Work

Dislocation driven evolution of passivity in L-PBF 316 L: Unveiling the impact of thermal exposure

Year: 2025

Type: article

Abstract: This study investigates the influence of subcritical thermal exposure on the passivation behaviour of laser powder bed fusion (L-PBF) processed 316 L stainless steel, with a focus on dislocation-driven mechanisms under industrially relevant conditions. A novel approach was taken by systematically examining the evolution of corrosion resistance as a function of both residual stress and dislocation density across a temperature range of 100–400 °C. The methodology integrated electrochemical characterisation with microstructural and crystallographic analysis. Results revealed a progressive decline in passive film stability up to 300 °C, corresponding with reduced dislocation density and stress relaxation. However, at 400 °C, passive film performance improved significantly despite further residual stress reduction. This behaviour was linked to the start of microstructural recovery, dissolution of subgrain boundaries, and a redistribution of geometrically necessary dislocations. • At 400 °C passivity improves, reversing the degradation trend. • Recovery in passivation is linked to GNDs, rather than residual stress magnitude. • At 400 °C, subgrain boundary redistribution occurred, without recrystallisation. • Shift in dislocation distribution from melt pool boundaries to subgrains at 400 °C. • dislocation density is the dominant factor governing passivity in L-PBF 316L.

Source: Corrosion Science

DOI: 10.1016/j.corsci.2025.113409

Authors: Arshad Yazdanpanah, Lorenzo D’Ambrosi, Giulia Bilanzone, Mona Khodabakhshi, Reynier I. Revilla

Institutions: University of Padua, Vrije Universiteit Brussel

Language: English

Topic: Hydrogen embrittlement and corrosion behaviors in metals

Subfield: Metals and Alloys

Field: Materials Science

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $4,070

Funders: European Commission, HORIZON EUROPE Excellent Science