Comparação de aços inoxidáveis endurecidos por precipitação obtidos pela rota tradicional e pela manufatura aditiva

Abstract

Stainless steels are ferrous alloys that stand out for their high corrosion resistance, provided by the chromium content in their composition, as well as for their good mechanical strength. Within this class of ferrous materials, precipitation-hardening stainless steels (PHSS) exhibit not only good corrosion resistance but also ultra-high strength due to the aging heat treatment performed after solution treatment, which promotes hardening through the precipitation of intermetallic compounds coherent with the matrix. Manufacturing PHSSs through the traditional route is challenging, as even in the solution-treated condition, these alloys present high strength, making plastic deformation and machining difficult. Thus, additive manufacturing (AM) has emerged as a promising alternative to meet the requirements of aerospace and nuclear industries, which demand components with complex and specific geometries. AM represents the fastest route from design to the final component, eliminating the need for molds or plastic deformation processes. Therefore, this work proposed a comparative study between the traditional and additive manufacturing routes for PHSS production, analyzing and discussing their impacts and challenges in terms of microstructure, mechanical properties, corrosion resistance, and applicability. The results showed that both routes can achieve similar microstructures and properties after appropriate heat treatments. Nevertheless, AM presented greater microstructural control, the ability to produce complex components, and high densification, although with slight anisotropy and lower ductility compared to the traditional route. Corrosion resistance was found to be governed by the same mechanisms in both routes, being strongly influenced by solution and aging parameters. Despite challenges related to standardization, porosity, and cost, additive manufacturing stands out as a promising and competitive alternative for the production of PHSSs.