Fe-Ni-based austenitic alloy excellent in irradiation resistance and sodium corrosion resistance and method of setting alloy components

摘要

PURPOSE:To obtain an Fe-Ni base austenitic alloy excellent in neutron irradia tion resistance by specifying the compsn. constituted of C, Si, Mn, Cr, Ni, Mo, W and Fe. CONSTITUTION:This Fe-Ni base austenitic alloy is the one constituted of, by weight, =0.2% C, =0.5% Si, =1.0% Mn, 13 to 18% Cr, 30 to 50% Ni, 2.0 to 6.0% Mo+W as well as 0.4 to 0.6 Mo/(Mo+W), if required, furthermore mixed with 0.10 to 0.30% Nb and =0.20% N, in which a part of Cr is substituted by 1.0 to 7.0% Re according to necessary and the balance Fe with inevitable impurities and having excellent irradiation resistance. In the above alloy, as for the alloy components, the kind and the amt. to be added of each alloy element are determined so that the average bond order and the average (d) orbital electron level obtd. by bond orders, (d) orbital electron levels and atomic fractions with an Ni base metal will be regulated to specified value, by which the alloy components can be set. By using this alloy, the long service life of high temp.-high pressure structural members such as core members for a fast beeder reactor can be attained.