Effect of WC and FeCrC reinforcements on the WAAM repair of stainless steel

In this study, the repair of AISI 304 stainless steel was performed using wire arc additive manufacturing (WAAM), and its effects on microstructure, hardness, and wear behavior were investigated. Five samples were fabricated using either plain 304 stainless steel wire or filler wires containing different WC and FeCrC particle ratios. Microstructure characterization using OM, SEM, EDS, and XRD revealed that WC additions led to grain refinement and increased carbide formation. Particularly in the 50WC sample, fine and uniformly distributed carbides contributed to an increase in both hardness and wear resistance. XRD results supported the formation of hard carbide phases such as Fe–Cr–C and Fe–W–C, in agreement with microstructural analyses. Microhardness tests showed the highest value (∼700 HV 0.1 ) in the 50WC sample, while the lowest was observed in the plain 304 wire and substrate. Ball-on-disc wear tests revealed that WC-containing samples had the lowest specific wear rates, primarily due to the presence of hard and homogeneously distributed carbide phases that enhanced surface hardness and wear resistance. The findings demonstrate that particle-filled wire reinforcements in WAAM significantly enhance mechanical and tribological performance in repaired stainless steel components.