Sustainable Hardfacing via Gtaw Powder Pre-placement: In Situ Synthesis of Multi-carbides From Recycled Wc/tic Inserts Cermets

This study investigates a sustainable and cost-effective route for production of a high-performance hardfacing by Gas Tungsten Arc Welding (GTAW) using recycled cermet insert powders (WC/TiC). The filler was deposited on an ASTM A-36 carbon steel substrate. Despite high dilution rate, the resulting weld exhibited superior hardness, a five-fold increase over the base metal. This counter-intuitive outcome is attributed to the strong reinforcement effect, promoted by the carbide-forming elements in the weld pool, which effectively compensate the high iron content from the substrate. Microstructural analysis confirmed the formation of a complex multi-carbide composite, including partially dissolved WC, stable TiC, and newly synthesized iron-tungsten-carbon ternary carbides (M ₆ C and M ₃ C) in a ferritic matrix. The complex formation and distribution contribute to the development of durable, versatile, and high-wear-resistant suitable for overlays for severe abrasive applications.