Pitting corrosion of SLM Inconel 718 sample under surface and heat treatments

Abstract In this study, the corrosion behavior of SLM Inconel 718 samples was investigated under different post-treatments including various heat treatments and surface electrochemical polishing. From the test results, the new generation of precipitation of γ′/γ″ phase from the samples after HT 1040 and HT1100 can lead to a corrosion resistance improvement. A serious corrosion resistance performance decline can be found from the sample after HT1200 due to grain growth and large amount of Cr element transformation to carbide. A dense passivation coating over sample surface generated from ECP process can significantly increase both corrosion potential and pitting potential.