Influence of Friction Stir Processing on the Friction, Wear and Corrosion Mechanisms of Solid-State Additively Manufactured 316L Duplex Stainless Steel

Friction stir processing (FSP) was employed as a post-surface processing technique to modify the tribological and corrosion behavior of cold-sprayed (CS) 316L SS deposits. Results indicate that the effect of FSP induced an austenitic phase transformation due to the combination of frictional heat and plastic deformation. Consequentially, the friction of the CS deposit after FSP decreased by 8.3%. Similarly, the wear rate was reduced by 55.1%. These properties were improved mostly due to the closure of pores (yielding a 99.97% density) and localized grain refinement. Electrochemical measurements revealed that the corrosion rate was reduced by similar to 65%. Also, the pitting corrosion resistance (Epit - Ecorr) increased, which can be majorly attributed to the densified surface and full austenitic phase transformation after FSP. Compared to the other samples, the highest polarization resistance at the corrosion potential (Rpol) was obtained for the FSP CS 316L SS. Based on these findings, it can be inferred that FSP is a viable method to improve the tribological and corrosion behavior of CS 316L SS deposits.