Influence of Nb stabilization on the recovery and recrystallization kinetics of a ferritic stainless steel with soft magnetic properties for automotive applications

• Autor(a) principal: Meyer,Nicolas
• Data de Publicação: 2013
• Outros Autores: Mantel,Marc, Dubois,P.E., Veron,Muriel, Brechet,Yves, Geoffroy,Olivier
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: REM. Revista Escola de Minas (Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0370-44672013000200004
• topic: Ferritic stainless steel; recrystallysation; magnetic properties; niobium stabilization

Usually niobium is added in ferritic stainless steels to avoid chromium carbides precipitation and then to improve corrosion resistance and to avoid embrittlemet. This study shows that a low Nb stabilization makes recrystallization nucleation much faster and prevents incomplete recrystallization. A qualitative interpretation, based on interaction with precipitates, is proposed and explains the main features of the softening kinetics as well as the microstructures obtained. Above a specific magnetizing frequency, the deformed state led to smaller losses than the recrystallized state. These results are believed to be attributed to a grain size effect. This leads to soft magnetic properties that makes 17%CrNb ferritic stainless steels a very interesting solution for the market of electromagnetic injection. Improving response-time of fuel injection valves is a great challenge for automotive industry in order to enhance car engine efficiency and to limit noxious gas emission.