For efficient and economical fabrication, the choice of welding processes should primarily be based on productivity and cost factors, together with material and weld position considerations.
Shielded Metal Arc Welding (SMAW)
• Versatility - readily applied to a variety of applications and a wide choice of electrodes
• Relative simplicity and portability of equipment
• Low cost
• Adaptable to confined spaces and remote locations
• Suitable for out-of-position welding
• Not as productive as continuous wire processes
• Likely to be more costly to deposit a given quantity of metal
• Frequent stop/starts to change electrode
• Relatively high metal wastage (electrode stubs)
• Current limits are lower than for continuous or automatic processes (reduces deposition rate)
Submerged Arc Welding (SAW)
• Lends itself to the production of consistently high quality welds with minimum operator skills.
• Minimum of welding fume and of arc visibility (radiation).
• Well suited to welding thick sections.
• Suitable for welding carbon, low alloy and alloy steels.
• Relatively high metal deposition rates
• Flat or horizontal position welding only
• Care required to preserve correct electrode alignment, as electrode
• Tip and weld pool are underneath solid flux cover
Flux Cored Arc Welding (FCAW)
• Versatility - suitable for a variety of positions and applications
• Capable of relatively high deposition rates
• Enables “one process” operation for individual projects – simplifies training, supervision and logistics
• Incorrect selection of consumables and parameters may lead to lower weld toughness
• Potential for lack-of-fusion type defects if welding parameters are incorrect or misalignment occurs
• Fume extraction may be required
Gas Tungsten Arc Welding (GTAW)
• Applicable to a very wide range of materials.
• Especially good for welding thin sections and delicate workpieces
• Capable of producing welds of high quality and appearance
• Generally restricted to flat or horizontal welding