A preparation process for preparing TC4ELI alloy by using pure titanium TA1 scrap

Abstract

A preparation process of TC4ELI alloy by using pure titanium TA1 residual waste, relates to the technical field of alloy preparation process, and its structure is: step one: raw material batching: raw materials include: pure titanium TA1 residual waste, titanium sponge, aluminum vanadium alloy, aluminum beans, iron nails; step two: mixing and pressing into blocks; step three: cloth, drying; step four: electron beam cold bed furnace smelting.The beneficial effects of the present application are that: compared with the traditional multiple VAR smelting, the process can effectively remove high and low density inclusions in the raw material, ensure the quality of the ingot; compared with the electron beam melting wire technology process, the preparation process is simple, the process requirement is lower, the cost is small, and the economic risk is low.

Description

Technical Field

[0001] This invention relates to the technical field of alloy preparation processes, and in particular to a preparation process for TC4ELI alloy using pure titanium TA1 waste material. Background Technology

[0002] Currently, there are two main methods for preparing TC4ELI titanium alloy in China: one is to use a traditional vacuum consumable arc furnace (VAR) for multiple melting processes. This involves mixing raw materials such as sponge titanium, aluminum-vanadium alloy, aluminum pellets, and iron nails (or aluminum-vanadium-iron alloy) in a certain proportion, pressing them into electrode blocks of a specific size using a hydraulic press, welding them into "round rod" consumable electrodes, and then vacuum melting them in a VAR furnace to form TC4ELI titanium alloy round ingots (generally requiring 2-3 repeated melting processes). In the AR melting process, the consumable electrode is melted by the electric arc and drips to the bottom of the crucible, gradually solidifying into an ingot. This means that impurities and inclusions contained in the raw materials (consumable electrode) will directly enter the ingot and cannot be effectively removed. The prepared TC4ELI titanium alloy has metallurgical defects such as high and low density inclusions and macroscopic segregation. In addition, the vacuum degree of the VAR melting furnace is generally 0.1 to 1.0 Pa, and the furnace chamber space is small with limited escape channels for gas impurities, resulting in poor degassing and an increase in the gas content in the ingot.

[0003] Another method involves using electron beam cold bed smelting technology to recover alloy scrap. The principle is to use a high-energy electron beam as a heat source in a vacuum forming environment to melt the fed alloy material. Following a planned forming path, the material is deposited point-by-point and layer-by-layer until a near-net-shape metal part is formed. However, in this method of recovering alloy scrap, the composition of the scrap is difficult to control, and errors are inevitable in the batching analysis. The material assembly process also struggles to achieve uniform composition, resulting in inhomogeneous ingot composition during smelting. Consequently, the prepared TC4ELI titanium alloy exhibits metallurgical defects such as macroscopic segregation. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a preparation process for TC4ELI alloy using pure titanium TA1 waste material, thereby solving the aforementioned technical problems.

[0005] This invention provides a preparation process for TC4ELI alloy using pure titanium TA1 waste material, comprising the following steps:

[0006] Step 1: Raw material preparation. Select high-purity raw materials: pure titanium TA1 waste, sponge titanium, aluminum vanadium alloy, aluminum briquettes, and iron nails; establish a raw material formulation database, including composition, quality, and volatile properties; calculate and control the proportion of raw materials to ensure that each raw material is added in the correct proportion.

[0007] Step 2: Mixing and pressing into blocks. Mixing is done using a mixing device, and the weight is transferred through an automatic weighing and control system. The hammer parameters are set on an 80MN hydraulic press for pressing.

[0008] Step 3: Fabric preparation and drying. Each piece of fabric is inspected using a machine vision system, and drying parameters are optimized based on the size and composition of the fabric.

[0009] Step 4: Electron beam cold hearth furnace melting. The dried titanium blocks are stacked into the feeder and sent into the electron beam cold hearth furnace for melting. BT22 titanium alloy ingots are obtained in one melting process. The temperature control system ensures that the temperature inside the electron beam cold hearth furnace is stable and reaches the required melting temperature. The furnace temperature, pressure, and current are monitored in real time through a monitoring system.

[0010] Step 5: Quality inspection. Use non-destructive testing methods to conduct a comprehensive inspection of the ingots to ensure that there are no internal defects; make detailed data records and analysis, and statistically analyze the test results of each batch of ingots.

[0011] Step 1: Raw material preparation;

[0012] The raw material calculation and material usage statistics are as follows: The total weight of sponge titanium (grade 1), aluminum vanadium alloy (AlV55), aluminum briquettes (99.8%), and iron nails (Fe) used in the experiment is 1509.46 kg. After being mixed by a mixing and spreading machine, the materials are placed in a single layer and double row in the material box. 1496 kg of TA1 pure titanium residue is evenly stacked on the top layer of the titanium briquettes. The total weight of the raw materials is 3005.46 kg.

[0013] Establish a raw material ingredient database, including composition, quality, and volatile properties;

[0014] Raw material ratio analysis:

[0015] (1) Analysis of normal smelting materials

[0016] The calculation for the batching of the normal smelting feed in the experiment is as follows:

[0017] Al%=(114×99.86%+191.6×41.09%)÷2731.6=7.05%

[0018] V%=191.600×58.45%÷2731.6=4.10%

[0019] Fe%=(1060×0.018%+114×0.073%+191.6×0.14%+2.96×99.652%+3.12×0.010%+1360×0.030%)÷2731.6=0.14%

[0020] O%=(1060×0.044%+191.6×0.063%+3.12×40.05%+1360×0.055%)

[0021] ÷2731.6=0.095%;

[0022] (2) Analysis of the first batch of material blocks

[0023] Based on experience, in the early stages of smelting, due to the lower smelting speed, the loss rate of volatile elements is relatively high. Therefore, the Al element content in the first batch is slightly increased. The batching calculation is as follows:

[0024] Al%=(12×99.86%+19.24×41.09%)÷273.74=7.26%

[0025] V%=19.24×58.45%÷273.74=4.10%

[0026] Fe%=(106×0.018%+12×0.073%+19.24×0.14%+0.292×99.652%+0.248×0.010%+136×0.030%)÷273.74=0.14%

[0027] O%=(106×0.044%+19.24×0.063%+0.248×40.05%+136×0.055%)

[0028] ÷273.74=0.085%;

[0029] Step 2: Mix the materials and press them into blocks;

[0030] Except for TA1 pure titanium residue, other materials are added to different hoppers on the mixing equipment. The materials are discharged through the bottom outlet of the hopper by vibration and are automatically weighed by the high-precision electronic scale of the equipment with a weighing accuracy of ±0.2g. After weighing, the materials are transferred to the mixer for mixing. The mixer rotates in both directions for 1 minute each. After 2 minutes, the materials are poured into the mold cavity of the 80MN hydraulic press. The pressing stroke and tonnage of the press hammer are set on the operating platform of the 80MN hydraulic press to press the materials into titanium blocks.

[0031] Based on the analysis of the titanium alloy smelting rules, the volatility of each element in TC4ELI titanium alloy (Ti-6Al-4V) is estimated, and the batching calculation is performed accordingly, giving a certain amount of the easily volatile component Al to be added.

[0032] Step 3: Fabric preparation and drying;

[0033] Each material block is inspected using a machine vision system to ensure that it meets the requirements, improving the accuracy and speed of the operation. Two large material boxes are used for material stacking. The lower layer is a single layer of alloy titanium blocks A (10 blocks / box), and the upper layer is for stacking scrap materials. Two blocks are placed on each side of each row, and scrap materials can be placed in the middle. Five rows are stacked in this way. 680 kg of TA1 plate edge material is stacked on the upper layer / sides. When stacking scrap materials, they are evenly stacked along the length direction. The front row of materials is stacked at the front of the first melted material box. The lower layer is a single block of alloy titanium blocks B, and the upper layer / sides are stacked with 68 kg of TA1 plate edge material.

[0034] Step three, drying the material block (titanium lump), specifically includes the following steps:

[0035] Step 31: Place the pressed titanium blocks from Step 2 into the drying hopper;

[0036] Step 32: Inspect the surface of the titanium blocks to confirm that all titanium blocks have added intermediate alloy, aluminum-vanadium alloy (AlV55), and aluminum briquettes;

[0037] Step 33: Using a 100kg range electronic scale, randomly sample 30% of the titanium blocks and record the weight. Then, use an electronic crane scale to weigh the total weight of the titanium blocks and record the weight.

[0038] Step 34: Dry the sampled and weighed titanium blocks for 2-4 hours at a temperature of 115-125℃.

[0039] Step 4: Electron beam cold hearth (EB) furnace melting. The assembled product is sent into the electron beam cold hearth furnace for melting, and TC4ELI titanium alloy ingots are obtained in one melting process.

[0040] Electron beam cold hearth furnace melting specifically includes the following steps:

[0041] Step 41: Place the titanium blocks from Step 3 into the material box in a double layer, one block per row; the first row contains the first batch of titanium blocks, followed by the normally smelted titanium blocks, and the last row contains the last batch of titanium blocks.

[0042] Step 42: Check the electron beam cold bed furnace, including: checking the filling hydrogen and oxygen gas pressure, checking the cooling water of the power cabinet, turning on the power cabinet and setting the power cabinet voltage;

[0043] Step 43: After verifying that the electron beam cold hearth furnace is correct in step 42, start the electron beam cold hearth furnace and start electron guns 1#, 2#, 3#, 4#, 5#, 6#, and 7# respectively, and set and record the current values ​​of electron guns 1# to 7#.

[0044] Step 44: After starting electron guns 1# to 7# in step 43, set the electron gun current value again. After setting the electron gun current value, start pushing the material for melting. During the melting process, ensure that there are no cold zones in the cooling bed.

[0045] Step 45: After the melting in step 44 is completed, the obtained ingot is removed from the EB furnace ingot pulling system and the ingot surface is processed, including removing oxide scale and "flattening" the ingot end face.

[0046] deal with;

[0047] Step 5: Quality inspection. The smelted ingots are removed from the EB furnace and inspected for quality using ultrasonic testing to ensure that there are no defects such as porosity or inclusions inside.

[0048] The beneficial effects of this invention are as follows: compared with the traditional multiple VAR melting process, this process can effectively remove high and low density inclusions in the raw materials and ensure the quality of the ingots; compared with the electron beam melting technology, the preparation process is simple, the process requirements are low, the cost is low, and the economic risk is low. Attached Figure Description

[0049] Figure 1 This is a curve showing the electron gun current fitting of the present invention;

[0050] Figure 2 This is a curve showing the fitting relationship between the vacuum level inside the EB electron beam cold hearth furnace and the sum of the currents of each gun according to the present invention.

[0051] Figure 3 This is a fitting curve of the feed rate and the drawing speed of the ingot according to the present invention; Detailed Implementation

[0052] Example 1

[0053] like Figure 1-3 As shown, this invention provides a preparation process for TC4ELI alloy using pure titanium TA1 waste material, comprising the following steps:

[0054] Step 1: Raw material preparation;

[0055] Step 2: Mix the materials and press them into blocks;

[0056] Step 3: Fabric preparation and drying;

[0057] Step 4: Electron beam cold hearth (EB) furnace melting. The assembled product is sent into the electron beam cold hearth furnace for melting, and TC4ELI titanium alloy ingots are obtained in one melting process.

[0058] Step 5: Quality inspection. The smelted ingots are removed from the EB furnace for ingot quality and composition inspection.

[0059] In step one, the raw material batching calculation and material usage statistics are as follows: The total weight of sponge titanium (grade 1), aluminum vanadium alloy (AlV55), aluminum briquettes (99.8%), and iron nails (Fe) used in the experiment is 1509.46 kg. After being mixed by a mixing and spreading machine, the materials are placed in a single layer and double row in the material box. 1496 kg of TA1 pure titanium residue is evenly stacked on the top layer of the titanium briquettes. The total weight of the batched materials is 3005.46 kg.

[0060] Ingredient analysis:

[0061] (1) Analysis of normal smelting materials

[0062] The calculation for the batching of the normal smelting feed in the experiment is as follows:

[0063] Al%=(114×99.86%+191.6×41.09%)÷2731.6=7.05%

[0064] V%=191.600×58.45%÷2731.6=4.10%

[0065] Fe%=(1060×0.018%+114×0.073%+191.6×0.14%+2.96×99.652%+3.12×0.010%+1360×0.030%)÷2731.6=0.14%

[0066] O%=(1060×0.044%+191.6×0.063%+3.12×40.05%+1360×0.055%)÷2731.6=0.095%;

[0067] (2) Analysis of the first batch of material blocks

[0068] Based on experience, in the early stages of smelting, due to the lower smelting speed, the loss rate of volatile elements is relatively high. Therefore, the Al element content in the first batch is slightly increased. The batching calculation is as follows:

[0069] Al%=(12×99.86%+19.24×41.09%)÷273.74=7.26%

[0070] V%=19.24×58.45%÷273.74=4.10%

[0071] Fe%=(106×0.018%+12×0.073%+19.24×0.14%+0.292×99.652%+0.248×0.010%+136×0.030%)÷273.74=0.14%

[0072] O%=(106×0.044%+19.24×0.063%+0.248×40.05%+136×0.055%)÷273.74=0.085%;

[0073] In step two, raw materials such as TA1 pure titanium residue, aluminum-vanadium alloy (AlV55), and aluminum briquettes (99.86%) are added to different hoppers on the mixing equipment, except for the TA1 pure titanium residue. The materials are discharged through the bottom outlet of the hopper by vibration and are automatically weighed by the high-precision electronic scale of the equipment with a weighing accuracy of ±0.2g. After weighing, the materials are poured into the feeding trolley. The materials are transported to the mixer by the feeding trolley for mixing. The mixer rotates in both directions for 1 minute each. After 2 minutes, the materials are poured into the mold cavity of the 80MN hydraulic press. The pressing stroke and tonnage of the press hammer are set on the operating platform of the 80MN hydraulic press to press the materials into blocks (titanium briquettes).

[0074] Based on the analysis of titanium alloy smelting rules, the volatility of each element in TC4ELI titanium alloy (Ti-6Al-4V) was estimated, and the batching calculation was performed accordingly, with a certain amount of supplementary addition of the easily volatile component Al. The experiment used raw materials such as sponge titanium (grade 1), TA1 pure titanium residue, aluminum-vanadium alloy (AlV55), aluminum briquettes (99.86%), and iron nails (Fe). Except for the TA1 pure titanium residue, the other materials were weighed and mixed by a fully automatic mixing and distributing machine, and pressed into titanium lumps with specifications of 580×380×95mm in an 80MN hydraulic press; then, they were stacked in the feeding hopper according to certain rules.

[0075] In step three, the materials from step one are selected and sheared to match the materials, thus achieving the loading rules and material balance. Two large material boxes are used for stacking. The lower layer is a single layer of alloy titanium agglomerates A (10 pieces / box), and the upper layer is for stacking scrap materials. Two pieces are placed in each row (placed on both sides, with scrap materials in the middle), and this stacking method is used for 5 rows. 680kg of TA1 plate edge material is then stacked on the upper / both sides. When stacking the scrap materials, they are evenly stacked along the length direction. The front row of materials is stacked at the front of the first-melted material box, the lower layer is a single piece of alloy titanium agglomerate B, and the upper / both sides are stacked with 68kg of TA1 plate edge material.

[0076] Step 3, drying the material block (titanium lump), specifically includes the following steps:

[0077] Step 31: Place the pressed material blocks (titanium lumps) from Step 2 into the drying hopper;

[0078] Step 32: Visually inspect the surface of the material blocks (titanium blocks) to confirm that all material blocks (titanium blocks) have added intermediate alloy, aluminum-vanadium alloy (AlV55), and aluminum briquettes;

[0079] Step 33: Using a 100kg range electronic scale, randomly sample 30% of the material blocks (titanium blocks) and record the weight. Then, use an electronic crane scale to weigh the total weight of the material blocks (titanium blocks) and record the weight.

[0080] Step 34: Dry the sampled and weighed material blocks (titanium blocks) for 2-4 hours at a temperature of 115-125℃.

[0081] In step four, the dried material blocks (titanium lumps) from step three are sequentially stacked into the feeder and sent to the electron beam cold hearth furnace for melting. The TC4ELI titanium alloy ingot is obtained in one melting process. The ingot is then removed from the EB furnace for inspection.

[0082] Step 4, electron beam cold hearth furnace melting, specifically includes the following steps:

[0083] Step 41: Place the pressed material blocks (titanium blocks) from Step 2 into the material box in a double layer, one block per row; the first row contains the first batch of material blocks (titanium blocks), followed by the normal smelted material (titanium blocks), and the last row contains the last batch of material blocks (titanium blocks).

[0084] Step 42: Check the electron beam cold bed furnace, including: checking the filling hydrogen and oxygen gas pressure, checking the cooling water of the power cabinet, turning on the power cabinet and setting the power cabinet voltage;

[0085] Step 43: After verifying that the electron beam cooling furnace in Step 4.2 is correct, start the electron beam cooling furnace and start electron guns #1, #2, #3, #4, #5, #6, and #7 respectively, and set #1 to #7.

[0086] Record the electron gun current value;

[0087] Step 44: After starting electron guns 1# to 7# in step 4.3, set the electron gun current value again. After setting the electron gun current value, start pushing the material for melting. During the melting process, ensure that there are no cold zones in the cooling bed.

[0088] Step 45: After the melting in step 44 is completed, the obtained ingot is removed from the EB furnace ingot pulling system and the ingot surface is processed, including removing oxide scale and "flattening" the ingot end face.

[0089] deal with;

[0090] Step 5: Quality inspection. The smelted ingots are removed from the EB furnace and inspected for quality using ultrasonic testing to ensure that there are no defects such as porosity or inclusions inside.

Claims

1. A preparation process for preparing TC4ELI alloy by using pure titanium TA1 scrap, characterized in that: Comprising the following steps: Step one: raw material preparation, select high purity raw materials: pure titanium TA1 scrap, titanium sponge, aluminum vanadium alloy, aluminum beans and iron nails; Establish raw material batching database, including composition, quality and volatile quality; Calculate and control the proportion of raw materials to ensure that each raw material is put in according to the correct proportion; The analysis of the batching: (1) The proportion of raw materials is calculated as follows: (2) The analysis of the first row of material block is calculated as follows: In the early stage of melting, due to the low melting speed, the volatile element volatilization loss rate is large, so the Al element batching value of the first row of material batching value is slightly improved, and the batching calculation is as follows: Step two: mixing, pressing into blocks, using mixing equipment to mix, weighing and transmitting through automatic weighing and control system; Set the press hammer head parameters on the 80MN oil press for pressing; Step three: cloth, drying, check each block through the machine vision system, optimize the drying parameters according to the size and composition of the block for drying; Step four: electron beam cold bed furnace melting, the dried material block titanium lump is placed into the feeder in turn and sent into the electron beam cold bed furnace for melting, and titanium alloy ingot is obtained by one melting, the temperature in the electron beam cold bed furnace is stabilized through the temperature control system to reach the required melting temperature; The temperature, pressure and current in the furnace are monitored through the real-time monitoring system; Step five: quality inspection, using non-destructive testing method to detect the ingot comprehensively to ensure that there is no defect inside; Make detailed data record and analysis, and analyze the detection results of each batch of ingot.

2. The preparation process for preparing TC4ELI alloy using pure titanium TA1 waste material according to claim 1, characterized in that: Said step four specifically comprises the following steps: Step 41: place the material block titanium lump in step three into the material box according to one block per row, double layer; Among them, the first row is the first row of material block titanium lump, then the normal melting material titanium lump, and the last row is the tail row of material block titanium lump; Step 42: check the electron beam cold bed furnace, including: check the filling hydrogen and oxygen gas pressure, check the power cabinet cooling water, start the power cabinet and set the power cabinet voltage; Step 43: after the electron beam cold bed furnace in step 42 is checked without error, start the electron beam cold bed furnace, start 1#, 2#, 3#, 4#, 5#, 6# and 7# electron guns respectively, set the current values of 1#-7# electron guns and record them; Step 44: after the start of 1#-7# electron guns in step 43, set the current values of the electron guns again, start pushing material for melting after setting the current values of the electron guns, and ensure that there is no cold zone in the cold bed during melting; Step 45: after the melting in step 44 is finished, take out the obtained ingot from the electron beam cold bed furnace ingot pulling system, and carry out ingot surface processing, including removing the oxide skin and processing the flat head of the ingot end face.

3. The preparation process for preparing TC4ELI alloy using pure titanium TA1 waste material according to claim 1, characterized in that: The non-destructive testing method is ultrasonic detection.

4. The preparation process for preparing TC4ELI alloy using pure titanium TA1 waste material according to claim 1, characterized in that: The size of the material block titanium lump is 580*380*95mm.

5. The preparation process for preparing TC4ELI alloy using pure titanium TA1 waste material according to claim 1, characterized in that: The titanium sponge is grade 1 titanium sponge, the aluminum vanadium alloy is AlV55, and the aluminum bean content is 99.8%.

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