HIGH NI AUSTENITIC STEEL EXCELLENT IN HIGH TEMPERATURE STRENGTH

摘要

PURPOSE:To improve the swelling resistance, high temp. creep strength and phase stability under the irradiation of neutrons in an austenitic steel by adding a high Ni austenitic steel with solid solution strengthening elements, Mo and W, in combination, adding carbon nitride precipitation strengthening elements, Nb and V, in combination and adding N independently. CONSTITUTION:Composition. of this high Ni austenitic steel is constituted of, by weight, =0.5% Si, =1.0% Mn, 13 to 18% Cr, 30 to 50% Ni, 2.0 to 6.0% Mo+W, 0.1 to 0.8% Nb+V (V/Nb=0.1 to 2.7), 0.01 to 0.2% N, and the balance Fe with inevitable impurities. Furthermore, since H causes He embrittlement, a part thereof (0 to 81%) is preferably substituted by C. Moreover, for improving its swelling resistance, 0.08% P is preferably added, and for refining precipitates, 0.1% B is preferably added. At the time of producing an atomic furnace core constituting element by using this steel, it is subjected to 30% cold working and is finished.