Effect of oscillating traverse welding on microstructure evolution and characteristic of hypoeutectic hardfacing alloy

Oscillating traverse welding causes overlapping of the distinctive weld and heat effects on the previous weld. This study investigates microstructure characteristics and evolution of hypoeutectic Fe-Cr-C hardfacing alloy clad by oscillating traverse gas tungsten arc welding. Iron, chromium and chromium carbide were used to clad on A36 steel substrate. Clad alloy presents a primary α phase and lamellar eutectic composition of α + M23C6 carbide. In the heat-affected zone (HAZ) of the previous weld, M23C6 carbide transforms into a worm-like structure instead of lamellar. Due to the arc's heat effect, carbide morphology evolution starts with the detaching of lamellas, followed by breaking up and coarsening, and finally transforming into a worm-like structure. The hardness profile shows that the lowest hardness exists at the region closest to the fusion boundary. The hardness performance attributed to the heat affected matrix α phase and worm-like carbides.