| 摘要 |
PROBLEM TO BE SOLVED: To provide a Ni-based heat resistant alloy having excellent creep strength and fracture ductility.SOLUTION: The Ni-based heat resistant alloy has a chemical composition containing, by mass%, C:less than 0.05%, Si:1.0% or less, Mn:1.0% or less, Cr:15.0% or more and less than 28.0%, Al:more than 0.5% and 2.5% or less, Nb:2.0 to 5.0%, B:0.0005 to 0.01%, Mo:0 to 3.0%, W:0 to 11%, Ti:0 to 2.0% or the like and the balance Ni of 50% or more and impurities and satisfying following formula (1), and volume fraction of a gamma prime phase of a basal phase is 10 to 25 vol.% and initial grain boundary coverage factor is 70% or more. [Nb]>1.0+0.4×[Mo]... Formula (1), where each symbol of element in the formula (1) is substituted by the content represented by mass% of corresponding element.SELECTED DRAWING: None |
