Welding in automatic or semi-automatic mode often takes place with the use of a consumable element such as flux wire. One of its main advantages is the ability to save gas, which would be spent on preventing oxidation.
Wire description
The most common use of flux wire is when it is necessary to work with metals such as copper, titanium and aluminum. Another feature concerns the weld. It turns out to be very smooth and quite durable. Most often, the main component is granular flux. Although this is not always the case, and there are cases when oxide is used, salt components. Also, in some cases, a combined type of salt oxide base is used.
Main advantages
Start with the fact that the flux wire has a high degree of melting. This allows you to apply it to work with refractory materials. In addition, a high welding speed is ensured during operation, and the working arc is characterized by stability and softness. The arc also burns evenly, which makes the seam even. One of the significant advantages is that after welding with flux wire from the weld it is enough to simply remove the slag coating.
In addition to the listed positive qualities, one can distinguish many others:
- good welding site protection;
- high speed of work is accompanied by profitability;
- it is possible to carry out melting to a sufficiently large depth, and during operation there are no splashes;
- no harmful volatile substances are released during operation;
- You can control the amount of oxygen that is contained in the weld;
- Using flux-cored welding technology helps optimize the weld structure.
It is worth noting that the protection of the welding section is possible just because the wire contains flux. Because of this, atmospheric gases do not reach the place of welding, which means that they do not oxidize the material being welded. It is worth noting that due to the presence of such a number of advantages, the flux wire for the semiautomatic device is used not only by amateurs for welding, but also by professionals.
The main areas of application
Most often, a welding machine that works using this type of wire is used to connect materials such as non-ferrous metal, alloy steel and other highly alloyed substances.
Depending on what needs to be welded, the composition of the flux will change. Suppose, if it is necessary to interconnect by welding a material that belongs to the group of low alloy steels, then oxide flux should be used. If you have to work with non-ferrous metal, then the flux welding wire must have a salt composition. For alloyed steel, a combined composition of oxide and salts is used.
In addition, another main parameter of the wire will change - the diameter. This indicator fluctuates in a rather large range, from 0.6 mm to 8 mm. Of course, the thicker the wire for welding, the more time it will take for it to melt. And the feed rate will already depend on this. Because of these factors, it turns out that if the thickness of the material is low or its composition can be easily welded, then using a thick wire is simply unprofitable.
Wire diameter selection
As already described above, when welding with flux wire, an element with a diameter of 0.6 to 8 mm is used. In addition to the feed rate, its melting speed also depends on this parameter. These several factors are very important and must be taken into account when choosing.
Suppose, in order to get the maximum possible straight seam, it is necessary that the wire is long. For example, if it is necessary to weld together a sufficiently refractory material, and the seam must be strong and thick, then the thickness of the electrode must be taken larger. If it is necessary to carry out work with sufficiently soft metals in terms of welding, then there is no need to use a thick wire.
If the diameter was chosen correctly and all the rules of the work are observed, then welding with flux-free wire without gas is able to provide high quality weld, high margin of safety and create a connection that will be resistant to weathering. These three factors allow the use of structures that are connected in this way even in places with extreme conditions, for example, in an area with high pressure.
disadvantages
Despite the large number of pluses, like any other thing, the wire has its own negative qualities.
Firstly, the cost of this type of element is quite high, which means that cooking with flux wire is not always profitable, in terms of cost or cost. Secondly, finding such an electrode on sale is much more difficult than any other. Thirdly, it also happens that even with the help of flux material, it is not possible to solve the problem of poor weldability of the material and it is necessary to spend money on additional measures, which further increases the cost of the process.
Varieties of wire
Today it is important to consider not only the thickness and diameter, but also what you need to work with.
For example, with regard to steel, it is impossible to use the same wire with the same parameters for any material, since they can be from different groups, for example, in terms of alloying composition. In addition, there is also such material as stainless steel. As for copper welding, it is necessary to use a consumable with a diameter of 0.8 mm, which is specially created for use with copper parts. Such a wire will help to improve the quality of the weld when welding with normal temperatures.
As for the main technical characteristics and their values, they are as follows:
- tensile strength is 480-580 MPa;
- yield strength from 400 to 490 MPa;
- elongation is in the range from 22 to 27%;
- as a protective gas, if necessary, you can use carbon dioxide.
Powder material
Today, flux-cored flux-cored wire is also actively used. It is a tube inside which a welding flux is placed, containing metal powder as an additive. It also has its own characteristics and can be used for different purposes, but in practice it is usually used only for welding low alloy steel or for not too strong carbon steel.
There are several basic requirements that apply to working with such a consumable.
First, the flux powder should provide a stable arc, as well as the ease with which it will appear. Secondly, during melting, there should be no spatter of material and uniformity of melting. Naturally, it is necessary that the final result, that is, the seam, has no flaws. During welding, slag will appear on the coating, which after cooling should easily be removed from the surface.
Types of Powder Welding Wire
Further, it is worth saying that there are different ways of using and protecting from external influences. According to these two criteria, flux-cored wire is divided into gas-shielding and self-shielding.
As for the first type, it is used in cases where it is necessary to work in automatic or semi-automatic mode, and low-alloy steel or low-carbon steel acts as the processed material. Carbon dioxide and sometimes its mixture with argon are also used during operation. If you choose the right flux powder, you can improve some welding parameters. For example, you can increase the speed of vertical welding or improve the strength of the joints of difficult to weld steel.
As for the application of such welding technology, it is relevant mainly for creating overlaps, as well as at corners of structures or at joints. As mentioned earlier, it can be used both in the automatic welding mode and in the semi-automatic one.
Self-protective wire
The peculiarity of the self-protective wire is that it is made in the form of an electrode that is “turned” inside out. A feature of the application is that welding with such a consumable can be used at very different and even extreme temperatures. In addition, work is permitted under strong gusts of wind and other similar weather conditions.
It is worth highlighting several more advantages that the self-protective type of wire for welding with flux powder has.
- makes it possible to carry out welding in any position;
- since the arc in this case is open type, that is, the ability to slowly move the processed metal;
- the wire is coated with a special substance that increases pressure resistance;
- it is possible to control the chemical composition, which means that you can get a certain slag composition if necessary.
Powder Welding Benefits and Reviews
As for the advantages that powder welding has, these are all points regarding open methods and semi-automatic. In other words, there are no such problems as in the case of a protective gas stream that can blow off a strong wind.
If we talk about the main advantage of welding with wire from this category, then this is the lack of need for lengthy preparatory work.
Reviews about the flux wire and about working with it are quite good, but there are also bad ones. The bottom line is that for a small amount of work, the wire fits perfectly and costs less than a gas cylinder. However, in the event that it will be necessary to cook a lot, then constantly buying such a consumable will be very expensive, this is the main problem. It’s worth buying wire if you don’t need to cook too much.