A kind of preparation method of titanium alloy plate material

Abstract

The invention discloses a method for preparing a titanium alloy plate. The TC4 billet was prepared by plasma-vacuum consumable arc combination process; the first fire final forging was 880°C, and the deformation amount was 60-75%; the second fire final forging was 850°C, and the deformation amount was 25-65%; the third fire was final forging The second final forging is 800℃, and the deformation is 45‑75%. Rolling 20mm finished plate, the pass deformation is 4-6mm, and the rolling is reversed when the deformation is 50%; when rolling 2-10mm plate and strip, it is hot-rolled-then warm-rolled, and the first-fire rolling temperature is 960-1050℃ , the temperature of the second fire and the second rolling is 950-1000℃, and the third fire and the fourth fire adopt the warm rolling process. The annealing temperature is 600-650°C, and the holding time is 5-10h. The invention adopts high-temperature melting, dissolution, flotation, and sedimentation to remove inclusions, uses the principle of partial pressure to degas, reduces the burning loss of low-melting-point alloy element aluminum, omits the electrode preparation process, simplifies the production process, and can directly use titanium residues , Reduce the cost of casting ingots, the product is uniform fine-grained structure, has the advantages of wide processing temperature range, good matching of plate strength, plasticity and fracture toughness.

Description

technical field [0001] The invention relates to titanium and titanium alloy processing, belongs to the technical field of nonferrous metal pressure processing, and in particular relates to a preparation method of a titanium alloy plate. Background technique [0002] Ti-6Al-4V is the earliest developed and most widely used (α+β) two-phase titanium alloy. Because the melting temperature of titanium alloy exceeds 1800°C, and at high temperature, titanium is easily mixed with oxygen, hydrogen, and water vapor in the environment. , carbon dioxide and metal oxide Fe 2 o 3 , SiO 2 Effect, causing the alloy to absorb oxygen, increase hydrogen, increase iron, and increase silicon. Affected by the high-temperature metallurgical properties of titanium alloy, the content of impurities such as iron, oxygen, and hydrogen in this alloy is relatively high. According to the requirements of the national standard, the upper limits of iron, oxygen, and hydrogen allowed by this alloy are as f...

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Problems solved by technology

[0003] At present, the smelting of Ti-6Al-4V alloy mainly adopts 2-4 times of consumable electrode smelting process. This smelting process has two influences on the melting process of Ti-6Al-4V alloy and the quality of the ingot. One is arc smelting Through the high temperature of 5000°C and the high vacuum of 0.001-0.01Pa to melt and purify the titanium alloy liquid, during the melting process of the alloy, the volatilization loss of the metal aluminum with a low melting point is extremely large, which not only increases the production cost, but also makes it extremely difficult to control the alloy composition.

The second is that the consumable electrode smelting process has a shallow metal molten pool and the alloy remains in the liquid state for a very short time. The high-density and low-density inclusions in the alloy cannot be effectively removed. This high-density and low-density inclusion is the cause of alloy crack initiation. And the source of crack propagation is an important reason for the failure of aircraft structural parts, and also reduces the plasticity and processing properties of the alloy, shortening the service life of the alloy

However, the thermal conductivity of titanium alloy is very poor, and the deformation energy generated during thermal processing is not easy to be effectively exported. Affected by the thermal effect of deformation, the processing process can easily lead to excessive temperature in the local area of ​​the workpiece, resulting in overheating, over-burning and coarse structure in the local area of ​​the alloy. , the performance and quality of the alloy will be unstable due to the uneven structure

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