About Electrodes and Types of SMAW Welding Wires


Fitter mate must know the name of the electrode because this thing is a basic requirement of fitter work. But maybe my friend fitter did not have the time or did not care about 'what exactly is the electrode? The following explanation hopefully can add to our insight as a fitter. Electrodes that we usually call 'welding wires' are objects used to conduct electrical welding. Flame arises when the tip of the welding wire as a burner is tangent to the welding metal.

In general, Electrodes can be divided into 2 groups:

1. Webbed / coated electrodes

2. Plain electrodes

Webbed Electrodes

What is meant by a webbed electrode is a core material of wire coated (flux) of certain chemicals adapted to the type of welding?

The SMAW welding wires that we use every day are included as webbed electrodes. These electrodes consist of two parts with different functions, namely:

1. Electrode Core Parts, which function:

-As a conductor of electricity.

-As an added ingredient

For materials, the electrode core is made of ferrous and non-ferrous metals, such as carbon steel, alloy steel, aluminum, brass, and others.

2. Electrode Coating Parts, which function:

-To provide protective gas to the welded metal, protect air contamination when the metal is liquid.

- Form a slag layer, which coats the welding results from air oxidation during the cooling process.

-Prevent the cooling process so it is not too fast.

-Easy to ignite.

-Control the stability of the bow.

Definition of Flux / Electrode Coating

Flux is a part that lines the core of a welding wire made from a mixture of special chemicals with different percentages for each type of electrode. Types of flux-making chemicals such as cellulose, calcium carbonate (Ca C03), titanium dioxide (rutile), kaolin, potassium manganese oxide, iron oxide, iron powder, silicon iron, manganese iron and so on.

The flux coating on the core wire can be by means of destruction, spray or dip. The thickness of the membrane ranges from 70% to 50% of the diameter of the electrode depending on the type of membrane. At the time of welding, this electrode membrane will also melt and produce CO2 gas that protects the welding fluid, electric arcs and some workpieces against the outside air. Outside air containing O2 and N will be able to influence the mechanical properties of the Ias metal. The membrane fluid called slag will float and freeze over the hot welding surface.

The coating on the electrodes that have been opened from the wrapper must be stored in a heating cabinet or oven at a temperature of 15 degrees higher than the temperature of the outside air because the coating is very sensitive to moisture.

If left moist, it will cause the following things:

The coating is easy to peel off, making it difficult to ignite
Excessive spark
Foam is not stable
Excessive smoke

Types of SMAW Welding Wire

Friend fitter, Types of Welding Wire or other designations 'Eektroda' can be distinguished vary depending on how to use and the type of material being welded, including:

- Soft Steel Electrodes

- Nickel Electrodes

- Aluminum electrodes

- Cast Iron Electrodes

- And others

What we discuss on this occasion is about electrodes for soft steel that we often encounter in the field (site).

Soft Steel Electrodes

Basically the types of soft steel electrode wire cores are made of the same material, the difference lies in the type of membrane (flux). Here are some types of electrodes that are commonly used:

       1. E 6010 and E 6011

This electrode is a type of cellulose membrane electrode that can be used for slurry with deep penetration. Welding can be in any position and thin slag can be easily cleaned. Welding deposits usually have good mechanical properties and can be used for work with radiographic testing. Cellulose membrane with 5% wetness at the time of welding will produce a protective gas. E 6011 contains Potassium to help stabilize the arc when AC current is used.

       2. E 6012 and E 6013

Both of these electrodes are rutile membrane types that can produce moderate penetration. Both can be used for welding all positions, but most types of E 6013 are very good for downright or downward welding positions. Type E 6012 can generally be used at relatively higher amperes than E 6013. E 6013 containing more potassium makes it easier to use at low engine voltages. Small diameter electrodes are mostly used for thin plate welding.

       3. E 6020

This type of electrode can produce moderate weld penetration and the slag is easily removed from the weld layer. The electrode membrane mainly contains iron oxide and manganese. Slag liquid that is too liquid and easily flows is suitable for flat welding but makes it difficult for welding with other positions such as vertical and overhead positions.

       4. Iron Powder Electrodes

Electrodes of this type include E 6027, E 7014. E 7018. E 7024 and E 7028 contain iron powder to increase welding efficiency. Generally, the electrode membrane will be thicker as the percentage of iron powder increases. The presence of iron powder and increased thickness of the membrane will require higher amperage.

       5. Low Hydrogen Electrodes

Electrodes of this type include E 7015, E 7016 and E 7018.

This type of electrode membrane contains low hydrogen (less than 0.5%) so that the weld deposit can also be free of porosity. These electrodes are used for welding that requires high quality, free of porosity, for example for welding of pressure vessels and pipes. Besides that, the use of these electrodes is also widely used in fabrication and construction workshops.

Thank you for reading about SMAW Electrodes and Types of Welding Wire.

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