Study of deformation-induced phase transformation in plain low carbon steel at low strain rate

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Vol. 527; no. 20; pp. 5072 - 5077
• Main Authors: Chung, J.H., Park, J.K., Kim, T.H., Kim, K.H., Ok, S.Y.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 25.07.2010; Elsevier
• Subjects: Austenite; Constant-composition solid-solid phase transformations: polymorphic, massive, and order-disorder; Critical temperature; Cross-disciplinary physics: materials science; rheology; Deformation effects; Deformation-induced massive transformation; Electron probe micro-analyzer (EPMA); Exact sciences and technology; Flow softening; Hot compression; Low carbon steels; Materials science; Mathematical models; Microstructure; Phase diagrams and microstructures developed by solidification and solid-solid phase transformations; Physics; Softening; Steel; Strain rate; Thermodynamic models; Deformation-induced massive transformation; Steel; Hot compression; Flow softening; Electron probe micro-analyzer (EPMA); Hot deformation; Phase transformations; Low carbon steel; Strain softening; Austenitic ferritic steel; Critical points; Electron microprobe analysis; Thermodynamic model; Phase equilibria; Supercooling; Strain rate
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/j.msea.2010.04.095

Hot-deformation behavior of super-cooled austenite within the austenite–ferrite (γ–α) phase field was studied in low carbon steels (0.15 wt.%) at various strain rates. Flow softening was observed during the hot-deformation at temperatures lower than critical temperature. The critical temperature was observed to be significantly higher than T 0 temperature. This was due to large shift of γ–α phase-equilibrium to a higher temperature during hot-deformation. A thermodynamic model to account the effect of non-uniform deformation-induced stress on the γ–α phase-equilibrium during hot-deformation was proposed and its prediction was in good agreement with the experimentally measured critical temperature.