鋼の固液共存状態におけるSi-Mn 系脱酸介在物の形態と組成解析

Translated title of the contribution: Morphology and Composition of Inclusions in Si-Mn Deoxidized Steel at the Solid-liquid Equilibrium Temperature

Research output: Contribution to journalArticlepeer-review

Abstract

Morphology and composition of inclusions change with temperature. However, besides the temperature conditions during steelmaking or continuous casting, other factors contributing to changes in the morphology and composition of inclusions during solidification are still unknown. In this study, the formation of complex inclusions in Si-Mn deoxidized steel after isothermal holding at the solid-liquid equilibrium temperature (TS) of steel was investigated. The typical inclusions found in the alloy were MnO-SiO2 based, spherically shaped and homogeneously distributed. With isothermal holding at the solid-liquid equilibrium temperature of steel, formation of a secondary SiO2-rich inclusion phase occurred. The changes in the composition of the inclusions depended on the manganese and silicon contents in the metal. The general mechanism of inclusion formation observed in this study can be divided into three steps: 1) the formation of primary MnO-SiO2 inclusions above the liquidus temperature when the steel is in a completely molten state as a result of the deoxidation process; 2) the nucleation of secondary inclusions as the molten steel becomes supersaturated with the solute elements while holding at the solid-liquid equilibrium temperature; and 3) the growth and coalescence of inclusions due to natural convection in the molten alloy. From this, the inclusions formed in Si-Mn deoxidized alloys held isothermally at the solid-liquid equilibrium temperature were of three types: primary MnO-SiO2 inclusions, secondary SiO2 inclusions and complex inclusions with both primary MnO-SiO2 inclusions and precipitated secondary SiO2 inclusions.

Translated title of the contributionMorphology and Composition of Inclusions in Si-Mn Deoxidized Steel at the Solid-liquid Equilibrium Temperature
Original languageJapanese
Pages (from-to)509-516
Number of pages8
JournalTetsu-To-Hagane/Journal of the Iron and Steel Institute of Japan
Volume108
Issue number8
DOIs
Publication statusPublished - 2022 Aug

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Physical and Theoretical Chemistry
  • Metals and Alloys
  • Materials Chemistry

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