Ni-Cr-Co alloy with high-temperature corrosion resistance and surface-modified poppet valve using the same

摘要

Provided are a surface coating material having excellent resistance to cracking and peeling, and excellent high-temperature corrosion resistance, and a poppet valve coated therewith. Ni-Cr-Co alloy of the present invention, Cr is 40.0-50.0 mass%, Co is 10.0-20.0 mass%, Nb is 0.5-5.0 mass%, Fe is 0.01-5.0 mass%, Si is 0.1-3.0 mass% %, With the balance being 26.0 to 40.0% by mass of Ni and inevitable impurities. Furthermore, the element selected from Mo, W, Mn, Ti, Al, B, C may be contained in a total of 5.0 mass% or less, Ti, Al is 3.0 mass% or less, B, C is respectively Each is 1.0 mass% or less. In the poppet valve of the present invention, at least the umbrella surface is coated with the Ni—Cr—Co alloy.