摘要 |
A lid material (1) is provided which comprises: a core layer (2) composed of an Fe-Ni alloy or an Fe-Ni-Co alloy; a nickel-based (Ni-based) metal layer (3) press- and diffusion-bonded onto the core layer (2) and composed of a Ni-based metal, such as pure Ni, mainly comprising Ni; and a brazing material layer (5) press-bonded onto the Ni-based metal layer (3). The Ni-based metal layer (3) has a maximum-to-minimum thickness ratio T1/T2 of 1.4 to 15. The lid material (1) is produced by press-bonding a Ni-based metal foil onto a core sheet for formation of the Ni-based metal layer on the core layer, then diffusion-annealing the Ni-based metal layer and the core layer, and press-bonding a brazing material foil onto the Ni-based metal layer with a reduction ratio of 30 to 65%. <IMAGE> |