CN112025069A - Electron beam welding process for dissimilar metals of titanium alloy and niobium alloy - Google Patents
Electron beam welding process for dissimilar metals of titanium alloy and niobium alloy Download PDFInfo
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- CN112025069A CN112025069A CN202010689945.4A CN202010689945A CN112025069A CN 112025069 A CN112025069 A CN 112025069A CN 202010689945 A CN202010689945 A CN 202010689945A CN 112025069 A CN112025069 A CN 112025069A
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K15/00—Electron-beam welding or cutting
- B23K15/0033—Preliminary treatment
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K15/00—Electron-beam welding or cutting
- B23K15/0046—Welding
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K2103/00—Materials to be soldered, welded or cut
- B23K2103/18—Dissimilar materials
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Abstract
The invention provides an electron beam welding process for dissimilar metals of titanium alloy and niobium alloy, which mainly comprises the following steps: (1) cleaning before welding; (2) adjusting the position of an impact point between the electron beam and the basic parent metal; (3) and adjusting welding process parameters. The invention provides an electron beam welding scheme for solving the problem of dissimilar metals of titanium alloy and niobium alloy by selecting a cleaning process before welding, welding process parameters and the position of an electron beam impact point, realizes the reliable connection of the two metals, has the strength after welding reaching more than 90 percent of the strength of a niobium side parent material, and has important significance for reducing the cost and the weight of the whole structure.
Description
Technical Field
The invention belongs to the technical field of welding, and particularly relates to an electron beam welding process for dissimilar metals of titanium alloy and niobium alloy.
Background
Niobium alloys are mainly used for the manufacture of thrust chambers and nozzle extensions for liquid and solid rocket engines due to their good high temperature properties. In some space engines, the thrust chamber body is usually made of niobium alloy, while the head is usually made of titanium alloy in consideration of cost and weight, and the whole body can be formed by welding niobium-hafnium alloy and titanium alloy. The existing welding technology has the disadvantages of weak welding strength and high cost for achieving ideal welding strength.
Disclosure of Invention
In order to solve the problems, the invention provides an electron beam welding process for titanium alloy and niobium alloy dissimilar metal, which realizes the reliable connection of the titanium alloy and the niobium alloy dissimilar metal, and the connection strength reaches more than 90% of the strength of a niobium alloy base metal.
The technical scheme adopted by the invention is as follows: an electron beam welding process for dissimilar metals of titanium alloy and niobium alloy comprises the following steps:
step 1, mechanically cleaning the alloy surface before welding, cleaning the surfaces of titanium alloy and niobium alloy parts by mechanical processing or manual polishing, and then cleaning by alcohol;
step 4, drying, and drying the parts by using hot air at the temperature of 30-75 ℃;
step 5, selecting the impact point position of the electron beam and the basic parent metal, wherein the electron beam deflects the impact point of the electron beam to one side of the niobium alloy in a deflection mode;
step 6, welding, namely adjusting process parameters according to the thickness of the part to be welded, wherein the welding voltage is not less than 60KV, the welding beam current is 18-52 mA, and the welding speed is 600-720 mm/min;
and 7, processing the surface of the welding seam by adopting decorative welding.
Further optimizing, the acid solution in step 2 is hydrofluoric acid, nitric acid and sulfuric acid aqueous solution.
And (5) further optimizing, wherein the electron beam impact point deviates to one side of the niobium alloy by 0.3-0.6 mm.
Further optimization, the focusing current adopts subsurface focusing.
The invention has the beneficial effects that:
1. by cleaning before welding, the performance of the alloy is ensured, and the performance of a welding seam is improved;
2. the uniformity of the weld joint structure is improved by selecting the position of the impact point;
3. by optimizing the welding process parameters, the reliable connection of the two alloys is realized, and the strength after welding reaches over 90 percent of that of the niobium side parent material.
Drawings
FIG. 1 is a schematic view of an electron beam welding process for dissimilar metals of titanium alloy and niobium alloy;
reference numerals: 1-titanium alloy 2-niobium alloy 3-electron beam 511-electron beam welding code
Detailed Description
The invention is further described below with reference to the accompanying drawings:
cleaning process before welding
Niobium and titanium are active metals and are easy to react with elements such as nitrogen, hydrogen, oxygen and the like at a certain temperature. Titanium absorbs a large amount of hydrogen at 300 ℃, and when the beta titanium alloy containing hydrogen is eutectoically decomposed and the alpha titanium containing hydrogen is cooled, TiH can be precipitated to make the alloy brittle. Niobium is relatively stable at room temperature, does not react with acids (including aqua regia) at room temperature, and reacts with many non-metals (e.g., oxygen, chlorine) when heated. Niobium absorbs hydrogen at 250 c and nitrogen at 300 c, thereby degrading weld performance.
Therefore, both alloy parts are subjected to severe pre-weld cleaning prior to welding. The pre-weld cleaning includes mechanical cleaning and chemical cleaning. For mechanical cleaning, mechanical processing or manual polishing is used, and then alcohol is used for cleaning; the chemical cleaning is mainly performed by using an acid solution, and the acid solution generally consists of hydrofluoric acid, nitric acid, sulfuric acid and water. Washing the pickled vegetable seeds by running water, rinsing the pickled vegetable seeds by distilled water, and drying the pickled vegetable seeds by hot air at the temperature of 30-75 ℃.
Secondly, selecting the position of the impact point of the electron beam current 3 and the basic parent metal
Niobium alloy 2 has a melting point about 800 c higher than that of titanium alloy 1, and when welding, one side of titanium alloy 1 is first melted, while niobium alloy 2 is partially or subsequently melted, which reduces the uniformity of the weld structure and affects the weld performance. Therefore, when the heat transfer performance of the two metals is not greatly different, the electron beam impact point is deviated to one side of the high melting point metal, namely to one side of the niobium alloy 2, as shown in fig. 1, the electron beam 3 is deviated to one side of the niobium alloy 2, and the impact point of the electron beam 3 and the base metal is deviated to one side of the niobium alloy 2 by 0.3-0.6 mm generally according to the thickness of the alloy part.
Optimization of electron beam welding process
And adjusting process parameters according to the thickness of the material to be welded, wherein the adjusted process parameters comprise welding voltage, welding beam current and welding speed. The welding speed is not too fast to ensure the sufficient fusion of the niobium alloy 2 and the titanium alloy 1, and the focusing current adopts subsurface focusing to ensure the good formation and the complete penetration of the welding line. The electron beam current 3 adopts a deflection mode to ensure the uniformity of the weld joint structure. After the welding is completed, the surface of the welded seam is treated by using a modified welding method, as shown in fig. 1, an electron beam welding code 511 indicates that the welding method is vacuum electron beam welding.
Example one
Selecting a plurality of groups of alloy test pieces with the thickness of 2.0mm, wherein the welding voltage is 60KV, the welding speed is 660mm/min, the distance of the niobium side of an impact point is 0.5mm, and the welding beam current is respectively as follows: 12mA, 16mA, 18mA, 20mA, 23mA, 25mA, 28mA 30mA, 33mA and 35 mA. After a post-welding tensile test, the welding beam current is excellent in welding strength within the range of 18-30mA, and meets the requirements.
Example two
Selecting a plurality of groups of alloy test pieces with the thickness of 2.5mm, wherein the welding voltage is 60KV, the welding speed is 660mm/min, the distance of the niobium side of an impact point is 0.5mm, and the welding beam current is respectively as follows: 22mA, 25mA, 28mA, 32mA, 35mA, 38mA, 40mA 42mA, 45mA, 48 mA. After a post-welding tensile test, the welding beam current is excellent in welding strength within the range of 28-42mA, and meets the requirement.
EXAMPLE III
Selecting a plurality of groups of alloy test pieces with the thickness of 4.0mm, wherein the welding voltage is 60KV, the welding speed is 660mm/min, the distance of the niobium side of an impact point is 0.5mm, and the welding beam current is respectively as follows: 32mA, 35mA, 38mA, 40mA, 42mA, 45mA, 48mA 52mA, 55mA, 58 mA. After a post-welding tensile test, the welding beam current is excellent in welding strength within the range of 40-52mA, and meets the requirement.
Example four
Selecting a plurality of groups of alloy test pieces with the thickness of 5.0mm, wherein the welding voltage is 60KV, the welding speed is 660mm/min, the distance of the niobium side of an impact point is 0.5mm, and the welding beam current is respectively as follows: 32mA, 35mA, 38mA, 40mA, 42mA, 45mA, 48mA 52mA, 55mA, 58 mA. After a post-welding tensile test, the welding beam current is excellent in welding strength within the range of 40-52mA, and meets the requirement.
EXAMPLE five
Selecting a plurality of groups of alloy test pieces with the thickness of 2.0mm, wherein the welding beam current is 25mA, the welding speed is 660mm/min, the niobium side distance of an impact point is 0.5mm, and the welding voltage is respectively as follows: 45KV, 50KV, 55KV, 60KV, 65KV, 70KV, 85KV, 100KV, 125KV and 150 KV. After the post-welding tensile test, the welding strength is excellent when the welding voltage reaches or exceeds 60KV, and the requirement is met.
EXAMPLE six
Selecting a plurality of groups of alloy test pieces with the thickness of 2.5mm, wherein the welding beam is 35mA, the welding speed is 660mm/min, the niobium side distance of an impact point is 0.5mm, and the welding voltage is respectively as follows: 45KV, 50KV, 55KV, 60KV, 65KV, 70KV, 85KV, 100KV, 125KV and 150 KV. After the post-welding tensile test, the welding strength is excellent when the welding voltage reaches or exceeds 60KV, and the requirement is met.
EXAMPLE seven
Selecting a plurality of groups of alloy test pieces with the thickness of 4.0mm, wherein the welding beam current is 45mA, the welding speed is 600mm/min, the niobium side distance of an impact point is 0.5mm, and the welding voltage is respectively as follows: 45KV, 50KV, 55KV, 60KV, 65KV, 70KV, 85KV, 100KV, 125KV and 150 KV. After the post-welding tensile test, the welding strength is excellent when the welding voltage reaches or exceeds 60KV, and the requirement is met.
Example eight
Selecting a plurality of groups of alloy test pieces with the thickness of 5.0mm, wherein the welding beam current is 45mA, the welding speed is 600mm/min, the niobium side distance of an impact point is 0.5mm, and the welding voltage is respectively as follows: 45KV, 50KV, 55KV, 60KV, 65KV, 70KV, 85KV, 100KV, 125KV and 150 KV. After the post-welding tensile test, the welding strength is excellent when the welding voltage reaches or exceeds 60KV, and the requirement is met.
Example nine
Selecting a plurality of groups of alloy test pieces with the thickness of 2.0mm, wherein the welding voltage is 60KV, the welding beam current is 25mA, the side distance of the impact point niobium is 0.5mm, and the welding speed is respectively as follows: 560mm/min, 600mm/min, 630mm/min, 660mm/min, 690mm/min, 720mm/min, 760mm/min, 790 mm/min. After the tensile test after welding, the welding strength is excellent when the welding speed is 660-.
Example ten
Selecting a plurality of groups of alloy test pieces with the thickness of 2.5mm, wherein the welding voltage is 60KV, the welding beam current is 35mA, the distance of the niobium side of an impact point is 0.5mm, and the welding speed is respectively as follows: 560mm/min, 600mm/min, 630mm/min, 660mm/min, 690mm/min, 720mm/min, 760mm/min, 790 mm/min. After the tensile test after welding, the welding strength is excellent when the welding speed is 600-720mm/min, thereby meeting the requirement.
EXAMPLE eleven
Selecting a plurality of groups of alloy test pieces with the thickness of 4.0mm, wherein the welding voltage is 60KV, the welding beam current is 45mA, the distance of the niobium side of an impact point is 0.5mm, and the welding speed is respectively as follows: 560mm/min, 600mm/min, 630mm/min, 660mm/min, 690mm/min, 720mm/min, 760mm/min, 790 mm/min. After the tensile test after welding, the welding strength is excellent when the welding speed is 600-720mm/min, thereby meeting the requirement.
Example twelve
Selecting a plurality of groups of alloy test pieces with the thickness of 5.0mm, wherein the welding voltage is 60KV, the welding beam current is 45mA, the distance of the niobium side of an impact point is 0.5mm, and the welding speed is respectively as follows: 560mm/min, 600mm/min, 630mm/min, 660mm/min, 690mm/min, 720mm/min, 760mm/min, 790 mm/min. After the tensile test after welding, the welding strength is excellent when the welding speed is 600-720mm/min, thereby meeting the requirement.
EXAMPLE thirteen
Selecting a plurality of groups of alloy test pieces with the thickness of 2.0mm, wherein the welding voltage is 60KV, the welding beam current is 25mA, the welding speed is 660mm/min, and the distances of the impact points on the niobium side are respectively as follows: 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8 mm. After the post-welding tensile test, the welding strength is excellent when the distance of the impact point on the niobium side is 0.3-0.5mm, and the requirement is met.
Example fourteen
Selecting a plurality of groups of alloy test pieces with the thickness of 2.5mm, wherein the welding voltage is 60KV, the welding beam current is 35mA, the welding speed is 660mm/min, and the distances of the impact points on the niobium side are respectively as follows: 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8 mm. After the post-welding tensile test, the welding strength is excellent when the distance of the impact point on the niobium side is 0.4-0.6mm, and the requirement is met.
Example fifteen
Selecting a plurality of groups of alloy test pieces with the thickness of 4.0mm, wherein the welding voltage is 60KV, the welding beam current is 45mA, the welding speed is 600mm/min, and the distances of the impact points on the niobium side are respectively as follows: 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8 mm. After the post-welding tensile test, the welding strength is excellent when the distance of the impact point on the niobium side is 0.4-0.6mm, and the requirement is met.
Example sixteen
Selecting a plurality of groups of alloy test pieces with the thickness of 5.0mm, wherein the welding voltage is 60KV, the welding beam current is 45mA, the welding speed is 600mm/min, and the distances of the impact points on the niobium side are respectively as follows: 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8 mm. After the post-welding tensile test, the welding strength is excellent when the distance of the impact point on the niobium side is 0.4-0.6mm, and the requirement is met.
Through tests, welding process parameters are optimized, welding strength can be obviously improved by selecting a proper range of the welding parameters, and the conclusion is as shown in the following table, wherein table 1 lists the welding process parameters of electron beam welding structures of titanium alloy 1 and niobium alloy 2 with different thicknesses.
TABLE 1 Electron Beam welding Process parameters for titanium alloy 1 and niobium alloy 2 of different thicknesses
TABLE 22.5 mm thick mechanical properties of titanium alloy 1 and niobium alloy 2 after welding
It can be seen from table 2 that the present invention proposes a solution for electron beam welding of dissimilar metals of titanium alloy 1 and niobium alloy 2 by selecting a cleaning process before welding, welding process parameters and an electron beam impact point position, and realizes reliable connection of the two metals, the strength after welding reaches more than 90% of the strength of the niobium side parent material, when the temperature does not exceed 400 ℃, the fracture position is on the niobium side parent material, which indicates that the strength performance of the weld is excellent, and when the temperature reaches 800 ℃, the fracture position occurs in the fusion zone, which indicates that the weld has a certain high temperature strength.
Claims (4)
1. An electron beam welding process for dissimilar metals of titanium alloy and niobium alloy is characterized by comprising the following steps:
step 1, mechanically cleaning the alloy surface before welding, cleaning the surfaces of titanium alloy and niobium alloy parts by mechanical processing or manual polishing, and then cleaning by alcohol;
step 2, surface chemical cleaning of the alloy before welding, and surface cleaning of titanium alloy and niobium alloy parts by adopting an acidic solution;
step 3, cleaning, namely washing the parts by using running water, and then rinsing the parts by using distilled water;
step 4, drying, and drying the parts by using hot air at the temperature of 30-75 ℃;
step 5, selecting the impact point position of the electron beam and the basic parent metal, wherein the electron beam deflects the impact point of the electron beam to one side of the niobium alloy in a deflection mode;
step 6, welding, namely adjusting process parameters according to the thickness of the part to be welded, wherein the welding voltage is not less than 60KV, the welding beam current is 18-52 mA, and the welding speed is 600-720 mm/min;
and 7, processing the surface of the welding seam by adopting decorative welding.
2. An electron beam welding process for dissimilar metals of titanium alloy and niobium alloy according to claim 1, wherein: and 2, the acidic solution is hydrofluoric acid, nitric acid and sulfuric acid aqueous solution.
3. An electron beam welding process for dissimilar metals of titanium alloy and niobium alloy according to claim 1, wherein: and 5, deviating the electron beam impact point to one side of the niobium alloy by 0.3-0.6 mm.
4. An electron beam welding process for dissimilar metals of titanium alloy and niobium alloy according to claim 1, wherein: the focusing current employs subsurface focusing.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115121928A (en) * | 2022-08-01 | 2022-09-30 | 宁波江丰电子材料股份有限公司 | Welding method of tantalum-titanium dissimilar metal |
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| GB924886A (en) * | 1961-01-07 | 1963-05-01 | Heraeus Gmbh W C | Improvements in or relating to the melting of metal |
| CN101274388A (en) * | 2008-05-05 | 2008-10-01 | 西北有色金属研究院 | Electro-beam welding method of niobium alloy and titanium alloy thick plate |
| CN107414279A (en) * | 2017-09-19 | 2017-12-01 | 南昌航空大学 | A kind of connection method for slab TiNi alloy and titanium alloy dissimilar materials |
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2020
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|---|---|---|---|---|
| GB924886A (en) * | 1961-01-07 | 1963-05-01 | Heraeus Gmbh W C | Improvements in or relating to the melting of metal |
| CN101274388A (en) * | 2008-05-05 | 2008-10-01 | 西北有色金属研究院 | Electro-beam welding method of niobium alloy and titanium alloy thick plate |
| CN107414279A (en) * | 2017-09-19 | 2017-12-01 | 南昌航空大学 | A kind of connection method for slab TiNi alloy and titanium alloy dissimilar materials |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN115121928A (en) * | 2022-08-01 | 2022-09-30 | 宁波江丰电子材料股份有限公司 | Welding method of tantalum-titanium dissimilar metal |
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Application publication date: 20201204 |