In 1924 the first TIG patent was registered. From then on, its use has been continuous given its proven quality and effectiveness to weld all metals. TIG welding is a system that welds successfully, including those difficult to weld metals. A skilled operator with the proper welding technique will achieve homogeneous and very good looking welds.
Tungsten Arc Welding
Although this is what translates into Spanish, this type of welding is commonly referred to as TIG, the acronym for Tungsten Inert Gas. Similarly, it is usual among experts in the area to call it GTAW welding, also from the English Gas Tungsten Arc Welding. What its acronym or name in Spanish does not neglect is to name tungsten. This welding occurs on the basis of this chemical element.
Its use is in the form of a non-consumable electrode to direct the current to the welding arc. Represented with the letter W, since it is also known as Tungsten, tungsten is characterized by its silvery-white colour and an amazing hardness. The way to fuse it is only reaching 3,422 degrees, in fact, it is the highest melting temperature among the chemical elements.
What characterizes a TIG welding?
In appearance, she does not vary from other welding processes. Holding the welder or torch with one hand and a rod in the other next to the use of gloves, welding helmet and protective clothing is what is observed before a TIG procedure.
It is a procedure where fusion is achieved thanks to a non-consumable electrode and a protective gas. This protective gas is usually argon. It works by wrapping molten material and tungsten electrode ensuring there is no oxidation. In addition to these characteristics, there are other points of TIG welding :
- Its application occurs in all metals.
- It is a basically manual process that demands operator expertise, given its difficulty in the procedure.
- The heat source is caused by an electric arc. The appropriate type of electric current is both continuous and alternating; although the most usual is the continuous one. With this, the electrodes degrade less due to the lower temperature.
- The type of electrode to be used is non-consumable in nature.
- It is a procedure protected by inert gas to prevent contamination of the electrode. Due to its low thermal conductivity and good stability, argon is the most used gas. However, in specific situations, the use of Helium and mixtures of Argon-Helium or Argon-Hydrogen is also among the possibilities.
- It makes possible the union of virtually all metals. With mastery of the technique, no fusion defects are perceived, but a quality weld.
- TIG welds are strong and resistant to corrosion
- The heat input and the addition of filler metal can be controlled separately, as well as the penetration of the root passage weld.
- Unlike another arc welding, there are no sparks or splashes.
- The use of input material is only for specific applications.
In the opinion of experts, the advantages of TIG welding exceed their possible disadvantages. However, it is necessary to take them into account. It requires taking care of certain parameters to obtain the highest quality in the final welding so that the knowledge and skill of those who try it must be real. Another aspect is its cost, considered quite high.
Good preparation before welding
The first thing is to have the necessary equipment. The DC or AC power generator, the high frequency or pulse generator, the gas circuit, the cooling circuit and the electrode holder must be available.
The selection of the correct tungsten electrode is of the utmost importance . To choose it, there are two factors to take into account: thickness of the material and amperage to be used in welding. Based on this information, the choice of electrode diameter and length will be appropriate. However, before being introduced into the clamp, the tip of the tungsten rod must be ground, making it rounded or pointed.
Then you choose the configuration of electricity, cleaning-penetration, air on, maximum amps and gas. The welding table must be ready, a wide and clear table. A trained operator knows that his protective equipment is mandatory to avoid burns and even blindness. If it is ready, then the next step is to weld.
The welding bath is started with the pressure of the pedal that is adjusted to size. Treading hard or lightening the pedal will achieve the perfect fusion in both pieces of metal . TIG welding shows several ways. Fillet welding is considered the simplest and joins two metals at a right angle.
When there are two metals leaning against each other, it is known as back welding. One of the most complicated is the so-called butt welding. In it, the edges of the metals are those that touch. The strength welds are those strong welds at points that do not merit being seen, and the cosmetics are those of beauty and smooth finish.
Recommendations for the technique
- The distance between the electrode and the piece must be taken care of. The tungsten must be totally avoided touching the piece . If it happens, it will be evidenced with a different sound and color, so it will be necessary to clean its end to continue. The practice will prevent this and be more stable.
- For the best protection of welding, the ideal inclination angle of the electrode holder is 90 degrees.
- It is key to know what material or alloy is going to be welded in order to select the correct input material.
- When gathering the material that is thought to be correct, it is worth doing test welds. In fact, it is of high recommendation when the piece and the material are of high cost. It is better to be able to make rectifications on time.
- A very important recommendation is the care in cleaning before welding . This will avoid double labor or waste of material. A soft, clean, dry, lint-free cloth will help to avoid contamination of the weld.