Modelling and characterization of Chi phase grain boundary precipitation during agging of Fe-C-Ni-Mo stainless steel

High molybdenum stainless steels may contain the Chi precipitate (, Fe36Cr12Mo10) which may lead to undesirable effects on strength, toughness and corrosion resistance. In the present work, specimens of a 12Cr-9Ni-4Mo wt% steel are heat treated at different temperatures and times, and the average p...

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Detalles Bibliográficos
Autores: Xu, W., San-Martín, David, Rivera-Díaz del Castillo, P.E.J., Zwaag, S. van der
Tipo de recurso: artículo
Fecha de publicación:2007
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/77612
Acceso en línea:http://hdl.handle.net/10261/77612
Access Level:acceso abierto
Palabra clave:Chi precipitate
Precipitation kinetics
Particle size distribution
Modelling
Stainless steel
Descripción
Sumario:High molybdenum stainless steels may contain the Chi precipitate (, Fe36Cr12Mo10) which may lead to undesirable effects on strength, toughness and corrosion resistance. In the present work, specimens of a 12Cr-9Ni-4Mo wt% steel are heat treated at different temperatures and times, and the average particle size and particle size distribution of Chi precipitate are studied quantitatively. A computer model based onthe KWN framework has been developed to describe the evolution of Chi precipitation. The kinetic model takes the natural advantages of the KWN model to describe the precipitate particle size distribution, and is coupled with the thermodynamic software ThermoCalc® for calculating the instantaneous local thermodynamic equilibrium condition at the interface and the driving force for nucleation. A modified version of Zener’s theory accounting for capillarity effects at early growth stages is implemented in this model. The prediction of the model is compared to experimental results and both the average particle size and the particle size distribution are found to be in good agreement with experimental observations.