On June 11, 2026, the Estrel Hotel in Berlin will host the third edition of WAAMathon, the only conference dedicated exclusively to Wire Arc Additive Manufacturing. Organized by Berlin.Industrial.Group., the event brings together engineers and industry leaders to discuss the practical realities of process optimization and material handling. While WAAM is a relatively young technology, it has reached a level of maturity that allows for a focus on real-world applications and the integration of these systems into established industrial workflows.
One highlight of this year’s program is a presentation by Sebastian Recke (Senior Key Account Manager at GEFERTEC) and René Liers (WAAM Project Manager at Siemens Energy) titled “Significant advantages of 3D printing for service parts and serial production.” Using steam turbine vanes as a central case study, they will trace the journey of a component from its initial CAD/CAM design through to final serial production. Their insights offer a clear look at how WAAM is being used to rethink spare parts strategies and improve manufacturing efficiency. We interviewed both experts to dig deeper into their findings ahead of the event. You can read the interview below and register for WAAMathon HERE to join the discussion in Berlin.
Sebastian Recke (Left) and René Liers (right)
3DN: WAAM is often chosen for its deposition rates. What specific limitations of traditional casting or forging for steam turbine vanes led Siemens Energy and GEFERTEC to settle on WAAM as the superior alternative?
René Liers: Traditional manufacturing of steam turbine vanes is heavily constrained by material procurement and material efficiency. The flat stock used for milling the twisted stator vanes has to be sourced internationally, with lead times stretching to several months due to supply chain dependencies. At the same time, the complex geometry of the vanes results in machining volumes of up to 70 percent, leading to high material waste, long machine times, and significant tool wear.
Alternative additive approaches such as powder-bed processes were evaluated early on but proved too slow and uneconomical for the component size and required throughput. WAAM, by contrast, offered a combination of high deposition rates, the ability to produce near-net-shape geometries, and the use of standard, readily available welding wire. That makes it a far better fit for industrial serial production.
3DN: You mention moving from “initial idea to CAD/CAM.” What were the most significant hurdles in developing a digital workflow that could handle the complexities of turbine vane geometries while ensuring structural integrity?
Sebastian Recke: One of the main challenges was translating the highly twisted geometry of turbine vanes into a stable, repeatable WAAM process. Unlike conventional machining, the additive process required close coordination between CAD design, CAM programming, and process parameters to ensure consistent layer buildup and dimensional accuracy.
In parallel, structural integrity had to be proven from the outset. With no applicable standards available, the workflow development went hand in hand with extensive validation measures, including CT scanning, destructive testing, metallurgical analysis, and chemical verification. The resulting insights were continuously fed back into the digital workflow and machine parameters until a stable, qualified process suitable for serial production was achieved.
The twisted geometry of turbine vanes was difficult to translate into a highly repeatable WAAM process.
3DN: For service parts in high-stress environments like steam turbines, material properties are non-negotiable. How do the mechanical properties of these WAAM-produced vanes compare to their traditionally manufactured counterparts?
Liers: The mechanical properties of the WAAM-produced vanes were validated through an extensive qualification phase. Early production batches underwent 100 percent CT inspection to detect porosity, complemented by destructive tests for hardness and bending strength as well as detailed metallurgical examinations.
Recke: Based on these results, the process parameters were systematically optimized. The outcome is a stable manufacturing process whose quality assurance requirements in serial production are comparable to those used for cast components. Today Siemens can rely on sample inspections rather than full testing. In practice, this has demonstrated that WAAM-produced vanes meet the necessary mechanical and material requirements for use in steam turbines.
3DN: Many companies successfully print a “one-off” part, but moving into serial production is a different feat. What were the critical milestones in scaling the GEFERTEC process to meet Siemens Energy’s production volume requirements?
Liers: The decisive milestone was the full qualification of the WAAM process for serial production. This included establishing reliable automation within the arc machine, defining stable parameter sets, and validating the process through exhaustive inspection and testing during the initial production runs.
Another key step was optimizing machine utilization. By producing nine or sixteen turbine blades simultaneously, idle times were eliminated and the machine’s capacity was fully exploited. Today, the process runs largely unattended in a three-shift operation and has already delivered well over 3,000 turbine blades, demonstrating its robustness at an industrial production scale.
Turbine vanes created via WAAM
3DN: Beyond speed and cost, what impact does moving to WAAM have on the CO2 footprint of part replacement, considering reduced material waste and localized production?
Recke: Beyond lead time and cost, WAAM has a relevant impact on the CO₂ footprint through its much lower material demand. In conventional manufacturing, a substantial share of emissions is already generated during the production of the semi-finished material itself. When up to 70 percent of that material is later removed during machining, the associated CO₂ burden is effectively lost. By reducing the machining volume to around 20 percent, WAAM directly lowers the amount of primary material required and with it the embedded CO₂ emissions.
In addition, the use of standard welding wire instead of internationally sourced flat material shortens supply chains. Taken together, these effects lead to a measurable reduction in the overall carbon footprint of part replacement.
3DN: Could you provide a “then vs. now” comparison? What does the lead time look like for a steam turbine vane via traditional sourcing versus the GEFERTEC/Siemens Energy WAAM workflow?
Liers: Traditionally, lead times were dominated by raw material procurement, which could take several months, especially when sourcing flat stock internationally. This made it difficult to respond flexibly to customer demands for shorter delivery times.
With the WAAM workflow, these dependencies are largely eliminated. Standard wire material is readily available, and components are produced directly to near-net shape. As a result, delivery times have been reduced by up to 75 percent, enabling much faster response times for both new builds and service parts.
Using WAAM reduces lead times thanks to the availability of standard wire material.
3DN: Now that steam turbine vanes have proven the concept for serial production, what other high-criticality components are currently in your sights for the WAAM treatment?
With the successful serial production of turbine vanes, attention is increasingly turning to other components where WAAM can unlock similar benefits. In particular, parts that suffer from high material waste in conventional machining or face long procurement times are strong candidates.
In parallel, the WAAM process opens up new design possibilities that are not feasible with subtractive manufacturing alone. Ongoing development work between Siemens Energy and GEFERTEC focuses on increased automation, integrated quality monitoring, and leveraging additive design freedom for future high-criticality turbine components.
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*Cover Photo Credits: WAAMathon