Twin hot-wire arc welding additive manufacturing deposition of high tungsten Stellite-6 hard-facing coating: Processing, microstructure and wear properties

• Published in: Materials today communications 2023-06, Vol.35, p.105572, Article 105572
• Main Authors: Toozandehjani, Meysam, Ostovan, Farhad, Shamshirsaz, Mahnaz
• Format: Article
• Language: English
• Subjects: Hard-facing; Microstructure; Stellite-6 (CoCrCW) alloy; Wear resistance; Wire arc additive manufacturing (WAAM)
• ISSN: 2352-4928; 2352-4928
• DOI: 10.1016/j.mtcomm.2023.105572

In order to gain the advantages of excellent wear properties of hard-facing stellite-6 alloy, a single layer of high tungsten Stellite-6 coating was deposited onto St37 and Mo40 steel substrates using a twin hot-wire arc welding additive manufacturing process. The wire rods used were initially manufactured by a powder metallurgy route (ball milling + spark plasma sintering + extrusion) from pure raw materials. A comparative study was carried out in terms of microstructure, phase composition, hardness and wear resistance. Stellite-6 coatings were found to be metallurgically well-bonded to both substrates with proper penetration and no cracks or pores. The dendritic microstructure of Stellite-6 coating deposited on St37 substrate (S6–1) was finer with higher percentage of eutectic structure (35.3 %), higher concentration of Tungsten (W) and less amount of Iron (Fe). Consequently, S6–1 coating showed higher hardness and wear resistance due to the finer dendritic size, more and uniform distribution of Chromium (Cr-) and W-rich carbides in inter-dendritic areas and less Fe dilution. [Display omitted]