Nucleation rate and number of precipitates in V and Nb-microalloyed steels
Recrystallization-precipitation-time-temperature (RPTT) diagrams were experimentally determined for two microalloyed steels with V and Nb, respectively, at a strain of 0.35 and a strain rate of 3.63 s-1. From the RPTT diagrams, and applying the classic theory of nucleation, the nucleation rate was c...
| Autores: | , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2014 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/109665 |
| Acceso en línea: | http://hdl.handle.net/10261/109665 |
| Access Level: | acceso abierto |
| Palabra clave: | Nucleation rate Nucleus size Precipitate Microalloyed steel |
| Sumario: | Recrystallization-precipitation-time-temperature (RPTT) diagrams were experimentally determined for two microalloyed steels with V and Nb, respectively, at a strain of 0.35 and a strain rate of 3.63 s-1. From the RPTT diagrams, and applying the classic theory of nucleation, the nucleation rate was calculated for both steels. In order to determine the mentioned magnitudes, several parameters were calculated, such as: the Zeldovich factor (Z), the energy of formation of the nucleus (¿G), the driving force for precipitation (¿Gv), the critical radius for nucleation (Rc), and the dislocation density at the start of precipitation (¿), among others. The calculated data has made it possible to clarify the shape of precipitation start and finish curves and to plot the nucleation rate as a function of temperature. The number of precipitates was calculated by integration of the nucleation rate expression. In this way, substantial differences were established between the two types of microalloyed steels, including the final size of the V(C, N) and Nb(C, N) precipitates. |
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