Theoretical Design and Advanced Microstructure in Super High Strength Steels

A theoretical design procedure based on phase transformation theory alone has been successfully applied to design steels with a microstructure consisting of a mixture of bainitic ferrite and retained austenite. Using thermodynamics and kinetics models, a set of four carbide free bainitic steels with...

Descripción completa

Detalles Bibliográficos
Autores: García Caballero, Francisca, Santofimia, Maria Jesús, García Mateo, Carlos, Chao, Jesús, García de Andrés, Carlos
Tipo de recurso: artículo
Fecha de publicación:2009
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/34339
Acceso en línea:http://hdl.handle.net/10261/34339 doi:10.1016/j.matdes.2008.08.042
Access Level:acceso abierto
Palabra clave:Ferrous metals and alloys
Microstructure
Mechanical Properties
Descripción
Sumario:A theoretical design procedure based on phase transformation theory alone has been successfully applied to design steels with a microstructure consisting of a mixture of bainitic ferrite and retained austenite. Using thermodynamics and kinetics models, a set of four carbide free bainitic steels with a 0.3 wt-% carbon content were designed and manufactured following a thermo-mechanical treatment consisting of hot rolling and two-step cooling. The designed steels present significant combinations of strength and ductility, with tensile strengths ranging from 1500 to 1800 MPa and total elongations over 15%. However, a carbon content of 0.3 wt% is still high for in-use properties such as weldability. In this sense, a reduction in the average carbon content of advanced bainitic steels was proposed. Improved bainitic steels with a carbon content of 0.2 wt% reached combinations of strength and ductility comparable to those in TRIP assisted steels.