Sustainable Recycling of CuZn40Pb2 Brass for Sanitary Fittings: Process Optimization and Microstructural Assessment

This study evaluates the feasibility of producing CuZn40Pb2 brass sanitary fittings with partial recycled materials while ensuring compliance with industrial standards. It compares two casting methods, continuous horizontal and discontinuous vertical, using pure, recycled, and mixed charges. The cast billets were subjected to hot extrusion, forging, and machining. The research investigates how casting method, charge composition, and processing influence microstructure and product quality through chemical analysis, optical microscopy, and radiography. All samples displayed a typical α+β microstructure, with lead mainly situated at grain boundaries. Vertical casting exhibited more heterogeneity, lead segregation, and internal defects. Horizontal casting with proper processing and 25% virgin material produced a uniform structure and mechanical properties comparable to those of fully primary material parts. Lead segregation was under 0.56% in horizontally cast billets, whereas vertically cast billets showed differences up to 3.41%. These results demonstrate that using recycled brass for sanitary fittings is feasible and environmentally friendly, supporting a circular economy in metallurgy.