CN1274456C - Preparation method of multicomponent composite rare earth-tungsten electrode material - Google Patents
Preparation method of multicomponent composite rare earth-tungsten electrode material Download PDFInfo
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- CN1274456C CN1274456C CN 200410080295 CN200410080295A CN1274456C CN 1274456 C CN1274456 C CN 1274456C CN 200410080295 CN200410080295 CN 200410080295 CN 200410080295 A CN200410080295 A CN 200410080295A CN 1274456 C CN1274456 C CN 1274456C
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Abstract
A preparation method of a multi-element composite rare earth-tungsten electrode material belongs to the field of rare earth refractory metal functional materials. Aiming at the problems that the existing multi-element composite rare earth-tungsten electrode has poor processing performance and low yield in industrial production, and the production cost is increased. Calculated as a percentage by weight of the final product, i.e. La2O3、Y2O3And CeO2The content of each rare earth oxide is 0.4-1.4%, the total content of the three rare earth oxides is 2.0-2.2%, and the balance is tungsten; weighing corresponding lanthanum nitrate, yttrium nitrate and cerium nitrate according to the weight content of each rare earth oxide to prepare a mixed solution, weighing corresponding APT (ammonium paratungstate) according to the weight content of tungsten, adding deionized water, stirring to obtain a uniform suspension, then adding the rare earth nitrate solution, stirring, evaporating and drying; finally, the average particle size of the powder is 1.2-1.4 μm after primary hydrogen reduction (550 ℃ C.) and secondary hydrogen reduction (850 ℃ C.). The process of APT calcination is omitted, the process is simplified, economy and energy conservation are realized, and the yield and the production stability are improved.
Description
Technical field:
The preparation method of multicomponent composite rare-earth-tungsten electrode material belongs to rare earth refractory metal field of functional materials.
Background technology:
Tungsten electrode is the critical material in inert gas-shielded arc welding and plasma welding, cutting, spraying, melting and the particular electrical light source, and using more at present is that thorium tungsten electrode (contains ThO
2) and the cerium tungsten electrode (contain CeO
2).Thorium tungsten electrode all will bring radiological hazard to environment and health in its production and use; The cerium tungsten electrode only can replace thorium tungsten electrode in the small dimension welding aspect tungsten electrode.
From nineteen seventies, countries in the world are developed multiple unit, composite tungsten electrode material in succession, and to substitute thorium tungsten, the novel rare-earth-tungsten electrode of developing (contains La with cerium tungsten electrode, lanthanum-tungsten electrode
2O
3), the yttrium tungsten electrode (contains Y
2O
3), and multicomponent composite rare-earth-tungsten electrode (contain La
2O
3, Y
2O
3, CeO
2) be main.Above-mentioned various rare-earth-tungsten electrode material all has merits and demerits separately: lanthanum-tungsten electrode arc stability and electrode anti-scorching performance when medium and small current work is good, but its poor processability, scaling loss is serious when big electric current uses; Arc pressure was big when the yttrium tungsten electrode used, and the anti-scorching performance of electrode is good when big current work, but its processing difficulties, arc stability is poor when little electric current uses; Though the comprehensive welding performance of multicomponent composite rare-earth-tungsten electrode can compare favourably with thorium tungsten electrode, can adapt to various operating modes with alternative thorium tungsten electrode, however its poor processability, yield rate is low in industrial production, has increased production cost.Thereby the production cost of great number makes it be difficult to substitute thorium tungsten electrode on a large scale.
In original application patent (CN1204696A, CN1203136A), the tungsten electrode processing technology is: rare earth nitrate aqueous solution and WO
3Mixing and doping through through a hydrogen reducing (500-540 ℃) and secondary hydrogen reducing (640-920 ℃), makes tungsten powder, repressed then, sintering, swage, chain draws the electrode that is processed into all size.This patent improves the technology in the commercial process, by the adjustment critical process, thereby the yield rate of multicomponent composite rare-earth-tungsten electrode and production stability is improved, thereby saves man-hour, cuts down the consumption of energy.
Summary of the invention:
The object of the present invention is to provide the preparation method of the multicomponent composite rare-earth-tungsten electrode material of a kind of "dead" pollution, serviceability and good processability.
The preparation method of multicomponent composite rare-earth-tungsten electrode material, its feature is made up of following steps:
1. press the end product percentage by weight and calculate, be i.e. La
2O
3, Y
2O
3And CeO
2Every kind of rare earth oxide content is 0.4-1.4%, the total content of three kinds of rare earth oxides be 2.0-2.2%. all the other be tungsten; Take by weighing corresponding lanthanum nitrate, yttrium nitrate, cerous nitrate amount by every kind of rare earth oxide weight content and be configured to mixed solution, take by weighing corresponding APT (para-tungstic acid ammonia) by the tungsten weight content, and the adding deionized water and stirring obtains uniform suspension, add above-mentioned rare earth nitrate solution then, stirring, evaporation drying;
2) after the evaporation drying through a hydrogen reducing, temperature is 550 ℃-700 ℃; Secondary hydrogen reducing, temperature are 850 ℃-1000 ℃ and make multicomponent composite rare-earth-tungsten electrode material that particle mean size is controlled at 1.2-1.4 μ m.
With the mixed-powder preparation processing method of tungsten routinely of reduction gained, carry out sintering, plastic working, be processed into the electrode of all size at last.
That the conventional preparation of tungsten manufacturing procedure is that compacting, pre-burning, incipient fusion sintering, cogging, 203,202,201, chain are drawn, twisted is straight, cut-out, polishing etc., obtains finished electrode at last.
The production of traditional electrode removes part producer (R﹠D institution) with WO
3, WO
2.9Deng being outside the raw material, great majority directly are raw materials for production with APT, oneself calcining preparation WO
3, WO
2.9Deng, prepare final products with rare earth nitrate doping, evaporation drying, twice hydrogen reducing after the conventional tungsten Mo prepares processing method then.Preparation technology of the present invention changes traditional doping process, directly as the product doped raw material, substitutes conventional WO with APT
3, WO
2.9Deng, same rare earth nitrate doping has saved the operation of APT calcining, has simplified technology, economical and energy saving.
In view of multiplex composite rare-earth element in reduction process has important refining effect to powder, by carrying out a large amount of tests of groping, determined the technological parameter of hydrogen reducing and secondary hydrogen reducing, one time the hydrogen reducing temperature is: 550-700 ℃; Secondary hydrogen reducing temperature is: 850-1000 ℃; What this was different from the original application patent goes back (one time hydrogen reducing temperature: 500-540 ℃ of raw parameter; Secondary hydrogen reducing temperature: 640-920 ℃).Under this reducing condition, can obtain particle mean size and be rare earth oxide-tungsten mixed-powder of 1.2-1.4 μ m, more favourable to the subsequent production operation.And use the method, rare earth oxide is disperse degree height in tungsten powder, is more evenly distributed.Powder is gone back the influence of raw parameter in reduction process less, and the granularity fluctuation is less within a certain period of time, helps the control of technology.In the following process process, can improve the yield rate of product.
Utilize the multicomponent composite rare-earth-tungsten electrode of this method preparation not only to have better machining property, high rate of finished products, and welding performance is good, combination property has surpassed thorium tungsten, cerium tungsten electrode.
Description of drawings
Fig. 1. multicomponent composite rare-earth-tungsten electrode static characteristic of arc curve
The specific embodiment
Comparative Examples 1:
APT is prepared into WO through calcining
3, with WO
3Powder is put into the pot that mixes, and adds the 0.44%La that presses the end product percentage by weight
2O
3, 1.32%Y
2O
3, 0.44%CeO
2Take by weighing the mixed solution of lanthanum nitrate, yttrium nitrate, cerous nitrate (according to oxide weight conversion nitrate amount) preparation, fully stir evaporate to dryness and drying after, obtain mixed-powder, mixed-powder is once reduced (temperature: 520 ℃ in reduction furnace; Time: 2h), secondary reduction (temperature: 800 ℃; Time: 4h), make the mixed-powder of rare earth oxide and tungsten powder, particle mean size is 1.7 μ m.After powder after the reduction added glycerine, alcohol mixings 1h by a certain percentage,, suppress (filling amount: 680g; Compacting pressure: 6.5MPa), after the pre-burning (temperature: 1150 ℃), incipient fusion sintering (being incubated 30min under 90% blowout current), that the processing of swaging, chain draw, twist is straight, be processed into all size tungsten electrode after cutting off and polishing.The finished product rate is shown in table 1. under each operation of its process segment:
Table 1.WO
3With yield rate under each operation of rare earth nitrate doping process segment
| Operation | 203 | 202 | 201 | Finished product Φ 2.4*175 | The process segment yield rate |
| Output capacity | 95.9％ | 96.5％ | 95.7％ | 67.9％ | 60.1％ |
Example 1:
Whenever get APT powder 1Kg, add deionized water 1000ml, stir, put into the pot that mixes, add the 0.44%La that presses the end product percentage by weight
2O
3, 1.32%Y
2O
3, 0.44%CeO
2Take by weighing the mixed solution of lanthanum nitrate, yttrium nitrate, cerous nitrate (according to oxide weight conversion nitrate amount) preparation, after fully stirring evaporate to dryness and drying, obtain mixed-powder, mixed-powder is once reduced in reduction furnace (temperature: 550 ℃), behind the secondary reduction (temperature: 850 ℃), make the mixed-powder of rare earth oxide and tungsten powder, particle mean size is 1.2 μ m.After powder after the reduction added glycerine, alcohol mixings 1h by a certain percentage,, suppress (filling amount: 680g; Compacting pressure: 6.5MPa), after the pre-burning (temperature: 1150 ℃), incipient fusion sintering (being incubated 30min under 90% blowout current), that the processing of swaging, chain draw, twist is straight, be processed into all size tungsten electrode after cutting off and polishing.The finished product rate is shown in table 2. under each operation of its process segment:
Yield rate under table 2.APT and each operation of rare earth nitrate doping process segment
| Operation | 203 | 202 | 201 | Finished product Φ 2.4*175 | Total yield rate of process segment |
| Output capacity | 98.0％ | 99.7％ | 99.7％ | 72.5％ | 70.6％ |
Can see that the yield rate of product is enhanced, save man-hour, energy consumption, reduce production cost, make product have more the market competitiveness.
Example 2:
Whenever get APT powder 1Kg, add deionized water 1000ml, stir, put into the pot that mixes, add the .55%La that presses the end product percentage by weight
2O
3, 1.10%Y
2O
3, 0.55%CeO
2Take by weighing the mixed solution of lanthanum nitrate, yttrium nitrate, cerous nitrate (according to oxide weight conversion nitrate amount) preparation, after fully stirring evaporate to dryness and drying, obtain mixed-powder, mixed-powder is once reduced (temperature: 600 ℃), secondary reduction temperature in reduction furnace: 900 ℃) after, make the mixed-powder of rare earth oxide and tungsten powder, particle mean size is 1.3 μ m.。After powder after the reduction added glycerine, alcohol mixings 1h by a certain percentage,, suppress (filling amount: 680g; Compacting pressure: 6.5MPa), after the pre-burning (temperature: 1150 ℃), incipient fusion sintering (being incubated 30min under 90% blowout current), that the processing of swaging, chain draw, twist is straight, be processed into all size tungsten electrode after cutting off and polishing.
Yield rate under table 3.APT and each operation of rare earth nitrate doping process segment
| Operation | 203 | 202 | 201 | Finished product Φ 2.4*175 | Total yield rate of process segment |
| Output capacity | 99.0％ | 98.7％ | 99.5％ | 71.3％ | 69.3％ |
Example 3:
Whenever get APT powder 1Kg, add deionized water 1000ml, stir, put into the pot that mixes, add the 0.73%La that presses the end product percentage by weight
2O
3, 0.73%Y
2O
3, 0.73%CeO
2Take by weighing the mixed solution of lanthanum nitrate, yttrium nitrate, cerous nitrate (according to oxide weight conversion nitrate amount) preparation, fully stir evaporate to dryness and drying after, obtain mixed-powder, mixed-powder is once reduced (temperature: 700 ℃ in reduction furnace; ), the secondary reduction temperature: 1000 ℃) after, make the mixed-powder of rare earth oxide and tungsten powder, particle mean size is 1.4 μ m.。After powder after the reduction added glycerine, alcohol mixings 1h by a certain percentage,, suppress (filling amount: 680g; Compacting pressure: 6.5MPa), after the pre-burning (temperature: 1150 ℃), incipient fusion sintering (being incubated 30min under 90% blowout current), that the processing of swaging, chain draw, twist is straight, be processed into all size tungsten electrode after cutting off and polishing.
Yield rate under table 4.APT and each operation of rare earth nitrate doping process segment
| Operation | 203 | 202 | 201 | Finished product Φ 2.4*175 | Total yield rate of process segment |
| Output capacity | 98.6％ | 98.0％ | 99.1％ | 72.5％ | 69.4％ |
Below electrode welding performance in above three examples is tested, and the thorium tungsten electrode of same size is carried out the welding performance test doing contrast, test job is welded test center-Harbin institute of welding in country and is carried out, and its result is as follows:
1. electrode is numbered:
Electrode numbering 1#: contain 0.44% (weight) La
2O
3, 1.32% (weight) Y
2O
3, 0.44% (weight) CeO
2, all the other are W.
Electrode numbering 2#: contain 0.55% (weight) La
2O
3, 1.10% (weight) Y
2O
3, 0.55% (weight) CeO
2, all the other are W.
Electrode numbering 3#: contain 0.73% (weight) La
2O
3, 0.73% (weight) Y
2O
3, 0.73% (weight) CeO
2, all the other are W.
Electrode numbering 4#: contain 2.2% (weight) ThO
2Thorium tungsten electrode (Beijing Tungsten and Molybdenum Materials Factory's product), this electrode is electrode as a comparison.
2. striking performance:
(1) experiment condition
The tungsten filament diameter is Φ 2.4mm, tip cone angle 45 degree, and argon flow amount is 8L/min, electrode extension 3mm, arc length 3mm.Adopt the straight polarity direct current mode, tungsten filament is a negative electrode, and anode is the water-cooled red copper.
(2) experimental facilities
IGCT control DC TIG welding connects power supply, model YC-300TSPVTA.Digital multimeter, model Bestillingsnr is numbered 1287.Electronic balance AEL-200.
(3) experimental result
The test result of 1#, 2#, 3#, 4# electrode: when 30A, 80A, 150A welding current, each repeats striking 30 times, and arcing initiation success rate reaches 100%, the striking function admirable.
3. anti-scorching performance:
(1) experiment condition
Electrode diameter is Φ 2.4mm, and used anode is the water-cooled red copper in the test, welding current 180A, and arc duration 20min, electrode extension 3mm, arc length 3mm, argon flow amount 8L/min, current type and polarity are straight polarity direct current.
(2) experimental facilities
IGCT control DC TIG welding connects power supply, model YC-300TSPVTA.Slide measure, model 025, numbering 096583.Electronic balance AEL-200.
(3) result of the test
Test result sees Table 3.
The anti-scorching performance of table 3. multicomponent composite rare-earth-tungsten electrode
| Sample number | 1# | 2# | 3# | 4# |
| Scaling loss amount (mg) | 0.4 | 0.95 | 0.45 | 1.65 |
Wherein the average scaling loss amount minimum of 1# tungsten electrode has best anti-scorching performance, and the anti-scorching performance of 1#, 2#, three kinds of multicomponent composite rare-earth-tungsten electrodes of 3# all is better than the 4# thorium tungsten electrode.
4. static characteristic of arc curve
(1) experiment condition
The tungsten filament diameter is Φ 2.4mm, tip cone angle 45 degree, and argon flow amount is 8L/min, electrode extension 3mm, arc length 3mm.Adopt the straight polarity direct current mode, tungsten filament is a negative electrode, and anode is the water-cooled red copper.
(2) experimental facilities
IGCT control DC TIG welding connects power supply, model YC-300TSPVTA.Digital multimeter, model Bestillingsnr is numbered 1287.Electronic balance AEL-200.
(3) experimental technique and result
After the arcing, rapidly loop current being transferred to 20A, is 20A at electric current by from small to large order successively, 30A, 40A, 50A, 60A, 80A, 100A is during 140A, after treating that arc burning is stable, measure pairing steady-state current, magnitude of voltage, make the static characteristic of arc curve (VA characteristic curve) of 1#, 2#, 3#, 4# electrode respectively according to the voltage that records, current value, as shown in Figure 1.
As can see from Figure 1, many 1#, its static characteristic of arc curve of 2# electrode all are better than thorium tungsten electrode, and 3# electrode arc transfer curve and thorium tungsten electrode are suitable.
By top welding performance test result, can know that the comprehensive welding performance of multicomponent composite rare-earth-tungsten electrode has has all met and exceeded thorium tungsten electrode, can under various operating modes, substitute thorium tungsten electrode.
Claims (1)
1, the preparation method of multicomponent composite rare-earth-tungsten electrode material is characterized in that, is made up of following steps:
1) presses the end product percentage by weight and calculate, be i.e. La
2O
3, Y
2O
3And CeO
2Every kind of rare earth oxide content is 0.4-1.4%, and the total content of these three kinds of rare earth oxides is 2.0-2.2%, and all the other are tungsten; Take by weighing corresponding lanthanum nitrate, yttrium nitrate, cerous nitrate amount by every kind of rare earth oxide weight content and be configured to mixed solution, take by weighing corresponding para-tungstic acid ammonia by the tungsten weight content, and the adding deionized water and stirring obtains uniform suspension, add above-mentioned rare earth nitrate solution then, stirring, evaporation drying;
2) after the evaporation drying through a hydrogen reducing, temperature is 550 ℃-700 ℃; Secondary hydrogen reducing, temperature are 850 ℃-1000 ℃ and make multicomponent composite rare-earth-tungsten electrode material that particle mean size is controlled at 1.2-1.4 μ m.
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| CN100446898C (en) * | 2007-05-11 | 2008-12-31 | 北京工业大学 | Method for sintering multielement composite electron emission material of rare earth tungsten |
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