Cold cathode EB furnace smelting method for forging-free direct rolling Ti-Al-Nb-Zr-Mo alloy ingot
阅读说明：本技术 免锻直轧Ti-Al-Nb-Zr-Mo合金铸锭的冷阴极EB炉熔炼方法 (Cold cathode EB furnace smelting method for forging-free direct rolling Ti-Al-Nb-Zr-Mo alloy ingot ) 是由 张玉勤 邓亚杰 黄海广 张浩泽 史亚鸣 李志敏 蒋业华 于 2020-11-23 设计创作，主要内容包括：本发明提供一种免锻直轧Ti-Al-Nb-Zr-Mo合金铸锭的冷阴极EB炉熔炼方法,其特征在于包括下列各步骤：1)备料,2)混料、压块,3)装料,4)开启1～4号电子枪对冷床内的散装料进行真空熔炼,得冷凝壳,5)将进料区的压块料推入熔炼区,开启1～7号电子枪对压块料进行真空熔炼、拉锭,6)用5～7号电子枪对铸锭进行补缩,直至钛合金液通过冷床全部流入结晶器后,停止熔炼,得成分与组织均匀、高低密度夹杂少、高纯净、且无需锻造直接就能轧制成材的Ti-Al-Nb-Zr-Mo合金铸锭。产品性能优于现有产品,工艺流程短,成材率提高到80%,成本降低15%～30%,效果明显。(The invention provides a cold cathode EB furnace smelting method of a forging-free direct rolling Ti-Al-Nb-Zr-Mo alloy ingot, which is characterized by comprising the following steps: 1) preparing materials, 2) mixing and briquetting, 3) charging, 4) starting No. 1-4 electron guns to carry out vacuum melting on bulk materials in a cooling bed to obtain a condensation shell, 5) pushing the briquetting materials in a feeding area into a melting area, starting No. 1-7 electron guns to carry out vacuum melting and ingot pulling on the briquetting materials, 6) feeding ingots by using No. 5-7 electron guns until titanium alloy liquid flows into a crystallizer completely through the cooling bed, and stopping melting to obtain the Ti-Al-Nb-Zr-Mo alloy ingot which is uniform in components and tissues, less in high-low density inclusion, high in purity and capable of being directly rolled into a material without forging. The product performance is superior to the existing product, the process flow is short, the yield is improved to 80 percent, the cost is reduced by 15 to 30 percent, and the effect is obvious.)
1. A cold cathode EB furnace smelting method of a forging-free direct rolling Ti-Al-Nb-Zr-Mo alloy ingot is characterized by comprising the following steps:
(1) the materials are prepared according to the following mass ratio:
aluminum niobium alloy 5.7wt.% to 6.3wt. -%)
Aluminum bean 4.05wt.% to 4.77wt. -%)
Zirconium sponge 1.5wt.% to 2.5wt. -%)
1.5wt.% to 1.7wt.% of aluminum molybdenum alloy
Titanium sponge balance
The sum of the above components is 100 wt.%;
(2) mixing the prepared materials in the step (1), taking a proper amount of mixture as bulk materials, pressing the rest of the mixture into blocks, drying the blocks at 100-120 ℃ for 5-6 h, and cooling the blocks along with a furnace to obtain pressed blocks;
(3) flatly paving the bulk material in the step (2) in an EB furnace cooling bed provided with a seven-rod electron beam gun, and then putting a proper amount of briquetting material in the step (2) into a feeding area of the EB furnace;
(4) closing the furnace door of the EB furnace, and vacuumizing to 1.8 multiplied by 10-3～4.4×10-3torr, then using hydrogen and oxygen to sweep the surface of the electron gun and dust in the furnace into the furnace for cleaning, and then continuously vacuumizing until the vacuum degree is 3.9 multiplied by 10-3～4.4×10-3When torr is reached, opening No. 1-4 electron guns to smelt the bulk materials in the cooling bed, controlling the power of No. 1-4 electron guns to be 100-130 kW, after smelting for 100-120 min, closing the electron guns, cooling for 20-40 min to obtain a condensation shell, and cooling for 25-35 min along with the furnace;
(5) under a vacuum of 1.8X 10-3～3.5×10-3During torr, pushing the briquetting material in the feeding area into the smelting area, and starting No. 1-7 electron gunsSmelting the pressed block materials, controlling the power of No. 1-2 electron guns to be 70-90 kW, the power of No. 3-4 electron guns to be 160-180 kW, the power of No. 5 electron guns to be 110-140 kW, and the power of No. 6-7 electron beam guns to be 50-80 kW, enabling the smelted titanium alloy liquid to flow into a crystallizer through a cooling bed, pulling ingots at the speed of 12-18 mm/min, and continuously pushing, smelting and pulling the ingots till the pressed block materials are completely smelted;
(6) turning off No. 1-4 electron gun at vacuum degree of 1.8 × 10-3～3.5×10-3And (3) feeding the cast ingot by using No. 5-7 electron guns during torr, controlling the power of the No. 5-7 electron guns to be 70-100 kW until the titanium alloy liquid completely flows into the crystallizer through the cooling bed, closing the No. 5-7 electron guns, stopping ingot pulling, and cooling along with the crystallizer for 3-4 hours to obtain the Ti-Al-Nb-Zr-Mo alloy cast ingot.
2. The cold cathode EB furnace smelting method for the forging-free direct rolling of the Ti-Al-Nb-Zr-Mo alloy ingot according to the claim 1, wherein the granularity of the aluminum-niobium alloy in the step (1) is 1-10 mm, the content of aluminum is 47-52 wt.%, the content of Nb is 48-53 wt.%, and the sum of aluminum and niobium is 100 wt.%.
3. The cold cathode EB furnace smelting method of the forging-free direct rolling Ti-Al-Nb-Zr-Mo alloy ingot casting according to claim 1, wherein the Al content in the aluminum beans in the step (1) is more than or equal to 99.9 wt.%.
4. The cold cathode EB furnace smelting method of the forging-free direct rolling Ti-Al-Nb-Zr-Mo alloy ingot casting according to claim 1, wherein the granularity of the sponge zirconium in the step (1) is 3-10 mm, and the Zr content is more than or equal to 99.4 wt.%.
5. The cold cathode EB furnace smelting method for the forging-free direct rolling of the Ti-Al-Nb-Zr-Mo alloy ingot according to claim 1, wherein the granularity of the aluminum-molybdenum alloy in the step (1) is 1-3 mm, the content of Al is 35-40 wt.%, the content of Mo is 60-65 wt.%, and the sum of aluminum and molybdenum is 100 wt.%.
6. The cold cathode EB furnace smelting method of the forging-free direct rolling Ti-Al-Nb-Zr-Mo alloy ingot casting according to the claim 1, characterized in that the ingot casting of the step (6) is a round ingot or a flat ingot.
7. The cold cathode EB furnace smelting method of the forging-free direct rolling Ti-Al-Nb-Zr-Mo alloy ingot casting according to the claim 1, wherein the components of the Ti-Al-Nb-Zr-Mo alloy ingot casting in the step (6) are as follows: al: 5.5wt.% to 6.5wt.%, Nb: 2.5wt.% to 3.5wt.%, Zr: 1.5-2.5 wt.%, 0.6-1.5 wt.% Mo, and the balance Ti.
Technical Field
The invention relates to a cold cathode EB furnace smelting method of a forging-free direct rolling Ti-Al-Nb-Zr-Mo alloy ingot, belonging to the technical field of nonferrous metal processing.
Background
The Ti-6Al-3Nb-2Zr-1Mo (TA 31) titanium alloy not only has small density, high specific strength, good plasticity and corrosion resistance, but also has excellent fracture toughness, stress corrosion fracture toughness, impact toughness, weldability and the like, can be processed into products such as pipes, plates, rods, section bars and the like, particularly has outstanding seawater and marine atmospheric corrosion resistance, is a high-quality light structural material in the fields of marine oil drilling platforms, marine engineering equipment, ships, submarines, deep submergence vehicles, offshore facilities and the like, and has wide application prospect. In the field of titanium material processing, sponge titanium and alloy raw materials are mixed according to a proportion and then smelted into a high-quality titanium alloy ingot with no segregation of chemical components, uniform tissue and less high-low density inclusions, which is an important basis of all subsequent titanium material processing processes, and only the high-quality titanium alloy ingot can be made into various titanium materials with high quality and stable batch performance through subsequent processing.
At present, the TA31 alloy material generally adopts the following preparation process flow: firstly, mixing titanium sponge and alloy raw materials, pressing and welding the mixture into an electrode, smelting the electrode into a round ingot through a vacuum consumable arc furnace (VAR) for 2-3 times, then forging and cogging the round ingot, and rolling the round ingot into products such as pipes, plates, rods, profiles and the like. Because the problems that high-density and low-density impurities are difficult to remove, the components and the structure are not uniform, multiple remelting is needed and the like exist in the VAR smelting of the TA31 alloy, an ingot must be forged, cogging and rolled into a material in subsequent processing, the process flow is long, the comprehensive yield is low, the cost of the processed material is high, and the large-scale application of the TA31 alloy is greatly limited.
Therefore, there is a need to improve the prior art by providing a cold cathode EB furnace melting method for directly rolling Ti-Al-Nb-Zr-Mo alloy ingots without forging.
Disclosure of Invention
The TA31 alloy contains volatile Al element and high melting point Nb element, so that the technical problem to be solved by the invention is how to control the Al element not to be volatilized and the Nb element to be uniformly distributed under the high vacuum condition of the EB furnace, and the high-quality ingot which has uniform components and tissues, less high-low density impurities, high purity and can be directly rolled into a finished product without forging can be obtained by single smelting.
The invention provides a cold cathode EB furnace smelting method of a forging-free direct rolling Ti-Al-Nb-Zr-Mo alloy ingot for solving the technical problems.
The invention is realized by the following technical scheme: a cold cathode EB furnace smelting method of a forging-free direct rolling Ti-Al-Nb-Zr-Mo alloy ingot is characterized by comprising the following steps:
(1) the materials are prepared according to the following mass ratio:
aluminum niobium alloy 5.7wt.% to 6.3wt. -%)
Aluminum bean 4.05wt.% to 4.77wt. -%)
Zirconium sponge 1.5wt.% to 2.5wt. -%)
1.5wt.% to 1.7wt.% of aluminum molybdenum alloy
Titanium sponge balance
The sum of the above components is 100 wt.%;
(2) mixing the prepared materials in the step (1), taking a proper amount of mixture as bulk materials, pressing the rest of the mixture into blocks, drying the blocks at 100-120 ℃ for 5-6 h, and cooling the blocks along with a furnace to obtain pressed blocks;
(3) flatly paving the bulk material in the step (2) in an EB furnace cooling bed provided with a seven-rod electron beam gun, and then putting a proper amount of briquetting material in the step (2) into a feeding area of the EB furnace;
(4) closing the furnace door of the EB furnace, and vacuumizing to 1.8 multiplied by 10-3～4.4×10-3torr, then using hydrogen and oxygen to sweep the surface of the electron gun and dust in the furnace into the furnace for cleaning, and then continuously vacuumizing until the vacuum degree is 3.9 multiplied by 10-3～4.4×10- 3When torr is reached, opening No. 1-4 electron guns to smelt the bulk materials in the cooling bed, controlling the power of No. 1-4 electron guns to be 100-130 kW, after smelting for 100-120 min, closing the electron guns, cooling for 20-40 min to obtain a condensation shell, and cooling for 25-35 min along with the furnace;
(5) under a vacuum of 1.8X 10-3～3.5×10-3During torr, pushing the briquetting materials in the feeding area into a smelting area, starting No. 1-7 electron guns to smelt the briquetting materials, controlling the power of No. 1-2 electron guns to be 70-90 kW, the power of No. 3-4 electron guns to be 160-180 kW, the power of No. 5 electron guns to be 110-140 kW, the power of No. 6-7 electron beam guns to be 50-80 kW, enabling the smelted titanium alloy liquid to flow into a crystallizer through a cooling bed, pulling ingots at the speed of 12-18 mm/min, and continuously pushing, smelting and pulling ingots until the briquetting materials are completely smelted;
(6) turning off No. 1-4 electron gun at vacuum degree of 1.8 × 10-3～3.5×10-3And (3) feeding the cast ingot by using No. 5-7 electron guns during torr, controlling the power of the No. 5-7 electron guns to be 70-100 kW until the titanium alloy liquid completely flows into the crystallizer through the cooling bed, closing the No. 5-7 electron guns, stopping ingot pulling, and cooling along with the crystallizer for 3-4 hours to obtain the Ti-Al-Nb-Zr-Mo alloy cast ingot.
The granularity of the aluminum-niobium alloy in the step (1) is 1-10 mm, the aluminum content is 47-52 wt.%, the Nb content is 48-53 wt.%, and the sum of the aluminum and the niobium is 100 wt.%.
The content of Al in the aluminum beans in the step (1) is more than or equal to 99.9 wt.%.
The granularity of the sponge zirconium in the step (1) is 3-10 mm, and the Zr content is more than or equal to 99.4 wt.%.
The granularity of the aluminum-molybdenum alloy in the step (1) is 1-3 mm, the content of Al is 35-40 wt.%, the content of Mo is 60-65 wt.%, and the sum of aluminum and molybdenum is 100 wt.%.
And (4) the cast ingot in the step (6) is a round ingot or a flat ingot.
The Ti-Al-Nb-Zr-Mo alloy ingot casting in the step (6) comprises the following components: al: 5.5wt.% to 6.5wt.%, Nb: 2.5wt.% to 3.5wt.%, Zr: 1.5-2.5 wt.%, 0.6-1.5 wt.% Mo, and the balance Ti.
The invention has the following advantages and beneficial technical effects: by adopting the technology, particularly, the reasonable alloy proportion is achieved, and corresponding process parameters are controlled in the smelting process of the EB furnace, so that the high-quality TA31 alloy cast ingot which has uniform components and tissues, less high-low density impurities, high purity and can be directly rolled into a finished product without forging is obtained by single smelting, the product performance is superior to the prior art, the process flow is shortened, the comprehensive finished product rate of the product is improved to more than 80 percent, the production cost is reduced by 15 to 30 percent, and the method has obvious market application prospect.
Drawings
FIG. 1 is a schematic diagram of the electron gun distribution and the interior area of an EB furnace for melting round ingots.
FIG. 2 is another schematic view of the EB furnace interior zone and electron gun distribution for ingot melting.
FIG. 3 is an X-ray diffraction pattern of the ingot obtained in examples 1 to 3 of the present invention.
FIG. 4 is an optical microstructure of a round ingot melted in example 1 of the present invention.
FIG. 5 is an optical microstructure of a slab ingot melted in example 2 of the present invention.
FIG. 6 is an optical microstructure of a round ingot melted in example 3 of the present invention.
Detailed Description
The present invention will be described in further detail with reference to specific embodiments, but the scope of the present invention is not limited to the description.
Example 1
The cold cathode EB furnace smelting method of the forging-free direct rolling Ti-Al-Nb-Zr-Mo alloy ingot comprises the following steps:
(1) the materials are prepared according to the following mass ratio:
aluminum niobium alloy 6.3wt. -%)
Aluminum bean 4.05wt. -%)
Zirconium sponge 1.5wt. -%)
Aluminum molybdenum alloy 1.5wt. -%)
Titanium sponge 86.65 wt.%;
wherein: the granularity of the aluminum-niobium alloy is 1-10 mm, the content of aluminum is 47wt.%, and the content of Nb is 53 wt.%;
the content of Al in the aluminum beans is more than or equal to 99.9 wt.%;
the granularity of the sponge zirconium is 3-10 mm, and the Zr content is more than or equal to 99.4 wt.%;
the granularity of the aluminum-molybdenum alloy is 1-3 mm, the content of Al is 35wt.%, and the content of Mo is 65 wt.%;
(2) mixing the prepared materials in the step (1), taking a proper amount of the mixture as bulk materials, pressing the rest of the mixture into blocks, drying the blocks at 100 ℃ for 6 hours, and cooling the blocks along with a furnace to obtain pressed blocks;
(3) flatly paving the bulk material in the step (2) in an EB furnace cooling bed provided with a seven-rod electron gun, and then putting a proper amount of briquetting material in the step (2) into a feeding area of the EB furnace, wherein a circular crystallizer is adopted as a crystallizer of the EB furnace;
(4) closing the furnace door of the EB furnace, and vacuumizing to 1.8 multiplied by 10-3torr, then using hydrogen and oxygen to sweep the surface of the electron gun and dust in the furnace into the furnace for cleaning, and then continuously vacuumizing until the vacuum degree is 3.9 multiplied by 10-3When torr is carried out, opening No. 1-4 electron guns to smelt the bulk materials in the cooling bed, controlling the power of No. 1-4 electron guns to be 100kW, after smelting for 120min, closing the electron guns, cooling for 40min to obtain a condensed shell, and cooling for 35min along with the furnace;
(5) under a vacuum of 1.8X 10-3During torr, pushing the briquetting materials in the feeding area into a smelting area, starting No. 1-7 electron guns to smelt the briquetting materials, controlling the power of No. 1-2 electron guns to be 90kW, the power of No. 3-4 electron guns to be 160kW, the power of No. 5 electron guns to be 110kW, the power of No. 6-7 electron beam guns to be 50kW, enabling the smelted titanium alloy liquid to flow into a crystallizer through a cooling bed, pulling ingots at the speed of 12mm/min, and continuously pushing, smelting and pulling the ingots until the briquetting materials are completely smelted;
(6) turning off No. 1-4 electron gun at vacuum degree of 1.8 × 10-3Feeding ingots by using No. 5-7 electron guns during torr, controlling the power of the No. 5-7 electron guns to be 70kW until titanium alloy liquid completely flows into the crystallizer through a cooling bed, closing the No. 5-7 electron guns, stopping ingot pulling, cooling for 3 hours along with the furnace to obtain Ti-Al-Nb-Zr-Mo alloy round ingots, peeling the round ingots, performing component detection, detecting the periphery of each cross section, and performing detection every other cross sectionA section is taken at 100mm, the detection result is shown in table 1, the requirements of GB/T3620.1-2016 titanium and titanium alloy brand and chemical composition are met, the average deviation of the element content at each part is small, and the ingot casting component is uniform.
TABLE 1
Element(s)
Al
Nb
Zr
Mo
Mean value of
5.87
3.05
2.01
0.99
Mean absolute deviation
0.102573
0.00137
0.001277
0.000293
Example 2
The cold cathode EB furnace smelting method of the forging-free direct rolling Ti-Al-Nb-Zr-Mo alloy ingot comprises the following steps:
(1) the materials are prepared according to the following mass ratio:
aluminum niobium alloy 6.0wt. -%)
Aluminum bean 4.45wt.%
Zirconium sponge 2.0wt. -%)
Aluminum molybdenum alloy 1.6wt. -%)
85.95wt.% titanium sponge;
wherein: the granularity of the aluminum-niobium alloy is 1-10 mm, the content of aluminum is 47wt.%, and the content of Nb is 53 wt.%;
the content of Al in the aluminum beans is more than or equal to 99.9 wt.%;
the granularity of the sponge zirconium is 3-10 mm, and the Zr content is more than or equal to 99.4 wt.%;
the granularity of the aluminum-molybdenum alloy is 1-3 mm, the content of Al is 35wt.%, and the content of Mo is 65 wt.%;
(2) mixing the prepared materials in the step (1), taking a proper amount of the mixture as bulk materials, pressing the rest of the mixture into blocks, drying the blocks at 100 ℃ for 6 hours, and cooling the blocks along with a furnace to obtain pressed blocks;
(3) flatly paving the bulk material in the step (2) in an EB furnace cooling bed provided with a seven-rod electron gun, and then putting a proper amount of briquetting material in the step (2) into a feeding area of the EB furnace, wherein a flat crystallizer is adopted as a crystallizer of the EB furnace;
(4) closing the furnace door of the EB furnace, and vacuumizing to 3.5 multiplied by 10-3torr, then using hydrogen and oxygen to sweep the surface of the electron gun and dust in the furnace into the furnace for cleaning, and then continuously vacuumizing until the vacuum degree is 4.2 multiplied by 10-3When torr is carried out, opening No. 1-4 electron guns to smelt the bulk materials in the cooling bed, controlling the power of No. 1-4 electron guns to be 120kW, after smelting for 110min, closing the electron guns, cooling for 30min to obtain a condensed shell, and cooling for 30min along with the furnace;
(5) under vacuum degree of 2.8X 10-3During torr, pushing the briquetting materials in the feeding area into a smelting area, starting No. 1-7 electron guns to smelt the briquetting materials, controlling the power of No. 1-2 electron guns to be 80kW, the power of No. 3-4 electron guns to be 170kW, the power of No. 5 electron guns to be 130kW, the power of No. 6-7 electron beam guns to be 7kW, enabling the smelted titanium alloy liquid to flow into a crystallizer through a cooling bed, pulling ingots at the speed of 16mm/min, and continuously pushing, smelting and pulling the ingots until the briquetting materials are completely smelted;
(6) turning off No. 1-4 electron gun at vacuum degree3.2×10-3And (3) feeding the ingot by using No. 5-7 electron guns during torr, controlling the power of the No. 5-7 electron guns to be 70kW until all titanium alloy liquid flows into the crystallizer through the cooling bed, closing the No. 5-7 electron guns, stopping ingot pulling, cooling along with the furnace for 3.5 hours to obtain a Ti-Al-Nb-Zr-Mo alloy flat ingot, peeling and removing the head of the smelted flat ingot, performing component detection, wherein 6 parts are taken for each section, 2 parts are taken for each wide surface, 1 part is taken for each narrow surface, one section is taken at intervals of 100mm, and the detection result is shown in Table 2. Meets the requirements of GB/T3620.1-2016 titanium and titanium alloy mark and chemical composition, and has small average deviation of element content, indicating that the ingot has uniform composition.
TABLE 2
Element(s)
Al
Nb
Zr
Mo
Mean value of
6.02
3.00
1.98
1.02
Mean absolute deviation
0.09263
0.00247
0.001523
0.000321
Example 3
The cold cathode EB furnace smelting method of the forging-free direct rolling Ti-Al-Nb-Zr-Mo alloy ingot comprises the following steps:
(1) the materials are prepared according to the following mass ratio:
aluminum niobium alloy 5.7wt. -%)
Aluminum bean 4.77wt. -%)
Zirconium sponge 2.5wt. -%)
Aluminum molybdenum alloy 1.7wt. -%)
Titanium sponge 85.33 wt.%;
wherein: the granularity of the aluminum-niobium alloy is 1-10 mm, the content of aluminum is 47wt.%, and the content of Nb is 53 wt.%;
the content of Al in the aluminum beans is more than or equal to 99.9 wt.%;
the granularity of the sponge zirconium is 3-10 mm, and the Zr content is more than or equal to 99.4 wt.%;
the granularity of the aluminum-molybdenum alloy is 1-3 mm, the content of Al is 35wt.%, and the content of Mo is 65 wt.%;
(2) mixing the prepared materials in the step (1), taking a proper amount of the mixture as bulk materials, pressing the rest of the mixture into blocks, drying the blocks at 100 ℃ for 6 hours, and cooling the blocks along with a furnace to obtain pressed blocks;
(3) flatly paving the bulk material in the step (2) in an EB furnace cooling bed provided with a seven-rod electron gun, and then putting a proper amount of briquetting material in the step (2) into a feeding area of the EB furnace, wherein a circular crystallizer is adopted as a crystallizer of the EB furnace;
(4) closing the furnace door of the EB furnace, and vacuumizing to 4.4 multiplied by 10-3torr, then using hydrogen and oxygen to sweep the surface of the electron gun and dust in the furnace into the furnace for cleaning, and then continuously vacuumizing until the vacuum degree is 4.4 multiplied by 10-3When torr is carried out, opening No. 1-4 electron guns to smelt the bulk materials in the cooling bed, controlling the power of No. 1-4 electron guns to be 130kW, after smelting for 100min, closing the electron guns, cooling for 40min to obtain a condensed shell, and cooling for 35min along with the furnace;
(5) under vacuum degree of 3.5X 10-3During torr, pushing the briquetting material in the feeding area into the smelting area, and starting No. 1-7 electron guns to melt the briquetting materialSmelting, controlling the power of No. 1-2 electron guns to be 90kW, the power of No. 3-4 electron guns to be 180kW, the power of No. 5 electron guns to be 140kW and the power of No. 6-7 electron beam guns to be 80kW, enabling the smelted titanium alloy liquid to flow into a crystallizer through a cooling bed, pulling an ingot at the speed of 18mm/min, and continuously pushing, smelting and pulling the ingot in the way until the pressing material is completely smelted;
(6) turning off No. 1-4 electron gun at vacuum degree of 3.5 × 10-3And (3) feeding the ingot by using No. 5-7 electron guns during torr, controlling the power of the No. 5-7 electron guns to be 100kW until all titanium alloy liquid flows into the crystallizer through the cooling bed, closing the No. 5-7 electron guns, stopping ingot pulling, cooling for 4 hours along with the furnace to obtain a Ti-Al-Nb-Zr-Mo alloy round ingot, peeling the round ingot, performing component detection, taking the periphery of each section for detection, taking one section every 100mm, wherein the detection result is shown in table 3, the requirements of GB/T3620.1-2016 titanium alloy brands and chemical components are met, the average deviation of element contents in each section is small, and the ingot components are uniform.
TABLE 3
Element(s)
Al
Nb
Zr
Mo
Mean value of
6.13
3.06
2.00
0.98
Mean absolute deviation
0.10233
0.00165
0.00134
0.000234
As can be seen from the X-ray diffraction patterns of the corresponding examples 1, 2 and 3 in the attached figure 3, the round ingot smelted by the invention mainly consists of alpha-Ti phase.
As can be seen from the optical microscopic structure images of examples 1, 2 and 3 corresponding to FIGS. 4, 5 and 6, the cast ingot structure is a coarse sheet-like widmannstatten structure.
The round ingots smelted in the examples 1 and 3 are directly subjected to a cross piercing process without forging to obtain a large-diameter seamless tube, and the seamless tube is subjected to annealing treatment at about 900 ℃, and then mechanical property detection to obtain Rm=910MPa，Rp0.2=820MPa, a = 12.3%. The mechanical properties of the seamless tube obtained by using the existing seamless tube rolling technology, namely, casting ingots after multiple VAR smelting and inclined rolling perforation after forging are as follows: rm=880MPa，Rp0.2=785MPa, a = 12%. Therefore, the mechanical properties of the Ti-Al-Nb-Zr-Mo alloy round ingot obtained by the invention are beyond the level of the prior art, and the seamless tube obtained by direct cross piercing processing does not need a forging process.
Directly carrying out a hot rolling process on the slab ingot smelted in the example 2 without forging to obtain a 5mm plate, carrying out annealing treatment at 900 ℃, and carrying out mechanical property detection on the plate to obtain Rm=920MPa，Rp0.2=830MPa, a = 12.8%. The mechanical properties of the plate obtained by using the existing plate rolling technology, namely, casting ingots after multiple VAR smelting, forging and hot rolling are as follows after annealing: rm=880MPa，Rp0.2=780MPa, a = 12%. Therefore, the mechanical property of the Ti-Al-Nb-Zr-Mo alloy slab ingot obtained by the invention is beyond the level of the prior art without a forging process and by direct hot rolling processing.
The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and all the simple modifications, changes and equivalent structural changes of the above embodiments according to the technical spirit of the present invention still belong to the present invention.