Corrosion Characteristics of Laser-Engineered Net Shaping Additively-Manufactured 316L Stainless Steel

The single-loop electrochemical potentiokinetic reactivation (EPR) test was used to quantify the degree of sensitization for 316L stainless steel (SS) produced by laser-engineered net shaping (LENS (R)) additive manufacturing (AM). EPR tests were also used to monitor how the sensitivity of the as-deposited and heat-treated AM material compared to wrought 316L SS. A solution-annealing heat treatment that recrystallized the material was also applied to AM-316L SS. The EPR tests showed that as-deposited AM-316L SS displayed low levels of sensitization. Heat-treated AM-316L SS demonstrated some improvements in resistance to corrosion, but overall did not perform as well as wrought 316L material. Optical micrographs of the AM-316L SS samples collected after conducting the EPR tests also showed localization in the as-deposited AM-316L SS material; however, these features were reduced after heat treatment, suggesting greater resistance to corrosion.