The electrode which we usually call ‘welding wire’ is the object used to perform electric welding. An arc of flame arises when the end of the welding wire as a burner is in contact with the welding metal.
Due to the large number of types of electrodes used for various types of welding processes, in order to facilitate their selection/identification according to the material to be welded and the method of welding, a symbol or code system was created that would be able to identify the types of protective coating materials, strength mechanics, position / method of welding and the type of current and electrical polarity desired.
Each of the advanced electric welding wire industry countries developed their own standard symbols, in this case for their own benefit, so that the number and types of symbols became very numerous. However, with the agreement between them, there are similarities or similarities in mechanical properties and chemical composition, so that a conversion list can be compiled for alternative uses if a party / owner wants the type of electrode made in a particular country. In general, electrodes can be divided into 2 groups, namely coated/coated electrodes and plain electrodes
What is meant by a coated electrode is a wire core material that is coated with a flux of certain chemicals according to the type of welding. SMAW welding wire that we usually use everyday includes a coated electrode. This electrode consists of two parts with different functions, namely:
1. Electrode Core Part, which functions:
As a conductor of electric current.
As an additive
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 Section, which functions:
- To provide a shielding gas to the metal being welded, protecting against air contamination when the metal is in a molten state.
- Forms a slag layer, which coats the weld resulting from air oxidation during the cooling process.
- Prevent the cooling process from being too fast.
- Easy ignition.
- Controls arc stability.
One of the classification systems for electrodes (welding wire) is the AWS filler metal specifications. AWS A5.1 is a welding wire (electrode) specification for welding carbon steel by the SMAW welding process. The following is an example from the AWS A5.1 specification.
welding electrode E6010
The letter “E” in the numbering/coding stands for Electrode. Then the 2nd digit, which is “60”, means the tensile strength is at least 60 ksi. The 3rd digit indicates the allowable welding position to produce the desired weld with the electrode. In the example above, the number “1” indicates that all welding positions can be used, namely flat, horizontal, vertical and overhead. The last two digits indicate the type of current and the type of the covering electrode.