Preparation method of titanium alloy plate

Abstract

The invention discloses a preparation method of a titanium alloy plate. A TC4 casting blank is prepared by adopting a plasma-vacuum consumable arc combined process; the first heating number finish forging temperature is 880 DEG C, and the deformation is 60-75%; the second heating number finish forging temperature is 850 DEG C, and the deformation is 25-65%; and the third heating number final heating temperature is 800 DEG C, and the deformation is 45-75%. A 20mm finished plate is rolled, the pass deformation is 4-6mm, and reversing rolling is carried out when the deformation is 50%; and when a 2-10 mm plate strip is rolled, hot rolling is conducted firstly, then warm rolling is conducted, the rolling temperature of the first heating number is 960-1050 DEG C, the rolling temperature of the second heating number is 950-1000 DEG C, and the warm rolling technology is adopted in the third heating number and the fourth heating number. The annealing temperature is 600-650 DEG C, and the heat preservation time is 5-10 hours. According to the preparation method, high-temperature melting, dissolving, flotation and sedimentation are adopted to remove inclusions, and a partial pressure principle is utilized to remove gas, so that burning loss of low-melting-point alloy element aluminum is reduced, an electrode preparation process is omitted, and a production process is simplified; titanium residues can be directly utilized, so that the ingot casting cost is reduced; and a product has a uniform fine grain structure, and the preparation method has the advantages of being wide in machining temperature range, good in strength, plasticity and fracture toughness matching property.

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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