Pb-less brass with high dezincification resistance in LCA perspective

摘要

Recently, environmental problem has become a significant issue. Particularly in water supplies, the public demand for using Pb-free brass with high dezincification resistance is getting more increase. In the present study, we have developed a new technique for removing Pb from brass as an alternative to recycle scrap brass containing Pb in life cycle assessment (LCA) perspective. Brass containing 2.15 mass % Pb were melted and calcium-silicon (Ca-Si) compound was then added into the molten brass so that it reacted with Pb to form Ca-Pb-Si -like compound. This Ca-Pb-Si -like compound was then skimmed off from the molten brass. In order to increase dezincification resistance, alloying element P was added into the molten brass. After casting into a metal mold, the ingot was annealed at 550℃ for 0.5 h. The specimen from the ingot was characterized by EMPA and fluorescence X-ray analysis. Dezincification test was carried out by using a galvanostatic anodic polarization. The results show that Pb content decreases significantly up to 55 % and dezincification resistance increases considerably.