Austenitic steel excellent in stress corrosion cracking resistance and its use

摘要

PURPOSE:To stabilize the structure in a steel and to improve its toughness and irradiation stress corrosion cracking resistance, in an austenitic steel contg. specified amounts of Ni and Cr, by providing the steel with a whole austenitic phase and forming the austenitic phase of single crystals. CONSTITUTION:The compsn. of this austenitic steel is constituted of, by weight, 15 to 30% Ni, 10 to 17.67% Cr and =45% Fe. the steel contains Cr and Ni in such a manner that it has a whole austenitic structue at 700 deg.C in an equilibrium diagram and contains an austenitic phase or an austenitic phase and a ferritic phase, and the same austenitic phase is formed of single crystals. By producing a structural member used in a radiation exposure environment such as an atomic furnace core, intergranular type stress corrosion cracking induced by the irradiation can be prevented.