Repeated Impact Resistance of Stellite 6 Hardfacing Layer Produced by Gas Metal Arc Welding

Cobalt-chromium-based alloys, such as Stellite 6, exhibit exceptional wear resistance, chemical stability, and thermal stability, making them suitable for demanding industrial applications. However, the manufacturing of components from Stellite 6 is challenging due to the alloy's high hardness and poor machinability. Hardfacing of enhancing layers on components made from a material with superior machinability and/or more desirable bulk properties has been identified as an effective solution to Stellite 6 manufacturing limitations. The advantages of hardfacing by gas metal arc welding include high deposition rates, cost-effectiveness, and the capability to fabricate large-area structures. Recent studies have characterised Stellite 6 produced by this method in terms of its resistance to external thermal, chemical, or certain mechanical factors. However, to date, limited research has investigated its behaviour under repeated impact loading conditions. The present study investigates the impact resistance of an alloy equivalent to Stellite 6 hardfaced by gas metal arc welding onto a steel substrate. Testing was performed in different positions – above the beads and above their overlaps – in order to evaluate potential differences in impact life. The results indicated that, despite minor variations in morphology and mechanical properties between the distinct positions, the impact lifetime was equivalent in both. The findings of this study provide valuable information for the design and utilisation of components hardfaced with Stellite 6 in applications where impact protection is crucial.