Determination of the critical parameters for the onset of dynamic recrystallization (DRX) in advanced ultrahigh strength steels (A-UHSS) microalloyed with boron
In this research work, the double differentiation mathematical method was used to identify more accurately the criti- cal stress ሺ ߪ ) and critical strain ሺ ߝ ) associated with the onset of dynamic recrystallization (DRX), which is based on changes of the strain hardening rate )ߝ߲/ߪ߲ ൌ ߠሺ as a f...
| Autores: | , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2012 |
| País: | España |
| Institución: | Universitat Politècnica de Catalunya (UPC) |
| Repositorio: | UPCommons. Portal del coneixement obert de la UPC |
| Idioma: | inglés |
| OAI Identifier: | oai:upcommons.upc.edu:2117/18712 |
| Acceso en línea: | https://hdl.handle.net/2117/18712 |
| Access Level: | acceso abierto |
| Palabra clave: | Steel Acer d'alta resistència |
| Sumario: | In this research work, the double differentiation mathematical method was used to identify more accurately the criti- cal stress ሺ ߪ ) and critical strain ሺ ߝ ) associated with the onset of dynamic recrystallization (DRX), which is based on changes of the strain hardening rate )ߝ߲/ߪ߲ ൌ ߠሺ as a function of the flow stress (Poliak and Jonas method, simplified by Najafizadeh and Jonas). For this purpose, a low carbon advanced ultra-high strength steel (A-UHSS) microalloyed with different amounts of boron (14, 33, 82, 126 and 214 ppm) was deformed by uniaxial hot-compression tests at high tempe- ratures 1100 ݀݊ܽ ሺ950,1000,1050 ° )ܥ and constant true strain rates ሺ 10 ିଷ ,10 ିଶ 10 ݀݊ܽ ିଵ ݏ ିଵ ) . Results indicate that both ߪ and ߝ increase with decreasing deformation temperature and in creasing strain rate. On the other hand, these criti- cal parameters tend to decrease as boron content increases. Such a behavior is attributed to a solute drag effect by boron atoms on the austenitic grain boundaries and also to a solid solution softening effect. |
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