Advanced Ultra high Strength Bainitic Steels

The addition of about 2 wt.% of silicon to steel enables the production of a distinctive microstructure consisting of a mixture of bainitic ferrite, carbon-enriched retained austenite, and some martensite. With careful design, impressive combinations of strength and toughness have been reported for...

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Detalhes bibliográficos
Autores: García Caballero, Francisca, García Mateo, Carlos, Capdevila, Carlos, García de Andrés, Carlos
Formato: artículo
Fecha de publicación:2007
País:España
Recursos:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/75883
Acesso em linha:http://hdl.handle.net/10261/75883
Access Level:acceso abierto
Palavra-chave:Bainite
Materials design
Mechanical properties
Microstructural characterization
Phase transformation modelling
Steels
Descrição
Resumo:The addition of about 2 wt.% of silicon to steel enables the production of a distinctive microstructure consisting of a mixture of bainitic ferrite, carbon-enriched retained austenite, and some martensite. With careful design, impressive combinations of strength and toughness have been reported for high-silicon bainitic steels. More recently, it has been demonstrated experimentally that models based on phase transformation theory can be applied successfully to the design of carbide-free bainitic steels. Toughness values of nearly 130 MPa m1/2 were obtained for strength in the range of 1600–1700 MPa. However, the concepts of bainite transformation theory can be exploited even further to design steels that transform to bainite at temperatures as low as 150°C. Microstructure obtained is so refined that it is possible to achieve a strength in excess of 2.5 GPa in a material which has considerable toughness (30 MPa m1/2). Such properties have never been achieved before with bainite. It is intended to provide a description of the characteristics and significance of this remarkable microstructure in the context of the mechanism of transformation