Corrosion Resistance of Laser Powder Bed Fused AISI 316L Stainless Steel and Effect of Direct Annealing

Abstract

Alloy parts produced by an additive manufacturing method with rapid heat transfer from fast melting and solidification have different microstructures, characteristics, and performances compared with materials made by the conventional process. In this study, the corrosion and oxidation resistance of SS316L, which was prepared by the powder bed fusion process, was compared with those of cold-rolled SS316L. Additionally, the surface oxide film on stainless steel was thoroughly assessed since the film has the greatest influence on the corrosion and oxidation resistance. The effect of heat treatment on corrosion and oxidation resistance of SS316L fabricated by additive manufacturing was investigated. The SS316L has a microstructure formed by sub-grain cells, in which locally concentrated alloying elements form a stable passive film. As a result, it has a higher level of corrosion resistance and oxidation resistance than conventional cold-rolled materials. However, it was confirmed that the sub-grain cell was removed by heat treatment, which resulted in the degradation of corrosion and oxidation resistance.

Additive Manufacturing of AISI 316L Stainless Steel: A Review

“…In the PBF technique, the thermal history of the components being Bassis et al [150] have studied the effect of a slow strain rate on the stress corrosion resistance of AISI 316L produced by the wire laser additive manufacturing process, showing that the corrosion performance of the WLAM samples is lesser than the counterpart AISI 316L alloy, as expressed in the potentiodynamic polarization analysis. Bae et al [151] have investigated the corrosion resistance of L-PBF AISI 316L stainless steel and the effect of heat treatment in comparison with cold-rolled AISI 316L. As it has been demonstrated, the SLMfabricated AISI 316L materials with sub-grain cells have excellent corrosion and oxidation resistance due to their higher chemical stability compared with conventional cold-rolled SS316L.…”

The Heat Treatment Effects on the Microstructure, Hardness, and Sigma Phase Content of L-PBF SAE 316L Stainless Steel

“…560 MPa), good wear resistance, widespread availability, favorable machinability, fracture toughness (max. 12.3 kJ/m 2 ), biocompatibility, weldability, and a relatively economical cost [17][18][19][20][21][22][23]. This alloy has opened new avenues, especially with the advent of L-PBF technology, leading to its exploration in hydrogen-related applications, aerospace endeavors, and nuclear industries.…”