Determination of Viscosity for Liquid Fe–Cr–Mn–Ni Alloys

Abstract

The determination of viscosity of liquid Cr–Mn–Ni steel (16% Cr, 7% Mn) alloyed with 3–20% nickel is of interest in the present experimental investigation. The alloys are manufactured using a cold crucible induction levitation melting. The viscosity measurement is performed using a vibrating finger viscometer for high temperatures (≥1500 °C) and viscosities below 10 mPa s. The BN–ZrO2 vibrating finger is set in a driven harmonic oscillation in its resonance frequency of ca. 26 Hz. The constant peak‐to‐peak amplitude of the oscillator is controlled using a laser micrometer and a powered field coil. The viscosity of Fe–Cr–Mn–Ni alloys is slightly decreased from 3 to 6% nickel and from 6 to 9% nickel a slight increase of the isothermal viscosity is observed. Finally, the viscosity decreased significantly from 9 to 20% nickel content in the samples. The variation in the viscosity at high temperatures can be caused by a change in the primary solidification behavior, as shown in the phase diagram of the Cr–Mn–Ni steel. The temperature function of the viscosity of the high‐alloyed steels is expressed using the Arrhenius function. A precise viscosity measurement is necessary for a mathematical modeling of the vacuum inert gas atomization of steel powder manufacturing.