Welding is a fabrication process of combining two different metals using a molten material. It involves several processes and techniques.
Arc welding is the most common and basic form of welding. Under the arc welding category, there is stick welding, metal inert gas (MIG) welding, and tungsten inert gas (TIG) welding.
Let’s see in-depth about how to get started with these welding methods.
1. Stick Welding
Stick Welding is also well-known as Shielded Metal Arc Welding (SMAW). This type of welding is applicable for outdoor welding.
While performing stick welding, an electric arc generates between the workpiece and the metal electrode. An electric current passes through the electrode to form a weld pool on the workpiece.
The electrode has a flux coating and it melts to form a layer over the weld pool and prevents it from corrosion and contamination. The flux layer is then removed after the weld has cooled down.
Setting up Stick Welder
A stick welder has four main components:
- Ground clamp is plugged into the welding machine and clamped onto the base metal.
- The Slag removal removes the flux layer formed on the weld.
- The choice of electrodes depends on the requirement. Most commonly available welding electrodes include 7018, 7014, 6012, 6010, etc. To understand which electrode is appropriate for the welding, it is essential to know what these four digits stand for. The first two digits specify the lowest tensile strength which should be equal to the tensile strength of the base material. The 3rd digit specifies the position of the electrode for the welding whereas the 4th digit specifies the current application for the electrode and its coating.
- The Power source is essential to supply current to the electrodes to start the welding process.
Creating an arc by the striking electrode is the most difficult step. Usually, stick welding is practised on scrap pieces to master the skill.
2. Metal Inert Gas (MIG) Welding
Metal Inert Gas or MIG welding is also known as Gas Metal Arc Welding (GMAW). It is the most popular welding method as it is easy to use, gives high productivity, and is inexpensive.
In this process, the MIG welder creates an arc between the wire electrode and the metal workpiece. It melts the electrode wire to create a weld joint.
The fundamentals of MIG welding:
A. In MIG Wire, the consumable electrode used ranges from 0.5 mm to 1.5 mm. A wire feed mechanism continuously feeds the wire into the welding gun.
B. Welding Gun is the most important component in MIG welding. It facilitates the flow of inert gas and wire electrode.
C. Inert Gas Cylinder attached to the welder gun acts as a shielding gas and prevents the formation of oxides.
D. Workpiece is attached with a clamp and connected to the power supply. It should be clean and dust-free.
The most common techniques a welder uses in MIG welding are forehand or pushing and backhand or pulling. The backhand or pulling technique yields higher access than the forehand or pushing technique.
3. Tungsten Inert Gas (TIG) Welding
Tungsten Inert Gas (TIG) Welding is the advanced type of welding producing high-quality welds. It is a versatile method with its application over a wide range of metals.
In this process, an arc creates between the tungsten electrode and the base metal. The base metal melts due to the heat produced by the arc. This base metal is later on fused and processed into a high-quality weld. This welding process is also known as Gas Tungsten Arc Welding (GTAW).
The equipment of a TIG welding machine:
A. Tungsten Electrode has high electrical and thermal conductivity making it a great choice for TIG welding. Also, tungsten has a high melting point by the virtue of which it is a non-consumable electrode.
B. Gas Nozzles, made from thermal-resistant ceramic material, resists the high temperature of the welding process.
C. A TIG welder supplies current to the welding process.
D. The Workpiece should be clean and free from impurities for high-quality welds.
E. The TIG torch holds the electrode and gas nozzles. It regulates the amount of distribution of shielding gas.
F. Water Cooling System is essential to maintain over-heating of the torch from high temperatures.
A TIG welding machine operates in two ways: automatic and semi-automatic. The TIG welder configures the gas flow length, filler rod position, speed, and arc length in an automatic way, and the process starts.
In a semi-automatic way, the welder is responsible for configuring gas flow and current settings along with maintaining the position of the filler rod and tungsten electrode.
To start with TIG welding, initiate with the gas flow in the TIG torch. Then the welder presses the foot pedal to create an arc between the workpiece and tungsten electrode. This melts the filler metal creating a weld pool on the workpiece. A weld joint generates on the cooling of the weld pool.
TIG welding is a slow and complex process of producing high-quality welds. Thus, it has more industrial applications.
Once you know which metal is to be welded, then you can start the setup for the welding machine.
For beginners, it is advisable to master the skills using scraps and then proceed with projects. It is also advisable to use a multi-purpose welding machine to get an advantage of a practising stick, MIG, and TIG welding at a time.
We, at KP Fabrication, use the TIG and MIG welding processes to produce high-quality welds for our customers in the given time. You can connect with us at email@example.com or 08 9271 3433.