Influence of annealing and tempering on the wear and corrosion behavior of WC/W₂C reinforced composites fabricated by laser powder bed fusion

WC/W₂C particle reinforced stainless steel composites were fabricated via laser powder bed fusion (LPBF) and subsequently heat‑treated under two schemes: direct tempering (200–600 °C) and solution annealing at 1050 °C followed by tempering. The effects of these heat treatments on the microstructure, wear performance, corrosion behaviour, and mechanical properties were systematically investigated. While low‑temperature tempering (≤ 400 °C) promoted carbon redistribution and increased retained austenite from 17.6 % to 61.7 %, tempering at 600 °C—as well as the solution‑annealed and tempered condition—suppressed austenite (≈ 0 %) and triggered extensive precipitation of Cr‑rich carbides. Solution annealing homogenized the matrix, eliminated austenite, and thickened the in-situ reaction layers to ∼5 μm. Intergranular corrosion susceptibility correlated directly with carbide‑induced Cr‑depleted zones, with the highest degree of sensitization (DOS > 220) occurring after the 600 °C and 1050 °C + 600 °C treatments, significantly exceeding that of other conditions (DOS < 150). Wear resistance was governed primarily by matrix hardness; wear volume loss increased markedly from 2 × 10⁴ μm³ to 5 × 10⁵ μm³, attributed to abrasive carbide debris and thermal softening. Compression tests demonstrated high deformability (> 60 %) after heat treatment; however, the as‑built composite exhibited the highest compressive strength (∼4500 MPa) but underwent premature failure, owing to residual stress.