TIG welding (Tungsten Inert Gas), or non-consumable welding electrode is when the arc ignites between the tungsten electrode and the parts to be welded. Thus, there is no transfer of molten metal in the arc gap. This makes it possible to facilitate the burning of an electric arc and significantly increase its stability. In addition, tig welding reduces evaporation losses, eliminates possible metal spatter and limits the effect of gas from the arc column on the molten metal. As a result, the quality of the weld is raised to a new, more perfect level.
Tig-welding can be on alternating or direct current, and in the case of the latter, only direct polarity is used, that is, when the parts to be welded are connected to the plus terminal, and a non-consumable electrode is connected to the minus terminal. The need to connect in this way is due to the fact that if you swap the terminals, then there is a possibility of overheating of the refractory tungsten metal and, therefore, its resistance will significantly decrease. In addition, chipping or melting of the electrode may occur, resulting in inevitable weld defects.
Tig weldingimplies the presence of the following main elements in the design of the installation: an AC or DC power supply, an arc discharge stabilizer, an oscillator, a current control device, a current pulse generator, a gas solenoid valve, and a device for suppressing current components.
Tig-welding is the most versatile type of joining metals, as it allows welding a wide variety of materials at any position in space.
The high-quality process of welding parts is achieved due to the fact that it takes a little more time than any other type of welding. In this regard, tig welding is used only when the quality characteristics of the resulting weld are of decisive importance.
A distinctive feature of this type of welding is that pure argon is used to join absolutely any materials, while for other types of welding it is necessary to select gas in accordance with the metals being welded.
Tig-welding is a rather complex and painstaking process. Therefore, a specially trained qualified welder is needed to carry it out. The technological process will require sufficient skill from him, since it is necessary to ensure sufficient and timely supply of filler material with one hand, while the welding torch will be in the other hand.
When choosing a welding machineof this kind should be guided by the following considerations:
- Need to determine the power source of the welding machine.
- Estimate the complexity and scope of the work ahead.
- Take into account the type of current consumed: direct or alternating.
You should also know that some welding machines can use both direct and alternating current at the same time. This is necessary for welding different materials such as aluminum and steel. Welding units have a fairly wide range of current values from 3 to 500 A.
