Advanced Welding Processes: Technologies and Process Control

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Advanced welding processes
∑ reduced repair rates;
∑ reduced joint preparation time;
∑ removal of the operator from hazardous area;
∑ reduced weld size;
∑ reduction in post-weld operations;
∑ improved operating factor;
∑ reduction in potential safety hazards;
∑ simplified equipment setting.
Some or all of these requirements have been met in many of the more
advanced process developments which have occurred; these will be described
in detail in the following chapters, but the current trends in the application of
this technology are examined below.
2.5 Process application trends
Several important trends may be identified on an international level in the
application of welding processes; these are:
∑ process change in consumable electrode arc welding processes;
∑ the increased use of automation;
∑ increased interest in new processes (e.g. laser welding);
∑ the requirement to fabricate advanced materials.
2.5.1 Consumable trends
The use of GMAW and flux cored arc welding (FCAW) processes at the
expense of traditional MMA welding is evident in many industrialized countries.
The figures for the production and consumption of welding consumables in
the UK, Japan and the USA are shown in Fig. 2.6. [19] The latest figures [20]
indicate that the amount of welding performed with MMAW electrodes will
stabilize at between 10 and 20% in industrialized countries, whilst slightly
higher figures would be expected in the developing countries. The use of
submerged arc consumables has already stabilized at around 13% of deposited
weld metal. [21]
This trend illustrates the importance of establishing the overall cost of the
welding operation; the flux-cored consumable is inevitably more costly to
manufacture and often more than four times more expensive to purchase
when compared with the solid wires used for GMAW. The increase in deposition
rate, higher operating factor, improved process tolerance and enhanced joint
quality can, however, result in a reduction in the overall cost of the weld in
spite of the higher consumable costs. The total cost will depend on the
application; it can be shown for example that for a simple 6 mm horizontal/
vertical fillet GMAW welding with a solid wire gives the lowest overall cost,