NICKEL-BASE CORROSION-RESISTANT ALLOY AND CORROSION-RESISTANT MEMBERS MADE OF THE ALLOY FOR THE APPARATUS FOR REACTION WITH SUPERCRITICAL AMMONIA

摘要

The invention intends to provide a material that exhibits excellent corrosion resistance to supercritical ammonia and is suitable for a supercritical ammonia reactor. An Ni-based corrosion resistant alloy includes from 15% or more to 50% or less by mass of Cr and any one or both of Mo and W, wherein a [(content of Mo) + 0.5 × (content of W)] is from 1.5% or more to 8.5% or less by mass, a value of 1.8 × [% content of Cr]/{[% content of Mo] + 0.5 × [% content of W]} is from 3.0 or more to 70.0 or less and the balance is Ni and an unavoidable impurity. Preferably, content of Fe is less than 3% by mass, and content of C is less than 0.05% by mass. The alloy is used to configure a supercritical ammonia reactor or the material is coated on a surface that contacts with a supercritical ammonia fluid. The alloy exhibits excellent corrosion resistance to supercritical ammonia and a mineralizer added the supercritical ammonia. The safety and reliability of an apparatus can be improved, the producing cost can be reduced, the apparatus lifetime can be extended and the running cost can be reduced.