Superconducting niobium pipe and preparation method thereof

[0020] The embodiment of the present invention discloses a method for preparing a superconducting niobium tube, which includes the following steps:

[0021] Forging the superconducting niobium ingot, the temperature during the forging process is less than or equal to 60°C;

[0022] Perform the first heat treatment on the forged superconducting niobium ingot;

[0023] Coating lubricant on the surface of the superconducting niobium ingot after the first heat treatment, and then performing back extrusion;

[0024] The back-extruded superconducting niobium tube blank is subjected to a second heat treatment to obtain a superconducting niobium tube.

[0025] Residual resistivity is an important index to measure superconducting materials. In order to ensure that the prepared superconducting niobium tube has a lower residual resistivity, in the process of preparing the superconducting niobium tube, the present invention limits the temperature in the forging process, and coats a lubr...

[0036] 1) The superconducting niobium ingot is obtained by electron beam melting, the diameter of the superconducting niobium ingot is 290mm, the length is 600mm, the content of niobium in the superconducting niobium ingot is 99.995wt%, and the residual resistivity (RRR) is 350. Cutting the first superconducting niobium ingot from the superconducting niobium ingot, so that the bottom surface area of ​​the first superconducting niobium ingot is 1 / 4 of the bottom surface area of ​​the superconducting niobium ingot, and the length is 40mm;

[0037] 2) Forging the first superconducting niobium ingot obtained in step 1) at a temperature below 60°C to obtain a superconducting niobium ingot with a diameter of 90 mm and a length of 55 mm;

[0038] 3) turning the outer diameter of the superconducting niobium ingot obtained in step 2) to obtain a superconducting niobium ingot with a diameter of 84 mm and a length of 50 mm;

[0039] 4) Perform heat treatment on the superconducting niobiu...

[0045] 1) The superconducting niobium ingot is obtained by electron beam melting, the diameter of the superconducting niobium ingot is 300mm, the length is 600mm, the content of niobium in the superconducting niobium ingot is 99.995wt%, and the residual resistivity (RRR) is 360. The first superconducting niobium ingot is intercepted on the superconducting niobium ingot, so that the bottom surface area of ​​the first superconducting niobium ingot is 1 / 4 of the bottom surface area of ​​the superconducting niobium ingot, and the length is 35mm;

[0046] 2) Forging the first superconducting niobium ingot obtained in step 1) at a temperature below 60°C to obtain a superconducting niobium ingot with a diameter of 90 mm and a length of 45 mm;

[0047] 3) turning the outer diameter of the superconducting niobium ingot obtained in step 2) to obtain a superconducting niobium ingot with a diameter of 84 mm and a length of 40 mm;

[0048] 4) Perform heat treatment on the superconducting n...