When someone is thinking about buying a welding machine, they may not even suspect various models on the market. The choice of equipment depends on the ability to weld metal thickness and types of alloys. This overview will show the types of welding machines by power source and welding mode, which will facilitate the selection of a product that will best suit future tasks.
The distinction between welding machines by source type
To understand what types of welding tools are, it is worth knowing that the equipment is divided into classes of power sources and welding methods. The voltage from the 220 V and 6-32 A network is not suitable for the welding process, so it needs to be converted. For this, the following options have been developed.
This equipment consumes alternating current from the mains with a frequency of 50 Hz and changes its oscillations up to 100 kHz. In addition, the voltage is rectified twice. Ultimately, welding is carried out at a constant current of 30-300 A with a 50-80 V voltage, promoting smooth seams, deep penetration, and less metal spatter.
To implement the process, the inverter circuit contains:
- a step-down transformer;
- rectifying unit (diode bridges);
- second transformer.
Two cables are coming from the device, one connected to the product and the electrode arm. The benefits of the inverter are:
- In comparison to other welding current sources, the dimensions are small.
- The low weight of 3-6 kg.
- Quiet operation (pleasant rustle of an electric arc).
The inverters themselves are divided according to the type of communications used in them.
Due to the use of smaller Mosfet inverters, these welding machines are frequently less expensive. About 50 years ago, transistors were invented. For welding ferrous metals, they are dependable and effective in converting current. But they weigh more than analogs. For the regular operation of the inverter, there should be about 20 such transistors in the electronic circuit (for 180 A models). These welding machines have overheating protection, which is triggered after 60 degrees, so the models have a 30-40% low duty cycle. Free layout and large parts make it easier for the technician to access during repairs.
This is a newer generation of transistors that can be found in low-cost welding machines. IGBTs are lighter than analogs, and up to ten units are required in inverters with a power of 180 A. All of this contributes to even lower welding equipment dimensions and weight savings. After 90 degrees, IGBT transistors begin to overheat, extending the device’s overall usage time. On the one hand, there are fewer pieces in such a welding machine plan, but they are minimal, making it more difficult to replace things.
Among other types of welding tools for manual welding, rectifiers stand out, which are distinguished by their relative cheapness and the ability to create high-quality seams. Depending on the model’s dominance, they consume a current of 220 V from the network, lower it through a transformer to 40-80 V, and increase the power to 200-400 A. Further, the energy moves through the diode block and is rectified. The design has elements of start-up and security.
Welding is carried out with the direct current. The machine is reliable and durable. There are versions for home and industrial use. Cast iron, ferrous and non-ferrous metals are all suitable for welding. The main problems are heavyweight and large dimensions. The rest of the network “sags” extensively when boiled, and other devices may not work correctly.
The cheapest type of welding machine is a transformer. They are made up of two types of windings: primary and secondary. Magnetic induction is used to power the devices. The amperage can be increased or decreased by adjusting the spacing between the windings. Welding is done with alternating current. The devices can be used to connect ferrous metals. They are dependable and uncomplicated. High weight, heavy hum, high metal spatter, and big dimensions are all downsides of this sort of equipment.
Types of welding mechanisms depending on the type of welding
Considering what kind of welding machines are by the type of power source, let’s move on to their varieties by welding modes.
MMA manual arc welding machines
These types of welding machines are built based on inverters, transformers, or rectifiers. A consumable electrode is fixed to a holder by the welder. The metal rod serves as a filler material and closes the arc on the product. The outer coating, melting, creates a gas cloud to protect the weld pool from the external environment.
Application. Ferrous metals can be joined with this sort of welding. If you install electrodes with a stainless steel rod, you will be able to weld alloy steel. But the speed of work turns out to be slow; enough experience need to get a high-quality connection, you constantly have to control the length of the arc since the electrode decreases.
Semiautomatic MIG / MAG welding machines
MIG / MAG welding is called semiautomatic since the seam is carried out using a torch, but the wire inside is fed from a unique mechanism from a coil. The principle of operation is similar to MMA, and only a compact burner is provided instead of a holder. An electric arc connects the metals (the ground cable is connected to the product, and the plus remains on the wire).
Application. Long, clean seams can be created thanks to the continuous addition of the additive. Because there is no slag in the weld pool, the welder should keep it under control. The gas fed from the cylinder through the burner nozzle acts as a shield from the elements. This method of welding is quick and can join metals with thicknesses ranging from 0.6 to 20.0 mm. Depending on the type of wire installed, you can weld ferrous metal, stainless steel, aluminum. But it would be best if you carried a balloon with you. The weld pool becomes defenseless even with the wind and works outdoors (the supplied gas is blown off).
TIG arc welding machines
Inverters do TIG welding. An electric arc exists here, but it burns between the product and the non-consumable tungsten electrode. The latter has a 1.6-3.2 mm diameter and is sharpened in the shape of a pointed cone. This enables the creation of narrow seams. Joints can be made both employing only welded edges and with the help of an additionally supplied additive with the welder’s free hand. The weld pool is protected by argon blown out of the torch nozzle.
Application. You may weld ferrous metals and stainless steel with direct current welding. For aluminum welding, there are different types of AC/DC fusing equipment. It will be possible to cook very carefully and economically with such equipment, but the method’s speed is significantly inferior to the semiautomatic device.
Universal welding machines
Welding machines with universal models combine multiple welding modes at the same time.
Here are the options:
- MMA + MIG. Cooking with coated electrodes and wire supplied from a drum is possible with this model. The first example is suitable for electrofusion cutting and serial fabrication of sheet metal parts or body repairs in the second.
- MIG + TIG. The semiautomatic device with the ability to connect an argon burner. Allows you to quickly suture stainless and ferrous metals using the MIG mode and join aluminum by switching to TIG.
- MMA + TIG. Inverter for welding with common electrodes and tungsten rods. Practical for alternating welding of ferrous and non-ferrous metals where high speed is not required.
- 3 in 1. The most versatile machines are capable of welding in MMA, TIG, and MIG modes. There are various slots on the front panel for connecting the appropriate burners for this purpose. This type of equipment is bought for the most diverse duties.
Spot welding machines
Spot welding machines are available in double-sided pliers or gun-and-hammer models for single-sided welding. The former is used for assembling thin-sheet structures (boxes, doors, gates, wickets).
The end is used in body repairs when it is required to weld to the plane without access to the backside. There are hand-held portable examples with a weight of up to 16 kg and stationary resistance welding machines. The thickness of the welded metal varies from 3 to 9 mm.
Plasma welding machines
These natures of devices use an electric arc burning in a nozzle between the cathode and the anode. Compressed air from the compressor is moved through it, which forms the plasma. Closing the mass on the product permits you to transfer the arc and make it not a duty but a cutting arc. If using filler wire, then this method is suitable for welding parts.
Gas welding machine
The apparatus here means an acetylene generator that generates gas by the interaction of carbide with water. Additionally, an oxygen cylinder is connected, supporting combustion and developing a flame temperature up to 3000 degrees. But recently used not devices, but simply couple cylinders (acetylene + oxygen or propane + oxygen). Then for welding, it remains only to purchase a torch and two sleeves.
The flame heats the edges of the metal, and the filler wire fills the weld pool and raises the weld height.
Application. This method is suitable for welding pipes and vessels with wall thicknesses up to 4 mm. Gas welding does not need electricity and can be carried out in the field, but the welding speed is shallow, and the probability of product deformation from heating is high.
Recognizing the difference in the types of welding machines by the power source and welding method, you can choose equipment for specific tasks, whether welding parts in a garage, body repair, or serial production of products in a workshop.