Microstructural and Mechanical Evaluation of a Cr-Mo-V Cold-Work Tool Steel Produced via Electron Beam Melting (EBM)

Abstract

In this work, a highly alloyed cold work tool steel, Uddeholm Vanadis 4 Extra, was manufactured via the electron beam melting (EBM) technique. The corresponding material microstructure and carbide precipitation behavior as well as the microstructural changes after heat treatment were characterized, and key mechanical properties were investigated. In the as-built condition, the microstructure consists of a discontinuous network of very fine primary Mo- and V-rich carbides dispersed in an auto-tempered martensite matrix together with ≈15% of retained austenite. Adjusted heat treatment procedures allowed optimizing the microstructure by the elimination of Mo-rich carbides and the precipitation of fine and different sized V-rich carbides, along with a decrease in the retained austenite content below 2%. Hardness response, compressive strength, and abrasive wear properties of the EBM-manufactured material are similar or superior to its as-HIP forged counterparts manufactured using traditional powder metallurgy route. In the material as built by EBM, an impact toughness of 16–17 J was achieved. Hot isostatic pressing (HIP) was applied in order to further increase ductility and to investigate its impact upon the microstructure and properties of the material. After HIPing with optimized protocols, the ductility increased over 20 J.

Powder‐Based Additive Manufacturing: A Critical Review of Materials, Methods, Opportunities, and Challenges

“…In 2021, Zafar et al [ 114 ] used molybdenum powder material for EBM printing. In 2021, Botero et al [ 115 ] used EBM to manufacture high‐alloy cold‐worked tool steel, called Uddeholm Vanadis 4 Extra. The ductility is significantly improved.…”

“…Performance parameters of different types of EBM equipment. [115] Process (Reproduced with permission. [293] Copyright 2019, Elsevier.)…”

PBF-EB of Fe-Cr-V Alloy for Wear Applications

“…However, most of the materials that have been investigated were non-iron based, as their manufacturing was often combined with high production and material costs, or stainless or maraging steel [ 1 , 2 , 3 , 4 ]. Interest in the use of AM for cost-driven industries, tool steel applications in particular, has been increasing recently, which is reflected in the number of publications in the last years [ 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 ].…”

“…Most common publications from Sander, Botero, etc. deal with an FeCrMoVC alloy, Uddeholms Vanadis 4 Extra©, Vibenite© 480 by VBN Components, FeCu-C alloy, and FeCr-10V, respectively [ 7 , 10 , 11 , 23 , 25 , 26 ].…”

Manufacturing of Tool Steels by PBF-EB

“…As-built hardness was in the 620 HV0.1 to 740 HV0.1 range [22]. The highly alloyed cold-working tool steel Uddeholm Vanadis 4 Extra (C: 1.4, Cr: 4.7, Mo: 3.5, and V: 3.7 in wt-%) has been additively processed using PBF-EB [23,24]. Employing powder bed temperatures up to 1000 • C and area energies between 1.5 and 2.0 J/mm 2 , dense specimens were obtained.…”