1) Tantalum ingots are melted three times by electron beam, and the diameter of the ingots is 153mm;
2) Using a spark punch and a wire cutting machine to cut holes in tantalum ingots, the tantalum hollow ingots with an inner diameter of 45mm were obtained;
3) Step 2) The obtained hollow tantalum ingots are preheated to 120℃ in a box type resistance furnace, and then the inner and outer surfaces of tantalum tube billet are coated with anti-oxidation coating;
4) The hollow tantalum ingots obtained in step 3 are heated to 850℃ by induction at medium frequency, and the tantalum tube billet is squeezed to a diameter of 95mm and an inner diameter of 45mm in the oil pressure forward extrusion equipment with a diameter of 155mm. Then, the squeezed tantalum tube blank is pickled in the mixed solution of nitric acid and hydrofluoric acid, the concentration of nitric acid is 68wt%, the concentration of hydrofluoric acid is 50wt%, and the volume ratio of nitric acid and hydrofluoric acid is 20: (2 ~ 3);
5) The tantalum tube blank obtained in step 4 is subjected to vacuum heat treatment at a temperature of 1300℃ and a time of 90min; The tantalum alloy tube blank was straightened by 3T electrohydraulic hammer, and the straightness was checked visually. Round and bore the tantalum tube blank after being straightened to remove the defects on the inside and outside surfaces;
6) The tantalum tube blank obtained in step 5 is rolled by ring cold rolling machine. The outer diameter of the tube blank after rolling is 82mm, the inner diameter is 20mm, and the diameter of the mandrel in the rolling process is 44.5mm ~ 42mm; After rolling again, the outer diameter of the tantalum tube blank after rolling is 67mm, the inner diameter is 14.5mm, and the diameter of the mandrel in the rolling process is 40.5mm ~ 38mm. After rolling again, the outer diameter of the tantalum tube blank after rolling is 54.0mm, the inner diameter is 10mm, and the diameter of the mandrel during rolling is 36.5mm ~ 34mm.
7) The tantalum tube billet obtained in step 6 is pickled in the mixed solution of nitric acid and hydrofluoric acid, the concentration of nitric acid is 68wt%, the concentration of hydrofluoric acid is 50wt%, and the volume ratio of nitric acid and hydrofluoric acid is 20: (2 ~ 3);
8) The tantalum tube blank obtained in step 7 is annealed in vacuum at 1200℃ for 60min, and then the inner and outer surfaces of tantalum tube blank are repaired manually, surface defects are removed, internal and external surface defects are checked and mechanical or manual repair is carried out;
