... on the earth crust,is now well understood by people for its low density,high strength and excellent corrosion resistance and ... many fields,such as chemical industry ,petrochemical industry,used in surgical implants,seawater desalination,ocean environment protection,motor vehicle ... .0150.0150.0150.015Fe max0.300.400.500.250.200.30O max0.250.200.250.150.180.25Al max 5.5~6 ...