Mechanisms of interfacial reactions between 316L stainless steel and MnO–SiO2 oxide during isothermal heating
Cheng-song Liu1,2, Fu-kang Li1,2, Hua Zhang1,2, Jie Li3, Yong Wang1,2, Yuan-yuan Lu3, Li Xiong3, Hong-wei Ni1,2
1 The State Key Laboratory of Refractories and Metallurgy, Wuhan University of Science and Technology, Wuhan 430081, Hubei, China; 2 Hubei Provincial Key Laboratory for New Processes of Ironmaking and Steelmaking, Wuhan University of Science and Technology, Wuhan 430081, Hubei, China; 3 Hubei Guoan Special Steel Inspection Co., Ltd., Huangshi 435000, Hubei, China
Mechanisms of interfacial reactions between 316L stainless steel and MnO–SiO2 oxide during isothermal heating
Cheng-song Liu1,2, Fu-kang Li1,2, Hua Zhang1,2, Jie Li3, Yong Wang1,2, Yuan-yuan Lu3, Li Xiong3, Hong-wei Ni1,2
1 The State Key Laboratory of Refractories and Metallurgy, Wuhan University of Science and Technology, Wuhan 430081, Hubei, China; 2 Hubei Provincial Key Laboratory for New Processes of Ironmaking and Steelmaking, Wuhan University of Science and Technology, Wuhan 430081, Hubei, China; 3 Hubei Guoan Special Steel Inspection Co., Ltd., Huangshi 435000, Hubei, China
摘要 Diffusion couple experiments were performed to study the thermodynamic and kinetic mechanisms of interfacial reactions between the 316L stainless steel and the composite MnO–SiO2 oxide during isothermal heating at 1473 K (1200 °C) for 1, 3, 5, and 10 h and at 1173, 1273, 1373, 1473, and 1573 K (900, 1000, 1100, 1200, and 1300 °C) for 3 h. Compositional variations in the 316L stainless steel and the composite MnO–SiO2 oxide in the vicinity of the steel–oxide interface in each diffusion couple specimen were determined. Before and after isothermal heating, thermodynamic equilibria between the oxide and steel at the interface were estimated in accordance with the calculation of the Gibbs free energy change in the interfacial steel–oxide reactions. The diffusion coefficients of Mn, Cr, and Si in 316L stainless steel under different experimental conditions were quantitatively acquired. The results showed that solid-state interfacial reactions occurred between the Cr in the 316L stainless steel and composite MnO–SiO2 oxide during isothermal heating, which resulted in the depletion of Cr and accumulation of Si and Mn in the steel in the vicinity of the steel–oxide interface. The widths of the Crdepleted zone, Mn-accumulated zone and Si-accumulated zone all showed increasing trends with increasing isothermal heating temperature and time. The average values of the diffusion coefficients of Mn, Cr, and Si in the steel at 1473 K (1200 °C) were 1.21 × 10–14 ± 2.96 × 10–15, 1.69 × 10–14 ± 2.54 × 10–15, and 1.00 × 10–14 ± 1.96 × 10–15 m2 s-1, respectively, and they continued to increase with increasing isothermal heating temperature.
Abstract：Diffusion couple experiments were performed to study the thermodynamic and kinetic mechanisms of interfacial reactions between the 316L stainless steel and the composite MnO–SiO2 oxide during isothermal heating at 1473 K (1200 °C) for 1, 3, 5, and 10 h and at 1173, 1273, 1373, 1473, and 1573 K (900, 1000, 1100, 1200, and 1300 °C) for 3 h. Compositional variations in the 316L stainless steel and the composite MnO–SiO2 oxide in the vicinity of the steel–oxide interface in each diffusion couple specimen were determined. Before and after isothermal heating, thermodynamic equilibria between the oxide and steel at the interface were estimated in accordance with the calculation of the Gibbs free energy change in the interfacial steel–oxide reactions. The diffusion coefficients of Mn, Cr, and Si in 316L stainless steel under different experimental conditions were quantitatively acquired. The results showed that solid-state interfacial reactions occurred between the Cr in the 316L stainless steel and composite MnO–SiO2 oxide during isothermal heating, which resulted in the depletion of Cr and accumulation of Si and Mn in the steel in the vicinity of the steel–oxide interface. The widths of the Crdepleted zone, Mn-accumulated zone and Si-accumulated zone all showed increasing trends with increasing isothermal heating temperature and time. The average values of the diffusion coefficients of Mn, Cr, and Si in the steel at 1473 K (1200 °C) were 1.21 × 10–14 ± 2.96 × 10–15, 1.69 × 10–14 ± 2.54 × 10–15, and 1.00 × 10–14 ± 1.96 × 10–15 m2 s-1, respectively, and they continued to increase with increasing isothermal heating temperature.
Cheng-song Liu,Fu-kang Li,Hua Zhang, et al. Mechanisms of interfacial reactions between 316L stainless steel and MnO–SiO2 oxide during isothermal heating[J]. Journal of Iron and Steel Research International, 2023, 30(8): 1511-1523.
2023, Vol. 30 
