Control of mesoscopic structure of super metal by fine dispersion of inclusion particles

2000 Fiscal Year Final Research Report Summary

• Project/Area Number: 10450278
• Research Category: Grant-in-Aid for Scientific Research (B).
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Metal making engineering
• Research Institution: Tohoku University
• Principal Investigator: SUITO Hideaki Institute for Advanced Materials Processing, Tohoku University, Professor, 素材工学研究所, 教授 (70030054)
• Co-Investigator(Kenkyū-buntansha): OHTA Hiroki Institute for Advanced Materials Processing, Tohoku University, Research Associate, 素材工学研究所, 助手 (20271976) ; TAKAHASHI Junichi Institute for Advanced Materials Processing, Tohoku University, Research Associate, 素材工学研究所, 助手 (20261472) ; INOUE Ryo Institute for Advanced Materials Processing, Tohoku University, Associate Professor, 素材工学研究所, 助教授 (70111309)
• Project Period (FY): 1998 – 2000
• Keywords: Inclusion / Deoxidation product / Nitride / Fine dispersion / Austenite grain size / Control of grain size

Research Abstract

An Fe-10 mass pct Ni melt was deoxidized by M (M=Si, Ti, Al, Zr, and Ce) at 1600℃, and then was quenched in water. The mean spatial diameter of inclusions tended to increase with increasing holding time, but did not show the systematic trend with respect to the deoxidation power (Si<Ti<Al< Zr<Ce). The number of particle sections per unit area decreased with decreasing deoxidation power and with increasing holding time. In all deoxidation experiments, the initial primary deoxidation products contained FeO and the content of FeO decreased with increasing the deoxidation power and holding time.
An appropriate amount of Fe-50 mass% Ti alloy was added into Fe-10 mass% Ni melt, and then quenched. The number of particles per unit area, N_A, in nondendritic zone is significantly smaller than that in dendritic zone, and the N_A values in both zones increase with area fraction of solid and holding time at 1400℃.
An appropriate amount of Fe-50 mass% M (M=Al, Zr, Ce) alloy or Ni-Mg alloy was added into Fe-10 mass% Ni melt, and then stirred at 1600℃. Thereafter, An Fe-50 mass% Ti alloy was added into the melt, and then stirred. The melt was cooled to 1400℃ and quenched. The N_A values for the TiN+MgO particles are considerably higher than those in other deoxidation. The size of TiN+MgO particles are smaller than those in other deoxidation. The N_A values for TiN and TiN+M_xO_y (M=Al, Zr and Ce) particles in dendritic mode are higher than those in nondendritic mode, while the size of TiN and TiN+M_xO_y (M=Al, Zr and Ce) particles in dendritic mode are smaller than those in nondendritic mode. The N_A values for the TiN and TiN+M_xO_y particles tend to slightly increase with holding time at 1400℃, but the values remain mostly unchanged.