The most common and popular fabrication process to join two or more parts by heat or pressure is ‘welding.’ The process works best on metals, steels, thermoplastics. It is relatively simple to weld some materials, but some materials require complicated techniques.
Few materials are even termed as ‘unwieldable,’ which is not a word in the dictionary, but many use it as an engineering terminology. The parts that are to be welded together are ‘parent material’ while the material to join is ‘consumable’ or ‘filler.’
The consumable part is usually similar in composition, which makes it easy to form a homogenous weld. When consumable with different composition is used, then it is a heterogeneous weld.
The Welding Process
Some of the basic processes in welding, depending on the type of material, are
- Joining Metals
There are two other ways to join metal apart from welding, which include soldering and brazing. The welding process melts the base material, and the filler is added. The high temperature causes a weld pool, and it cools to form a joint.
- Joining Plastics
In welding plastics, heat is used to join the materials. The first stage is preparing the surface, the second stage is applying heat and pressure, and the last is cooling the materials.
- Joining Wood
Of all the materials, wood is not the ideal material to weld. The friction of the materials causes heat to make a weld. A considerable amount of pressure enables friction that leads to heat that bonds the wooden pieces together.
The Reasons to Weld Pipes
One of the most common applications is welding steel pipes. The process is simple and does not pose any hassle or difficulty. Before the welding takes place, one has to make sure that the pipes are aligned with each other. Metal pipe welding is possible with MIG (metal inert gas), SMA (stick metal arc), and TIG (tungsten inert gas).
If the two pipes are long, then the worker uses clamps to hold the pipes together. The worker will fire the welding torch to open an arc between the pipe and the welding tool. The flame of the torch makes a small puddle on the steel surface, which is ‘track weld.’ The worker moves the arc again to make another puddle. The worker will continue to move the arc until a series of track weld has formed.
The worker will move the welding torch along the circumference of the pipe to connect the two pipes. After the connection is visible, then the worker will extinguish the arc and let the puddle cool and dry for a few minutes.
The arc welding process is traditional and remains more or less the same even after so many decades. The process involves connecting two pieces of metal by using an electric arc. The arc is capable of generating immense heat that melts the metal parts. The molten form of the metal is mixed with a consumable to bind the two metal parts together. For a long time, steel is the default material for welding, while aluminum is difficult to weld by an electric arc.
The Basic Tools Essential for the Welding Process
The worker who welds different parts or material together is called a ‘welder.’ The equipment for the welding process includes a welding torch, electrode, safety glasses, and gear. The two steel pipes join together by creating a joint once the pipes melt at the seam. Some of the common equipment for welding are
- MIG and TIG Welders
One of the most common tools is a ‘stick welder,’ which is fairly simple to operate. One does not need any special environment to weld steel pipes. One thing to consider is that the stick welder needs frequent electrode replacement rather than other types of welding. In arc welding, an electric current is passed to weld materials. The two types of arc welding are MIG and TIG
- Wire and Electrode Feeds
Many of the welds require a feed to provide extra strength to the joint. In stick welding, an electrode provides the feed, while in MIG welding, a wire supplies the feed.
- Safety gear
The high temperatures and heat during the welding process can be quite dangerous, so safety precautions are necessary. The welder has to wear a special helmet to protect the eyes and wear ear plugs. The welder also wears welding gloves to protect the hands and solid boots to prevent any spark.
Apart from the main tools, a welder also uses an angle grinder to remove any bends in the joint. Wire brushes are also handy to clean the surfaces during and after the welding process. Some of the other small tools include
- Electrode tip cleaners
- Chipping sledge hammer
- Cutting pliers
The Difference between TIG and MIG Welding
The TIG welding is quite versatile and allows joining all kinds of big and small materials. A non-filler tungsten electrode is used to heat the steel pipe. But TIG is time-consuming and results in high production costs. Also, welders must be specially trained to manage the precision and accuracy necessary for the TIG welding process. But the TIG process gives smooth and durable welds.
The MIG welding best suits large and thick materials. There is a wire that acts as an electrode and filler. The MIG welding is quite faster and less expensive as compared to TIG welding.