. "int and an alloy mainly containing Al and being excellent in resistance against pitting corrosion and being formed and stacked in a layer on the metal having a high melting point. [0027] In the foregoing, a preferable mode is one wherein an element or elements to be added to the alloy containing mainly Al include any one of Nd (Neodymium), Ti (Titanium), Cr (Cromium), and Ta, or at least one group" . . .