Surface Tension Measurements of 430 Stainless Steel

Abstract

The surface tension of 430 stainless steel was measured using an electromagnetic levitation (EML) method at temperatures of 1707–2000 K, under a 5 vol% H2–He atmosphere. For comparison, the surface tension was also measured using a constrained drop method; specifically the advanced sessile drop method. At 1823 K, the surface tension of the 430 stainless steel was estimated from the electromagnetic levitation and the constrained drop methods to be 1.802 and 1.614 N/m, respectively. A subsequent analysis of oxygen content showed that the former contained ~7 ppm oxygen, whereas the latter had 60 ppm. It was therefore considered that the observed difference in measurements was the result of a contamination by oxygen. Furthermore, the EML experimental results were found to be close to the theoretically calculated values for the Fe–Cr–Si system. Consequently, for complex multi-component commercial steels such as the 430 stainless steel, the levitation method is recommended for the measurement of surface tension.