Forging technology for abnormal structure of TC18 titanium alloy raw material

Abstract

The invention belongs to the technical field of forging technologies, and discloses a forging technology for an abnormal structure of a TC18 titanium alloy raw material. The forging technology comprises the following steps: a, carrying out beta forging above a phase change point on blanks by 1-2 fire, wherein forging temperature is 15-30 DEG C above the phase change point, and deformation is controlled to be between 20% and 40%; b, carrying out forging below the phase change point on the blanks by more than 2 fire, wherein the forging temperature is 20-40 DEG C below the phase change point, and the deformation is controlled to be between 15% and 30%; and c, carrying out beta forging above the phase change point on the blanks by 1 fire, wherein the forging temperature is 10-20 DEG C above the phase change point, and the deformation is controlled to be 15% and 25%. By the technology, the structure defect of fine-crystal bright bands can be avoided effectively, and TC18 titanium alloy free forge pieces can be produced in batches.

Description

technical field [0001] The invention belongs to the technical field of forging technology, and in particular relates to a forging technology for abnormal structure of TC18 titanium alloy raw material. Background technique [0002] TC18 titanium alloy forgings, as one of the hard-to-deform alloys, is a high-strength titanium alloy developed by the former Soviet Union in the late 1960s. The nominal composition is Ti-5A1-5Mo-5V-1Cr-1Fe. The alloy transition type α+β Alloy, the alloy has the performance characteristics of α+β titanium alloy and β titanium alloy, and has the advantages of good deformation plasticity and high hardenability. The strength is equivalent, and it is the highest strength titanium alloy in the annealed state. The most prominent advantage of TC18 titanium alloy is that the maximum hardened surface thickness can reach 250mm, while the hardened section of Ti-1023 with the same strength level is only 100mm, and Ti-17 is 150mm. Therefore, this alloy is used ...

AI Technical Summary

Problems solved by technology

[0011] However, when the raw material has a layered structure and a fine-grained structure, if you continue to use the conventional forging process, that is, first perform forging below the phase transition point, and finally perform one-fire β forging in the first to second fires, the microstructure will change from equiaxed structure Basket structure, although the structure has changed, but at the same time it will form a fine-grained bright band structure in the area with the largest deformation of the forging, which is an unqualified structure