Effect of α-α´ phase separation on notch impact behavior of oxide dispersion strengthened (ODS) Fe20Cr5Al alloy

The effects of Fe-rich (α) and Cr-enriched (α′) phase separation, occurring during aging at 475 °C on the microstructure and mechanical properties of Fe–20Cr–6Al ODS alloy (PM2000™) hot-rolled tube, were investigated by means of atom probe tomography, microhardness, tensile and V-notched Charpy impa...

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Detalles Bibliográficos
Autores: Chao, Jesús, Capdevila, Carlos, Serrano, M., García-Junceda, A., Jiménez, José Antonio, Miller, Michael K.
Tipo de recurso: artículo
Fecha de publicación:2013
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/88475
Acceso en línea:http://hdl.handle.net/10261/88475
Access Level:acceso abierto
Palabra clave:Toughness
Phase separation
Mechanical alloying
Tomography
Oxide dispersion strengthened ferritic alloys
Descripción
Sumario:The effects of Fe-rich (α) and Cr-enriched (α′) phase separation, occurring during aging at 475 °C on the microstructure and mechanical properties of Fe–20Cr–6Al ODS alloy (PM2000™) hot-rolled tube, were investigated by means of atom probe tomography, microhardness, tensile and V-notched Charpy impact tests. Disregarding of the aging treatment, this material presents splitting of crack-divider type in longitudinal-transverse (LT) specimens, whereas crack-arrester type is observed in longitudinal-short transverse (LS) specimens, which induces significant differences in ductile-to-brittle transition temperature (DBTT) and upper shelf energy (USE). Additionally, a significant increase in DBTT and decrease in USE were recorded during aging at 475 °C as a function of aging time. The main cause of embrittlement is the α–α′ phase separation with an apparent activation energy measured in the range of 214–240 kJ/mol, which is consistent with the activation energy for Cr diffusion in this type of alloy