Patent ID: 8888069

Claim:
A valve, including: a valve body; a valve case; a first valve seat disposed on sliding surfaces of the valve body; and a second valve seat disposed on a sliding surface of the valve case; wherein each of said first and second valve seats is constructed of a welded metal comprising at least one of: a Co base alloy, an Ni base alloy, and an Fe base alloy; wherein each of said first and second valve seats has a plurality of layers in a thickness direction, including: an inner layer with a dendrite structure, a middle layer with a processing structure, and a surface layer with a cubic structure, and a layer of base material; and wherein said surface layer of each of said first and second valve seats is formed by a base portion made of the cubic structure, wherein dispersed in the base portion is: a granular eutectic chemical compound having a grain diameter equal to or less than 100 μm, or a blocky eutectic chemical compound having a block diameter equal to or less than 100 μm.