2006 Volume 46 Issue 12 Pages 1810-1816
The surface tension of molten low-carbon (LC) steel containing Ti, Nb or B and the contact angle between the molten steel and solid alumina were measured using the sessile droplet method under an Ar gas atmosphere at 1500°C, 1575°C and 1600°C. The results show that Ti decreases the surface tension of molten LC steel and the contact angle. The interfacial tension between molten LC steel containing Ti and solid alumina decreases with the increase in Ti content. The work of adhesion between molten LC steel and solid alumina decreases slightly at 1550°C, but increases at 1600°C with increasing Ti content. The addition of a small amount of Nb or B to molten LC steel decreases slightly the surface tension of the molten steel. The effect of Nb on the contact angle between molten LC steel and solid alumina is less, but B markedly decreases the contact angle when the B content increases from 0.0504 to 0.0999 mass%. It can be deduced that fine bubbles are more easily entrapped by the solidifying shell for LC steel with Ti or B than that with Nb, while fine alumina inclusions are more easily entrapped by the solidifying shell for LC steel with B than that with Ti or Nb.
