Ni-Based CW6MC: Effect of the Internal Revert Recycle on the Soundness of the Alloy

The CW6MC alloy is a nickel-based alloy used to withstand acidic environments, especially in the oil and gas industry where it is used in the production of valves, impellers, and pipes. This alloy is the foundry counterpart of the best known A625 for plastic deformation. Regarding nickel-based alloys, a scrap market like that in the case of steel has not yet been established, therefore, especially in the case of foundries, scrap generally comes from internal recycling (casting waste, feeders, sprues, runners, etc.) to be certain of the origin and quality of the material. In this work, four castings with different percentage of recycled content (0%, 30%, 70%, 100%) were produced in accordance with the technical specifications and analysed to evaluate the effect of scrap on the final chemical composition, the microstructure, the mechanical properties and corrosion resistance. Following the analyses carried out, it was determined that the amount of acceptable scrap content (of those analysed) without compromising the material properties corresponds to 30%.