Wire arc additive manufactured (WAAM) steel components for structural applications.

Realizing weight reduction is a very important driver for civil constructions and offshore installations to reduce material consumption, fabrication, transportation and erection costs, as well as environmental impacts. Today, critical structural steel components demand for more advanced design leading to shape optimization against economic and strength constraints. Most of these components involve complex shapes, and, therefore, additive manufacturing is the key process of fabrication. With the simple use of wire-arc additive manufacturing (WAAM) and high deposition rates, complex geometries can be quickly produced, and one can reach extremely high levels of material’s capacity utilization. That is why it has become popular to produce highly efficient structures where the material is perfectly utilized. But the manufacturing process leads to quite different macro-mechanical and micro-structural properties lowering the fatigue resistance and resistance to corrosion. However, the fatigue and corrosion behaviours, and their combined effects on steel parts made by WAAM processes were so far scarcely researched. Therefore, in this research, the unexplored characteristics of robotic WAAM structural components when subjected to (i) fatigue problems due to cyclic loading; (ii) localized deterioration due to corrosion and (iii) their combined effects, will be thoroughly studied both experimentally and theoretically.