Preparation method of high-tungsten and high-cobalt nickel alloy high- purity fine-grained bar material

Abstract

The invention discloses a preparation method of a high-tungsten and high-cobalt nickel alloy high- purity fine-grained bar material. The alloy composition is of 25 wt.% - 45wt.% of tungsten, 15 wt.% -30 wt.% of cobalt and the balance nickel. A vacuum induction melting mode is adopted, a high-tungsten high-cobalt nickel alloy ingot is heated to 1150 - 1250 DEG C after casting, and forging is carried out after heat preservation; the forging adopts a repeated deformation route alternating radial drawing-out with axial upsetting, the deformation amount of each firing is 15% - 35%, blanks after different firing forging in the middle is subjected to furnace returning heat preservation, and the time of furnace returning heat preservation is 30 - 120 min; and the final forging temperature is greater than or equal to 1000 DEG C, and the deformation amount of the last firing forging is more than or equal to 25%. According to the preparation method of a high-tungsten and high-cobalt nickel alloyhigh- purity fine-grained bar material, the oxygen content of a prepared high-tungsten high-cobalt nickel alloy bar material is less than or equal to 30 ppm, the sulfur content is less than or equalto 20 ppm, and the sound speed can reach 5015 m / s; and according to the preparation method, the requirement on equipment capacity can be reduced by adopting a hot forging mode, the obtained bar material is uniform in deformation, free of defects such as surface cracks, has internal structure with fine and uniform grains, has ideal microstructure and excellent mechanical property, the grain size can exceed 5 grade, the grade difference does not exceed 2 grade, ultrasonic flaw detection can reach class A, the elongation reaches 68%, and the tensile strength reaches 980 MPa.

Description

technical field [0001] The invention belongs to the technical field of metal materials, and relates to a method for preparing high-purity fine-grained nickel alloy high-tungsten and high-cobalt rod stock. Background technique [0002] The drug-shaped cover is the main element for forming a jet or projectile in the shaped charge structure. During the working process of the shaped charge structure, the energy-gathering effect produced by the explosive makes the liner lined in the concave of the shaped charge structure compressed into a columnar high-speed metal jet. The shaped charge jet has high energy density and direction Strong characteristics, can penetrate armor, rocks and other hard targets. The liner material is very important to the length, speed, continuous stability and final penetration performance of the jet, and the key control factor to form a high-quality jet is the plasticity of the liner material. [0003] In addition, the wall of the drug-type cover is clo...

AI Technical Summary

Problems solved by technology

However, with the vacuum induction melting method, the oxygen content in the high-tungsten and high-cobalt nickel alloy is still above 70ppm, and the final plastic properties cannot meet the plasticity requirements of the high-speed deformation of the liner.

[0006] In 2011, the U.S. patent US7921778B2 announced a high-tungsten and high-cobalt nickel alloy composition, which has the advantages of high density, high sound velocity, and high fracture ductility. Research and report on the purification method of the alloy; so far, no research on high-tungsten high-cobalt-nickel alloy has been found in China, let alone the research results on the purification method and sound velocity test

However, the cold deformation process alloy has great resistance, high requirements on equipment capacity, mold size and mold material, especially not suitable for large-scale nickel alloy blanks, and annealing process is required to obtain uniform grain size. The process is relatively complicated

In addition, the cold rolling process obtained in the US patent is suitable for sheet preparation, but not for bar preparation

So far, no research on high-tungsten, high-cobalt-nickel alloys has been found in China, let alone research on free forging process and grain uniformity control

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