Valve having facing layers of co-free Ni-base Alloy

A combination of materials which form hard facing layers provided on engagement portions of a valve body and engagement portions of a valve box,

• wherein said hard facing layers on the engagement portions of the valve body and the engagement portions of the valve box consist of cobalt-free Ni-base alloys,
• one of said Ni-base alloys for the hard facing layers comprises not more than 15% Fe and less than 2% W (tungsten), and
• the other of said Ni-base alloys for the hard facing layers comprises more than 15% Fe.

A combination of materials which form hard facing layers provided on engagement portions of a valve body and engagement portions of a valve box,

• wherein said hard facing layers on the engagement portions of the valve body and the engagement portions of the valve box consist of cobalt-free Ni-base alloys,
• one of said Ni-base alloys for the hard facing layers essentially consists of, by weight, 15 to 20% Cr, 5 to 10% Si, 10 to 15% Fe, less than 2% W, and the balance of Ni and unavoidable impurities, and has a Vickers hardness (Hv) in a range from 510 to 630, and the other of said Ni-base alloys for the hard facing layers essentially consists of, by weight, 5 to 15% Cr, 5 to 10% Si, more than 15% and not more than 30% Fe, 1 to 4% W, and the balance of Ni and unavoidable impurities, and has a Vickers hardness (Hv) in a range from 400 to 470.