Correct Electrode Selection
As a rule, selection of an electrode is as straight forward as picking one that is of a similar chemical composition to the parent metal. However, for some metals there is a choice of several electrodes, each of which has particular properties to suit specific classes of work.
Firstly, select a stick electrode that matches the strength properties and composition of the base metal. For example, when working on mild steel, generally any E60 or E70 electrode will work.
Next, match the electrode type to the welding position and consider the available power source. Remember, certain electrodes can only be used with DC or AC, while other electrodes can be used with both DC and AC.
Assess the joint design and fit-up and select an electrode that will provide the best penetration characteristics (digging, medium or light). When working on a joint with tight fit-up or one that is not beveled, electrodes such as E6010 or E6011 will provide digging arcs to ensure sufficient penetration. For thin materials or joints with wide root openings, select an electrode with a light or soft arc such as an E6013.
To avoid weld cracking on thick, heavy material and/or complicated joint designs, select an electrode with maximum ductility. Also consider the service condition the component will encounter and the specifications it must meet. Will it be used in a low temperature, high temperature or shock-loading environment? For these applications, a low hydrogen E7018 electrode works well.
Also consider the production efficiency. When working in the flat position, electrodes with a high iron powder content, such as E7024, offer higher deposition rates.
For critical applications, always check the welding specification and procedures for the electrode type.
Often one electrode in the group will be more suitable for general applications due to its all-round qualities.
The below table demonstrates just a few of the wide range of electrodes from ISOARC with their typical areas of application
A premium quality electrode for general structural & sheet metal work in all positions including vertical- down using low carbon steels.
An iron powder electrode for high speed welding for H-V fillets & fat butt joints. Medium to heavy structural applications in low carbon steels.
A premium quality, all positional hydrogen controlled electrode. Used for carbon steels in pressure vessel applications & where high integrity welding is required. It is used for free machining steels containing sulphur.
Rutile basic coated low carbon electrodes for welding austenitic stainless steel.
Rutile basic coated low carbon electrode for welding mild steel to stainless steel & difficult to weld material.
As an example, the average welder will carry out most fabrication using mild steel & for that he has a choice of various standard ISOARC electrodes, each of which will have qualities suited to particular tasks. For general mild steel work, ISOARC Vytex electrodes will handle virtually all applications. It is suitable for welding mild steel in all positions using AC or DC power sources.
It has easy striking characteristics & tolerance for work where fit-up & plate surfaces are not considered good, making it the most attractive electrode of its class.
Continuous development & improvements of ISOARC Vytex have provided in-built operating qualities which appeal to the beginner & experienced operator alike.
For further advice on the selection of electrodes for specific applications, or to obtain a copy of the Welding Consumables Selection Chart, contact your local Thuthuka representative on 011 918 5270.