This invention describes a method for preparing Ti-0.3Mo-0.8Ni residue into ingots using a dual-process, comprising the following steps: 1. Placing the Ti-0.3Mo-0.8Ni residue in an electron beam cold hearth furnace, followed by electron beam cold hearth melting to obtain an electron beam cold hearth melted ingot; 2. Performing two vacuum consumable electrode arc melting processes on the electron beam cold hearth melted ingot to obtain the final Ti-0.3Mo-0.8Ni ingot. This invention prepares Ti-0.3Mo-0.8Ni ingots from Ti-0.3Mo-0.8Ni residue using a dual-process of electron beam cold hearth melting and vacuum consumable electrode arc melting. By controlling the material placement and process parameters of the dual-process, the uniform distribution of elements in the Ti-0.3Mo-0.8Ni ingot is ensured, improving the utilization rate of the Ti-0.3Mo-0.8Ni residue, reducing the production cost of Ti-0.3Mo-0.8Ni ingots, and increasing production efficiency. The Ti-0.3Mo-0.8Ni ingots of this invention meet national standards and do not exhibit cracking or surface peeling during subsequent processing.
Due to the complex processing characteristics of titanium, the production process is lengthy and yield is low, resulting in a large amount of titanium and titanium alloy block and shaving waste. This has long been a major problem hindering the development of the titanium industry. Countries worldwide have invested significant human and material resources in researching recycling and processing technologies for titanium and titanium alloy waste, achieving a series of results. Some titanium waste has been recycled and reused, achieving the goals of resource conservation and cost reduction.
There are two conventional methods for smelting Ti-0.3Mo-0.8Ni scrap: The first method involves welding the Ti-0.3Mo-0.8Ni scrap into electrodes and then performing vacuum consumable electrode arc melting. This method has the following main problems: 1. It requires welding the titanium scrap into consumable electrodes of a specific shape, making the recycling process complex and inefficient; 2. Welding is mostly done using tungsten inert gas welding (TIG) or tungsten inert plasma welding (TIP), which carries the risk of high-density impurities entering the weld and tungsten inclusions; 3. Melting requires welding electrodes, and given the characteristics of vacuum consumable electrode arc melting, high-density and low-density inclusions cannot be completely eliminated from the product, compromising subsequent product quality; 4. The welded electrodes carry the risk of cracking during melting, increasing the risk of arc formation between the electrode and crucible, posing a significant safety hazard; 5. The recycled ingots need to be forged into corresponding tubes, plates, and bars, making the entire recycling process complex. The increased process fails to achieve the goals of improving efficiency and reducing costs. The second method uses electron beam cold hearth melting, which eliminates the need for welding electrodes and boasts strong recycling and impurity removal capabilities, far surpassing vacuum consumable melting in reducing both high-density and low-density inclusions. However, it suffers from the following problems: 1. Electron beam cold hearth melting requires a considerable time for initial casting, resulting in differences in composition between the beginning and end stages compared to normal melting; 2. The high temperature of electron beam cold hearth melting is unfavorable for recycling titanium alloy scraps containing low-melting-point elements; 3. The weak stirring during electron beam cold hearth melting, lacking stable arc stirring, compromises the uniformity of the titanium alloy ingot composition, easily leading to segregation; 4 Ingots directly smelted from Ti-0.3Mo-0.8Ni scraps by electron beam cold hearth melting exhibit severe peeling and cracking when rolled into finished products; 5 Domestically, electron beam cold hearth melting is primarily used for recycling pure titanium scraps, while recycling titanium alloy scraps is still in the experimental stage. Therefore, conventional methods are no longer suitable for scrap recycling to prepare titanium alloy ingots.
