Engenharia de Materiais
URI permanente desta comunidadehttps://repositorio.fei.edu.br/handle/FEI/17
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2 resultados
Resultados da Pesquisa
Artigo de evento 0 Citação(ões) na Scopus Ferrite-to-austenite transformation during cold working of a duplex stainless steel(2011-09-23) Rodrigo Magnabosco; TAVARES, D. B.; FORGAS, A.; DE MOURA NETO, C.Ferrite-austenite duplex stainless steels (DSS) are replacing austenitic stainless steels in many applications due to its high mechanical and corrosion resistance. However, magnetic measurements of ferrite volume fraction using a ferritscope of cold worked samples indicate a reduction in the ferrite content with increasing mechanical work. Considering this fact, this work studies the influence of the cold working on the ferrite/austenite ratio. Samples of UNS S31803 DSS sheet, originally 3 mm thick, were solution-treated at 1175°C for 30 minutes and water quenched; after that, different levels of cold working were applied. Ferrite volume fraction was determined using two distinct methods: quantitative stereology with an optical microscope and magnetic measurements using a ferritscope; a detailed microstructural characterization, including X-ray diffractometry, was conducted to base the discussion of a possible ferrite-to-austenite diffusionless transformation.Artigo de evento 3 Citação(ões) na Scopus Comparative study of ferrite quantification methods applied to duplex stainless steels(2011-09-23) Rodrigo Magnabosco; SPOMBERG, S.Duplex stainless steels (DSS) present approximately the same quantities of ferrite (magnetic phase) and austenite. These steels are replacing austenitic stainless steels in some applications due to its high mechanical and corrosion resistance. However, changes in the volumetric percentage of those phases can modify material properties, justifying the development of this study, which has as principal aim a comparison between three different ferrite quantification methods. Samples of two different DSS (UNS S31803 or UNS S32750), originally supplied as 20mm round bars, were solution-treated between 1000°C and 1250°C, in order to obtain different ferrite/austenite ratios. Ferrite quantification was performed in three sections: longitudinal, transverse and diagonally oriented to the rolling direction. The volume fraction of ferrite was determined using three distinct methods: quantitative stereology with an optical microscope, magnetic measurements using a ferritscope, and X-ray analysis by comparison of the relative intensities of peaks corresponding to the planes that generate maximum intensity of diffraction for single-phase samples. Results are discussed, analysing the reliability of the studied methods.