Interaction Between Oxide Inclusions and Low-Density Steel During Heat Treatment

作者：Wang, Weisheng; Zhu, Hangyu^*; Zhou, Jie; Song, Mingming; Wang, Lanqing

来源：Metallurgical and Materials Transactions B: Process Metallurgy and Materials Processing Science , 2022, 53(5): 2991-3002.

DOI：10.1007/s11663-022-02580-9

• SI SOLID ALLOY
• MGO-CENTER-DOT-AL2O3 SPINEL INCLUSIONS
• INTERFACIAL REACTION
• MNO-SIO2-FEO OXIDE
• MN
• TRANSFORMATION
• BEHAVIOR
• MECHANISM
• DIFFUSION
• TOUGHNESS

A novel liquid-metal-suction (LMS) method was performed to prepare diffusion couple specimens. The Al2O3/steel and MgO/steel interface characteristics were investigated after heat treatment at 1373 K (1100 degrees C) for 10 hours using an electron probe microanalyzer (EPMA) and scanning electron microscopy (SEM). The results indicated that the bulk oxide and steel combined tightly. After heat treatment, the diffusion of oxygen from the oxide to the steel matrix resulted in the formation of oxide particles in the particle precipitation zone (PPZ) on the steel side. At the A1203/steel interface, fine Al2O3 and coarse Al2O3 were observed in the PPZ after heat treatment. At the MgO/steel interface, MgO center dot Al2O3 (MA) spinel particles and dendritic Al2O3 were observed in the PPZ, and a thin MA spinel layer was detected on the bulk MgO side. After heating at 1373 K (1100 degrees C), the typical non-metallic inclusions (NMIs) in the low-density samples included AlN, MnS, AlN-MnS, and a small amount of Al2O3-MnS, whereas MnS-containing NMIs became spherical or near-spherical, and the number of fine AlN inclusions increased. In addition, the Mn diffusion from the steel matrix to the interface was revealed based on Fick's second law, and the Mn contents detected through EPMA analysis after heat treatment were consistent with the theoretical calculation.