Characterization of the anisotropic necking in duplex stainless steels with lamellar microstructures

Autor(es)

Terricabras, Adria Gallifa ^[1] ; Schoen, Claudio Geraldo ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Escola Politecn, Dept Met & Mat Engn, Av Prof Mello Moraes 2463, BR-05508900 Sao Paulo, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING; v. 717, p. 20-25, FEB 21 2018.
• Citações Web of Science: 2

Resumo

Duplex stainless steels are characterized by oriented microstructures, in which its constituent phases, ferrite (alpha) and austenite (gamma) form layered or fibrous phase arrangements depending on forming operations (e.g. rolling). These microstructures have the potential to induce anisotropy in the macroscopic mechanical properties of the material. A very interesting phenomenon related to this microstructurally-induced anisotropy is the subject of investigation in the present work: a sample submitted to tensile testing, which presents a regular initial geometry (either circular or square transverse sections), exhibits an anisotropic necking zone after fracture (with the transverse section becoming, respectively, elliptical and rectangular). The phenomenon is most surprising since the region of the specimen which remains homogeneously strained (that is, outside the necking zone) remains regular. This result suggest that this anisotropy develops due to the cavitation damage orientation in the necking zone. Present results confirm that the lamellar microstructure, typical of these steels, is responsible for the observed anisotropy. Observation of fracture surfaces clearly demonstrate that cavities align according to the underlying microstructure and a model is introduced to explain the observed anisotropy in elongation observed in samples extracted parallel or perpendicular to the rolling direction in rolled plates. (AU)

• Processo FAPESP: 16/05768-2 - Estudo da anisotropia plástica na estricção em aços inoxidáveis duplex
• Beneficiário: Claudio Geraldo Schon
• Modalidade de apoio: Auxílio à Pesquisa - Regular