| abstract |
Provided is a Ni-base heat-resistant alloy member capable of preventing surface defects during hot working even when the thickness is 20 mm or more. A Ni-based heat-resistant alloy member having a thickness of 20 mm or more, and in mass%, C: 0.01 to 0.15%, Si: 1% or less, Mn: 2% or less, P: 0.03 %: S: 0.01% or less, Ni: 48-58%, Co: 8-16%, Cr: 18-25%, Mo: 6-12%, Ti: 0.05-0.8%, A chemical composition comprising Al: 0.05 to 1.6%, B: 0.0001 to 0.01%, N: 0.02% or less and O: 0.01% or less, with the balance being Fe and impurities. A Ni-based heat-resistant alloy member having a metal structure composed of recrystallized grains having an ASTM grain size number of 7 or more and a central portion of the member having a metal structure consisting of crystal grains having an ASTM grain size number of 4 or less . [Selection figure] None |