Zirconium alloy compositions having excellent corrosion resistance by the control of various metal-oxide and precipitate and preparation method thereof

Abstract

Disclosed herein are a zirconium alloy composition, which exhibits excellent corrosion resistance by varying the kinds of metal oxides and controlling the size of precipitates of the composition, including: 1.05˜1.45 wt % of Nb; one or more selected from the group consisting of 0.1˜0.7 wt % of Fe and 0.05˜0.6 wt % of Cr; and residual Zr, and a method of preparing the same. The zirconium alloy composition exhibits excellent corrosion resistance by controlling the kinds and amounts of the elements included in the zirconium alloy composition and the heat-treatment temperature and thus varying the kinds of metal oxides formed during an oxidation process and controlling the size of precipitates of the zirconium alloy, so that it can be usefully used as a raw material for nuclear fuel cladding tubes, spacer grids, nuclear reactor internals and the like of a light-water reactor or a heavy-water reactor in a nuclear power plant.

1 . A zirconium alloy composition, which exhibits excellent corrosion resistance by varying the kinds of metal oxides and controlling the size of precipitates of the composition, comprising:
 1.05˜1.45 wt % of Nb;   one or more selected from the group consisting of 0.1˜0.7 wt % of Fe and 0.05˜0.6 wt % of Cr; and   residual Zr.   
     
     
         2 . The zirconium alloy composition according to  claim 1 , further comprising: 0.12 wt % of Sn. 
     
     
         3 . The zirconium alloy composition according to  claim 1 , wherein the zirconium alloy composition comprises: 1.15˜1.25 wt % of Nb, 0.12˜0.45 wt % of Fe, and residual Zr. 
     
     
         4 . The zirconium alloy composition according to  claim 3 , further comprising: 0.12 wt % of Sn. 
     
     
         5 . The zirconium alloy composition according to  claim 1 , wherein the zirconium alloy composition comprises: 1.15˜1.25 wt % of Nb, 0.05˜0.45 wt % of Cr, and residual Zr. 
     
     
         6 . The zirconium alloy composition according to  claim 5 , further comprising: 0.12 wt % of Sn. 
     
     
         7 . The zirconium alloy composition according to  claim 1 , wherein the zirconium alloy composition comprises: 1.05˜1.45 wt % of Nb, 0.10˜0.45 wt % of Fe, 0.05˜0.45 wt % of Cr, and residual Zr. 
     
     
         8 . The zirconium alloy composition according to  claim 7 , further comprising: 0.12 wt % of Sn. 
     
     
         9 . The zirconium alloy composition according to  claim 1 , wherein the metal oxides are selected from the group consisting of niobium oxides, iron oxides, and chromium oxides. 
     
     
         10 .- 14 . (canceled) 
     
     
         15 . A method of preparing a zirconium alloy composition, which exhibits excellent corrosion resistance by varying the kinds of metal oxides and controlling the size of precipitates of the composition, comprising the steps of:
 mixing elements constituting a zirconium alloy composition comprising 1.05˜1.45 wt % of Nb, one or more selected from the group consisting of 0.1˜0.7 wt % of Fe and 0.05˜0.6 wt % of Cr, and residual Zr to form a mixture and then melting the mixture to obtain an ingot (step 1);   forging the obtained ingot in a β-phase region (step 2);   solution-heat-treating the forged ingot in the β-phase region and then quenching the solution-heat-treated ingot (step 3);   hot-working the quenched ingot and then extruding the hot-worked ingot to obtain an intermediate product (step 4);   primarily heat-treating the obtained intermediate product (step 5);   cold-working and secondarily heat-treating the primarily heat-treated intermediate product several times (step 6); and   cold-working the secondarily heat-treated intermediate product and then finally heat-treating the cold-worked intermediate product (step 7).   
     
     
         16 . The method of preparing a zirconium alloy composition according to  claim 15 , wherein the hot working in step 4 is conducted at 560˜650° C. for 15˜40 minutes. 
     
     
         17 . The method of preparing a zirconium alloy composition according to  claim 15 , wherein the primary heat treatment in step 5 is conducted at 550˜650° C. for 1˜5 hours. 
     
     
         18 . The method of preparing a zirconium alloy composition according to  claim 15 , wherein the final heat treatment in step 7 is conducted at 450˜580° C. for 2˜10 hours. 
     
     
         19 . The method of preparing a zirconium alloy composition according to  claim 15 , wherein the elements constituting the zirconium alloy composition further comprise 0.12 wt % of Sn. 
     
     
         20 . The method of preparing a zirconium alloy composition according to  claim 15 , wherein the elements constituting the zirconium alloy composition comprise 1.15˜1.25 wt % of Nb, 0.12˜0.45 wt % of Fe, and residual Zr. 
     
     
         21 . The method of preparing a zirconium alloy composition according to  claim 20 , wherein the elements constituting the zirconium alloy composition further comprise 0.12 wt % of Sn. 
     
     
         22 . The method of preparing a zirconium alloy composition according to  claim 15 , wherein the elements constituting the zirconium alloy composition comprise 1.15˜1.25 wt % of Nb, 0.05˜0.45 wt % of Cr, and residual Zr. 
     
     
         23 . The method of preparing a zirconium alloy composition according to  claim 22 , wherein the elements constituting the zirconium alloy composition further comprise 0.12 wt % of Sn. 
     
     
         24 . The method of preparing a zirconium alloy composition according to  claim 15 , wherein the elements constituting the zirconium alloy composition comprise 1.05˜1.45 wt % of Nb, 0.10˜0.45 wt % of Fe, 0.05˜0.45 wt % of Cr, and residual Zr. 
     
     
         25 . The method of preparing a zirconium alloy composition according to  claim 24 , wherein the elements constituting the zirconium alloy composition further comprise 0.12 wt % of Sn.