In order to take power system with excellent performance and no radioactive contamination of tungsten electrode, tungsten trioxide powder of lanthanum oxide was added , after reduction, vertical melt , swaging , drawing obtained Φ2.7mm lanthanum tungsten electrode with the same specifications cerium tungsten, tungsten thorium power level for the electrical performance comparison , while a scanning electron microscope , measuring the electrical performance test tungsten lanthanum , cerium tungsten electrodes lanthanum , cerium content and microstructure of the distribution . The results showed that: Lanthanum tungsten electrode tungsten electrical performance than cerium , thorium tungsten ; lanthanum oxide, lanthanum tungsten migration rate , evaporation rate is low , to form a better lap dovetail organization with high temperature creep performance.

Lanthanum tungsten electrode manufacturing method with the use of lanthanum nitrate lanthanum tungsten-coated powder preparation methods, in common with the reduction of time is prolonged, the lanthanum average particle size of the tungsten powder coated grow . The lanthanum nitrate reduction by more sensitive to the impact of time , the average increase in grain size range. The method of the present invention , lanthanum tungsten-coated powder particle size by reducing the influence of time fluctuation is small, in the particle size range within a certain time basically converge. These two different approaches are eventually encapsulated in the form of La2O3 tungsten , plays the role of grain refinement , but due to their respective decomposition temperature differences inevitably lead to the difference in outcome . The method of the present invention , the specific process conditions, the particle size range of less volatile , and in accordance with repression, burn process requirements , which can effectively reduce gasification process , helping to eliminate harmful gases nitrogen oxide pollution is a more ideal method for preparing lanthanum tungsten electrodes .


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Case 1.

Take APT powder 1000 grams , adding 1000 grams of water , stir , add 60 grams of lanthanum lanthanum continue to stir , steam heated and concentrated , dried and sieved to obtain lanthanum tungsten-coated powder . The prepared lanthanum tungsten-coated powder loaded boat , put through a hydrogen reduction furnace , heated to conduct a reduction temperature of 600 ℃, the reduction time is 2 hours. Then continue to a second temperature to 800 ℃ restore , restore time control in 3.5 hours , the hydrogen flow rate during 0.5m3 / h. Then lanthanum tungsten-coated powder into alcohol , glycerin lubricant mixing one hour after sifting , pressing, burn , pressing, calcining process conditions: loading powder quantity :650-700g / root , repression burn pressure : 60 ~ 80MPa sintering temperature : 1050 ~ 1400 ℃, sintering time : 40 ~ 60 minutes. Then using a conventional vertical melt sintering process , process conditions are as follows : vertical melt temperature : 2600 ~ 3000 ℃, holding time : 20 minutes Cooling time: 2 minutes , cooling time: 3 minutes . Finally finished processing , vertical melt billets after passing inspection , will be qualified blanks , into protected with a hydrogen furnace , then the sample temperature for 20 minutes to process requirements , as required swaging , and then processed to the desired product with different specifications .

Example 2.

Take tungsten powder 700 g , add 700 grams of water , stir , add 55 grams of lanthanum lanthanum continue to stir , steam heated and concentrated , dried and sieved to obtain lanthanum tungsten-coated powder . The prepared lanthanum tungsten-coated powder loaded boat , put through a hydrogen reduction furnace , heated to conduct a reduction temperature of 650 ℃, the reduction time 2 hours . Then continue to a second temperature to 900 ℃ restore , restore time control in four hours , during the hydrogen flow 0.5m3 / h. Other conditions are the same in Example 1 .

Example 3.

Take tungsten trioxide powder 850 g , add 850 grams of water , stir , add 58 grams of lanthanum lanthanum , continue stirring evenly, by steam heated and concentrated , dried and sieved to obtain lanthanum tungsten-coated powder . The prepared lanthanum tungsten-coated powder loaded boat , put through a hydrogen reduction furnace , heating get in a reduction temperature of 670 ℃, the reduction time 2.5 hours . Continue to warm to 970 ℃ for secondary reduction, reduction time control in five hours , during the hydrogen flow 0.5m3 / h. Other conditions are the same in Example 1 .


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1. Experimental Materials : APT, tungsten oxide , tungsten powder: purity of more than 99.5% ( by weight ) ; iron : content is less than 0.0025% ; Molybdenum : less than 0.01 % ; arsenic: content is less than 0.0025% ; alumina : content is less than 0.005% ; phosphorus: content is less than 0.01% ; oxidation residue traces of material size APT: 25 ~ 36μm; WO3: 8 ~ 9μm; tungsten powder : 2 ~ 2.5μm;

2. Lanthanum tungsten-coated powder Preparation: Materials used by Solid : H2O = 1:1 ratio mixing thoroughly stirred and then the prepared tungsten electrodes grade requirement ratio quantity of lanthanum acetate was added uniformly continued mixing uniformly , heated and concentrated by means of steam , drying, sieving step before being sent to restore.

3 Restore the prepared lanthanum tungsten-coated powder loaded boat after reduction furnace temperature decomposition and a secondary reduction, a reduction temperature of 600 ~ 700 ℃ , the restore time is 2 to 3 hours . Second reduction temperature : 800 ~ 970 ℃, time is 3-5 hours. These processes are carried out in a hydrogen atmosphere , the hydrogen flow control : 0.5 ~ 1.5m3 / h.

4 It will be restored after pressure type lanthanum tungsten powder coated aggregate batches for 2-5 hours , then physical and chemical analysis , to be lanthanum tungsten-coated powder has an average particle size of lanthanum oxide content and uniformity are in compliance with technical requirements , the addition of alcohol , glycerine lubricant mixing one hour after sifting , pressing, burn , pressing, calcining process conditions: loading powder quantity :650-700g / root , repression burn pressure : 60 ~ 80MPa, the sintering temperature : 1050 ~ 1400 ℃, sintering time : 40 ~ 60 minutes.

5 Vertical melt using conventional vertical melt sintering process , process conditions are as follows : vertical melt temperature : 2600 ~ 3000 ℃, holding time : 20 minutes Cooling time: 2 minutes , cooling time: 3 minutes .

6 Finished processing vertical melt billets after passing inspection , will be qualified blanks , into the furnace with hydrogen protection , according to the technological requirements of the sample temperature for 20 minutes , according to the requirements swaging , and then processed to different specifications of the finished product desired .


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Lanthanum tungsten electrode manufacturing method, comprising lanthanum tungsten-coated powder preparation , reduction, pressure type , melt down , and finished processing the preform , characterized in that : a. Using lanthanum acetate and including APT, tungsten and tungsten trioxide powder the solid material into a slurry with water mixed to prepare a lanthanum tungsten-coated powder ; b. lanthanum tungsten-coated powder decomposition of lanthanum was conducted in a hydrogen atmosphere , a reduction temperature is controlled at 600 ~ 700 ℃, time 2-3 hours , the second reduction temperature controlled at 800-970 ℃, reduction time 3-5 hours , the hydrogen flow control during the 0.5-2.0m3 / h.

The process of the invention include use of lanthanum acetate was added to APT, tungsten and tungsten trioxide powder of solid material , synthetic lanthanum tungsten-coated powder prepared by the method of lanthanum tungsten electrodes , instead of lanthanum nitrate used in the prior art tungsten-coated powder preparation Lanthanum the method of eliminating nitrogen oxides due to the gas generated by the decomposition of nitrate pollution. Since lanthanum acetate and lanthanum nitrate in the decomposition temperature differences, resulting in process effect differences. Prepared using lanthanum acetate, lanthanum tungsten-coated powder decomposition temperature greatly reduced , effectively simplify the process , and the method of the present invention is carried out in a hydrogen atmosphere using lanthanum decomposition avoids lanthanum compound is unstable in an oxidizing atmosphere of volatile , but also make the lanthanum salts decompose more fully, significantly improved vertical melt process the Chinese material conductive properties. With the lanthanum salt decomposition and reduction process to achieve continuous operation in the same device to complete two processes , greatly simplified the process, the reduction of working hours , saving energy , is an ideal method for producing lanthanum tungsten electrodes .


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Lanthanum tungsten electrode manufacturing method relates to a method mainly used for TIG ( tungsten inert gas welding ) and PLASMA ( plasma ) technology for metal welding , cutting, spray coating , smelting a method of manufacturing the tungsten electrode .

TIG tungsten electrode materials and PLSMA is a key technology in materials. Has been used in industry there are many types of tungsten electrodes . Tungsten electrodes widely used in the thoriated tungsten electrode shows better performance. However, due to which the body will produce thorium radiological hazards and the cumulative nature of the radioactive contamination of the environment , for people developed a cerium tungsten electrodes in an attempt to replace the technical field of TIG and PLSMA radioactive thorium tungsten electrode . Practical application shows that cerium tungsten electrodes in the small current welding , etc. successfully replaced thorium tungsten electrode , but in AC polarity , gas discharge light source , cathode emission materials, Shangmo completely replace thoriated tungsten electrodes , there is repeated arcing , poor reliability , burning rate, life expectancy and low defects. With the development of high-tech , machinery and electronics , petroleum, chemical , aerospace , shipbuilding , atomic energy and other fields, the metal being cut parent material type , shape, thickness and other requirements and more complex, the performance requirements for tungsten electrodes more increasingly harsh. Need to develop a better performance of the electrode in order to meet their needs. The results show that the addition of rare earth elements La, Y can effectively improve the performance of tungsten electrodes , especially lanthanum tungsten electrode has a long life and good performance from arc has broad application prospects .

Lanthanum tungsten electrode current manufacturing methods , the solid material is mainly used uniformly mixed with lanthanum nitrate , concentrated by heating , drying ( roasting ) , screening and other processes lanthanum tungsten-coated powder was prepared , and then restored , pressure type , vertical melting , billet and finished processing system to obtain lanthanum tungsten electrode . As is the use of nitrate -coated powder preparation method of the preparation process, will produce large amounts of NO pollution, and the decomposition temperature of the nitrate is high, it takes a long time to complete decomposition of calcination , resulting in process is difficult . And there may be generated due to decomposition of the nitrates incomplete , resulting in poor conductivity of billet , process performance deterioration phenomenon. Into the present application in September 1989 Patent No. 89107270.5 patent application , the disclosure of cerium acetate was prepared using the method of cerium tungsten electrodes , the method is effective to prevent the manufacturing process of cerium tungsten electrodes , preparing a NOx generated when powder coated environmental pollution , harsh operating conditions , but in the processing performance, there are still insufficient .


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Adding tungsten oxide, lanthanum tungsten electrodes produced . Specific data as follows :

Other grades dopant doping doping electron work function color coating head
WL10 La2O3 0.80 ~ 1.20% <0.20% 2.6 ~ 2.7 Black
WL15 La2O3 1.30 ~ 1.70% <0.20% 2.8 ~ 3.0 golden yellow
WL20 La2O3 1.80 ~ 2.20% <0.20% 2.8 ~ 3.2 Sky Blue

Lanthanum tungsten has the following advantages: * better * Mechanical cutting performance better creep resistance * High * recrystallization temperature ductility .

Lanthanum tungsten electrodes is already the internationally popular electrode materials, especially the content is 1.5% ( with a difference of 2.0% content ) of lanthanum tungsten electrodes .

Scientific research shows that 1.5% lanthanum tungsten, tungsten thorium with the nearest 2.0% demonstrated conductive properties, therefore , welding personnel can easily replace the electrode , rather than replace the device parameters.

In 1998 there is a very famous field trials , is to 2.0% tungsten thorium electrode , 2.0% cerium tungsten electrodes and two vendors 1.5% lanthanum tungsten electrodes at 70 Ann 150 amps , 300 volts DC environment for welding tasks , the result is that in both cases , 1.5% lanthanum tungsten electrodes have demonstrated its excellent welding performance , but also reflects its small burn rate characteristics.

Lanthanum tungsten electrode is also suitable for AC welding tasks , and performance excellence.


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Lanthanum tungsten electrode is a hundred years European countries have introduced a class of products , the purpose is expected to replace with radioactive thorium tungsten electrode . Once launched , lanthanum tungsten electrode will by the international community praised the welding , and its export volume has considerable tungsten electrodes with thorium . Lanthanum tungsten electrode is characterized by conductive properties closest to 2% thoriated tungsten electrodes , durable high burning rate of the current minimum .

Lanthanum oxide, lanthanum component comprising tungsten oxide, lanthanum into 2 %, 1.5% , 1%, three levels . Lanthanum is a rare earth, and no radioactive , it is known as lanthanum tungsten electrodes substituted products thoriated tungsten electrode . Lanthanum tungsten electrode is mainly used for DC welding, AC welding can also play a good effect . 1.5% lanthanum tungsten electrode , low current, easy arc starting and stable low current arc . 2% lanthanum tungsten thorium tungsten electrode life longer than in most use arcing easier . Especially good (a) to prevent thermal shock , (b) short cycle repeated ignition welding case , the welding good (c) to avoid contamination.

Lanthanum tungsten electrode welding performance is to add 1-2 % tungsten lanthanum oxide electrodes , electron work function at the 2.7-2.8ev, thorium tungsten electrode has the most similar properties. When used in the small current arc resistance and burning performance than thoriated tungsten electrodes have improved .

Lanthanum tungsten electrode due to non-radioactive and become a more promising alternative to thoriated tungsten electrodes . Another advantage is its high durability and burning rate of the current minimum , so lanthanum tungsten electrodes by Asia, Europe , America and Japan and other countries clients.


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Lanthanum tungsten electrode welding performance and conductive properties closest to 2% thoriated tungsten electrodes, and no radiological hazards, welders welding operation without changing any program can use this convenient alternative thorium tungsten electrode is an electrode, so lanthanum tungsten electrode become the most popular in Europe and Japan 2% thoriated tungsten electrodes alternatives. Lanthanum tungsten electrode is mainly used for DC welding, but for AC welding also performed well.

Lanthanum tungsten electrode manufacturing method relates to a method mainly used for TIG (tungsten inert gas welding) and PLASMA (plasma) technology for metal welding, cutting, spray coating, a melting method for manufacturing the tungsten electrode.

(1) using lanthanum acetate and including APT, WO3, and W powder of solid material made from a slurry of water mixed to prepare a lanthanum tungsten-coated powder;

(2) lanthanum lanthanum tungsten-coated powder decomposition of hydrogen atmosphere in the reduction process and simultaneously, a reduction temperature is controlled at 600 ~ 700 ℃, time is 2 to 3 hours, the second reduction temperature control 800 - 970 ℃, the hydrogen flow rate during the 0.5-2.0m3 / h.

10 / plastic box, the length is 150mm or 175mm, 1000  per carton.

Lanthanum tungsten electrode welding because of its good performance in the international welding industry concern. Lanthanum tungsten electrode conductivity closest WT20 thorium tungsten electrode. Therefore, welders welding operation without changing any program can use this convenient alternative thorium tungsten electrode electrode. This shift, whether in exchange conditions or under DC conditions are easier. Another advantage of lanthanum tungsten electrode performance at its current high durability and burning the minimum rate.


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The most common tungsten electrodes comprising lanthanum dioxide percent lanthanum, lanthanum oxide is known. In Europe and Japan, lanthanum tungsten electrode in most applications has been most commonly used to replace thoriated tungsten electrodes. Containing 2% lanthanum oxide, lanthanum oxide, lanthanum oxide, 1.5% and 1%, three. Lanthanum oxide has the lowest electron work function, arcing easiest tip temperature minimum, which helps to prevent grain growth, improve service life. By testing 2% lanthanum lanthanum tungsten electrode showed that: If no overload current, longer life than thorium tungsten, in most use arcing easier. Especially good (a) to prevent thermal shock, (b) short cycle repeated ignition welding case, the welding good (c) to avoid contamination. In welding pipes, welders lanthanum tungsten electrodes, especially for such satisfaction. Because long life to reduce downtime. And, in general case, it is 1.5% of lanthanum oxide to lanthanum tungsten electrodes, low current arcing and can easily stabilize the low current arc. Lanthanum tungsten electrodes in a rare earth, and no radioactivity. The lanthanum tungsten electrode is mainly used for DC welding, welding in the exchange will have a good effect. 1.0% lanthanum oxide containing tungsten lanthanum cerium tungsten electrodes are simultaneously appear on the market.

Content of 1.5% (with a difference of 2.0% concentration) lanthanum tungsten electrode has the nearest 2.0% thorium tungsten electrode demonstrated conductive properties, therefore, welding personnel can easily replace the electrode, rather than replacement of equipment parameters.

In 1998 there is a very famous field trials, is to 2.0% thoriated tungsten electrodes, 2.0% and 1.5% cerium lanthanum tungsten electrode tungsten electrodes at 70 Ann 150 amps, 300 volts DC environment for welding tasks, the result is In both cases, 1.5% lanthanum tungsten electrodes have demonstrated its excellent welding performance, but also reflects its small burn rate characteristics. Lanthanum tungsten electrode is also suitable for AC welding tasks, and performance excellence.


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characteristics as tungsten , makes it very suitable for TIG welding and other similar electrode material such work . In adding rare earth oxides of tungsten to stimulate its electronic work function , making the tungsten electrode welding performance can be improved : electrode arc better performance, higher stability of the arc column electrode burning rate is smaller. Usual additives earth oxide, cerium oxide , thorium oxide, lanthanum oxide, zirconium oxide and yttrium .

thoriated tungsten electrode : tungsten thorium oxide is added .

Thoriated tungsten electrode has the following advantages : lower electronic features , the higher the crystallization temperature , better conductivity , mechanical cutting properties

Thoriated tungsten electrode is a tungsten electrode material commonly used , it is also superior than that of pure tungsten welding performance , which is widely used in DC welding field . Thoriated tungsten electrode is simple , even when the overload current of the operation can be very good , there are still many companies use of this material , it is seen as a part of high quality welding . Thorium tungsten electrode during use , energy-saving effect is obvious, from the arc current 20-50% relative decline , the welding current is low , the process of using less prone to splashing , very easy to change the first round , the electrode life is longer. In the use of thorium tungsten electrode welding must maintain good ventilation , waste welding head to properly handle .

Thoriated tungsten electrode is a widely used additive oxide electrode , it is other than that of pure tungsten electrode and the oxide electrode is also advantageous to add the comprehensive welding performance in long-term use , it is the other oxide electrode irreplaceable . Thorium tungsten electrode is simple, current load, easy arc starting , stable arc, breaking the arc gap, low loss , long life, higher recrystallization temperature , conductivity better mechanical cutting performance. Thorium tungsten electrode is widely used in steel, stainless steel , nickel alloys and titanium welding, is a high- quality welding material of choice.


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