Effects of Travel Speed on the Microstructure and Abrasion Resistance of Hardfacing Alloys Deposited with Composite Powder Particles and Solid Wire

Abstract

Composite powder particles (CPP) preset on base metals were fused with a solid wire to form a melt by the intense heat provided by the arc. An X-ray diffractometer, scanning electron microscopy, and energy dispersive spectrometer were employed to investigate the effects of travel speed on the microstructure and abrasion resistance. It was found that the microstructure of hardfacing alloys with CPP consists of γ-Fe, M7C3, and (Ti, V) C. With an increase in the travel speed from 3.5 to 6 mm/s, the microstructure with CPP changed from a hypoeutectic to hypereutectic structure. For hardfacing alloys with CPP, the increase in the travel speed not only contributed to a reduction of the dilution ratio of base metals, but also deliberately increased the volume fraction of primary M7C3-type carbides, which indicated that the bonding function executed on powder components led to a significant improvement in abrasion resistance and increased the utilization ratio of the alloying elements. The wear mechanism of hardfacing alloys included micro-cutting of abrasive particles and micro-spalling.

Keywords

• composite powder particles
• solid wire
• open arc
• hardfacing
• high-chromium alloys