How to select the right welding electrode

The installation for electrode welding consists of a welding machine, an electrode holder, and a ground clamp. The terminals are positive and negative for the current flow. Different types of electrodes will require different polarities. This means that if the DCEP (Direct Current positive electrode) terminal is specified, the fuse is connected to the anode.

Factors before selecting welding electrode:

• Base Metal- 

1. The mechanical properties especially the tensile strength of the electrode and that of the base metal should be similar or as close as possible.
2. Differences in tensile strength between the welding electrode and base metal, there will always be the possibility of cracking and other intermittent welds. Therefore, to avoid cracks and other interruptions in welding, we should always choose an electrode having a minimum tensile strength equivalent to the strength of the base metal being welded.
3. When choosing an electrode, the thickness of the base metal is important. For thinner materials, an electrode with a soft arc and less penetrating power can give good results but for thicker materials, we need a straight arc electrode for maximum penetration, maximum ductility, and low hydrogen content for a perfect welding rod supplier.

• Power Supply-

1. Some electrodes can be used with alternating current (AC), some can be used with direct current power (DC) supply and some electrodes work well with both AC as well as DC. 

• Joint Preparation: 

1. The third factor to consider when choosing an electrode is joint preparation or groove configuration. If there is a tight spot or the root surface is not beveled, an arc bore electrode can be used for deeper penetration. 
2. For this purpose, Electrodes such as E6010 or E6011 can be used. If there is enough space between the root and the root chamfer, we can use electrodes with medium or low penetration, such as E6013 or E7018.
3. SMAW electrode arrays can be implemented in the following ways; 
4. Rapid Cooling Electrode
5. Filling Electrode Cooling 
6. Low Hydrogen Content

• Welding Quality/Weld finish:

1. The required weld quality and finish are also important factors to consider before choosing an electrode. Welding electrodes manufacturers in India, select based on finishing requirements such as flat, concave, or convex.
2. The quality of the weld should be consistent with the operational requirements of the job. For example, for ss 304 welding rod price and parts of cryogenic vessels that have to operate at very extreme temperatures and pressure with high impact loading or parts in an aggressive atmosphere, we needed an electrode with a low hydrogen content, such as the E7018, that could produce very strong welds with higher ductility.