Improved passivation performance of selective laser melted Inconel 718 alloy via tempering treatment

The passivation performance of the selective laser melted Inconel 718 alloy after tempering treatments was investigated, and the underlying mechanism for the improved passivation film protectiveness was explored. The dislocation reversion and the mitigated segregation of Nb, Mo and Ti at Laves and delta phases decreased the storage energy of lattice distortion were critical factors for the formation of more protective passivation film in chloridecontaining solutions. The film formation rate increased after tempering, presenting the increased electric field strength and the decreased dissolution rate accordingly, as well as for the point defect diffusion coefficient and the oxygen vacancy flux therein.