Effects of K2co3 Flux on the Microstructure and Abrasion Resistance of High-Chromium Hardfacing Alloys

In this study, we assessed the effects of K2CO3 flux on the microstructure and abrasion resistance of high-chromium alloys deposited by open arc self-shielded welding with composite powder particles (CPPs) and solid wire. A high-speed camera was used to capture the arc shape. Phase composition and microstructure of the as-prepared alloys were characterized by an x-ray diffractometer (XRD), a scanning electron microscopy (SEM) with an energy dispersive spectrometer (EDS). Abrasion resistance was investigated using wet sand rubber wheel wear tester. The results showed that the arc expanded outward and changed from a bell jar shape to a hemispherical shape with the addition of K2CO3 active fluxes. The CPP filling rate of hardfacing alloys was advanced and their microstructure changed from hypoeutectic to hypereutectic with increasing K2CO3 content. Abrasion resistance also improved significantly initially due to the appearance of primary M7C3 phases and then decreased for their grain refinement.