JPS6428346A - Improvement for nodular corrosion resistance of zr alloy - Google Patents

Abstract

PURPOSE:To improve the nodular corrosion resistance of a Zr alloy for light water reactor, by subjecting a Zr alloy containing specific amounts of Sn and Ni to cold working at a specific draft or above and then using the above Zr alloy in the above state or in a recrystallization-unfinished state after applying annealing under specific conditions. CONSTITUTION:A Zr alloy containing, by weight, 0.2-1.7% Sn and 0.03-0.3% Ni is cold-worked at >=5% draft, which is held in this as-cold-worked state or is subjected to recrystallization-unfinished annealing under the conditions given in a table. This Zr alloy is used in the as-cold-worked state or in a state of recrystallization-unfinished annealing. The use of Sn in the Zn alloy is desirable for the purpose of improving corrosion resistance, but the content exceeding the upper limit is unsuitable from the viewpoints of corrosion resistance and neutron economy, and, from the viewpoint of the effect of removing the adverse effect of N, the lower limit is fixed. Though the effectiveness of Ni appears from the lower limit, the upper limit is fixed from the viewpoints of hydrogen absorption and neutron absorption cross section. A corrosion resistance-improving effect is produced when cold working is carried out at >=5% draft. By the annealing under the above conditions, corrosion resistance can be improved to a greater extent.