Selection of Electrodes - Selection of a right kind of electrode for a particular application is very important to achieve desired properties in the welded joints. The choice of an electrode depends on the following factors
(a) Chemical composition of the base metal. In order to keep weld metal homogeneity the electrode should have chemical composition more or less g 3 similar to that of the plate to be welded.
(b) Thickness of work piece the values of electrode diameters for welding steel plates of different thicknesses. Preferably, electrode diameter should be less than the plate thickness.
(c) Nature of electrode coating (cellulose, rutile, low hydrogen etc.), arc behaviour and metal losses due to volatilisation and spatter.
(d) Positions (flat, horizontal, vertical, overhead), in which welding is to be carried out.
