Surface tension of molten stainless steels under plasma conditions

The surface tension and the density of 304 stainless steels with the sulfur contents of 10, 100 and 250 ppm were measured under low pressure Ar plasma conditions in the temperature range of 1823–2073 K. The measurements were carried out by the sessile drop method and a (La0.9Ca0.1)CrO3 substrate was used. No significant influence of the plasma was observed on the surface tension and its temperature coefficient. The surface tension and density of 304 stainless steel are expressed using the following equations: $$ \displaylines{ \gamma = - 0.12\times T + 1980 \ ({\rm mN/m}) \quad (10 \,{\rm ppm\, Sulfur})\cr \gamma = 0.29\times T + 1030 \ ({\rm mN/m})\quad (110 \,{\rm ppm \,Sulfur})\cr \gamma = 0.49\times T + 520\ ({\rm mN/m})\quad (250 \,{\rm ppm \,Sulfur})\cr \rho = - 0.616\times T + 8.11\times 10⁺³ \ ({\rm kg/m³})\cr} $$