Zirconium alloy having excellent corrosion resistance for nuclear fuel cladding tube and method of manufacturing the same

Abstract

A zirconium alloy is manufactured through melting; solution heat treatment at 1,000 to 1,050° C. (β) for 30 to 40 min and β-quenching using water; preheating at 630 to 650° C. for 20 to 30 min and hot rolling at a reduction ratio of 60 to 65%; primary intermediate vacuum annealing at 570 to 590° C. for 3 to 4 hr and primarily cold-rolled at a reduction ratio of 30 to 40%; secondary intermediate vacuum annealing at 560 to 580° C. for 2 to 3 hr and secondarily cold-rolled at a reduction ratio of 50 to 60%; tertiary intermediate vacuum annealing at 560 to 580° C. for 2 to 3 hr and tertiarily cold-rolled at a reduction ratio of 30 to 40%; and final vacuum annealing at 460 to 590° C. for 7 to 9 hr.

What is claimed is: 
     
         1 . A zirconium alloy for a nuclear fuel cladding tube, comprising:
 0.5 to 1.2 wt % of Nb, 0.4 to 0.8 wt % of Mo, 0.1 to 0.15 wt % of Cu, 0.15 to 0.2 wt % of Fe, and a balance of zirconium.   
     
     
         2 . The zirconium alloy for a nuclear fuel cladding tube of  claim 1 , 0.5 to 0.6 wt % of Nb, 0.4 to 0.5 wt % of Mo. 
     
     
         3 . The zirconium alloy for a nuclear fuel cladding tube of  claim 1 , 1.1 to 1.2 wt % of Nb, 0.4 to 0.5 wt % of Mo. 
     
     
         4 . The zirconium alloy for a nuclear fuel cladding tube of  claim 1 , 0.5 to 0.6 wt % of Nb, 0.7 to 0.8 wt % of Mo. 
     
     
         5 . A method of manufacturing a zirconium alloy for a nuclear fuel cladding tube, comprising steps of:
 (1) melting a mixture comprising 0.5 to 1.2 wt % of Nb, 0.4 to 0.8 wt % of Mo, 0.1 to 0.15 wt % of Cu, 0.15 to 0.2 wt % of Fe, and a balance of zirconium, thus preparing an ingot;   (2) subjecting the ingot prepared in step (1) to solution heat treatment at 1,000 to 1,050° C. (β) for 30 to 40 min and then to β-quenching using water;   (3) preheating the ingot treated in step (2) at 630 to 650° C. for 20 to 30 min and subjecting the ingot to hot rolling at a reduction ratio of 60 to 65%;   (4) subjecting the material hot-rolled in step (3), to primary intermediate vacuum annealing at 570 to 590° C. for 3 to 4 hr and then to primarily cold-rolled at a reduction ratio of 30 to 40%;   (5) subjecting the material primarily cold-rolled in step (4), to secondary intermediate vacuum annealing at 560 to 580° C. for 2 to 3 hr and then to secondarily cold-rolled at a reduction ratio of 50 to 60%;   (6) subjecting the material secondarily cold-rolled in step (5), to tertiary intermediate vacuum annealing at 560 to 580° C. for 2 to 3 hr and then to tertiarily cold-rolled at a reduction ratio of 30 to 40%; and   (7) subjecting the material tertiarily cold-rolled in step (6), to final vacuum annealing.   
     
     
         6 . The method of  claim 5 , wherein the rolled material is subjected to final vacuum annealing for 7 to 9 hr in three temperature ranges, including 460 to 470° C., 510 to 520° C., and 580 to 590° C.