Assessment of a Simplified Correlation Between Wettability Measurement and Dispersion/Coagulation Potency of Oxide Particles in Ferrous Alloy Melt

Abstract

This article seeks to demonstrate a direct and simplified correlation between the measurement of the wettability and the agglomeration potency of the inclusion particles in liquid ferrous alloy. The established methodology has been validated by the agreement between the calculated coagulation coefficient of Al 2 O 3 particles and the experimental data in the open literature. Subsequently, the coagulation coefficient of Al 2 O 3 , MgO, and Ti 2 O 3 particles in ferrous alloy melts was evaluated quantitatively by the proposed method using the actual experimental data of contact angle and surface tension. Meanwhile, the effect of the matrix composition has been investigated by comparing the Hamaker constant and coagulation coefficient between Ti 2 O 3 / pure iron and Ti 2 O 3 /low-carbon steel systems. It is noted that the change of coagulation coefficient associated with the contact angle is caused by the formation of a new phase at the oxide/metal interface at the high temperature. The present work aims to provide a deep understanding of the connection between inclusion motion behavior in the liquid alloy and the high temperature interfacial phenomenon.

Role of Interfacial Properties in the Evolution of Non-metallic Inclusions in Liquid Steel

“…This theoretical value is far smaller than the actual value of 0.27-0.63 for Al 2 O 3 inclusions in liquid steel. 33) Moreover, according to the work by Nakajima et al, 36) no significant difference in magnitude of the van der Waals force was observed among severe non-wetting inclusions (such as Al 2 O 3 ) and slightly non-wetting inclusions (such as MgO). Therefore, the van der Waals force is not responsible for the strong attraction between non-wetting inclusions.…”

“…( 11). Nakajima et al 36) proposed a new expression of the Hamaker constant by introducing the interfacial energy between inclusions and liquid steel, as:…”

“…This phenomenon is known as clustering, and is commonly observed in steelmaking, especially among inclusions unwetted by liquid steel. Nakajima et al 36) found that the Hamaker constants for Clusters, due to their large size, can float up more rapidly to the top slag. They are, however, very detrimental to steel properties if they remain in solidified steel.…”

Effect of Manufacturing Conditions and Al Addition on Inclusion Characteristics in Co-Based Dual-Phase High Entropy Alloy

“…where e is the turbulent energy dissipation rate (0.01 m 2 / s 3 ), r i is the radius of the inclusion particle (m), a is the ionic radius (2.8 9 10 À10 m for Al 2 O 3 ). [35] l is the dynamic viscosity of alloy, q HEA is the density of the liquid HEA, c IM is the interfacial energy (J/m 2 ) between the inclusion particle and the liquid HEA, these parameters were calculated by Thermo-Calc 2021b with the TCNI11 database due to the absence of physical parameters in the HEA system, the same method has been applied in Co-based dual-phase HEA. [9] Figure 10 shows the calculated coagulation coefficient of different inclusions in different alloys at 1500 °C with inclusion sizes of 2, 5, and 10 lm.…”

Evolution of Nonmetallic Inclusions with Varied Argon Stirring Condition during Vacuum Degassing Refining of a Bearing Steel

“…where γ MI (deg cm À2 ) is the interfacial tension between the inclusion and the molten steel; γ IG and γ MG (deg cm À2 ) are the interfacial tension of the inclusion and the molten steel with the gas phase, respectively; and θ (deg) is the contact angle and α (deg) is the visible contact angle between the inclusion and the molten steel. γ MG of Fe-1.02 mass% C liquid iron at 1873 K was 1696 deg cm À2 used in the current work proposed by Bretonnet; [42] c is the coagulation coefficient for the turbulent collision; μ M is the surface viscosity of the molten steel, 6.7 Â 10 À3 Pa s; [43] d I is the diameter of inclusions and is 8 μm as the average diameter of >5 μm inclusions in the current work; ρ M denotes the density of the molten steel, 7070 kg m À3 ; [43] ε is the turbulent energy dissipation rate, 0.01 m 2 s À3 ; [44] AIMI is the Hamaker constant; and L is the distance between anion and cation in a given inclusion, which was 2.8 Â 10 À10 m for oxide inclusions. [45] The reported γ IG , θ, and α at 1873 K are listed in Table 2.…”