Viscosity and structure studies of iron-based quaternary melts: The effect of P

This study systematically investigates the underlying principles and mechanisms governing viscosity across the entire range for the Fe-4.5C-0.1Ti-xP (in wt.%) melts. The viscosity profile exhibits distinct variations in different phases. In the solid -liquid transition region, the primary determinant of viscosity is the presence of solid phase particles, while in the region characterized by liquid phase, the primary influencing factor is the number of clusters. Notably, the impact of P content demonstrates a contrasting effect on low-temperature solid phase precipitation and high-temperature liquid phase structure. During the low-temperature solid phase precipitation stage, an increase in P content serves as a catalyst for graphite precipitation, resulting in an increase in system viscosity and, by extension, impacting an increase in system viscosity. In contrast, within the high-temperature liquid phase, the interaction of P with iron (Fe) results in the breakdown of mid-range clusters in the original system, leading to the formation of smaller clusters with a reduced overall cluster volume. Consequently, an increase in P content is associated with a decrease in viscosity. These findings provide a nuanced understanding of the interplay between P content and viscosity throughout different phases of the melt.