On the Viscosity of Molten Iron and Its Dilute Binary Alloys of Aluminum, Silicon and Oxygen

Viscosities of molten iron and its dilute binary alloys of aluminum, silicon, and oxygen have been measured by the oscillating crucible method, as a part of the study concerning the physical properties of molten iron and its alloys. The results are summarized as follows: (1) Viscosity of pure iron between 1820°K and 1970°K is expressed as η(m poise) = 2.76 exp(10.8 ×10^3/RT). (2) The addition of aluminum causes the decrease of viscosity which is larger than in the case of silicon. When the concentration of solute is 1 atomic%, the decrease of viscosity is about 36% by the addition of aluminum and about 15% by the addition of silicon. (3) The addition of oxygen causes the increase of viscosity. The increase of the viscosity is 0.4 m poise/100 ppm O. (4) Viscosity of molten aluminum containing dispersed alumina has been measured, and it has been shown that the increase of viscosity, compared with molten aluminum, is less than 1% when the volume fraction of dispersed alumina (∼10 μ) is 0.3%. From these results, some considerations were given to the change of fluidity of steel in the deoxidation process. Thus, it has been concluded that the fluidity of steel does not change remarkably in the deoxidation process, provided that the products of deoxidation are uniformly dispersed.