Titanium alloy ingot remelting method based on layered zone distribution

Abstract

The application provides a titanium alloy ingot remelting method based on layered area distribution, which comprises the following steps: opening a vacuum melting furnace chamber and distributing materials in a specified area in a water-cooled copper crucible; assembling a titanium alloy consumable electrode and an auxiliary electrode on an electrode rod clamp, adjusting the electrode rod position and the centering of raw materials in the water-cooled copper crucible; automatically melting after the titanium alloy consumable electrode and the raw materials in the crucible are arc struck; after the melting is completed, starting a turnover mechanism, pouring titanium liquid from one side of the water-cooled copper crucible into a mold in a casting chamber, and cooling the remaining titanium liquid into a solid shell in the water-cooled copper crucible; crystallizing the titanium liquid into an ingot in the mold; breaking the vacuum in the furnace chamber, discharging the ingot, and simultaneously removing the solid shell in the water-cooled copper crucible for local flattening treatment and still laying on the bottom of the water-cooled copper crucible for use as a solid shell. The application makes the inclusions in the medium and high risk raw materials more easily absorbed by the solid shell at the bottom of the crucible, so as to ensure the purity of the titanium liquid.

Description

Technical Field

[0001] This invention belongs to the field of titanium alloy smelting and relates to a method for remelting titanium alloy ingots based on layered regional material distribution. Background Technology

[0002] Currently, the most widely used titanium alloy ingot remelting processes in domestic industrial production are vacuum arc remelting (VAR remelting) and electron beam cold hearth remelting (EBCHR remelting). For high-end titanium alloys used in aerospace, marine and other high-end fields, these two remelting methods have the following limitations: 1) VAR furnace: The melting of titanium alloy consumable electrode and ingot crystallization are completed in the same crucible. The metallurgical quality of the ingot is significantly affected by the purity and uniformity of the consumable electrode and the raw materials, as well as process protection. At the same time, the arc refining capacity is limited and cannot completely dissolve inclusions, resulting in a high risk of inclusions in the ingot. Therefore, VAR melting can only be used to remelt high-quality ingots using sponge titanium and virgin intermediate alloy materials. It cannot achieve high-quality remelting of titanium alloy recycled materials. Remelted ingots from recycled materials are mostly used in general low-end fields. 2) EBCHR furnace: Offers high vacuum during melting and excellent electron beam refining capabilities. Utilizing a cooling bed to separate melting, refining, and crystallization effectively removes high- and low-density inclusions, resulting in excellent purification. However, it is difficult to accurately control the high saturated vapor pressure alloying elements such as aluminum in titanium alloys, and the chemical composition uniformity of the ingots is generally poor. Therefore, the EBCHR melting method allows for high-quality remelting and return to the furnace charge, resulting in remelted ingots free of inclusion defects. However, the content of certain elements, such as aluminum, in the ingots fluctuates significantly, failing to meet the requirements of high-end applications.

[0003] Meanwhile, a new type of vacuum melting equipment has been developed abroad, which has the function of efficiently remelting and returning the furnace charge, but the following problems still exist: 1) The cross-section of the water-cooled copper crucible is rectangular. The cross-section of the titanium alloy consumable electrode cannot cover the entire raw material in the crucible. The crucible ratio is too small, and the melting process is actually a regional melting. Half of the area in the crucible relies on the heat transfer of the molten liquid to melt, which poses a risk that the raw material is not completely melted. At the same time, the raw material distribution method is unreasonable. When the raw material on one side of the gating channel is melted, the impurities that may exist may not be completely dissolved or deposited and adsorbed. At this time, the ingot cast by the titanium liquid in the water-cooled copper crucible has the risk of inclusion. 2) The solidified shell has adsorbed inclusion particles. Even if it is reused as a consumable electrode for titanium alloy, there is still a risk of inclusions being introduced into the ingot.

[0004] Therefore, how to achieve high-quality remelting of titanium alloy return materials has become an area that the titanium industry urgently needs to break through. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a method for remelting titanium alloy ingots based on layered regional material distribution. This invention achieves layered material distribution within a water-cooled copper crucible, with the raw material distributed from top to bottom according to the level of inclusion risk from low to high. This makes it easier for inclusions and foreign matter that may be present in medium- and high-risk raw materials to be adsorbed by the solidified shell at the bottom of the crucible, facilitating the removal of inclusions introduced by the raw material. Through regional material distribution, the smelting and refining purification of the raw material within the water-cooled copper crucible are separated. The smelting process is located away from the gating system, allowing sufficient time for gravity separation and dissolution of the titanium molten material overflowing to the gating side. This further dissolves and adsorbs any inclusions and foreign matter that may be present in medium- and high-risk raw materials, ensuring the purity of the titanium molten material before casting.

[0006] To achieve the above technical objectives, the technical solution adopted in the embodiments of the present invention is as follows: A method for remelting titanium alloy ingots based on layered regional fabrication includes the following steps: (1) Open the vacuum melting furnace chamber and place the material in the designated area inside the water-cooled copper crucible; (2) Assemble the titanium alloy consumable electrode and the auxiliary electrode onto the electrode rod clamp, and adjust the position of the electrode rod to align with the raw material in the water-cooled copper crucible; (3) Close the furnace chamber and evacuate the vacuum, check for leaks, and after passing the test, lower the electrode rod, start the power supply, and automatically melt the raw materials in the crucible through the titanium alloy consumable electrode. (4) After the titanium alloy consumable electrode is melted, the flipping mechanism is started within 3 to 10 seconds to pour the titanium liquid from one side of the water-cooled copper crucible into the mold in the casting chamber. The remaining titanium liquid is cooled into a solidified shell in the water-cooled copper crucible. (5) The titanium liquid is cooled and crystallized in the mold to form an ingot; (6) Break the vacuum in the furnace chamber of the vacuum melting furnace, lift out the mold and cast ingots, and at the same time take out the solidified shell in the water-cooled copper crucible, flatten the part, and still lay it at the bottom of the water-cooled copper crucible as solidified shell; (7) Repeat steps (1) to (6) for the next smelting.

[0007] Furthermore, the designated area is an area away from the gating channel inside the water-cooled copper crucible, and one or more of low-risk, medium-risk, and high-risk raw materials are laid in the designated area.

[0008] Furthermore, the high-risk raw materials are laid in the bottom layer of the designated area, the medium-risk raw materials are laid in the middle layer of the designated area, and the low-risk raw materials are laid in the top layer of the designated area.

[0009] Furthermore, the high-risk raw material is a shaving-shaped return charge, the medium-risk raw material is a block-shaped return charge, and the low-risk raw material includes one or more of sponge titanium and virgin intermediate alloy materials.

[0010] Furthermore, the high-risk raw materials include one or more of the following: ingot and bar scraping shavings, slab planing shavings, and tube blank boring shavings; The medium-risk raw materials include one or more of the following: ingot risers, forged bar blank cuts, die forging flash, and slab cuts.

[0011] The beneficial effects of the technical solution provided by the embodiments of the present invention are as follows: (1) The present invention uses layered material distribution: high-risk raw materials are laid in the bottom layer of a designated area in the water-cooled copper crucible, medium-risk raw materials are laid in the middle layer of the designated area, and low-risk raw materials are laid in the top layer of the designated area. This enables the raw materials to be distributed from top to bottom in the water-cooled copper crucible according to the degree of inclusion risk from low to high. This makes it easier for foreign objects that may exist in medium and high-risk raw materials to be adsorbed by the condensed shell at the bottom of the crucible, which is beneficial to removing inclusions brought in by the raw materials.

[0012] (2) The present invention achieves the separation of raw material smelting and refining purification in the water-cooled copper crucible by regional material distribution: material is distributed only in a designated area far away from the gating channel of the water-cooled copper crucible. The smelting is far away from the gating channel, and the titanium liquid overflows to the side of the gating channel with sufficient time for specific gravity separation and dissolution separation, so that the foreign matter that may exist in the medium and high risk raw materials can be further dissolved and adsorbed, ensuring the purity of the titanium liquid before casting.

[0013] (3) The solidified shell is not reused as a consumable electrode of titanium alloy. Before each furnace smelting, it is only laid at the bottom of the water-cooled copper crucible as the solidified shell itself, so as to avoid secondary inclusions in the solidified shell being brought into the ingot. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the layered material distribution within the water-cooled copper crucible of the present invention.

[0015] Figure 2 This is a schematic diagram showing the situation inside the water-cooled copper crucible at a certain moment during the smelting process of this invention.

[0016] Figure 3 This is a schematic diagram showing the contents of the water-cooled copper crucible before casting, after the smelting process is complete in this invention.

[0017] Explanation of reference numerals in the attached diagram: 1-Electrode rod; 2-Auxiliary electrode; 3-Consumable electrode; 4-Water-cooled copper crucible; 5-Low-risk raw material; 6-Medium-risk raw material; 7-High-risk raw material; 8-Titanium liquid; 9-Solidified shell; 10-Gating system. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0019] Example 1 A method for remelting TC4 titanium alloy ingots based on layered regional fabrication includes the following steps: (1) Open the vacuum melting furnace chamber and place the material in the designated area inside the water-cooled copper crucible (away from the gating area, 1 / 2 the width of the bottom of the water-cooled copper crucible); like Figure 1 As shown, high-risk raw material ingot scraps are laid at the bottom layer (occupying 1 / 3 of the height) in the designated area; In the designated area, medium-risk raw material ingot risers are laid in the middle layer (occupying 1 / 3 of the height); Low-risk raw material sponge titanium and intermediate alloy new materials such as AlV55 and Al bean are laid on the upper layer (occupying 1 / 3 of the height) in the designated area; (2) Assemble the TC4 titanium alloy consumable electrode and auxiliary electrode onto the electrode rod clamp, and adjust the position of the electrode rod to align with the raw material in the water-cooled copper crucible; (3) Close the furnace chamber and evacuate. Perform a leak test. If the test is successful, lower the electrode rod and start the power supply. The TC4 titanium alloy consumable electrode ignites an arc with the raw material in the crucible, and automatic melting begins. During the melting process, the molten titanium continuously overflows from the designated area, filling the bottom of the water-cooled copper crucible. As melting progresses, the liquid level gradually rises. Figure 2-3 As shown; (4) After the titanium alloy consumable electrode is melted, the flipping mechanism is started in 3-5 seconds to pour the titanium liquid from one side of the water-cooled copper crucible into the mold in the casting chamber. The remaining titanium liquid is cooled into a solidified shell in the water-cooled copper crucible. (5) The titanium liquid cools and crystallizes in the mold to form an ingot; (6) Break the vacuum in the furnace chamber, lift out the mold and cast the ingot. At the same time, take out the solidified shell in the water-cooled copper crucible, flatten the part, and still lay it at the bottom of the water-cooled copper crucible as solidified shell. (7) Repeat steps (1) to (6) for the next smelting.

[0020] Example 2 A method for remelting TC4 titanium alloy ingots based on layered regional fabrication includes the following steps: (1) Open the vacuum melting furnace chamber and place the material in the designated area inside the water-cooled copper crucible (away from the gating area, 1 / 2 the width of the bottom of the water-cooled copper crucible); High-risk raw material slab shavings are laid at the bottom layer (occupying 1 / 3 of the height) in the designated area; In the designated area, lay the edge and head of the medium-risk raw material slab on the upper layer (occupying 2 / 3 of the height); (2) Assemble the TC4 titanium alloy consumable electrode and auxiliary electrode onto the electrode rod clamp, and adjust the position of the electrode rod to align with the raw material in the water-cooled copper crucible; (3) Close the furnace chamber and evacuate. Perform a leak test. If the test is successful, lower the electrode rod and start the power supply. The TC4 titanium alloy consumable electrode ignites an arc with the raw material in the crucible, and automatic melting begins. During the melting process, the molten titanium continuously overflows from the designated area, filling the bottom of the water-cooled copper crucible. As melting progresses, the liquid level gradually rises. Figure 2-3 As shown; (4) After the titanium alloy consumable electrode is melted, the flipping mechanism is started in 5-7 seconds to pour the titanium liquid from one side of the water-cooled copper crucible into the mold in the casting chamber. The remaining titanium liquid is cooled into a solidified shell in the water-cooled copper crucible. (5) The titanium liquid cools and crystallizes in the mold to form an ingot; (6) Break the vacuum in the furnace chamber, lift out the mold and cast the ingot. At the same time, take out the solidified shell in the water-cooled copper crucible, flatten the part, and still lay it at the bottom of the water-cooled copper crucible as solidified shell. (7) Repeat steps (1) to (6) for the next smelting.

[0021] Example 3 A method for remelting TC4 titanium alloy ingots based on layered regional fabrication includes the following steps: (1) Open the vacuum melting furnace chamber and place the material in the designated area inside the water-cooled copper crucible (away from the gating area, 1 / 2 the width of the bottom of the water-cooled copper crucible); Lay out the cut ends of medium-risk raw material forging billets in the designated area; (2) Assemble the TC4 titanium alloy consumable electrode and auxiliary electrode onto the electrode rod clamp, and adjust the position of the electrode rod to align with the raw material in the water-cooled copper crucible; (3) Close the furnace chamber and evacuate. Perform a leak test. If the test is successful, lower the electrode rod and start the power supply. The TC4 titanium alloy consumable electrode ignites an arc with the raw material in the crucible, and automatic melting begins. During the melting process, the molten titanium continuously overflows from the designated area, filling the bottom of the water-cooled copper crucible. As melting progresses, the liquid level gradually rises. Figure 2-3 As shown; (4) After the titanium alloy consumable electrode is melted, the flipping mechanism is started 7-10s to pour the titanium liquid from one side of the water-cooled copper crucible into the mold in the casting chamber. The remaining titanium liquid is cooled into a solidified shell in the water-cooled copper crucible. (5) The titanium liquid cools and crystallizes in the mold to form an ingot; (6) Break the vacuum in the furnace chamber, lift out the mold and cast the ingot. At the same time, take out the solidified shell in the water-cooled copper crucible, flatten the part, and still lay it at the bottom of the water-cooled copper crucible as solidified shell. (7) Repeat steps (1) to (6) for the next smelting.

[0022] Example 4 A method for remelting TA15 titanium alloy ingots based on layered regional fabrication includes the following steps: (1) Open the vacuum melting furnace chamber and place the material in the designated area inside the water-cooled copper crucible (away from the gating area, 1 / 3 of the bottom width of the water-cooled copper crucible); like Figure 1 As shown, high-risk raw material billet boring chips are laid in the bottom layer (occupying 1 / 3 of the height) of the designated area; In the designated area, lay the medium-risk raw material forging billet cut-off heads and slab edge cut-off heads in the middle layer (occupying 1 / 3 of the height); Low-risk raw material sponge titanium and intermediate alloy new materials such as Al-60Mo, AlV55, sponge zirconium, and aluminum briquettes are laid on the upper layer (occupying 1 / 3 of the height) in the designated area; (2) Assemble the TA15 titanium alloy consumable electrode and auxiliary electrode onto the electrode rod clamp, and adjust the position of the electrode rod to align with the raw material in the water-cooled copper crucible; (3) Close the furnace chamber and evacuate, perform a leak test, and after passing the test, lower the electrode rod, start the power supply, and automatically melt the raw material in the crucible by igniting an arc through the TA15 titanium alloy consumable electrode. During the melting process, the molten titanium continuously overflows from the designated area to fill the bottom of the water-cooled copper crucible. As the melting progresses, the liquid level gradually rises, such as... Figure 2-3 As shown; (4) After the titanium alloy consumable electrode is melted, the flipping mechanism is started 3s to 10s to pour the titanium liquid from one side of the water-cooled copper crucible into the mold in the casting chamber. The remaining titanium liquid is cooled into a solidified shell in the water-cooled copper crucible. (5) The titanium liquid cools and crystallizes in the mold to form an ingot; (6) Break the vacuum in the furnace chamber, lift out the mold and cast the ingot. At the same time, take out the solidified shell in the water-cooled copper crucible, flatten the part, and still lay it at the bottom of the water-cooled copper crucible as solidified shell. (7) Repeat steps (1) to (6) for the next smelting.

[0023] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for remelting titanium alloy ingots based on layered regional fabrication, characterized in that, Includes the following steps: (1) Open the vacuum melting furnace chamber and place the material in the designated area inside the water-cooled copper crucible; (2) Assemble the titanium alloy consumable electrode and the auxiliary electrode onto the electrode rod clamp, and adjust the position of the electrode rod to align with the raw material in the water-cooled copper crucible; (3) Close the furnace chamber and evacuate the vacuum, check for leaks, and after passing the test, lower the electrode rod, start the power supply, and automatically melt the raw materials in the crucible through the titanium alloy consumable electrode. (4) After the titanium alloy consumable electrode is melted, the flipping mechanism is started within 3 to 10 seconds to pour the titanium liquid from one side of the water-cooled copper crucible into the mold in the casting chamber. The remaining titanium liquid is cooled into a solidified shell in the water-cooled copper crucible. (5) The titanium liquid is cooled and crystallized in the mold to form an ingot; (6) Break the vacuum in the furnace chamber of the vacuum melting furnace, lift out the mold and cast ingots, and at the same time take out the solidified shell in the water-cooled copper crucible, flatten the part, and still lay it at the bottom of the water-cooled copper crucible as solidified shell; (7) Repeat steps (1) to (6) for the next smelting; In step (1), the designated area is the area away from the gating channel inside the water-cooled copper crucible, and one or more of low-risk raw materials, medium-risk raw materials and high-risk raw materials are laid in the designated area; The high-risk raw materials are laid at the bottom layer of the designated area, the medium-risk raw materials are laid at the middle layer of the designated area, and the low-risk raw materials are laid at the top layer of the designated area. The high-risk raw material is a shaving-shaped return charge, the medium-risk raw material is a block-shaped return charge, and the low-risk raw material includes one or more of sponge titanium and virgin intermediate alloy materials.

2. The method for remelting titanium alloy ingots based on layered regional fabrication according to claim 1, characterized in that, The high-risk raw materials include one or more of the following: ingot and bar stock peeling shavings, slab planing shavings, and tube blank boring shavings; The medium-risk raw materials include one or more of the following: ingot risers, forged bar blank cuts, die forging flash, and slab cuts.

Images