HOT-DIE NI-BASED ALLOY, HOT-FORGING DIE EMPLOYING SAME, AND FORGED-PRODUCT MANUFACTURING METHOD

Provided are a Ni-based alloy for hot die having a high high-temperature compressive strength and a good oxidation resistance and being capable of suppressing the deterioration in the working environment and the shape deterioration, a hot forging die using the Ni-based alloy for hot die, and a method for manufacturing a forged product using the hot forging die. The present invention provides a hot forging die comprising a Ni-based alloy for hot die comprising, in mass%, W: 7.0 to 15.0%, Mo: 2.5 to 11.0%, Al: 5.0 to 7.5%, Cr: 0.5 to 7.5%, and the balance of Ni with inevitable impurities, wherein at least 80% of a surface area of the Ni-based alloy for hot die is covered with an aluminum oxide layer. In addition to the composition, the Ni-based alloy for hot die may further comprise 7.0% or less of Ta and may further comprise one or two or more elements selected from Zr: 0.5% or less, Hf: 0.5% or less, rare-earth elements: 0.2% or less, Y: 0.2% or less, and Mg: 0.03% or less.