摘要 |
There is disclosed a valve comprising one valve seat ring, of a disc or a body, having a surface composed of a Cr-Mn-Fe system or a Cr-Ni-Fe system Fe-based precipitation hardening type alloy, and another valve seat ring thereof having a surface composed of a Cr-Ni system Ni-based alloy having a hardness Hv of 400 or more. The valves of this invention can have excellent wear resistance, cavitation erosion resistance and galling resistance, and since emitting no cobalt, the valves of this invention are suitable for various plants such as chemical plants, particularly nuclear power plants. |