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Arc welding, how to choose the right welding machine, types of arc welding machines
In the arsenal of any zealous owner, there are many devices and tools designed for independent work of various kinds. Among them there are a chainsaw, a jigsaw and, of course, a welding machine, without which it is extremely difficult to do to connect parts during the installation of metal parts of any structure. Choose a device for welding, based on power, ease of use and the specific purpose of the destination (professional welding or home use).
Content
- Types of welding machines video
- Welding rectifier
- Welding transformer
- Inverter
- Arc welding technology video
- How to choose electrodes for electric arc welding
Types of welding machines
First of all, it should be noted that absolutely all devices for welding have almost the same principle of operation - they weld / melt the metal using alternating or direct current. Distinguish only power sources and welding current conversion for the unit and consumables that are used in the welding process. Classify devices by current source can be:
- Welding rectifiers
- Welding transformers
- Inverters
Welding rectifier
An apparatus that converts alternating current into direct current is called a rectifier. This is a rather complex and bulky device, which, nevertheless, allows you to impose a very high-quality, almost jewelry seam. The quality can be achieved due to the fact that the rectifier ensures the stability of the welding current, which allows you to easily keep an electric arc.
The main disadvantage of this unit is its large weight, which does not allow you to move the device to the right place and excessive consumption of electricity. In addition, working on this device requires special knowledge and skills.
Welding transformer
Until recently, it was considered one of the most durable and traditional types of welding machines. This device, on the contrary, converts direct current into alternating current, lowering the mains voltage, to the necessary voltage - welding. This happens due to the presence of a transformer unit. Arc welding on this machine requires special electrodes for alternating current and the necessary skills. Without knowledge of the principle of operation of this device, the ability to weld and hold an electric arc, it is unlikely to be able to weld at least anything of high quality.
The main advantage of the transformer is its extraordinary durability and rather low cost.
The downside is the heavy weight and the need for special electrodes, which often do not exist on sale.
Inverter
Inverter welding machines, without exaggeration, can be called the most popular. There are several explanations for this at once.
- Firstly, the compactness and low weight of the unit.
- Secondly, the ability to connect to the consumer electricity network without any problems.
- Thirdly, the possibility of high-quality overlay welding seams.
Manual electric arc welding, performed using an inverter, is characterized by a minimal slagging of the seam, which allows you to perform work as efficiently as possible, without unnecessary snot and air cavities. In addition, each inverter-type apparatus has a built-in hot start function (Hot start), which allows you to ignite the electrode with one touch, while avoiding the usual sticking in contact with a metal part.
The principle of operation of the inverter is based on technology that allows you to use an ordinary home outlet as a current source. The current flows to the rectifier and is smoothed by a special filter. The resulting direct current is converted by transistors into alternating, high-frequency current.
Arc welding technology
Mastering the technology of electric arc welding, if desired, is easy. To do this, you only need a current source, consumables (electrodes) and a burning desire to learn welding yourself.
This technology is a process of welding various pieces of metal with each other, through the heat generated by an electric arc.
The first and extremely important stage of work is the preparation of the workplace. To do this, ground the equipment and the parts to be welded. Most often, a three-wire cable is used for this, with wires insulated from each other.
The first two cores are used to connect to a current source, and the third to a grounding device, by connecting it to a grounding bus and a grounding bolt.
The second step is to select the diameter of the electrode and adjust the intensity of the welding current. These parameters directly depend on the thickness of the metal. You can adjust the settings after applying a test seam.
The third stage that the novice welder has to master is directly himself welding process.
In order to just start the welding process, you need to remember that the electrode must be kept at an angle of 15 degrees, and it must certainly be inclined towards the weld. This situation needs to be worked out to automatism.
Next, you need to master the simplest methods of suturing.
The simplest way to weld, is to draw with the end of the electrode, the so-called figure eight along the connection line. This method is often called welding for dummies, because it is extremely easy to learn. Further, more complex options for connecting the metal can be learned after you have gained sufficient experience working with welding equipment, and the hand itself begins to feel the height of the electric arc.
How to choose electrodes for electric arc welding
The quality of the weld, directly depends on which electrodes were used in the work.
Electrodes for welding are divided into several categories:
Non-metallic, made from coal or graphite. During welding, they do not melt. They are used for thin welding even on sheet metal.
Metal, divided into melting / non-consumable and select them based on the grade of metals to be welded.
There are electrodes for alloyed, high alloyed and low alloyed steels, as well as for welding.
For welding machines that generate direct current, almost any electrodes that can be selected simply by diameter, based on the thickness of the parts to be welded, are suitable.
Units generating alternating current need a more careful selection of consumables. For them, it is best to purchase universal electrodes that are suitable for both direct and alternating current.
Electrodes of this type have many advantages, among which last place is:
- Great performance
- Profitability and low level of dispersion of metal
- Possibility of applying a high-quality seam even to rusty and wet parts prepared for welding.
- Possibility of use on almost any welding equipment.
- Good arc retention.
When purchasing universal electrodes, do not look for cheap products. They, as a rule, do not correspond to the declared technical characteristics. It is better to give preference to more expensive brands, which will be much better and the seam applied with their help will please with their reliability and accuracy.
