摘要 |
 Provided is an engine valve in which the component ratio of specific rare metals in the build-up metal of a face can be suppressed, and specific properties in terms of abrasion resistance, impact resistance and high-temperature corrosion resistance can all be met, in order to respond to the increasing severity of the usage environment. An engine valve wherein: a ring-shaped cladding section is provided, by means of build-up welding, on the cap part of a valve base, and a face is provided which forms a surface hardening layer on the cladding section; the build-up metal of the cladding section is formed from a Ni-Fe-Cr alloy; the component mass of the included elements is 8.0-40% W, 20.0-40.0% for the total of Mo and W, 20.0-50.0% Fe, 12.0-36.0% Cr, 1.0-2.5% B, with the remainder being Ni and unavoidable impurities; and the surface hardening layer forms a nitride layer, by means of nitriding treatment of the entire valve, on a finished surface formed on the face. Thus, the composition component ratio of rare metals can be suppressed, and it is possible to ensure specific properties. |