Microstructural Integrity of Recycled CuZn40Pb2 Brass in Defect-Free Sanitary Fittings: A Process Optimization Approach

To achieve local industrial sovereignty and reduce costs, this work examines the feasibility of producing lead brass sanitary fittings from partially recycled raw materials while ensuring compliance with quality standards. This alloy was produced using two casting methods: continuous horizontal and discontinuous vertical, from pure, recycled, or mixed charges. The resulting billets underwent successive steps of hot extrusion, cold drawing of rods, hot forging, and machining. The impact of casting type, charge composition, and production parameters on the microstructure and integrity of the final products was evaluated through chemical analysis, metallographic observations (Optical and SEM/EDS devices), and non-destructive testing (ultrasound and radiography). The results reveal that the α+β two-phase structure characteristic of CuZn40Pb2 brass is present in all samples, with lead particles mainly located at grain boundaries. Vertical casting causes microstructural heterogeneity, lead segregation, and occasionally critical internal defects, such as cracks in the final parts. However, horizontal casting, combined with optimized transformation parameters and the addition of 25% pure material to the charge instead of using recycled material alone, resulted in a homogeneous structure and quality comparable to that of alloys made from virgin materials. SEM/EDS results confirm microscopic observations. This study demonstrates that producing high-quality brass sanitary fittings from partially recycled resources is technically feasible, offering a local, economical, and regulatory-compliant alternative.