GRK2802: Density, Surface Tension and Viscosity of Liquid Low-Sulphur Manganese-Boron Steel via Maximum Bubble Pressure and Oscillating Crucible Methods

Abstract

This study investigates the thermophysical properties of low-sulphur manganese-boron steel with varying boron and sulphur contents at different temperatures. Density and surface tension were measured between 1550-1650 °C using the Maximum Bubble Pressure (MBP) method, while viscosity was examined between 1530-1570 °C using an improved Oscillating Crucible Viscometer (OCV). The methods yielded results with low error, consistent with existing literature. The density of the base steel decreased 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 sulphur (up to 130 ppm) did not significantly change the density. Sulphur, increasing from 39 ppm to 130 ppm, reduced the surface tension from 1416 ± 12 mN m-1 to 1302 ± 9 mN m-1 at 1650 °C. Boron’s effect on surface tension varied, possibly influenced by other elements like oxygen. Viscosity ranged from 5.74 to 6.44 mPa s, with boron and sulphur additions causing minimal changes, the largest deviation being 8%. These results provide valuable data for the simulation, modelling, control, and optimization of liquid steel processing.