STUDIES ON THE FLUIDITY OF MOLTEN IRON (III)

Abstract

The flowing properties of various molten irons were measured by the weight which flowed out through the capillary (2.3mm diameter, 15mm length). The flowabilities of these capillaries were determined by the mercury at room temperature. The flowing properties of the molten irons consisting of the almost same composition (C, Si, Mn, P, S) were different by its molten state, especially by the oxygen content or excess deoxidizer.
Now the authors measured the flowing properties of mercury, molten tin and bismuth by the same capillary which was used for molten iron, and obtained the relation between kinematic viscosity (ν=η/ρ) and the time (τ) required to let flow constant volume of the metal.
By the theory of hydrodynamics, τ is the function of ν, so that from the above relation for mercury, tin and bismuth the value of ν corresponding to τ which was experimentally measured about the molten iron could be obtained. The viscosity of molten iron was calculated from the value of ν.
The viscosity of molten pig generally used was 0.0156-0.0120 at 1250-1400°C, while that of steel (0.3% carbon) was 0.0195 at 1535°C. The viscosity of steel at 1620°C was estimated as 0.0169 by exterpolation, when the rate of viscosity-change of the molten steel against the temperature was assumed to be the same as that of molten pig.