Challenges and developments in wire arc additive manufacturing of steel: A review

Wire Arc Additive Manufacturing (WAAM) offers significant potential for enhancing steel component production. This review addresses critical challenges associated with WAAM, including defect formation, process optimization, and property enhancement. The review categorizes defects, such as porosity, cracks, and lack of fusion, and correlating them with process parameters including wire feed rate and travel speed, to identify key factors influencing component quality. The existing literature reveal that porosity can reduce tensile strength by 15-20 % and fatigue life by up to 50 %, while cracks can lead to a strength reduction of up to 30 %. Strategies for mitigating these defects, including process optimization, post-processing techniques, and emerging technologies, are discussed. Specifically, strategies to control heat input, reduce residual stresses, and refine microstructure have been shown to significantly improve build quality, mechanical properties, and overall performance of WAAM-produced steel component. This review provides valuable insights for industry practitioners for overcoming existing challenges and advancing the application of WAAM in steel production.