Numerical Simulation of Enhanced Crushing of Nitrogenous Droplet in Preparation of High Nitrogen Steel Powders by Aerosol Atomization

In the process of preparing nitrogen containing stainless steel powders by gas atomization, the banded molten droplets after first crushing were broken into small molten droplets generally with a diameter of 50-100 μm under the action of nitrogen flow shear. After secondary atomization, the internal nitrogen bubbles overflowed sdue to the unstable interface between the gas-liquid phase in the nitrogen-containing melt droplets, which lead to the enhanced crushing of the larger molten droplet due to the "escape" of nitrogen. This microscopic process cannot be directly observed and analyzed under experimental conditions, Fluent 16.0 was used to conduct numerical simulation of enhanced crushing process to obtain the movement track of molten droplets and the change of pressure value during the enhanced crushing process. At the same time,the internal mechanism of the two-phase flow coupling process and the effect of enhanced crushing were described.