Ni-BASED ALLOY AND HEAT TREATMENT FURNACE COMPONENT FORMED OF THE SAME

To provide: a Ni-based alloy which has excellent alkali corrosion resistance and excellent weldability; and a heat treatment furnace component which is formed of this Ni-based alloy.SOLUTION: This Ni-based alloy, which has excellent alkali corrosion resistance and excellent weldability, contains, in mass%, Al: 8.0%-16.0%, Zr: 0.01% or more and B: 0.001% or more with the balance being Ni and unavoidable impurities, while excluding the cases where Al is more than 12.0% and less than 13.5%. The total amount of Zr and B is 3.0% or less. At least Ni3Al and one of Ni, NiAl and NiZr compounds are precipitated on the surface; and the area ratios of the precipitated Ni3Al, Ni, NiAl and NiZr compounds satisfy 0.2