Tetsu-to-Hagane
Online ISSN : 1883-2954
Print ISSN : 0021-1575
ISSN-L : 0021-1575
Search
Advanced search
OR
Browse
Search
Volume 101, Issue 5
Displaying 1-5 of 5 articles from this issue
Show all abstracts
    • |<
    • <
    • 1
    • >
    • >|
Steelmaking
Regular Article
  • Direct Measurement of Agglomeration Force Exerted between Alumina Particles in Molten Steel
    Katsuhiro Sasai
    2015 Volume 101 Issue 5 Pages 275-283
    Published: 2015
    Released on J-STAGE: April 30, 2015
    DOIhttps://doi.org/10.2355/tetsutohagane.101.275
    JOURNAL OPEN ACCESS FULL-TEXT HTML
    Show abstractHide abstract
    As a fundamental study to clarify the agglomeration and coalescence of alumina inclusions in molten steel from the viewpoint of interfacial chemical interactions, it has been experimentally verified for the first time that significant agglomeration force is exerted between alumina particles in aluminum deoxidized molten steel by using a newly established experimental method. In this method, the agglomeration force exerted between alumina particles in molten steel is directly measured separately from the effect of molten steel flow. In addition, it has been quantitatively demonstrated that the contact angles measured between aluminum deoxidized molten steel and an alumina plate are larger than those between the molten iron-oxygen alloy and the alumina plate, which have already been measured by other researchers. Moreover, it has also been indicated by analyzing the actual measurement values of agglomeration force with an interaction model taking contact angles and interfacial properties into consideration that the agglomeration force between the alumina particles in aluminum deoxidized molten steel derives not from the van der Waals force but from the cavity bridge force occurring due to molten steel, which is unlikely to wet the alumina particles. Meanwhile, it has been assumed that the agglomeration force on spherical alumina inclusions in aluminum deoxidized molten steel calculated on the basis of the interaction model according to the cavity bridge force is greater than the buoyant force and drag force, and the alumina inclusions once coming into contact are therefore not prone to be simply dissociated even under molten steel flow. Thus, they maintain the agglomeration state and are subsequently sintered and form comparatively solidly bonded alumina clusters.
    View full abstract
    Download PDF (1538K) Full view HTML
Forming Processing and Thermomechanical Treatment
Regular Article
  • Simulation of Coming out of the Shaft from the Ceramics Sleeve During Rotation of the Rollers Connected under Small Shrink Fitting Ratio
    Nao-Aki Noda, Yoshikazu Sano, Yasushi Takase, Shota Harada, Dedi Surya ...
    2015 Volume 101 Issue 5 Pages 284-292
    Published: 2015
    Released on J-STAGE: April 30, 2015
    DOIhttps://doi.org/10.2355/tetsutohagane.101.284
    JOURNAL OPEN ACCESS FULL-TEXT HTML
    Show abstractHide abstract
    In this paper the loosening and coming out of a roller is considered by using FE analysis when a ceramics sleeve is shrinking fitted to two steel shafts. It should be noted that only small shrink fitting ratio can be applied for the connection because of the brittleness of ceramics. However care should be taken for coming out of the shafts during rotation under such small shrink fitting ratio. In this study therefore the finite element analysis is applied to simulate this behavior. Then, the coming out behavior during rotation can be realized by the simulation where the rotation of the roller is replaced by the shift of the load at an interval of the rotation angle. Under smaller shrink fitting ratio the shaft comes out, but under larger shrink fitting ratio the shaft does not. The effects of the magnitude of the load, friction coefficient, and stiffness of the shaft are also discussed.
    View full abstract
    Download PDF (7586K) Full view HTML
  • Influence of Heating Temperature on Edge Crack in Hot Rolling of 36%Ni-Fe Alloy
    Junichi Tateno, Takashi Samukawa, Yasuhiro Sodani
    2015 Volume 101 Issue 5 Pages 293-299
    Published: 2015
    Released on J-STAGE: April 30, 2015
    DOIhttps://doi.org/10.2355/tetsutohagane.101.293
    JOURNAL OPEN ACCESS FULL-TEXT HTML
    Show abstractHide abstract
    For the purpose of edge crack control in hot rolling of 36%Ni-Fe alloys, a high temperature tensile test and laboratory-scale hot rolling experiment were carried out. Intergranular oxidation has been considered to be one of the major factors in edge cracking. Edge cracks which initiate from intergranular oxidation grow to the inner side along coarse grain boundaries as the thickness reduction ratio increases. The depth of intergranular oxidation increases at higher reheating temperatures. However, recrystallization occurs at the crack tip, and this has the effect of suppressing crack growth. This suggests that promoting recrystallization during hot rolling by increasing the reheating temperature, rather than inhibition of intergranular oxidation as such, is effective for suppressing edge cracking.
    View full abstract
    Download PDF (1720K) Full view HTML
Transformations and Microstructures
Regular Article
  • Effect of Mo on γ to α Transformation and Precipitation Behavior in B-added Steel
    Taishi Fujishiro, Takuya Hara, Genichi Shigesato
    2015 Volume 101 Issue 5 Pages 300-307
    Published: 2015
    Released on J-STAGE: April 30, 2015
    DOIhttps://doi.org/10.2355/tetsutohagane.101.300
    JOURNAL OPEN ACCESS FULL-TEXT HTML
    Show abstractHide abstract
    Effect of the combined addition of molybdenum (Mo) and boron (B) on austenite (γ) to ferrite (α) transformation and precipitation behavior were investigated using low-alloy steels. B-added steel and Mo-B combined steel were held at 923 K (γ region) in order to precipitate boride. B content as precipitates increased and γ to α transformation was promoted with holding time at 923 K. In B-added steel, both M23(C,B)6 and M2B were observed. The transition from M23(C,B)6 to M2B caused by the increase in holding time at 923 K. By contrast, in Mo-B combined steel, no M2B was observed regardless of the holding time. Mo addition suppresses not only the M23(C,B)6 formation but also the M2B formation. M2B contains larger amounts of B than M23(C,B)6. B content as precipitates in Mo-B combined steel was much lower than that in B-added steel due to the suppression of M2B precipitates. The effect of Mo for B containing steel suppresses the precipitation of M23(C,B)6 and M2B and increases more segregated B in austenite grain boundary that contributes to γ to α transformation.
    View full abstract
    Download PDF (2521K) Full view HTML
Mechanical Properties
Regular Article
    • |<
    • <
    • 1
    • >
    • >|
feedback
 Top