Why is it not uncommon for the selected filler metal to have

Why is it not uncommon for the selected filler metal to havea chemical composition that is different from the material being welded

Solution

1)Welding alloys, also known as filler alloys, are consumables used during a welding process to fill in the gap between two edges being joined. The filler alloy melts into the weld pool along with a portion of the base metals of the work piece and solidifies into a weld joint metal. The composition of the weld joint metal is a mixture of the filler alloy and base metal.

2)The base metal refers to the composition of the workpiece being welded. Welding alloys, sometimes referred to as welding electrodes, must be compatible with specific base metals being welded. Typically, welding filler alloys are similar in composition to the base alloys or alloys of the parts being joined. Welding alloys or welding filler alloys forms melt with the base alloys of the parts being joined to fuse the parts together. The filler alloy selected should not form any brittle compounds when alloyed with base alloys of the parts.

3)When two different alloys are being joined, additional research is required to determine the welding alloy compatible with both alloys. In some cases, the two different alloys are incompatible due to melting points, exothermic heat of mixing, insolubility, brittle phase formation, and corrosion factors. In these cases a bimetal or trimetal transition joint may be used to weld dissimilar, incompatible alloys that would normally form brittle compounds. In other cases, welding should be abandoned due to non-weldability of the base metals or due to the release of toxic