NI-FE-CR-BASED ALLOY AND ENGINE VALVE COATED WITH SAME

摘要

Provided is a surface-hardening alloy which has a good shock resistance, a good wear resistance and a good high-temperature corrosion resistance and contains Fe that can be abundantly supplied and is less expensive. An Ni-Fe-Cr-based alloy characterized by containing 0-20.0 mass% of Mo and 8.0-40.0 mass% of W, a total of 20.0-40.0 mass% of Mo and W, 20.0-50.0 mass% of Fe, 12.0-36.0 mass% of Cr, 1.0-2.5 mass% of B with the balance comprising Ni and unavoidable impurities, and an engine valve coated with the same. The Ni-Fe-Cr-based alloy may further contain not greater than 15.0 mass% in total of element(s) selected from among Co, Mn, Cu, Si and C, wherein it is preferred that the content of Co is not greater than 15.0 mass%, the contents of Mn and Cu are each not greater than 5.0 mass%, the content of Si is not greater than 2.0 mass% and the content of C is not greater than 0.5 mass%.