Abstract
High-hardness materials with increased wear resistance associated with corrosion resistance are constantly demanded in the mining and oil & gas industries. Thus, flux-cored wires with tungsten carbide have been used for hard-facing applications aiming for greater wear resistance requirements. In the present paper, single bead welding experiments were carried out to evaluate the influences of advanced techniques of dynamic wire feeding in GTAW process (with wire longitudinal oscillation) over the weld bead morphology and mechanical properties. Moreover, the effect of the wire oscillation over the spread of the tungsten carbides within the molten zone was evaluated. A comparison between conventional wire feeding versus dynamic wire feeding was conducted. The wire oscillation frequency was varied in 0, 5, 10, and 15Hz. The filler metal used was the CORODUR OA-Br (MF 21/22 UM-60-CG) flux-cored wire with tungsten carbides, manufactured by Durum do Brasil, laid over an ASTM A36 steel substrate. The weld metal macrographs and carbide dispersion were based on optical microscopy (OM). Chemical composition was also verified using EDS analysis. Vickers micro hardness with 1kg load and dry sand ASTM G65 wear resistance tests were also conducted. The main results showed that the increase of the wire’s frequency reduced the weld bead reinforcement and dilution. Furthermore, wider weld beads were achieved with dynamic wires feeding. Regarding the tungsten carbide particles dispersion, the dynamic wire feeding results in a better and more uniform dispersion when compared to conventional wire feeding, which resulted in a greater weld bead surface hardness and abrasion resistance.
Keywords: Dynamic wire feeding, Hardfacing, Tungsten Carbides, GTAW.
Referência:
PIGOZZO, I. O.; RIFFEL, K. C.; SILVA, R. H. G.. Influences of the dynamic wire feeding of flux-cored wire with WC in GTAW process applied to hardfacing coatings. 27th ABCM International Congress of Mechanical Engineering, December 2023. Florianópolis, Brazil