An Analytical Model for Predicting Cu Separation in Cu‐Containing Steels During High‐Temperature Oxidation in Air

Scrap‐based steelmaking practices have resulted in the progressive enrichment of Cu within the scrap stream, which present challenges for long‐term management of Cu hot shortness. Current models developed to predict Cu separation have limited applicability to real alloys. This work develops a mass balance‐based analytical Cu separation model that predicts separated Cu layer thickness using an assumed oxidation curve for an alloy of known composition. A simple model for predicting Cu separation that neglects local Cu enrichment or bulk diffusion is presented, and model extensions to incorporate these effects are presented. Predictions using both modeling methods are compared to the literature data. The simple model agreed with measured Cu separations for shorter oxidation times while the solubility and diffusion modified model was more accurate for longer oxidation times or more highly alloyed steels. This model provides a potential tool to predict Cu separation and subsequent hot shortness susceptibility for an alloy of known composition.