Mechanism of Interfacial Reactions Between Type 430 Stainless Steel and Complex MgO-Al2O3-SiO2-CaO-MnO Oxide During Isothermal Heating

作者：Gan, Wenliang; Liu, Chengsong^*; Liao, Kai; Zhang, Hua; Ni, Hongwei

来源：Metallurgical and Materials Transactions B: Process Metallurgy and Materials Processing Science , 2022, 53(4): 2553-2569.

DOI：10.1007/s11663-022-02551-0

• INCLUSION FORMATION
• EVOLUTION
• BEHAVIOR

To quantitatively study the mechanism of interfacial reactions between type 430 stainless steel and complex MgO-Al2O3-SiO2-CaO-MnO oxide during the soaking process before hot-rolling, diffusion couple experiments at 1373 K and 1673 K (1100 degrees C and 1400 degrees C) with different MnO and SiO2 contents were conducted. Experimental results showed that the "solid-liquid'' and "solid-solid'' steel-oxide reactions occurred between the Cr, Mn and Si in the steel and the MnO and SiO2 in the MgO-Al2O3-SiO2-CaO-MnO oxide during the heating at 1373 K and 1673 K (1100 degrees C and 1400 degrees C), respectively, resulting in a change of steel and oxide compositions. Calculations on the Gibbs free energy changes of those steel-oxide reactions before and after isothermal heating indicated the thermodynamic equilibrium at the interface of the steel and oxide were generally achieved after the heating at 1373 K and 1673 K (1100 degrees C and 1400 degrees C) for 240 min. Diffusion coefficients of related elements in type 430 stainless steel at 1373 K and 1673 K (1100 degrees C and 1400 degrees C) were calculated: Cr, Mn, and Si at 1673 K (1400 degrees C) are in the range of 1.44 to 3.40 9 10(-12), 0.42 to 1.19 9 10(-11) and 0.52 to 1.34 9 10(-11) m(2) m(-1), respectively, while Mn and Si at 1373 K (1100 degrees C) are in the range of 0.80 to 3.71 9 10(-13) and 1.04 to 5.64 9 10(-13) m(2) s(-1), respectively.