Directed energy deposition and characterization of high‐speed steels with high vanadium content

Abstract

• We produced defect-free builds of high vanadium high speed steels using DED. • We investigated the intricate microstructure imparted by the DED process, which contains fine metal carbides. • Our alloys exhibit high micro-hardness values ranging between 850 HV and 1000 HV. • Based on our results, we propose novel DED processing strategies to design HVHSS alloys for hard-facing applications. High vanadium high speed steels (HVHSSs) are alloys that are often employed for hard-facing applications owing to their excellent hardness and wear-resistance. These properties, however, make them difficult to machine into functional parts, even when employing energy-intensive processes. In this work, we employ directed energy deposition (DED) as an alternative manufacturing route to produce defect-free HVHSSs builds. We study the printability of two alloy compositions—namely Fe-10V-4.5Cr-2.5C (V10) and Fe-15V-13Cr-4.5C (V15)—and confirm their exceptionally high microhardness, which ranges from 850 HV to 1000 HV. We ascribe the differences in mechanical properties between the two HVHSSs to the size and volume fraction of vanadium carbides in the microstructure as well as the phase content, all of which vary as a function of the cooling rate imposed by DED. Our work inspires new strategies to design near-net-shape parts for hard-facing applications via additive manufacturing.