INTERGRANULAR CORROSION RESISTANT FE-CR-MN SERIES ALLOY AND ITS USE

PURPOSE:To prevent the reduction in the concn. of a Cr element in the grain boundaries when the Fe-Cr-Mn series alloy is exposed to a neutron irradiation environment by specifying the content of Mn, Cr and Al in an Fe alloy and regulating its structure into the one essentially consisting of ferrite. CONSTITUTION:The compsn. of the alloy is formed from, by weight, 5 to 40% Mn, 5 to 18% Cr, 2 to 12% Al and the balance substantial Fe. Furthermore, its structure is regulated to the one essentially consisting of ferrite. It required, at least one kind of 0.001 to 0.5% C and 0.001 to 0.3% N or moreover at least one kind among Ti, Zr, Hf, Nb, Ta, etc., is incorporated thereto. By adding Al to the Fe-Cr-Mn series, the reduction of the Cr concn. in the grain boundaries can be prevented against neutron irradiation, so that the deterioration of the corrosion resistance and strength in the grain boundaries of the alloy can be prevented at the time of using the alloy for a core apparatus, structures or the like in a nuclear reactor pressure vessel.