-Induced Delayed Cracking Propagation in High Strength Steel

    pp. 558-567

    Bookmark

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

    Log in / Sign Up
    quantitative acoustic emission analysis has been applied to study crack propagation modes of hydrogeninduced delayed cracking. Two experiments are conducted; they are weld cracking of small y grooved bud joints and tearing of linear comliance specimens. In the latter case, hydrogen is charged thermally to attain uniform hydrogen concentration.
    The acoustic emission method is suited to detect weld cracking behaviour which changes in accordance with pre -and post- heating. Total counts of acoustic emissions can be used as an index to cross-sectional cracking percentage, and one can determine pre-heating temperature for crack free weld by using this index only.
    Fundamental experiments on the crack propagation behaviour in linear compliance specimens show that the crack propagation speed is influenced by the amount of hydrogen introduced and the stress-intensityfactor at crack tip, where logarithms of acoustic emission count rate and crack propagation speed are found to be linearly related. This relationship is independent of hydrogen content level. Further the energy release rate as emissions is dependent on the stress-intensity-factor and hydrogen level. It increases in accordance with the increase of both the stress-intensity-factor and hydrogen level.
  • Nucleation Sites of Austenite from Lath Martensite in Fe-0.2%C-X Alloys

    pp. 568-577

    Bookmark

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

    Log in / Sign Up
    The influence of alloying elements on the preferential nucleation sites of austenite formed from lath martensite in low carbon low alloy steels by heating above AC1 temperature was studied. The main results obtained are as follows.
    1) In plane carbon steel and low alloy steels containing 1%Mo, 0.2%Nb, or 1%Cr (carbide forming elements) as the third element, prior austenite grain boundaries act as preferential nucleation sites of austenite during the early stage of austenite formation. As the precipitation proceeds, austenite tends to nucleate also inside prior austenite grain.
    2) In an Fe-C-1%Ni alloy, not only prior austenite grain boundaries but also packet boundaries of lath martensite act as the preferential nucleation sites of austenite during the initial stage of austenite formation. As the precipitation proceeds, block boundaries and lath boundaries also become the nucleation sites of austenite. The similar precipitation behavior was observed in the alloys containing 2%Mn, 2%Cu, 1%Si, or 1%Co (non-carbide forming elements) as the third elements.
    3) The effect of the amount of third elements on the preferential nucleation sites of austenite was also studied in the alloys containing Si or Ni. In both cases, nucleation of austenite inside prior austenite grains is more dominant in the higher alloys.
    4) The effects of the formation temperature of austenite and prior austenite grain size on the preferential nucleation sites of austenite were found to be small.
    5) In the alloys containing Ni or Si, nucleation of austenite inside prior austenite grains was clearly observed. Such a phenomenon was approximately explained by the decrease of boundary tension due to micro-segregation of alloying elements on the grain boundary.
    x

    Readers Who Read This Article Also Read

    1. Heat Transfer Phenomena in Immersion Cooling of Heated Steel Plate and Influence of Water Stirring on Heat Transfer Tetsu-to-Hagané Vol.64(1978), No.1
    2. 第97回講演大会討論会講演概要 Tetsu-to-Hagané Vol.65(1979), No.2
    3. 第95回講演大会討論会講演概要 Tetsu-to-Hagané Vol.64(1978), No.2
  • Increase of Delayed Failure Strength by Partial Unloading Method

    pp. 578-584

    Bookmark

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

    Log in / Sign Up
    The effect of three types of pre-stressing, i. e. partial unloading, one cycle loading, and perfect unloading, on the delayed failure strength was investigated using the notched specimen of JIS SNCM8 steel quenched and tempered at 200°C. Using the test stress, σ, the maximum stress, σmax. (>σ), and the unloading stress, σa, the three types of pre-stressing are expressed as:
    partial unloading: σmax. →σmax.a (=σ), one cycle loading: σmax. →σmax. -2σa→σmax.a (=σ), and perfect unloading: σmax. →O→σmax.a (=σ). The results obtained are as follows:
    1) All the pre-stressing methods can markedly increase the lower limit stress σscc if the unloading stress σa is chosen appropriately. Among the three pre-stressing methods, the partial unloading method is the most effective for increasing the delayed failure strength, and the lower limit stress obtained by this method is 4.5 times as high as that obtained by usual delayed failure test.
    2) The minimum unloading stress necessary for increasing the lower limit stress σscc is smaller in the partial unloading method than the one cycle and perfect unloading methods.
    3) The reason why the delayed failure strength is increased by each pre-stressing method can be explained by the decrease of surface stress at the notch root, which will suppress the corrosion reaction and prevent the invasion of hydrogen atoms into the material.
  • The Effect of High-Temperature Solution Treatment on the Toughness of 10Ni High-Toughness Ultra-High Strength Steel

    pp. 585-594

    Bookmark

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

    Log in / Sign Up
    It has been found out in low-carbon 9 to 10 Ni high-toughness ultra-high strength steels that high-temperature solution treatment above 1200°C improves their toughness (vE shelf) significantly. This corresponds to the solution of coarse M6C carbides greater than 0.3μ, which are retained in the steels at the state as rolled or as ordinarily heat-treated. These carbides again precipitate between 900 to 1100°C during cooling after high-temperature solution treatment at the cooling rate slower than 0.5°C/s. The steels high-temperature solution-treated exhibit excellent vEshelf without deterioration of proof strength and ductile-to-brittle transition temperature, compared to conventional heat treatment, when they were again austenitized at lower temperature before aging.
  • α′→γ Reverse Transformation in an 18%Ni Maraging Steel

    pp. 595-604

    Bookmark

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

    Log in / Sign Up
    Mechanism of α′→γ reverse transformation has been examined by means of dilatometric measurements, X-ray analysis and structural observations in an 18% Ni maraging steel.
    The mechanism is changed in the range of heating rate between 100 and 500°C/min. At the lower heating rates, the stabilization (decrcase in Ms and increase in the content of retained γ) and the unstabilization (increase in Ms) of reverted γ are observed, and this phenomenon is concerned with the partitioning of the solute atoms in α′ during heating. Under these conditions, surface relieves are observed during the reverse transformation and γ grain boundaries inherit the former features completely when heated to the temperature range from Af to γ recrystallization temperature. From the above results, the mechanism of α′→γ reverse transformation at lower heating rates is inferred as follows; first, α′ is partitioned to solute rich and solute poor regions by short range diffusion, and in the subsequent α′→γ transformation, martensitic character participates partially.
    On the other hand, at the higher heating rates, either stabilization or unstabilization of the reverted γ is not observed, and accordingly it is considered that α′ transforms to γ martensitically without the diffusion process.
  • Strengthening and Toughening of Maraging Steel of Over 280 kg/mm2

    pp. 605-614

    Bookmark

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

    Log in / Sign Up
    In order to develop ultrahigh strength maraging steels of over 280 kg/mm2, effects of Mo, Ti, and Al contents and thermomechanical treatments on the strength, ductility, and toughness of Fe-16-17Ni-15Co-4-7Mo-1.0-4.5Ti-0.05-2.0Al alloys have been investigated. The peak-aged hardness increased in proportion to the amount of strengthening elements shown as (Mo+2Ti+1.75Al) %. The increases in the amounts of those elements, however, led to the unstable fractures in low stress level during tensile tests, and this meant that the strength corresponding to the aged hardness could not be achieved. This tendency was more pronounced in the alloys with higher Al and Ti contents than in the alloys with higher Mo contents. The combination of the superior KIC and fine grain size can prevent the low stress unstable fracture up to higher strength levels. It has been shown that, by the combination of appropriate alloy compositions and thermomechanical treatments, the ultrahigh tensile strength up to 330 kg/mm2 with the excellent ductility and toughness could be achieved in maraging steel.
    x

    Readers Who Read This Article Also Read

    1. Effect of Co, Mo and Ti Contents on Mechanical Properties of 18Ni Maraging Steels Tetsu-to-Hagané Vol.74(1988), No.10
    2. Grain Size Dependence of Fracture Toughness in an Ultrahigh Strength Maraging Steel Tetsu-to-Hagané Vol.69(1983), No.1
  • Hydrogen Permeation through Iron, Nickel, and Heat Resisting Alloys at Elevated Temperatures

    pp. 615-620

    Bookmark

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

    Log in / Sign Up
    Hydrogen permeabilities of several metals and alloys were measured over the temperature range of 200-1000°C and some factors affecting the hydrogen permeability were discussed. Materials studied were iron, nickel, 80Ni-20Cr alloy, 50Fe-30Ni-20Cr alloy, HK 40, Incoloy 800, Hastelloy X, and Inconel 600. The hydrogen permeability of nickel was proportional to the square root of the pressure and inversely proportional to the membrane thickness. The activation energy and pre-exponential factor for the hydrogen permeation through these metals and alloys were derived from the temperature coefficient. The hydrogen permeability of nickel was larger than that of iron (γ), and the permeabilities of the heat resisting alloys were between those of nickel and iron (γ). There was a close correlation between the hydrogen permeability and nickel content in the alloys, that is, the permeability increased with the increase of the nickel content in the alloys. The formation of the oxide film on the alloy surface in wet hydrogen resulted in a remarkable reduction of the hydrogen permeability at elevated temperatures.
  • Measurement of the Grain Size by X-ray Diffraction

    pp. 621-630

    Bookmark

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

    Log in / Sign Up
    We have developed the technique by which the grain size of austenitic stainless steels can be measured nondestructively and rapidly by utilizing the fact that the numbers of spots along Debye Scherrer rings relate to the numbers of grains in the area irradiated by X-ray.
    The principle and results of this study are as follows.
    1) It is shown theoretically that the numbers of spots along Debye Scherrrer rings diffracted by X-ray relate to those of grains in the irradiated area. Thus the diameter of grains, d can be counted in principle but this can not be done by a simple method. The relative standard deviation (D) of X-ray intensities which are measured at the points distributed along Debye Scherrer rings is theoretically shown to be related to the diameter of grains and its reliability is proved experimentally.
    2) The precision of proportional relation between D and d depends on sampling numbers. Larger sampling numbers give the higher precision. The number of points for intensity measurement along Debye Scherrer rings is limited by the limitation of the space, and consequently the number is enlarged by changing the measuring positions.
    3) The value of D are affected by the prefferred orientation and mixture of large grains. These effects should be corrected in order to enhance the precision and this can be done mathematically.
    x

    Readers Who Read This Article Also Read

    1. Heat Transfer Phenomena in Immersion Cooling of Heated Steel Plate and Influence of Water Stirring on Heat Transfer Tetsu-to-Hagané Vol.64(1978), No.1
    2. 第97回講演大会討論会講演概要 Tetsu-to-Hagané Vol.65(1979), No.2
    3. 第95回講演大会討論会講演概要 Tetsu-to-Hagané Vol.64(1978), No.2
  • X-ray Fluorescence Spectrometric Determination of Microamounts of Sulfur in Iron and Steel by the Glass Bead Sample Technique

    pp. 631-639

    Bookmark

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

    Log in / Sign Up
    An X-ray fluorescence spectrometric method was developed for the determination of microamounts of sulfur in iron and steel.
    Sulfur was separated as barium sulfate based on a conventional gravimetric method and then instead of weighing the precipitate the X-ray fluorescence analysis using a glass bead technique was applied to improve the precision and accuracy in the barium sulfate method.
    The outline of the method is as follows:
    Five grams of a sample are dissolved in nitric and hydrochloric acids. The solution is evaporated to dryness, the salts are dissolved in hydrochloric acid, and metallic zinc is added to reduce ferric ions to ferrous ions. After adjusting the acidity, barium sulfate is precipitated as usual. The filtered precipitate is dried, heated, and fused with 5 g of sodium tetraborate in a Pt-Au-Rh crucible to prepare a glass bead. The X-ray fluorescence intensity of Ba Lα is measured on the bottom surface of the bead and is converted to the sulfur content. Calibration standard beads are prepared from pure barium sulfate synthesized from sulfuric acid and barium chloride.
    The proposed method was applied to JSS standard carbon steels and satisfactory results were obtained. With some modifications in the sample treatment procedure the method was also applicable to steel making iron and stainless steel. The method gives accurate results for sulfur down to 0.001% and is useful as a standard method for the determination of sulfur in iron and steel.
  • On the Determination of Boron Nitride in Steel by Means of Electrolytic Extraction-Infrared Spectrometry

    pp. 640-649

    Bookmark

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

    Log in / Sign Up
    A study was made to establish the reliable method for the determination of boron nitride (BN) in steel.
    The recommendable procedure is as follows: The residue isolated from steel by electrolytic method is collected with a micropore filter (pore size, 0.2μ). The filter is incinerated by use of low temperature hydrogen plasma to decompose the organic substances that affect IR spectrum of BN. As cementite decreases the percentage of transmission of infrared rays, it is decomposed by the immersion in chemical agents solu-tion or by controlled-potential electrolysis. The residue thus freed from cementite and filter is mixed with potassium bromide, prepared into a disk of 10mm in diameter, and absorption intensity of the characteristic band at 1390 cm-1 is measured.
    By the method established, it is possible to analyze quantitatively a very small amounts of BN, down to about 0.0003% in steel.
  • The Current Situation and Problems of the Production of Ferro-Alloys in Japan

    pp. 650-658

    Bookmark

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

    Log in / Sign Up
  • Commencement of the Development Work of Jet Engins in the Last Wartime

    pp. 659-663

    Bookmark

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

    Log in / Sign Up
  • なんとかしてもらいたい三つの問題

    pp. 664-665

    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. Effect of Ni on the Behavior of Austenite Grain in Ni-Cr-Mo-V Steels Tetsu-to-Hagané Vol.58(1972), No.1
    2. Reverse Transformation of Low-carbon Low Alloy Steels Tetsu-to-Hagané Vol.60(1974), No.2
    3. Nucleation Sites of Austenite from Lath Martensite in Fe-0.2%C-X Alloys Tetsu-to-Hagané Vol.64(1978), No.5
  • 鉄鋼技術情報センターの設置について

    pp. 666-669

    Bookmark

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

    Log in / Sign Up
  • 抄録

    pp. 670-677

    Bookmark

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

    Log in / Sign Up

Article Access Ranking

18 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. 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
  6. Numerical Investigation of Applying High-carbon Metallic Briquette in Blast Furnace Ironmaking ISIJ International Vol.59(2019), No.5
  7. Evolution Mechanism of Inclusions in H13 Steel with Rare Earth Magnesium Alloy Addition ISIJ International Advance Publication
  8. Effect of Nut Coke Addition on Physicochemical Behaviour of Pellet Bed in Ironmaking Blast Furnace ISIJ International Vol.59(2019), No.5
  9. Formation of Non-Metallic Inclusion and Acicular Ferrite in Ti–Zr Deoxidized Steel ISIJ International Advance Publication
  10. Surface Tension Calculation of Molten Slag in SiO2–Al2O3–CaO–MgO Systems Based on a Statistical Modelling Approach ISIJ International Vol.59(2019), No.5

Search Phrase Ranking

18 Jun. (Last 30 Days)

  1. blast furnace
  2. blast furnace productivity
  3. blast furnace permeability
  4. deadman coke
  5. inclusions
  6. a structurally-based viscosity model of the fully liquid slags in the cao-mgo-al2o3-feo-sio2 system
  7. bubbling ladle
  8. isij xafs
  9. joo hyun park
  10. mold flux, b2o3