Types of Welding Electrodes

Let’s first understand what welding electrodes are and where they are used. Welding electrodes are used to conduct current through a work-piece to fuse 2 pieces. They are in the form of metal wires that are baked on chemical coating. The rod is utilized to sustain the welding arc. They provide the filler metal for the joint that is to be welded. There are various types of welding electrodes available in the market. But it is good to select the right type of electrode as it is directly relative to the strength and quality of the welding process. 

3 Main Types of Welding Electrodes:

1. Consumable Electrodes – It is the type of metal that supplies electricity to the weld joint. As the electrode itself undergoes melting in the process of welding it gets consumed and thus it is named as a consumable electrode. It acts as a filler and thus it supplies necessary filler material that is required to fill the root gap. The material of this electrode is selected based on the base material considering the chemical compatibility issue. This electrode doesn’t allow the autogenous mode of welding as filler is applied inherently. It is mostly used in the MIG welding process. Arc welding processes that use consumable electrodes are Shielded Metal Arc Welding, Gas Metal Arc Welding, Flux-cored arc welding, submerged arc welding, and electro gas welding. 

Some of its features include – 

• It has a low melting point and thus it burns slowly and melts while in the welding process.
• It is less expensive and easy to use.
• It comes in different materials based on the metal that needs to be joint.
• Mild, low alloy and nickel steel are the common coating used for the consumable electrodes.

Further classification of Consumable Electrodes –

• Bare electrodes: It is mostly made up of steel or aluminum alloy. 
• Covered electrodes: It is made up of various materials like cellulose, rutile or titania, iron oxide, iron powder, or low hydrogen compound. 
• Light coated electrode: It has a coating factor of 1.25 e.g. citobest electrode.
• Medium coated electrode: It has a coating factor of 1.45 e.g. over cord.
• Heavily coated electrode: It has the coating factor of 1.6-2.2 e.g. Citofine electrode.

2. Non Consumable electrode – It is also known as a refractory electrode. It is neither consumed nor melted in the welding process. It is more long-lasting than the consumable electrodes. It is made up of the material that is having a high melting point. Although it is difficult to use, it has a variety of uses and also it can be used with various metals. It allows all 3 modes of welding I.e. autogenous, homogeneous, heterogeneous. As it has an extended life it does not require frequent replacement. Arc welding processes that use non-consumable electrodes are Gas Tungsten Arc Welding, Atomic Hydrogen Welding, and Carbon Arc Welding. 

Few of its features include – 

• It required filler metal to fill the gap between the 2 metal parts that are to be joined.
• It is majorly used in TIG and carbon arc welding.
• Tungsten alloy electrodes are more expensive than carbon counterparts.

Further classification of Non-consumable Electrode – 

• Carbon Electrode: It is used in arc welding and cutting. 
• Tungsten Electrode: It is used in TIG welding. It is suitable for lighter welding applications. 

3. Flux Electrode: It is a type of consumable electrode that has a flux coating. It generates gases as it decomposes to prevent weld contamination. It introduces deoxidizers to purify the weld. It improves arc stability and provides alloying elements to improve weld quality. There are different types of flux coating available for this type of electrode. A few of the types of flux coating include cellulose, rutile, iron oxide, hydrogen controlled and iron powder electrodes. 

Types of Welding Electrodes based on the material used:

1. Steel Welding Electrodes – Steel is one of the most common materials used for making welding electrodes. There are different types of steel alloyed rods such as mild, low alloy, and stainless steel. Flux coating is applied based on the application type of the electrode. 

2. Bronze Welding Electrodes – It is used for MIG and TIG welding of the cast and wrought. It has a high resistance to corrosion, erosion, and cavitations. It is mainly used to join copper metal pieces to other metals. It is also used to repair damaged bronze pieces by brazing.

3. Aluminum Welding Electrodes – It is used while joining the aluminum pieces and alloys that are unequal. They are majorly used with MIG, TIG and Arc welding tools. 

4. Composite Welding Electrodes – It is made up of the combination of layers of materials. It helps in producing a stronger and quality weld. A few of its examples are flux-cored welding rods and metal cored welding rods. 

Conclusion:

After analyzing all the factors it becomes easy for you to narrow down to the most appropriate welding electrode that is suitable for your project. As the right electrode helps you in producing strong and quality welds. Although it is difficult to find the right electrode from the available options, a wide range of electrodes makes it easy to find the correct solution for the required application type. You can also consult the experts in the field or try exploring the manuals and guides for the reference purpose. It will help in getting the details of the different welding electrodes and the metals used for their manufacturing.