Prediction of Bainite Intervened in Ferrite-Pearlite Forging Steel I. Modeling
The successive ferrite ( ) + pearlite (P) transformations from austenite ( ) were modeled to predict the presence of bainite in as-forged medium-carbon manganese steels. The kinetics of diffusional transformations were calculated based on classical nucleation and growth theory coupled with CALPHAD m...
| Autores: | , , , , |
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| Formato: | artículo |
| Fecha de publicación: | 2009 |
| País: | España |
| Recursos: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/74332 |
| Acesso em linha: | http://hdl.handle.net/10261/74332 |
| Access Level: | acceso abierto |
| Palavra-chave: | phase transformations kinetic modeling medium-carbon manganese steel continuous-cooling Multicomponent thermodynamics proeutectoid ferrite pearlite Bainite |
| Resumo: | The successive ferrite ( ) + pearlite (P) transformations from austenite ( ) were modeled to predict the presence of bainite in as-forged medium-carbon manganese steels. The kinetics of diffusional transformations were calculated based on classical nucleation and growth theory coupled with CALPHAD multi-component thermodynamics. The description of the growth rate of proeutectoid- includes a time dependence due to the carbon enrichment in the remaining . The / interface was assumed to be in negligible-partitioned local equilibrium (NPLE). The kinetics calculation of P nucleating on the surface was integrated into the model. Given the transformation temperature range in continuous cooling, the growth rate of P was also expressed in the NPLE constraint for /cementite. The concentration of untransformed ( U) can be monitored and should be dependent on the extent of the preceding transformations. Thus, the energies available for the nucleation and diffusionless growth of bainitic- were evaluated from the thermodynamics of the U single-phase system, which is proposed as a method to predict the inclusion of bainite in the final þ P microstructure |
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