Controlled filling of casting mold with non-ferrous metal in presence of magnetic field, relates magnetic induction to measured casting parameters

摘要

Initially, the magnetic induction B 0 of the applied magnetic field exceeds the two values B 1 = 10/d h .(eta /sigma ) 1/2 and B 2 = (rho U/10sigma d h) 1/2. Variables invoked include the molten metal: density (rho ), electrical conductivity (sigma ) and dynamic viscosity (eta ). d h is the mean hydraulic diameter of the inlet gate and U is the mean influx velocity of the melt. The initial value B 0 remains constant up to the instant t 1. At the time t1 the melt front has reached the mold cavity, and from this time on, the strength of the magnetic field is reduced under control, to zero. The magnetic field acts at the lower end of the vertical casting channel, before the molten influx turns into the horizontal run (3). It acts at right angles to the flow in a flat rectangular channel (6). Reduction of the magnetic field intensity from the maximum value to zero, is steady and linear. Parameter(s) controlling the magnetic field strength, i.e. B 0, t 1, the duration (t 2-t 1) and the nature of the ramp, are determined from the measured volumetric flow of the molten metal, such that its mean velocity U, at any instant of the casting process, does not exceed the value U max = 10000eta /rho d h. An independent claim is included for the equipment used.