Preparation method of large-size high-performance nickel-tungsten alloy bar

The invention relates to a preparation method of a large-size high-performance nickel-tungsten alloy bar, and belongs to the technical field of nickel-tungsten alloy preparation. A nickel-tungsten alloy cast ingot is prepared through a vacuum induction melting technology and an electroslag remelting technology, the cast ingot is subjected to sheathing treatment after being homogenized, then heating upsetting and heating drawing-out treatment are repeatedly conducted till a primary bar with the length-diameter ratio not smaller than 2.5 is obtained, drawing-out treatment and turning are conducted on the primary bar, and the nickel-tungsten alloy bar is obtained, the diameter of the nickel-tungsten alloy bar ranges from 60 mm to 300 mm, and the length of the nickel-tungsten alloy bar is larger than or equal to 550 mm. According to the method, the cracking phenomenon of the nickel-tungsten alloy in the deformation process is effectively solved by optimizing the process steps and strictly controlling the process