Final answer:
For large structures, submerged arc welding (SAW) is the most ideal process due to its efficiency, high deposition rate, and capability of handling heavy-duty tasks. It is preferred over laser, electron, brazing, and tungsten welding methods for large structural projects.
So option (E) is correct
Step-by-step explanation:
For large structures, the most ideal welding process is often submerged arc welding (SAW). This process utilizes a granular flux that covers the weld, thus preventing spatter and reducing ultraviolet radiation. Due to its high deposition rate, efficiency, and deep weld penetration, SAW is favored for heavy-duty tasks, such as those involving steel structures, shipbuilding, and large machinery. Unlike processes such as laser or electron welding, submerged arc welding is better suited for the substantial material thicknesses and extended welds typical of large structural projects.
Other methods, like brazing, are typically used for joining different metals or for situations where lower temperatures are required, which may not be suitable for load-bearing structures. Tungsten arc welding, also known as TIG welding, is utilized for its precision and control but isn't typically geared towards the scale of work that large structures demand. Finally, the options of laser or electron beam welding can provide precise, high-quality welds but are often more expensive and require more intricate setup and operations, in contrast to the straightforward and robust nature of SAW for large-scale applications.