Understanding the effect of process-induced porosity on the localized corrosion 316L stainless steel manufactured by laser powder bed fusion

• Autor: Calizaya Chipana, Mariela Tabata
• Formato: tesis de maestría
• Fecha de Publicación: 2023
• Institución: Superintendencia Nacional de Educación Superior Universitaria
• Repositorio: Registro Nacional de Trabajos conducentes a Grados y Títulos - RENATI
• Lenguaje: inglés
• OAI Identifier: oai:renati.sunedu.gob.pe:renati/7041
• Enlace del recurso: https://renati.sunedu.gob.pe/handle/sunedu/3484789
• Nivel de acceso: acceso abierto
• Materia: Fabricación aditiva; Fusión de polvo en cama con láser; Corrosión por picadura; Porosidad; Polarización potenciodinámica cíclica; Microgrietas; Cavidades de gas; https://purl.org/pe-repo/ocde/ford#2.04.01

The wide adoption of Laser Powder Bed Fusion (LPBF) in additive manufacturing has led to the need for a comprehensive understanding of the corrosion behavior of LPBF-fabricated components [1]. This thesis focuses on the pitting corrosion behavior of 316L stainless steel, emphasizing the influence of process-induced porosity. The impact of various defects on pitting corrosion behavior was explored through a series of experimental investigations using cyclic potentiodynamic polarization in a 0.6M NaCl solution. The study revealed that LPBF 316L SS exhibited superior pitting resistance compared to its wrought counterpart [2]–[7], even in the presence of manufacturing defects. Interestingly, despite their larger size and open porosity, gas voids were not the preferred sites for pitting propagation. The presence of these voids did not accelerate the accumulation of metal cations, thus diminishing their impact on pitting corrosion. Instead, other defect types, such as lack of fusion (LOF) porous and microcracks, demonstrated a preference for pitting initiation and propagation. However, the size of LOF did not significantly affect the pitting resistance, suggesting other factors play a more substantial role. Notably, the presence of multiple defects significantly decreased the pitting potentials. Further research is needed to explore this underlying mechanism. These findings provide valuable insights into the behavior of different defects and their role in pitting corrosion, contributing to developing strategies for enhancing the corrosion resistance of LPBF-fabricated components.