Ni base casting superalloy and casting comprising said Ni base casting superalloy

摘要

PROBLEM TO BE SOLVED: To provide a Ni-based casting super alloy which is used for a large-sized high temperature member tolerable to increase in combustion gas temperature (e.g. a turbine blade) and which has crystal grain boundary intensity, high temperature intensity and acid resistance that are balanced at a higher level than conventional one, and which can achieve low cost.SOLUTION: There is provided the Ni-based casting super alloy containing 0.05 to 0.09 mass% of C, 0.01 to 0.04 mass% of B, 0.1 to 0.4 mass% of Hf, 0.05 mass% or less of Zr, 3.5 to 5 mass% of Al, 3 to 6 mass% of Ta, 3 to 5 mass% of Ti, 0.1 to 1 mass% of Nb, 8 to 12.5 mass% of Cr, 5 to 10 mass% of Co, 4 to 8 mass% of W, 1 to 2.5 mass% of Mo, and at least one of 0.02 to 2 mass% of Si and 0.1 to 5 mass% of Fe and the balance Ni with inevitable impurities.