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 percent 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 deg C for 0.5 h. The spocimen 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 percent and dezincification resistance increases considerably.