Joining of two metals and fusing them is called Welding. Metals like steel, brass, stainless steel can be welded. For a different process of welding different kind of energy sources are used. Though there are more than sixty processes used to join metals by welders. The reason for this difference in the heat, the pressure, types of equipment used. Some of the widely used welding processes are:
Shielded Metal Arc Welding (SMAW)
Different sources that are used for welding are gas flame, laser, electron beam, an electric arc.
- Arc Welding – It is the technique used to weld metals with the help of the heat generated by an electric arc. An electric arc produces intense heat over the metals to melt it at the joint points and an electrode (stick or wire) is manually put along the joint. The electrode used conducts current. It melts at a certain temperature produced by the electric current. It works as a filler metal in the welding process to join the metals. The arc welding equipments are not much expensive.
- SMAW – The term SMAW stands for Shielded Metal Arc Welding and also known as “Stick Welding”. The wire stick or the electrode is held in the torch. A clamp is used to hold the electrode with the torch. We see that rod vaporizes during welding. This is due to the coating of inert materials over the rod. This vapor or gas or inert gas cloud is helpful in protecting the molten metal from coming in contact with any oxygen. This cloud of molten metal is called ‘Slag’ after it gets settled on the pool of metal after it cools. This slag should be removed from the welded part so as to keep the welding strong.
- MIG Welding – The term is referred to Metal Inert Gas Welding. It can be automatic or semi-automatic. The metals like aluminum are welded by MIG Welding. The wire used is connected to a current source. This wire is the electrode that joins the two metal pieces using the continuous flow of current. The wire passes through the welding gun. Inert gases are also passed through the gun so as to keep the welding part free from airborne contaminants. This is a faster process than stick welding. Some precautions should be taken during MIG -Welding. Combustible materials should be kept away from the working area. Welders should use eye protection equipments. The welding should not be done outdoors due to the use of inert gases.
- TIG Welding – Gas Tungsten Arc Welding is called TIG – welding. In this process an arc is formed between an electrode of tungsten metal that does not melt and base metal is formed. A molten weld pool forms at the point where the arc hits the base metal. The filler metal is slowly and manually filled into the melted weld pool. The oxygen contamination over the tungsten electrode and weld pool. The resultant product is slag-free weld having corrosion resistance properties similar to the parent metal.
The above-mentioned processes are a few of the varied range of welding processes.