Preparation method of TC17 titanium alloy cast ingot and bar with long service life

The invention belongs to the technical field of non-ferrous metal processing, and relates to a preparation method of a long-life TC17 titanium alloy cast ingot and bar, which comprises the following steps of: establishing a third smelting model of vacuum self-consuming electric arc smelting of the titanium alloy cast ingot by adopting a numerical simulation technology; temperature field distribution in a molten pool in a conventional smelting mode serves as a reference basis, and smelting process parameters corresponding to the condition that the depth of the molten pool is shallower during third-time smelting under the counter-electropolarity smelting condition are obtained through simulation. According to a conventional preparation method, TC17 electrode block pressing, electrode welding and three times of vacuum self-consuming arc melting are carried out; when the third vacuum consumable electric arc smelting is carried out, a secondary ingot obtained after the secondary smelting is connected with a positi