1.0 INTRODUCTION
Welding is a material joining process used in making welds and a weld is a localised coalescence of metals or non metals produced either by heating the materials to suitable temperature with or without the application of pressure or by the application of pressure alone and with or without the use of filler material.
The various welding processes can be classified in many ways. They can be based on energy transfer, type of welding or mode of welding.