HEAT-RESISTANT NICKEL-BASED ALLOY EXCELLENT IN WELDABILITY

摘要

A heat-resistant nickel-based alloy comprising, in terms of wt. %, 0.05 to 0.25% of C, 18 to 250 of Cr, 15 to 250 of Co, up to 3.5% of Mo and 5 to 10% of W with the content of one or both of Mo and W being greater than 5 to 10% in terms of W + 1/2Mo, 1.0 to 5.0% of Ti, 1.0 to 4.0% of Al, 0.5 to 4.5% of Ta, 0.2 to 3.0% of Nb, 0.005 to 0.01 of Zr, 0.001 to 0.01% of B, and the balance of Ni and unavoidable impurity elements, wherein the (Al + Ti) content and the (W + 1/2Mo) content are within the range surrounded by the line connecting the points A, B, C, D and E in Fig. 1. Another alloy has substantially the same composition as described above except that the Cr content is 10 to 20% and the (A1 + Ti) content and the (W + 1/2Mo) content are within the range surrounded by the line connecting the points A, B, C, F, G, H and E in Fig.1. The alloys are useful as a material for a gas turbine or other structural parts to be exposed to high temperatures because of their high high- temperature strength and good weldability.