PURPOSE:To refine crystalline grains and to improve formability, particularly cold formability, by subjecting an alpha plus beta Zr alloy to specific hot working and then to heating up to a specific temp. CONSTITUTION:An alpha plus beta Zr alloy, such as Zr-2.5wt.% Nb alloy, is hot-worked at =30% draft at 700-900 deg.C in the alpha plus beta region, by which working strain necessary to refine crystalline grains can be stored. Subsequently, the above Zr alloy is heated up to 920-1050 deg.C in the beta region, by which fine recrystallization is brought about. By this method, the formability, particularly cold formability, of the above Zr alloy can be remarkably improved.
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