In the context of growing environmental concerns and the demand for more sustainable manufacturing practices, this study evaluates the environmental and economic performance of two production routes for a stainless steel support block used in steel mills. A comparative Life Cycle Assessment (LCA) and Life Cycle Costing (LCC) were conducted to assess a conventional subtractive manufacturing process based on Computer Numerical Control (CNC) machining versus a hybrid approach that combines Plasma Arc-Wire Arc Additive Manufacturing (PA-WAAM) with CNC finishing. The LCA was carried out using ReCiPe 2016 Midpoint and Endpoint methodologies in SimaPro, while the LCC employed a cradle-to-gate cost model. Results showed that the hybrid WAAM-CNC route reduced average environmental impacts by 49% across 18 categories and decreased steel consumption by approximately 70% due to near-net-shape fabrication. Although the hybrid method incurred an approximate 3.5 times increase in unit production cost, this was primarily attributed to equipment investment. In contrast, operational costs such as labor, materials, and consumables were significantly lower—by 66%, 28%, and 45%, respectively. These findings support the hybrid approach as a more sustainable manufacturing alternative with the potential for long-term cost optimization as additive technologies mature.

This study investigated the influence of printing parameters and strategies on the morphological characteristics of austenitic stainless steel beads deposited on carbon steel substrates, using plasma directed energy deposition (DED). The experimental setup varied the welding current, wire feed speed, and torch travel speed, and we analyzed three printing strategies: simple-linear, overlapping, and oscillating. Moreover, advanced 3D scanning and computational analysis were used to assess the key morphological features, including bead width and height. The results showed that the computational model developed by using parabolic assumptions accurately predicted the geometric outcomes of the overlapping beads. The oscillating printing strategy was the one that showed improved morphological uniformity and bead substrate wettability, so these features were used for multi-layer component manufacturing. The use of equivalent wavelength–amplitude values resulted in maximum combinations of bead height and width. Moreover, cost-effective carbon steel substrates were feasibly used in microstructural and elemental analyses, with the latter ones confirming the alignment of the bead composition with the wire-fed material. Overall, this study provides practical insights for optimizing plasma DED processes, thus enhancing the efficiency and quality of metal component manufacturing.

Directed energy deposition process needs a substrate, as a base for depositing layers of material, which is discarded after manufacturing. This study showed the feasibility of incorporating a substrate into the final product to reduce material waste and energy. For this purpose, double sided walls-substrate austenitic stainless steel structures were produced by Wire Arc Additive Manufacturing (WAAM). To assess the viability of this approach, mechanical tests such as tensile, hardness, and impact flexure tests were conducted on printed specimens, which were extracted through electrical discharge machining. This was completed with a fractographic analysis of the tested samples. A metallographic analysis was also performed both to assess the internal structure and to evaluate the effects of substrate integration on mechanical properties, thus showing various structural transitions across the bead-substrate interface, including the presence of vermicular and skeletal ferrite within an austenitic matrix. An EDX analysis showed chemical composition variations across the interface. Additionally, energy and cost assessments showed an 8% reduction in material usage, an 8.7% reduction in manufacturing time and an 8.4% reduction in energy consumption and associated $$\hbox {CO}_2$$ CO 2 emissions through substrate integration. The results confirmed the feasibility of integrating substrates into WAAM-fabricated components while maintaining mechanical characteristics within the expected range for stainless steel structures.