On the origin of the barrier in the bainite phase transformation. (15th January 2023)

• Record Type: Journal Article
• Authors: BENRABAH, Imed-Eddine; Brechet, Yves; Purdy, Gary; Hutchinson, Christopher; Zurob, Hatem
• Is Part Of: Scripta materialia. Number 223(2023)
• Publication Date: 2023-01-15
• Subjects: Materials -- Periodicals; Metallurgy -- Periodicals; Metalen; Legeringen; Materiaalkunde; Metals, metalworking and machinery industries; Metals; Electronic journals; 620.11
• DOI: 10.1016/j.scriptamat.2022.115076
• Languages: English
• ISSNs: 1359-6462

Abstract

Abstract: The experimental lengthening kinetics of bainitic ferrite in steels have been consistently shown in the literature to be slower than those predicted using the diffusional Zener-Hillert model. Reconciliation of the experimental and calculated kinetics has required the introduction of a 'barrier energy' which until now has not had a clear physical meaning. A modified diffusional growth model based on the Zener-Hillert model for plate-like ferrite growth is introduced with a physics-based barrier energy. The model assumes diffusion controlled growth and takes into account a barrier energy arising from interfacial disconnections motion and their interaction with defects in the matrix. The model is able to successfully describe the C-curve growth rate of Widmanstätten ferrite and bainitic ferrite in a wide range of steels. Graphical abstract: Image, graphical abstract