Tungsten electrodes are a safe, high-performance and truly high-quality fixture for welding. Currently, experts are actively used products of various markings. The choice of a particular option depends on the nature of the work and the type of welding machine that will be used as a tool for the implementation of the tasks.
Let's look at the characteristics that differ tungsten electrodes. It is immediately worth noting that such products are used when it is necessary to perform the so-called argon-arc welding, in other words - in the course of work, where the rod is heated in an argon protective gas medium.
The melting point of the material is about 3400 o C, and the boiling point is about 5900 o C. Tungsten is the most refractory metal used for the manufacture of electrodes. As can be seen, the material is able to maintain the original structure when exposed to the highest temperatures.
To improve the quality of tungsten electrodes, for example, to increase the stability of the arc, in their production various oxides of rare-earth metals are used as additives. Depending on the composition of these elements distinguish products of various brands.
Tungsten Electrodes - Marking
According to the standards, products of this category should have a special marking, which indicates their composition and type. The first in the list is always the designation "W", that is, tungsten. Subsequent values indicate an oxide that is used as a dopant.
How to choose suitable tungsten electrodes? Marking makes it possible to speed up the selection of products that will most effectively cope with the tasks:
- "W" (green) - electrodes made using pure tungsten. It is recommended to give preference to this solution when processing aluminum alloys on alternating current.
- "WTh" (red) - thoriated tungsten electrodes. Suitable for welding copper, corrosion-resistant steel, titanium under the influence of direct current.
- "WZr" (white) - zirconized tungsten electrodes. Products of this plan can be used for welding on direct and alternating current. Used for the treatment of light metals (magnesium, aluminum).
- "WLa" (black) - lanthanum tungsten for processing heavy metals with alternating and direct currents.
- “WCe” (gray) is a certed electrode that is used as an alternative to thoriated products.
Sharpening tungsten electrodes
To get a high quality duplicate of the welded connection, sufficient to give adequate attention to the nature of the sharpening products from tungsten. Arc shape at performance of works depends on the angle at which the sharpened electrode. The higher it is, the lower the penetration and wider the spot.
On the life of a tungsten product is significantly reflected in its blunting. How flat the end of the electrode will be depends on its diameter, the thickness of the metal and the magnitude of the welding current.
When processing metal with a thickness of no more than ten mm, welding with a tungsten electrode is performed from right to left. During processing, denser materials act in the opposite way.
In the manual method of welding thin sheet metal, the electrode is introduced somewhat laterally, not into the arc column. Metal of greater thickness is treated with transverse movements.
Semi-automatic and automatic welding involves placing the electrode perpendicular to the treated area. Often, the direction of movement is chosen so that the additive is ahead of the arc.
Tips for choosing
When selecting a refractory tungsten product, you should pay attention to the following criteria:
- Electrode parameters, labeling, composition, nature of alloying additives.
- Diameter (depending on the required thickness of the working seam).
- The density of the material of manufacture.
- The quality of sharpening.
- Specific geometry of the tip.
Naturally, when selecting electrodes to perform specific tasks, it is most easy to navigate according to the marking that is applied to the surface of products by manufacturers. The latter will indicate the possible scope, composition, conditions of operation.
Tungsten electrodes are one of the best solutions for welding. Products in this category are of high quality and efficiency. However, when choosing, one has to pay attention to the whole mass of important characteristics, which can confound untrained masters. To facilitate the task, it is worth referring to the above recommendations.