Industry has thoroughly studied the microstructure, mechanical properties, and the effect of heat-treatments on mild and low-alloy steel fusion welds, with particular attention being focused on the heat-affected zone of the base metal adjacent to the welds.  Recently, with the advent of wire-arc additive manufacturing (WAAM), the focus can be directed at the weld deposit as a discrete material and product form.  The WAAM process is a production method that progressively casts products into net or near-net shapes from standard welding consumables and is becoming a viable alternative to low-volume forgings, castings, or creating attachments to other product forms.    

Steels created using standard welding consumables as the feedstock for the WAAM process have the potential for widespread use on critical applications, including structures and pressure vessels, when the effects of post-processing steps such as heat treatment and other factors are better understood. This paper will summarize the results of studies on the mechanical and metallurgical properties, including the directional properties, of WAAM steels.  In addition, the effects of post-printing heat treatments (quenching, tempering, stress-relieving, normalizing, and annealing), on a variety of mild and low-alloy steel deposits will be presented. 

Jim Galloway
Welding Professor 
Conestoga College