Titanium, Tantalum and Niobium are used as alloying elements to improve the acid corrosion resistance of zirconium alloys. Among them, Ti exists in the form of solid solution in Zr, which effectively refines the grains and improves the strength of zirconium alloys. TiO2 is generated in the chemical film, which improves the stress corrosion cracking resistance of zirconium alloys. At the same time, since the price of titanium sponge, the raw material for titanium, is much lower than that of zirconium sponge, the raw material for Zr, titanium is used as an alloying element to reduce the cost of zirconium alloys. cost, but the increase in Ti content will lead to a substantial increase in the hardenability of the zirconium alloy and affect its processing performance, so the mass percentage of titanium in the zirconium alloy is controlled at 1% to 15%; Stress corrosion cracking ability, but Ta, as a β stable element in zirconium alloy, will cause Zr alloy to form β phase, which is not conducive to stress corrosion resistance. At the same time, the melting point of Ta is 2996 ℃, which is much higher than that of Zr. The melting and preparation process It is not easy to fully mix in Zr, and its price is much higher than that of zirconium, so the mass percentage of Ta in zirconium alloy is controlled at 0.05% to 5%; Nb increases the strength and creep resistance of zirconium alloy in Zr, inhibits Impurities such as C and Al are harmful to the corrosion resistance of zirconium and can reduce the hydrogen absorption of zirconium alloys. However, excessive Nb content will cause the formation of β phase in Zr, which will affect the stress corrosion resistance of zirconium alloys. Therefore, the control of zirconium alloys The mass percentage of Nb in the zirconium alloy is 0.05% to 2%; the present invention uses O as the α-phase stabilizing element of the zirconium alloy, improves the α-β transition temperature of the zirconium alloy, and improves the strength of the zirconium alloy as a solid solution element , under the condition of comprehensively considering the microstructure, mechanical properties and processing properties of zirconium alloys, the mass percentage content of O in zirconium alloys is controlled to be 0.05% to 2%; N, Ni, Cu, and H elements in zirconium alloys are all harmful Impurity elements seriously affect the corrosion resistance and mechanical properties of zirconium alloys, so the control of N in zirconium alloys does not exceed 0.01%, Ni does not exceed 0.1%, Cu does not exceed 0.01%, and H does not exceed 0.002%.
The above preferred melting speed of consumable electrodes in the smelting stage avoids the problems of low smelting efficiency and shallow molten pool caused by too slow melting speed, while too shallow molten pool is not conducive to degassing of the melt and decomposition of impurities, and at the same time avoids the problem of excessive melting speed. It will quickly lead to too deep molten pool, cause composition segregation, and at the same time avoid problems such as splashing during the smelting process, which will cause the crown of the ingot to be too high and too thick.
In the prior art, zirconium alloy controls the mass content of its impurity element Hf to be no more than 0.009% to ensure its corrosion resistance. Compared with the zirconium alloy of the present invention, the mass content of H, N, Cu, and Ni impurities is further limited. The corrosion resistance of zirconium alloys is regulated, avoiding the limitation of zirconium raw materials from Hf, expanding the source of zirconium raw materials to industrial zirconium with high Hf content, and reducing the preparation cost of zirconium alloys.
