Impact of incorporating FeNbC into weld flux on the abrasive wear resistance of coatings produced by SAW in a microalloyed steel

Owing to the global shortage of raw materials and an increase in their prices, there is a growing demand for engineering solutions to increase the lifespan and durability of equipment and components. Therefore, this study aims to combine surface engineering and welding engineering to produce a niobium-rich coating using submerged arc welding (SAW) deposition. SAW is a cost-effective technique that allows high deposition rates and technical simplicity, which can enhance mechanical properties and resistance to abrasive wear of components. This research involves the addition of a FeNbC powder alloy in percentages of 5, 10, and 15 wt% to a neutral commercial SAW flux, as an alternative to adding Nb to the microstructure of the deposited coating. The coating was characterized by optical microscopy to analyze the microstructure, such as the presence of phases; microhardness through a Vickers micro-durometer, and resistance to abrasive wear through the loss of mass using a rubber wheel-type abrasometer. The wear mechanisms were evaluated using scanning electron microscopy. The results showed that a Nb-rich coating can be deposited via SAW, and the coatings successfully increased microhardness by up to 110% and resistance to abrasive wear to values higher than the base metal used (microalloyed steel). The microstructure formed was rich in Fe₂Nb and NbC, proving the formation of Nb-rich phases. Additionally, the mechanism of abrasive wear was predominantly plastic for the base metal and changed to micro-cutting and micro-plowing after the addition of up to 15% of FeNbC.