Promotion of intragranular nucleation of ferrite in V-microalloyed steels
The intragranular nucleation of ferrite was studied in three low-carbon microalloyed steels. Recrystallization-Precipitation-TimeTemperature (RPTT) diagrams were determined by means of isothermal double-deformation hot torsion tests. Once the diagrams were drawn, several tests were carried out where...
| Autores: | , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2012 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/77502 |
| Acceso en línea: | http://hdl.handle.net/10261/77502 |
| Access Level: | acceso abierto |
| Palabra clave: | Microalloyed steel Precipitation Intragranular nucleation Ferrite grain refinement |
| Sumario: | The intragranular nucleation of ferrite was studied in three low-carbon microalloyed steels. Recrystallization-Precipitation-TimeTemperature (RPTT) diagrams were determined by means of isothermal double-deformation hot torsion tests. Once the diagrams were drawn, several tests were carried out where the samples suffered a single deformation and were cooled after a variable holding time at a characteristic temperature such as the precipitation nose temperature. Ferrite grain size was measured in these samples and the strengthening of austenite was measured by taking into account the unrecrystallized fraction of austenite before phase transformation. In this way, the relationship existing between precipitation state, fraction of austenite recrystallization and ferrite grain size was studied. It was found that V precipitates are more appropriate to promote intragranular nucleation than Nb precipitates. An increase in C, N and V contents promotes a precipitation state which seems to be more suitable for the intragranular nucleation to occur. The nucleation of very fine ferrite grains on V particles was assessed in another set of hot rolling simulation torsion tests carried under continuous-cooling conditions. |
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