Effects of aging time on intergranular and pitting corrosion behavior of Cu-bearing 304L stainless steel in comparison with 304L stainless steel

•304L-Cu SS shows lower intergranular corrosion resistance than 304L SS.•The aging treatment reduces the pitting corrosion resistance of 304L-Cu SS.•Cu-rich precipitation evokes the sensitization and pitting corrosion of 304L-Cu SS.

In this work, the effects of aging time on intergranular and pitting corrosion behavior of Cu-bearing 304L and 304L stainless steels were investigated by using the double loop electrochemical potentiokinetic reactivation (DL-EPR) and the potentiostatic polarization electrochemical methods. The results showed that the Cu-bearing 304L stainless steel possessed a higher intergranular corrosion tendency and a higher pitting corrosion rate for extended aging time. The TEM observation and 3D APT analysis confirmed that above behavior could mainly attribute to the precipitation of the Cu-rich phase in the Cu-bearing 304L stainless steel.