Study of Magnetism in Colmonoy-6 (AWS NiCr-C) Deposit on 316LN Stainless Steel

Study of magnetism in Ni–Cr hardface alloy deposit on 316LN stainless steel using magnetic force microscopy

“…The dilution significantly affects the microstructure and the mechanical properties of the deposit. The hardness values are found to decrease dramatically in the diluted regions as compared to the undiluted regions [3,4]. Even though both the substrate material and the Colomonoy-6 deposit are non-magnetic in nature, the diluted region is found to exhibit ferromagnetism [3,4].…”

“…Hardfacing of the mating surfaces has been widely used in components of SFR to avoid self-welding and galling [2,3]. Colmonoy-6 (American Welding Society (AWS) Ni-Cr-C) is used for hardfacing of 316 LN austenitic stainless steel components used in flowing liquid sodium environment to avoid galling and self-welding by enhancing the wear and corrosion resistance at temperatures up to 823 K [2,3]. The low induced radioactivity and adequate high temperature properties of the Ni-Cr alloy deposit ranks it ahead of cobalt based (e.g.…”

“…The low induced radioactivity and adequate high temperature properties of the Ni-Cr alloy deposit ranks it ahead of cobalt based (e.g. Stellite) hardfacing alloys for applications in nuclear reactors [2,3].…”

“…During GTAW deposition of Ni-Cr alloy over stainless steel, due to large difference in the melting range of the two alloys, the hardface coating suffers from significant dilution from the substrate austenitic steel. The effect of dilution is maximum in the first hardface layer deposited over the base metal and it reduces with increasing coating Contents lists available at ScienceDirect journal homepage: www.elsevier.com/locate/jmmm thickness, although the upper surface of the coating is still diluted to some extent by the previously deposited layers [2,3]. In case of PTAW deposit, with optimized deposition parameters, dilution could be much less than that from GTAW process.…”

“…Gas tungsten arc weld (GTAW) deposited Colmonoy-6 on stainless steel suffers with significant dilution from the substrate material [3]. The dilution significantly affects the microstructure and the mechanical properties of the deposit.…”