Arc Welding Overview
Arc Welding is a type of welding that is used to join the two metals permanently using the arc (Read about Arc Welding, parts, working, etc in detail). There are different types of arc welding used in the real life. According to the application, strength, and type of metal, the type of arc welding used. The classification of arc welding types depends upon the consumption of the electrode, it states that there are two types of arc welding; they are Consumable Electrode Arc Welding and Non-Consumable Electrode Arc Welding.
Table of Contents
Types of Arc Welding
We already read the definitions of what is consumable and non-consumable electrode type of Arc Welding? If you don’t, Read Here.
The consumable type of arc welding do consists of electrodes that will melt with the help of arc for filling the gaps of the metal pieces for their joining.
Consumable Electrode Type
The types of arc welding according to the consumable electrode type are
- Shielded Metal Arc Welding (SMAW)
- Submerged Arc Welding (SAW)
- Arc Blow Welding
- Electro Gas Welding
Shielded Metal Arc Welding (SMAW)
The Shielded Metal Types of Arc Welding also can be called Manual Arc Welding. It is the normal and frequently used types of welding. As like a normal welding type, it does consists Transformer, Electrode Holder, and Electrode.
Whenever the holder and electrode fed over the workpiece due to the current passage and closed-loop the arc will be developed. The developed arc will melt the electrode and molten metal will deposit over the bead (or workpiece). As the electrode is flux coated, after melting and deposition of molten metal over the workpiece, the flux will be covered over the bead (or weld) to prevent oxidization, avoid the voids, and holes in the weld.
The rate of melting of the metal will be depending upon the current input. If the current input is low then the rate of melting will be low. This lower current will lead to the Slag Inclusion (the trapping of flux in the welding bead).
The Shielded Metal types is operated by the human so it is called Manual Arc Welding. If the operation is done with the help of machine then it is called Automatic Arc Welding.
Note: The temperature of the arc core will be around 6000-7000 degrees centigrade.
Submerged Arc Welding (SAW)
The Submerged Arc Welding looks similar to the Shielded Metal Arc Welding. If the shielded metal type of arc welding is upgraded to semi-automatic then it is called submerged type of welding.
The flux and filler metal will be used separately. Instead of a Solid long cylindrical electrode, the copper-coated wire type of filler metal is used and instead of flux coating over the electrode, granular flux is used.
The copper wire is stored in the spool. As the copper wire is fed over the workpiece, the arc will be developed and the copper wire is melted over the metals that need to weld and simultaneously the flux too. The transverse movement of the submerged welding is used for long welds. The submerged types of welding are used to weld high-thick metals (or materials) that are more than 5 mm in thickness.
Electro Gas Welding
The Electro Gas Welding is also called Electro Slag Welding. The Electro Gas Welding does have a special character that the arc of the electrode will switch off automatically once the molten metal reached its higher temperature and the wire-shaped filler metal will be consumed to weld. Once the temperature of the molten metal is decreased and unable to consume the filler metal then the arc will restart automatically and heating will take place.
As the electrode is non-consumable and no flux material is coated over the electrode, we use the inert gases as a flux to prevent the bead from oxidization.
Non-Consumable Type
There are two types of non-consumable types of arc welding. They are
- Plasma Arc Welding (PAW)
- Tungsten Inert Gas Welding (TIG)
Let us read about these 2 types of non-consumable arc welding.
Plasma Arc Welding (PAW)
As the name indicates, this type of arc welding uses plasma as its main source. The plasma gas Nitrogen N is used to produce the arc. The type of electrode that is used in plasma arc welding is the Tungsten electrode (which is non-consumable). The plasma is allowed through the electrode to convert the nitrogen gas into the plasma. The maximum temperature that plasma welding acquire will be 20000-degree centigrade.
A Direct Current power source is used to supply the power and the maximum voltage used is 80 volts. The high temperature of the arc will melt the surface of the metal pieces so then a filler material is used to fill up or to join the two metal pieces. These types of arc welding are not only used for joining the metal but also for cutting the metal into pieces. If we do not use the filler metal then the temperature of the plasma itself can able to cut the metal.
The higher the heat, the higher will be the quality of the weld. The plasma temperature is high that is not possible for it to cool down normally so, a separate coolant like water is used to cool down the developed heat of the electrode.
Gas Tungsten Arc Welding (GTAW)
Gas Tungsten Arc Welding also called as Tungsten Inert Gas Welding shortly TIG. The positive polarity is acquired by the electrode (non-consumable electrode) and negative polarity by the workpiece. This will help the alloy materials to be welded. It uses the inert gases like Helium, and argon to protect the welding bead or weld from oxidization and voids.
The Gas Tungsten Types of Arc Welding uses the coolants for cooling the parts that are greater than 100 Amperes.
Applications Of Types Of Arc Welding
Applications Of Shielded Metal Arc Welding:
The applications of shielded metal arc welding are as follows
- It is used to high alloy steel, stainless steels.
- It can be used to weld the nickel and alloys of nickel.
Applications Of Submerged Arc Welding
The applications of submerged arc welding are as follows
- The submerged types of arc welding are used to make LPG Cylinders.
- It used to weld the low carbon steels, low alloy steels, high alloy steels, and stainless steels.
Applications of Electro Gas Welding
The applications of electro gas welding are
- These Types of Arc Welding is used in building ships.
- Electro Gas Welding is used to weld the thick metals.
- Electro Gas welding is used in the construction of pressure vessels, water turbines, and press frames
Applications Of Plasma Arc Welding
The applications of plasma arc welding are as follows
- Plasma Types of arc welding used to weld stainless steel, titanium, high melting alloys.
- In addition to high melting alloys, Plasma arc welding is used in Aeronautical Industry and precision instrument industries.
Applications Of Gas Tungsten Arc Welding
The applications of gas tungsten arc welding are as follows
- This type of welding used to weld alloys of Aluminum, Magnesium, Nimonic alloys, Monel, and Inconel.
- Gas Tungsten Types of Arc Welding is used at Air Craft Industry, Chemical Plants, and Nuclear Plant.
Conclusion
There is a number of applications that arc welding can help but the single type of welding will not work out for all types of metals and its alloys, they need different temperature, heat, and procedure to join. So, all the arc welding types processes will be used according to the metal and alloys. Even the strength of the weld will be not enough if we opt for only one type of welding process. All the arc welding types process do consist few similar parts and a small variation will differ them as different types.