Effect of temperature and sulphur content on the surface tension of Fe-C(3.9%)-Si(1.6%) alloy

This paper describes findings about the effect of temperature and sulphur c ontent on the surface tension of Fe-C (3.9%)-Si (1.6%) alloy. For measureme nts of surface tension the sessile drop method was used. The examinations w ere made on cylindrical specimens of dimensions Phi 3.5 x 3.5 mm weighing 0 .2 - 0.3 g. Throughout the whole measurement helium of high purity was pass ed through the furnace. The measurements were carried out at every 50 K ove r the temperature range of 1523 - 1873 K. Alloys with various sulphur conte nt levels from 0.016 - 0.50% were examined. The relationship between the su rface tension of this alloy and temperature (with sulphur content kept cons tant) can be adequately described by an equation of the type sigma = aT(2) - bT + c. Two ranges of temperature have been specified: range I of 1523-17 73 K when the temperature coefficient d sigma/dT>0 and range II of 1773-187 3 K when d sigma/dT<0.