TY - JOUR
T1 - Mn Depletion Behavior at Oxide/matrix Interface in Low Oxygen Weld Metal of Low Carbon Steel
AU - Homma, Ryuichi
AU - Shigesato, Genichi
AU - Fujioka, Masaaki
AU - Kadoi, Kota
AU - Inoue, Hiroshige
N1 - Publisher Copyright:
© 2022 The Iron and Steel Institute of Japan.
PY - 2022
Y1 - 2022
N2 - The structure of the oxide as a nucleus for intragranular ferrite formation in the low O weld metal and the formation mechanism of Mn depleted zone (MDZ) at the oxide/matrix interface were studied using liquid-tin quenched specimens at high-temperature conditions during laser welding of low carbon Ti added steel. At a high temperature of 1720 K, MDZ is formed around the complex oxides of (Ti,Mn)3O5, (Ti,Mn)2O3, and liquid phase oxides (containing Si, Mn, Ti, and S). The width of the MDZ increases with cooling, and at low temperatures (1275 K) MDZ is formed around the complex oxide consisting mainly of (Ti,Mn)2O3 with MnS and Si-Mn oxides. These MDZs are formed all around the complex oxides, regardless of the kind of oxide. The formation of MDZs is considered to promote the ferrite transformation around the oxides. The equilibrium Mn concentration in each of the oxide phases increases during the cooling process and the thermodynamically stable phase changes from (Ti,Mn)3O5 with a low equilibrium Mn concentration to (Ti,Mn)2O3 with a high equilibrium Mn concentration, which drives the diffusion of Mn from the matrix phase to the oxide. In this process, MDZs are formed all around the complex oxides.
AB - The structure of the oxide as a nucleus for intragranular ferrite formation in the low O weld metal and the formation mechanism of Mn depleted zone (MDZ) at the oxide/matrix interface were studied using liquid-tin quenched specimens at high-temperature conditions during laser welding of low carbon Ti added steel. At a high temperature of 1720 K, MDZ is formed around the complex oxides of (Ti,Mn)3O5, (Ti,Mn)2O3, and liquid phase oxides (containing Si, Mn, Ti, and S). The width of the MDZ increases with cooling, and at low temperatures (1275 K) MDZ is formed around the complex oxide consisting mainly of (Ti,Mn)2O3 with MnS and Si-Mn oxides. These MDZs are formed all around the complex oxides, regardless of the kind of oxide. The formation of MDZs is considered to promote the ferrite transformation around the oxides. The equilibrium Mn concentration in each of the oxide phases increases during the cooling process and the thermodynamically stable phase changes from (Ti,Mn)3O5 with a low equilibrium Mn concentration to (Ti,Mn)2O3 with a high equilibrium Mn concentration, which drives the diffusion of Mn from the matrix phase to the oxide. In this process, MDZs are formed all around the complex oxides.
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U2 - 10.2355/tetsutohagane.TETSU-2021-087
DO - 10.2355/tetsutohagane.TETSU-2021-087
M3 - Article
AN - SCOPUS:85125747570
SN - 0021-1575
VL - 108
SP - 211
EP - 223
JO - Tetsu-To-Hagane/Journal of the Iron and Steel Institute of Japan
JF - Tetsu-To-Hagane/Journal of the Iron and Steel Institute of Japan
IS - 3
ER -