High-Chromium (9-12Cr) Steels: Creep Enhancement by Conventional Thermomechanical Treatments

There is a worldwide need to develop materials for advanced power plants with steam temperatures of 700°C and above which have the capacity to achieve high efficiency and low CO2 emissions. This request involves the development of new grades of 9-12Cr heat-resistant steels, with a nanostructured mar...

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Detalles Bibliográficos
Autores: Vivas Méndez, Javier, San-Martín, David, García Caballero, Francisca, Capdevila, Carlos
Tipo de recurso: otro
Estado:Versión publicada
Fecha de publicación:2020
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/232470
Acceso en línea:http://hdl.handle.net/10261/232470
Access Level:acceso abierto
Palabra clave:Creep-resistant steels
Thermomechanical treatment
Creep fracture behavior
Microstructural degradation
Small punch creep tests
Ausforming
Descripción
Sumario:There is a worldwide need to develop materials for advanced power plants with steam temperatures of 700°C and above which have the capacity to achieve high efficiency and low CO2 emissions. This request involves the development of new grades of 9-12Cr heat-resistant steels, with a nanostructured martensite, mainly focusing on the long-term creep rupture strength of base metal and welded joints, creep-fatigue properties, and microstructure evolution during exposure at such elevated temperatures. The main shortcomings of actual 9-12Cr high-chromium steels are that the creep resistance is not enough to fulfill the engineering requirements at temperatures higher than 600°C and the material undergoes a cyclic softening. Creep strength at high temperature could be improved by a microstructural optimization through nano-precipitation, guided by computational thermodynamics, and thermomechanical control process optimization.