Upsetting-drawing deformation method for TB6 titanium alloy large-specification bar

Abstract

The invention discloses an upsetting-drawing deformation method for a TB6 titanium alloy large-specification bar. The upsetting-drawing deformation method comprises the steps that the TB6 titanium alloy bar is heated for preset time at the temperature of 10-40 DEG C below a beta phase transformation point; upsetting of the bar is carried out; multi-pass drawing-out is conducted in a hexagonal drawing-out forging manner; and chamfering, flattening and rounding are carried out. According to the method, the multi-pass hexagonal drawing-out manner is adopted, the deformation amount and the deformation pass are controlled, deformation of all parts of the TB6 titanium alloy large-specification bar can be uniform, deformation dead zones and core overheating are eliminated, and meanwhile the deformation process from a round bar to a hexagon and then to a round bar is achieved.

Description

technical field [0001] The invention belongs to the technical field of forging technology for titanium alloy materials, and in particular relates to a method for upsetting and drawing deformation of large-scale TB6 titanium alloy rods. Background technique [0002] TB6 titanium alloy is a typical nearly β-type titanium alloy with a nominal composition of Ti-10V-2Fe-3Al. The main characteristics of this alloy are high specific strength, good fracture toughness, low forging temperature, and good hardenability. This alloy is widely used in the central parts and connecting parts of helicopter rotor systems. TB6 titanium alloy cannot be directly used in the preparation of forgings due to the coarse grains of the as-cast structure, and it needs to be forged for multiple fires to refine the grains. When titanium alloy rods are forged, due to the small heat transfer coefficient of titanium alloy, there is a large temperature rise in the internal area of ​​titanium alloy, which is p...

AI Technical Summary

Problems solved by technology

When forging TB6 titanium alloy large-scale bars (≥300mm), in order to ensure the consistency of structure and performance, repeated upsetting and drawing are required. Conventional drawing is square, and there will be deformation dead zones in the bar, and the deformation of different parts of the bar will be uneven. The degree is relatively large, and the heart is prone to overheating

The unreasonable forging process prevents the original structure of the bar from being fully broken. The low-magnification structure of the bar is prone to coarse and uneven grains, and there are large or strip-like defects distributed in the high-magnification structure.

These defects will finally be inherited in the forging, which will eventually lead to unqualified forging structure and performance

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