Zirconium alloy having excellent corrosion resistance and creep resistance and method of manufacturing the same

Abstract

A zirconium alloy is manufactured through melting; solution heat treatment at 1,000 to 1,050° C. 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 440 to 650° C. for 7 to 9 hr.

What is claimed is: 
     
         1 . A zirconium alloy, comprising:
 1.1 to 1.2 wt % of Nb, 0.01 to 0.2 wt % of P, 0.2 to 0.3 wt % of Fe, and a balance of Zr.   
     
     
         2 . The zirconium alloy of  claim 1 , wherein P is added in an amount of 0.02 to 0.07 wt %. 
     
     
         3 . The zirconium alloy of  claim 1 , further comprising 0.01 to 0.15 wt % of Ta. 
     
     
         4 . The zirconium alloy of  claim 3 , wherein Ta is added in an amount of 0.03 to 0.1 wt %. 
     
     
         5 . A method of manufacturing a zirconium alloy, comprising steps of:
 (1) melting a mixture comprising 1.1 to 1.2 wt % of Nb, 0.01 to 0.2 wt % of P, 0.2 to 0.3 wt % of Fe, and a balance of Zr, thus preparing an ingot;   (2) subjecting the ingot prepared in step (1) to solution heat treatment at 1,000 to 1,050° C. (β-phase range) 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 at 440 to 650° C. for 7 to 9 hr.   
     
     
         6 . The method of  claim 5 , wherein in step (1), P is added in an amount of 0.02 to 0.07 wt %, and in step (7), the final vacuum annealing temperature is 460 to 600° C. 
     
     
         7 . The method of  claim 5 , wherein in step (1), the mixture further comprises 0.01 to 0.15 wt % of Ta. 
     
     
         8 . The method of  claim 7 , wherein Ta is added in an amount of 0.03 to 0.1 wt %, and in step (7), the final vacuum annealing temperature is 460 to 530° C. 
     
     
         9 . The method of  claim 5 , wherein P is compacted before melting the mixture in step (1). 
     
     
         10 . The method of  claim 6 , wherein P is compacted before melting the mixture in step (1). 
     
     
         11 . The method of  claim 8 , wherein P is compacted before melting the mixture in step (1). 
     
     
         12 . The method of  claim 8 , wherein P is compacted before melting the mixture in step (1).