Electrochemical and localized corrosion behavior of a 316 L SS/copper/316 L SS composite in 0.5 wt. % NaCl solution was investigated from cross-sectional and plane directions by electrochemical measurements and high -resolution microscopic examination. The galvanic coupling accelerated the dissolution at the internal surface and pitting attack at the external surface of the 316 L layer. Polarization up to 1 V/SCE resulted in formation of a corrosion product layer (ca. 992 nm) composed of metal oxides/hydroxides on top of the passive film, which consisted of a Fe2O3-rich outer layer (3.3 nm) and a Cr2O3-rich inner layer (4.1 nm). The copper corrosion was quite uniform.Data availability statement: The raw/processed data required to reproduce these findings cannot be shared at this time as the data also forms part of an ongoing study.