Influence of carbon nanotubes on microstructure and corrosion performance of additively manufactured 316L stainless steel

Laser powder bed fusion (LPBF) was performed on feedstock-modified 316L stainless steel powder with 1 and 2 vol% carbon nanotubes (CNT). The corrosion resistance was evaluated following cyclic potentiodynamic polarization tests conducted in 0.6 M NaCl at room temperature, 35 and 50 degrees C, and immersion tests in 6 % FeCl3. The CNT addition has increased the pitting potential and decreased number of pits formed during immersion in FeCl3 solution, which could be attributed to Mn-Si-O nano inclusions refinement and segregation of chromium around the inclusions. The observed corrosion behavior was correlated with the altered microstructure due to CNT addition.

Automated summary

Laser powder bed fusion (LPBF) was conducted on feedstock-modified 316L stainless steel powder with carbon nanotubes (CNT) additives. The addition of CNT improved the corrosion resistance of stainless steel, possibly due to the refinement of nano inclusions and segregation of chromium.