Solidification segregation behavior of Nb-containing 310S steel
Yu-tuo Zhang1,2, Hao Zou1
1 School of Materials Science and Engineering, Shenyang Ligong University, Shenyang 110159, Liaoning, China 2 Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, Liaoning, China
Abstract：The solidification characteristics and segregation behavior of solute elements Nb, Ni, Mn, Si, Cr and C in 0.3 wt.% Nb– 310S steel were investigated using the isothermal solidification quenching experiment and Thermo-Calc calculation. The phase transformation for 0.3%Nb–310S steel under equilibrium condition can be summarized as follows: liquid (L) → L + γ (1406 °C) → γ (1334 °C) → γ + NbC (1322 °C) → γ + NbC + M23C6 (1006 °C) → γ + NbC + M23C6 → σ (755 °C). The results showed that the solidification began with the formation of primary austenite dendrite. The volume fraction of the liquid phase decreased rapidly as the temperature decreased in the initial solidification stage, and then, the liquid phase fraction decreased slowly. When austenite formed, Mn and Ni were enriched in the solid phase, while Nb and C were rejected into the liquid. Nb was present the highest segregation coefficient in 0.3%Nb–310S austenitic stainless steel. The segregation of Nb was the most serious, followed by Mn, Ni and C. Cr and Si exhibited slight segregation during the solidification. The solidification was terminated by the formation of NbC phase.
Yu-tuo Zhang,Hao Zou. Solidification segregation behavior of Nb-containing 310S steel[J]. Journal of Iron and Steel Research International, 2023, 30(1): 82-87.
2023, Vol. 30 
