Chromium combustion in a nitrogen coflow

Abstract

The combustion of chromium powder in a coflow of nitrogen-containing gas in a range of specific flow rate of up to 20 cm³/(s · cm²) is studied. The use of forced filtration intensifies the combustion wave propagation in the Cr–N₂ system. In this case, the combustion rate increases simultaneously with the decreasing degree of nitridation. The superadiabatic heating modes in the case of purging with pure nitrogen and a hydrogen-argon mixture are revealed. It is shown that the use of the gaseous mixture promotes the formation of the inverse combustion wave. The hardening mode implemented during forced filtration allows fixing the high-temperature single-phase nonstoichiometric nitride Cr₂N.