NI-BASE ALLOY EXCELLENT IN MECHANICAL STRENGTH AS WELL AS IN INTERGRANULAR CORROSION RESISTANCE AND STRESS CORROSION CRACKING RESISTANCE IN HIGH HEAT-AFFECTED ZONE IN WELD ZONE

摘要

PURPOSE:To obtain a high-Cr Ni-base alloy particularly improved in intergranular stress corrosion cracking resistance and intergranular corrosion resistance in high-temp. water by providing a composition containing respectively prescribed amounts of C, Si, Mn, Cr, Fe, P, S, N, Nb, B, Mg, etc. CONSTITUTION:The title Ni-base alloy has a composition consisting of, by weight, =0.080% C, =1.0% Si, =1.0% Mn, 26-35% Cr, =25% Fe, =0.030% P, =0.030% S, =0.2% N, Nb in an amount of =4%, =50(%C-0.030)%, and further =[2.0-50(%C+%N)]%, =0.005% B, =0.05% Mg, and the balance Ni. The mechanical strength of this Ni-base alloy is superior as to provide =27kg/mm2 0.2% yield strength, and further, this alloy has excellent intergranular corrosion resistance and stress corrosion cracking resistance in a high heat-affected zone in a weld zone. Moreover, this alloy has various superior characteristics as material for nuclear power generation equipment in particular.