Selection of Electrode in the welding process
As we know the electrode plays an important role in the welding process, and without it, welding work becomes almost impossible, the selection of electrode in the welding process can be determined and selected based on its chemical composition.
The electrode in the welding process; Mainly performs as an electric conductor and as a filler metal. In addition, the electrode can be classified into two parts based on the work, which is called the consumable electrode and the non-consumable electrode, the consumable electrode itself is melted and filled into the joint as weld metal. Today we will discuss the selection of electrodes in the welding process. Before the selection of electrodes in the welding process, we need to know about the chemical composition of the metal because many types of welding defects occur if the chemical composition of the metal will be different from the electrode. In which the main defect is cracked.
In the context of metal identification, many institutions operate internationally and play an important role in metallurgy and the systems that are used by metal manufacturing companies and organizations to identify and use metals. Some of these organizations made systems that are used worldwide like: AWS System, BS System, and IS System.
We have discussed about these in detail, in bellow article.
Standards and systems used by most metal fabrication organizations provide some codes for identifying metals that provide detailed information about the chemical compositions of metals and, based on these, the welding procedure is constructed.
Selection of Electrode in welding process
Codes provided by metal-producing institutions to consumer associations to identify various metals at the time of metal formation make it easy to find out what proportion of mixtures of other ingredients in the metal is and what class the metal belongs to and what type Electrodes must be used.In the classification of metals and the selection of electrodes in the welding process.
Here are the main facts such as: –
- Group Number
- UNS Number
- A number
- P number etc. are the main ones that show the correct composition of metals and their mixtures, chemical composition and impurities and based on which the selection of electrode in the welding process is simplified and helps in the construction of welding processors.
Group Number: –
The main objective of implementing this numbering system is to reduce the number of welding process qualification records (PQR). There are several procedural requirements for operating PQR which cause loss of both time and money such as:
Therefore, to reduce these activities, ASME has done the grouping of base metals and assigned some numbers to each group of metals. These are called group numbers.
F-number: For filler metals (electrodes) welding process specification (WPS) and the qualification of welders is done to reduce the number of implements. F is the basis of user attributes for number grouping. It is therefore assumed that if a welder can satisfactorily weld with particular filler metal, it will be able to weld with all filler metals belonging to that particular ‘F’ number.
|F 1 to F 6||Steel and steel alloy|
|F 21 to F 26||Aluminum and alloy|
|F 31 to F 37||Copper and alloy|
|F 41 to F 46||Nickel and alloy|
|F 51 to F 56||Titanium and alloy|
|F 61||Zirconium and alloy|
|F 71 to F 72||Hard Facing Weld Metal Over Lay|
An integrated numbering system for metals and alloys; A joint effort between ASTM and SAE has been done to produce special identification of material based on chemical composition. This system also serves to classify metals based on their chemical composition. The issue is discussed in http://www.theweldings.com/uns-system/
A number grouping also facilitates the selection of electrodes and extends the use of filler metal or filler metal. “A” number grouping is based on the chemical composition of the weld metal.
P number range
|Steel and steel alloy||P1 TOP15|
|Aluminum and alloy||P21 to P26|
|Copper and alloy||P31 to P35|
|Nickel and alloy||P41 to P49|
|Titanium and alloy||P51 to P53|
|Zirconium and alloy||P61 to P62|
Above mentioned processes make easy to identify the base materials to be welding. After identifying the base metal, the Selection of Electrode in the welding process will be more comfortable, the common welding electrodes information chart along with the base metal chemical composition detail can be download by clicking the download link below.