When it comes to TIG welding, a lot of parameters that can have an effect on the end results revolve around the selection of tungsten electrodes. Therefore, it is important to pick up the right type of tungsten electrode for the job if you want the best results. And since it also results in a rather cleaner welding performance, you can save a lot of time and effort, which would be needed if a wrong tungsten electrode is used for the job. Today, we are going to learn about the differences in various types of tungsten electrodes and how you can identify the best one for your needs. But before we get into the details, we have some handy charts included in this guide to help you pick up the best option right away. Take a look at the table below where we will compare different types of tungsten electrodes that are usually needed for the job. While these are some of the most commonly used tungsten electrodes for the job, you must also know how to identify the electrodes before picking up a set. Fortunately, it is pretty easy to do so since manufacturers color-code the electrodes based on their type. Here’s how you can easily identify electrodes based on their types and even subtypes. While the information presented above will let you choose the right type of tungsten electrode for the job, there is more to it before you can use the electrodes. Along with that, you should also know the suitable amperage needed for the job based on the size of the electrode as well as the type of current you are using for the job. To put it simply, the suitable amperage levels vary for DC negative, AC symmetrical, and AC Un-Symmetrical waves. Here’s a quick guide to choosing the right amperage for the job.
Types Of Tungsten Electrodes
We hope that the information presented above will let you quickly identify the right type of tungsten electrode you need for the job and get a clean and sustainable weld via TIG welding technology. But before you can do that, you need to know how you can select the perfect electrode type based on the job. The electrodes are primarily classified on the basis of their chemical properties, or the composition of the compounds used for the manufacturing of these electrodes. In that, the most important part is the principle oxide and its percentage in the composition. While electrodes are designed with a certain color code to make the selection easier, it won’t tell you which type of option is the right one for the job. That you will have to decide first before you look for the electrodes. Here’s all you need to know about different types of tungsten electrodes and how they differ from one another.
1. Pure Tungsten Electrodes (Green)
Pure tungsten electrodes offer the best stability when you are using AC current. As the name suggests, it does not have any principal oxides. Argon or Helium are primarily used as shielding gas when working with pure tungsten electrodes. Another advantage of these electrodes is that they are comparatively cheaper since their production cost isn’t that high. However, it also means that the current carrying capacity of these electrodes is relatively lower and so is their resistance to welding contamination and welding defects.
2. Thoriated
Thoriated tungsten electrodes contain Thorium Dioxide where its percentage may vary between 0.8 to 2.2 percent. The added Thorium Dioxide adds up to the expected lifespan of the electrode and offers high electron emission at the time of the weld. It also introduces much better control of the arc and reduces the chances of welding contamination. But, you have to be careful when you are working with thoriated electrodes since it is made up of a radioactive material, Thoria.
a. Thoriated (Yellow)
Based on the percentage of Thorium Dioxide, there are 2 subtypes of thoriated electrodes. The yellow ones have 0.8 to 1.2% principal oxide content and are best suited for DC applications. And with the sharp point, it also becomes an ideal candidate for welding carbon steel. Though, you may find it difficult to maintain a rounded weld bead when you are working with AC current.
b. Thoriated (Red)
The red thoriated electrodes on the other hand have 1.7 to 2.2% Thorium Dioxide content. With the increased percentage of the principal oxide, the desirable characteristics of the electrodes also increase compared to the yellow electrodes. Red thoriated electrodes have a relatively higher melting point that works in the favor of the welder. It also means that the consumption rate of the electrode is much lower compared to others. As for the applications, red thoriated electrodes are used for titanium alloys and steel alloys.
3. Ceriated (Grey)
Ceriated electrodes are designed by introducing Cerium Oxide as the principal oxide in the composition. This oxide originates from an element called Ceria and it is mixed into the composition to increase arc stability and make the starting arc easier to attain. Unlike Thoria, Ceria is not a radioactive element. So, these electrodes work well with both AC and DC current inputs. Another benefit of Ceriated electrodes is that they offer a longer lifespan and their erosion rate is also low. The most common applications for Ceriated electrodes are aluminum, magnesium, titanium, and copper alloys.
4. Lanthanated
Lanthanated tungsten electrodes have a pretty common feature set compared to Ceriated electrodes. These electrodes also offer the benefit of a long lifespan as well as a low erosion rate which makes the welding process more efficient and cuts down the running costs of the procedure. To get these qualities, Lanthanum Oxide is mixed into the composition. Based on the percentage of Lanthanum Oxide, Lanthanated electrodes are further classified into 2 subtypes.
a. Lanthanated (Black)
For black Lanthanated electrodes, the oxide percentage varies between 0.8 to 1.2%. In this case, the oxide percentage is kept at a minimal level to present it as an alternative to pure tungsten electrodes or Ceriated electrodes for cost-cutting.
b. Lanthanated (Gold)
The golden Lanthanated electrodes, on the other hand have an increased percentage of Lanthanum Oxide, varying from 1.3 to 1.7%. This is a better alternative option for Thoriated electrodes if you wish to avoid the harmful effects caused by the radioactive oxide. Another benefit of golden Lanthanated electrodes is the added suitable amperage range.
c. Lanthanated (Blue)
The blue Lanthanated electrodes have the highest percentage of Lanthanum oxide, starting from 1.8% all the way up to 2.2%. Therefore, it has significantly better characteristics such as arc stability and amperage range. For that reason, blue Lanthanated electrodes are popular for AC welding and DCEN applications.
5. Zirconiated
The last type of tungsten electrode is the Zirconiated electrode which is created using Zirconium Oxide. Zirconium Oxide is obtained from an element called Zirconia which brings a few important characteristics to the electrodes. In the majority of cases, this electrode is introduced to minimize welding contamination. But with that, it also has the limitation of compatibility with only AC current.
a. Zirconiated (Brown)
The brown Zirconiated electrodes are marked if the Zirconium Oxide percentage stays between 0.15 to 0.5% in the composition. Apart from minimizing the tungsten contamination, it also maintains a stable arc which certainly helps to create a uniform weld bead. The current carrying capacity of brown Zirconiated electrodes is also much better than its competitors.
b. Zirconiated (White)
There is one more variant of Zirconiated electrodes which is marked by white color. These electrodes have a slightly larger percentage of Zirconium Oxide which is about 0.7 to 0.9%. It is not as popular as other options and only used for high-quality welding results on aluminum or magnesium workpieces.
6. Rare Earth Mix EWG
The most common type of electrodes that create a problem in identification are rare earth mix tungsten electrodes. These electrodes are not governed by any set of standard rules and the type and composition of principle oxide are determined by the manufacturer based on desired properties. Generally, the oxides used for the construction of rare earth mix electrodes are made up of rare earth element oxides whereas the composition depends upon the mass of the electrode. Since the type of principal oxide is not constant, it is hard to determine the qualities or chemical characteristics of rare earth mix electrodes. So, it is important to refer to the specifications offered by the manufacturer before selecting these electrodes for your job. Also, the color-coding is not constant for these electrodes and they can be available in any color except the ones that are used for standard types. Still, the most commonly used color for rare earth mix electrodes is purple.
Conclusion
Unlike MIG welding, TIG welding has a rather difficult learning curve, and it is strongly affected by a lot of crying parameters, primarily the type of tungsten electrode you are using for the job. If you select the wrong electrode for the job, the results won’t be good despite the skill or welding knowledge of the welder. But, it also means that you can easily improve the welding quality by simply choosing the right electrode for the job. And for that, we have brought you this helpful guide for tungsten electrodes. In this guide, you will find all the necessary information about tungsten electrodes, their types, color codes, and suitable applications. So, you can easily select the perfect tungsten electrode for the job by following this guide. If you are not sure about any aspect mentioned in the guide, make sure you let us know via the comment section. Comment * Name * Email * Website
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