Viscosity characteristics of alloyed iron melts

The viscosity of binary melts of iron with alloying elements (niobium, vanadium, molybdenum, tungsten, tantalum, chromium and nickel) and of 0.1 % C melts of iron with the same alloying additions was measured by torsional oscillations of an alundum crucible holding 40 g of melt in a high-temperature installation in an atmosphere of purified helium. The measurements were carried out under cooling conditions on the range of temperatures from 1750 to 1500 deg C. The relationship between the temperature and the viscosity of the melts under investigation obeys the Ya.I.Frenkel equation. In pure iron melts, the alloying elements possess, at small concentrations up to 8 at. %, a negative viscosity activity. The activation energy, the free energy and the entropy of viscous flow have been determined. From the viscosity characteristics, a suggestion is made on the structure of alloyed iron melts