A benchmark of mechanical properties and operational parameters of different steel filler metals for wire arc additive manufacturing

Additive manufacturing processes play a disruptive role in several industrial sectors. Among them, wire arc additive manufacturing (WAAM) is a very promising process for the production of large-scale steel components and structures. As a common characteristic of innovative technologies, this process requires additional research and experimental work in order to understand how its thermal cycles will modify the mechanical and metallurgical properties of the manufactured components. Considering the lack of literature on the properties of WAAM components from specific steel alloys, the present work proposes a benchmark evaluation of five different steel filler metals based on their mechanical properties and operational parameters when applied for additive manufacturing. The mechanical properties, such as the tensile strength, yield strength, elongation, Charpy impact toughness, and hardness, were evaluated together with operational parameters such as cost, printability, spatter, and fume formation during manufacturing, defect-free printing, and heat input. These were analyzed in order to obtain a full evaluation and comparison of the five filler metals. The experimentally determined results of every above-mentioned aspect were higher or similar to the values found in the literature for generic steel filler metals used in additive manufacturing. This means that a designer or welding engineer can select the WAAM steel filler metal for further testing based on the welding wire datasheet. Besides that, a comparison was performed between blocks manufactured by WAAM with some frequently used base metals, in plate format, confirming its applicability.