Welding as a method in repair work
Welding methods vary. Stands out:
- gas,
- timely,
- electric,
- laser,
- hybrid.
Gas welding
It is called autogenesis. It is the primary method of joining metals. Its advantages are the simple technique, the low cost of the equipment, the large area of welded thickness, and the high productivity. The disadvantages should also be borne in mind, i.e. the considerable cost of operating gases, the difficulty in welding aluminium, and the poor aesthetics of the welds. Gas welding is used for repair and overhaul work. Thin pipes in district heating, water or gas installations, for example, can be welded. Gas welding is ideally suited for field conditions. Acetylene is the most commonly used gas for gas welding.
The characteristics of the acetylene-oxygen flame are:
- very high temperature, i.e. 3100 degrees Celsius;
- the deoxygenating property of the mid-flame;
- considerable specific power;
- simple flame control.
Welding on time
Another popular method is termite welding, also known as aluminothermic welding. The heat source is the combustion of thermite. Thermite was initially used as a fuel to produce pure metals without the use of carbon. Termite welding is used to repair steel pivots, cracked shafts, casting defects, as well as to join railway rails and any iron or steel objects.
Laser welding
This is a state-of-the-art welding technique. It uses a laser beam. It has a high energy density. Laser welding is used for the welding of metals that are difficult to fuse, titanium, aluminium, alloy steels, carbon steels. The high efficiency is a huge advantage of laser welding, which is competitive with other advanced processes such as electron welding.
Hybrid welding
The combination of arc welding and laser welding makes it possible to obtain welds that are more flexible compared to conventional laser welding. The speed of the process is maintained. Hybrid welding is widely used, among others, in the shipbuilding or car body industry. Hybrid welding is also called HLAW (hybrid laser arc welding). This method has the advantages of laser welding as well as the GMA method. It is a very effective way of joining materials.
Electric welding
It is the most popular. Its advantages are economy and strength of joints. There are gas-shielded welding, covered arc welding, welding with coated electrodes, arc welding with a non-consumable electrode.
