Density, Surface Tension, and Viscosity of Liquid Low‐Sulfur Manganese–Boron Steel via Maximum Bubble Pressure and Oscillating Crucible Methods

In this study, the thermophysical properties of low‐sulfur manganese–boron steel with varying boron and sulfur contents at different temperatures are investigated. Density and surface tension are measured between 1550 and 1650 °C using the maximum bubble pressure method, while viscosity is examined between 1530 and 1570 °C using an improved oscillating crucible viscometer. The methods yield results with low error, consistent with existing literature. The density of the base steel decreases from 7057 ± 25 kg m−3 at 1550 °C to 6843 ± 85 kg m−3 at 1650 °C. The addition of boron (up to 57 ppm) and sulfur (up to 130 ppm) does not significantly change the density. Sulfur, increasing from 39 to 130 ppm, reduces the surface tension from 1416 ± 12 to 1302 ± 9 mN m−1 at 1650 °C. Boron's effect on surface tension varies, possibly influenced by other elements like oxygen. Viscosity ranges from 5.74 to 6.44 mPa s, with boron and sulfur additions causing minimal changes, the largest deviation being 8%. In these results, valuable data for the simulation, modeling, control, and optimization of liquid steel processing are provided.