Corrosion Behavior of Additively Manufactured Stainless Steels

Additively manufactured stainless steels, particularly 316L produced by laser powder bed fusion, exhibit unique microstructures and surface conditions that distinguish their corrosion behaviour from conventionally wrought counterparts. Rapid melting and solidification generate fine cellular substructures, high dislocation densities and elemental segregation, while layer-wise deposition creates inherent surface roughness, porosity and microstructural anisotropy. These features influence passive film formation, localised attack and stress corrosion cracking, with practical implications for marine, biomedical and energy applications. Understanding the interplay between process parameters, post-processing treatments and the resulting metallurgical states is essential to predict and mitigate pitting, crevice corrosion and cracking under service conditions.

Research from Nature Portfolio

Recent studies have uncovered the role of Mn-rich silicate slags in pitting corrosion of as-built LPBF 316L stainless steel in chloride environments. High-fidelity melt-pool simulations show that these slags originate in the liquid metal and deposit on component surfaces, introducing cracks and heterogeneities in oxide films. Rapid solidification and high-temperature oxidation during LPBF alter surface oxide chemistry, fundamentally changing pitting initiation and growth mechanisms. This mechanistic insight points to the importance of feedstock purity and tailored process controls to reduce defect-induced corrosion in seawater-exposed parts.

Corrosion Behavior of Additively Manufactured Stainless Steels publication trend

The graph below shows the total number of articles in corrosion behavior of additively manufactured stainless steels across all publications each year (not limited to Nature Index journals).

Technical terms

Additive Manufacturing (AM): Layer-by-layer fabrication of metal components directly from digital designs.

Laser Powder Bed Fusion (LPBF): A powder-bed AM method in which a laser selectively melts metal powders to build parts.

Pitting corrosion: Localised breakdown of the protective oxide film, leading to the formation of small cavities or pits.

Stress Corrosion Cracking (SCC): A failure mechanism caused by the combined action of tensile stress and a corrosive environment.

Re-passivation: Restoration of the protective oxide film after localised breakdown.

Cellular substructure: Fine networks of segregated elements and dislocations formed during rapid solidification in AM alloys.

References

1. Critical role of slags in pitting corrosion of additively manufactured stainless steel in simulated seawater. Nature Communications (2024).
2. Influence of feature size and shape on corrosion of 316L lattice structures fabricated by laser powder bed fusion. Additive Manufacturing (2023).
3. Printed cellular structure enhancing re-passivation of stress corrosion cracking in high-temperature water. Corrosion Science (2025).
4. Effect of heat treatment and electroless Ni-P coating on mechanical property and corrosion behaviour of 316L stainless steel fabricated by laser powder bed fusion. Virtual and Physical Prototyping (2024).