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Through Optimum Use and Innovation of Welding and Joining Technologies
Improving Global Quality of Life
4
Needs and challenges in welding and joining technologies
Another area of improvement of efficiency is the increase of temperature of combustion in any kind of gas
turbines. The related materials, for example Ti-alloys in aircraft engines, Cr-steels in steam turbines or super
alloys in the helium driven turbine for the 2020 pebble bed reactor all require special welding processes.
These have to be energy efficient and adaptable to the metallurgical needs of the related materials.
Welding of heavy gauge sections bears a tremendous potential of materials and energy saving. It should
be expected that EB-welding will be the process of choice for such visionary applications, already under
development now.
An education aspect of the EB welding process will be a serious challenge for coming decades. For successful
and wider implementation of the EB welding (which involves high degree of application flexibility) there
exists a need for more intense communication and transparency to the potential end-users.
4.3
Repair welds and material response
In order to extend service life of aging welded structures, there is need for advanced welding technologies
for repair. Most of the repair welding procedures are principally different from welding during fabrication
regarding the parameters, the weld sequences as well as the metallurgical conditions and the design
features. This means that ideal welding conditions cannot always be achieved during repair welding.
Additionally, poor material conditions of the component segments to be repaired might result from previous
service operation. Here, advanced welding simulation technologies need to be developed to predict final
microstructural conditions and the residual stress state of the repaired area to achieve optimum repair
welding procedures and prevent further problems.
Figure 4.7
Bronze-steel or bronze-cast iron
combinations are an economic method to produce
worm gears (Reproduced courtesy: Probeam)
Figure 4.8
Housing of a gas turbine being
prepared for EB welding (Reproduced courtesy:
Probeam)
