The rate of CO bubble nucleation at oxide metal interfaces within liquid iron alloys

Abstract

Baker, Warner, and Jenkins found that levitated droplets of Fe-0.8 pet C alloys exploded when decarburized at 1660°C, whereas during the present investigation, the drops remained intact during decarburization at temperatures above 1850°C. Therefore, the object of this work was to determine whether heterogeneous nucleation of CO bubbles at an iron-iron oxide interface could occur at 1900°K but could not occur at 2200°K. An equation was developed to calculate the nucleation rate of CO bubbles at an iron-iron oxide interface in iron at 1900°K containing 0.8 pct C and in iron at 2200°K containing 0.1 pct C. The results of the calculation showed that an iron-iron oxide interface could not serve as a site for CO bubble nucleation. Therefore, a new mechanism is postulated in which cavities swept into the levitated droplet from the surface serve as nuclei for CO bubble formation instead of nuclei formed at the iron-iron oxide interface.