TUBES OF ZIRCONIUM-BASED ALLOYS AND THEIR MANUFACTURING METHOD

摘要

Tubes for use in nuclear reactors made from two zirconium base alloys: one is a binary alloy containing mainly 2.5-2.8 wt.% Nb, 0.1-0.13 wt.% O, 0.05-0.13 wt% Fe, the balance of Zr, and the other is a multicomponent alloy containing 0.9-1.2 wt.% niobium, 1.1-1.42 wt.% tin, 0.3-0.47 wt.% iron, 0.05-0.12 wt.% oxygen, the balance of zr and a method to manufacture the said tubes with such characteristics where the DHC velocity is lower than 6.times.10-8 m/s at 250 .degree.C, the threshold stress intensity facto r is not less than 10 MPa~m at 250 .degree.C, fracture toughness resistance, dJ/da, is larger than 250 MPa at 250 .degree.C and the tensile strength exceeds 480 MPa at 300 .degree.C.