Assessment of niobium segregation energy in migrating ferrite/austenite phase interfaces

• Published in: International journal of materials research Vol. 101; no. 10; pp. 1232 - 1240
• Main Authors: Okamoto, Riki, Ågren, John
• Format: Journal Article
• Language: English
• Published: Munich De Gruyter 01.10.2010; Hanser
• Subjects: Applied sciences; Assessments; Austenite; Chemical engineering; Diffusion; Diffusivity; Exact sciences and technology; Ferrite; Kemiteknik; Low carbon steels; Mathematical models; Metallurgical process and manufacturing engineering; Metallurgisk process- och produktionsteknik; Metals. Metallurgy; Niobium; Segregation; Segregations; Solute drag; TECHNOLOGY; TEKNIKVETENSKAP; Thermodynamics; Transformation; Thermodynamics; Ferrite; Transformation; Segregation; Austenite; Solute drag; Diffusion; Microstructure; Interface; Niobium
• ISSN: 1862-5282; 2195-8556
• DOI: 10.3139/146.110413

The effects of physical parameters on the total dissipation of Gibbs energy inside migrating ferrite/austenite interfaces have been re-investigated using Odqvist's solute drag model. It is shown that the mobility of the ferrite/austenite phase interface and the diffusivity of niobium in the interface have a strong effect on the Gibbs energy dissipation. As the phase interface mobility was recently reassessed, it is clear that the Gibbs energy of niobium segregation and the diffusivity of niobium in the interface must also be reassessed. In this paper both parameters are reassessed in the Fe–C–Nb system using new physical parameters and experimental results from ultra-low carbon steels.