A method for single-shot smelting tc4 titanium alloy ingots in an electron beam cold hearth furnace

Abstract

The invention discloses a method for smelting TC4 titanium alloy ingots at one time through an electron beam cold hearth and belongs to the technical field of titanium alloy ingot preparation. The method comprises the following steps that (1), the percentages of raw materials used for preparing the titanium alloy ingots through TC4 are confirmed, and the raw materials are weighed; (2), the raw materials in the step (1) are pressed into material blocks on an oil press after being mixed; (3), the material blocks pressed in the step (2) are dried after being placed into a workbin; (4), the material blocks dried in the step (3) are sent into the electron beam cold hearth for smelting, and the TC4 titanium alloy ingots are obtained by through one-time smelting. According to the method for smelting the TC4 titanium alloy ingots at one time through the electron beam cold hearth, the problems that raw material cost is increased due to self-consuming smelting, the raw materials are prone to being oxidized, or other pollution are caused are solved, the pollution of the raw materials in the crushing process is avoid. After the raw materials are placed in the workbin in a stacked mode in order and enter the hearth after being directly mixed and pressed, the qualified ingots are formed at one time through smelting, and producing cost is greatly lowered.

Description

technical field [0001] The invention relates to a method for casting TC4 titanium alloy ingots, in particular to a method for single-smelting TC4 titanium alloy ingots in an electron beam cooling bed furnace, and belongs to the technical field of titanium alloy ingot preparation. Background technique [0002] At present, the most used titanium alloys on engines are mainly Ti-6Al-4V and Ti-6242S. The traditional titanium alloys used in aircraft engines are purified and smelted multiple times in a vacuum consumable furnace, and the chemical composition can be uniformed by multiple smelting. However, due to the inherent characteristics of the sponge titanium production process and the inherent defects of the vacuum consumable arc melting process, impurities can only be discharged through a narrow circular gap between the side wall of a bottomed crystallizer and the consumable furnace electrode. The width usually does not exceed 30~50mm. The titanium alloy ingots produced in thi...

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Problems solved by technology

[0003] At present, electron beam cooling bed melting technology has become the international industrial standard for producing high-quality titanium ingots for aero-engine rotating parts. Electron beam cooling bed furnace melting technology can eliminate high-density and low-density inclusions and obtain fine-grained and homogeneous In addition to casting ingots, it can also greatly reduce the production cost of titanium alloy materials. The United States took the lead in conducting research on the single-shot melting technology of electron beam cold hearth furnaces. Electron beam cold hearth furnace melting requires vacuum (about 10-3 Torr to 10- 2Torr) environment, can effectively remove the gas elements and volatile elements in the alloy, improve the purity of the ingot, but also cause difficulty in the control of volatile alloy elements (mainly Al elements), and the volatilization amount is very large

[0004] Al element is the most widely added alloying element in the melting and casting process of titanium alloy ingots. In the process of melting titanium alloy ingots in the electron beam cold hearth furnace melting furnace, the saturated vapor pressure of Al elements is much higher than that of matrix elements, resulting in smelting. During the process, the alloying element Al was volatilized and lost in a large area, so the chemical composition of the ingot could not meet the standard

[0005] The disadvantages of the prior art are mainly that the shape requirements of the raw materials are complicated and the cost is high

Sponge titanium and aluminum beans are evenly mixed and pressed into electrode blocks, welded into electrodes and then placed in a vacuum consumable electric arc furnace to obtain Ti-Al master alloy by one-time melting. This method has at least the following obvious disadvantages: 1) One-time vacuum self-consumption The cost of smelting leads to an increase in the cost of raw materials; 2) The pressed electrode block is likely to cause oxidation or other pollution of the raw material during the welding process of the electrode, resulting in a decline in the quality of the raw material; 3) The Ti-Al master alloy obtained by smelting by this method itself has Severe segregation (uneven chemical composition) problem makes it difficult to guarantee the quality of subsequent ingots

Breaking of Ti-Al master alloys into Ti-Al master alloy particles again leads to increased cost of raw materials and contamination of raw materials from crushing tools during the crushing procedure

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