Efeito do tempo entre passes na interação recristalização-precipitação de um aço inoxidável austenítico com alto teor de nióbio e nitrogênio

Detalhes bibliográficos
Ano de defesa: 2014
Autor(a) principal: Silva, Mariana Beatriz dos Reis
Orientador(a): Jorge Júnior, Alberto Moreira lattes
Banca de defesa: Não Informado pela instituição
Tipo de documento: Tese
Tipo de acesso: Acesso aberto
Idioma: por
Instituição de defesa: Universidade Federal de São Carlos
Programa de Pós-Graduação: Programa de Pós-Graduação em Ciência e Engenharia de Materiais - PPGCEM
Departamento: Não Informado pela instituição
País: BR
Palavras-chave em Português:
Área do conhecimento CNPq:
Link de acesso: https://repositorio.ufscar.br/handle/ufscar/726
Resumo: In this work was studied the influence of interpass time on the recrystallizationprecipitation interaction occurring during the thermomechanical processing of ISO 5832-9 austenitic stainless steel, which has high contents of niobium (0.28%) and nitrogen (0.35%). The simulation of the industrial processing was carried out through hot torsion testing with multiple deformations in continuous cooling, in which the interpass time ranged between 5 and 50 s. The obtained plastic flow curves showed that shortest interpass times lead to increased levels of stress during straining and that the non-recrystallization temperature for this steel is close to 1100°C. The microstructural evolution was investigated by interrupting the tests on certain deformations before and after Tnr, and for this it was used the microscopy techniques of optical, transmission electron and scanning electron associated with electron backscattered diffraction. Small interpass times resulted in a larger volume fraction of small precipitates (< 50 nm) and smaller grain sizes. It was observed that dynamic recrystallization also occurs, and that these smaller precipitates were effective in pinning grain boundaries and dislocations (continue...).