ZIRCONIUM ALLOY COMPOSITION HAVING EXCELLENT HIGH TEMPERATURE OXIDATION AND CORROSION RESISTANCE, AND MANUFACTURING METHOD THEREOF

摘要

The objective of the present invention is to provide a zirconium alloy composition and a manufacturing method thereof, wherein the zirconium alloy composition is capable of improving high-temperature oxidation and corrosion resistance by applying an improved manufacturing method and adjusting the contents of alloy elements such as niobium, copper, iron, and oxygen during a long-term high-burnup operation under a high-temperature and high-pressure environment in a reactor of a nuclear power plant, or in the event of a loss-of-coolant accident (LOCA) among design-based accidents. To this end, the zirconium alloy composition according to the present invention comprises: 1.1 to 2.2 wt.% of niobium (Nb); 0.01 to 0.5 wt.% of copper (Cu); 600 to 1400 ppm of oxygen (O); and zirconium (Zr) as a remainder. Also, to achieve the aforementioned objective, the manufacturing method of a zirconium alloy composition, according to the present invention, comprises: a step (S I) of producing an ingot by repeating dissolution of additive elements of the alloy composition 3 to 4 times; a step (S II) of surrounding the ingot produced in the aforementioned step (S I) with stainless steel, heat-treating the ingot for 20 to 30 minutes at ambient temperature, and then water-cooling the ingot; a step (S III) of heat-treating the ingot which has been water-cooled in the aforementioned step (S II) for 20 to 30 minutes at 600 to 650°C and then hot-rolling the ingot; steps (S IV, S V, and S VI) of intermediately heat-treating the plate which has been hot-rolled in the aforementioned step (S III) for 2 to 5 hours at 550 to 590°C and then repeating the cold-rolling of the plate 3 times; and a step (S VII) of finally heat-treating the plate which has been rolled in the step (S VI).