Have You Met SAM: Steel Additive Manufacturing

“Have you met SAM?” This question was on a banner above our stand at Formnext last November.  We believe the usage rate of additively manufactured steel parts is far too low. Currently, the Steel Additive Manufacturing (SAM) market is reported to be roughly 3 thousand tonnes, with fewer than a dozen different steel grades in regular use.  This is minuscule compared to the 2 billion tonnes of steel produced annually and thousands of unique steel grades used globally, each optimized for specific applications.

The main barriers to the widespread adoption of additive manufacturing in industrial-scale production are widely acknowledged: high part costs and the challenge of ensuring consistent quality over time. At ArcelorMittal, we are leveraging our metallurgical and digital expertise and collaborating with key additive technology providers to develop steel solutions addressing these challenges.

Print smarter and faster

Our primary approach to reducing the high cost of parts is to improve the productivity and quality of the printing process. With 20 years of numerical modeling experience, our R&D team has developed algorithms and metallurgical models that enable faster printing and the ability to print more difficult materials such as H13. Changing only the printing strategy, we have demonstrated 30% faster prints at our Beta customers. Additionally, by incorporating heat management, we can print H13 crack-free without pre-heating; fully dense 5 kilograms parts have been proven and we have just removed a 25 kilogram H13 print from the build plate without visible cracking, though scanning for internal cracks is still to be done. We believe this approach could be especially interesting for the installed base of printers. To make these unique algorithms widely accessible, we are collaborating with Materialise to integrate them into the Magics platform and are eager to work directly with major machine OEMs to create value for all end users.

Industry needs consistency

To address the repeatability issues of serial production, one approach is to offer a larger batch size, providing a homogeneous powder that requires fewer incoming quality control checks and fewer printing parameter adjustments. Our other approach is metallurgical. Our new steel grade, AdamIQ™ SAM 3, is a highly reliable feedstock for laser powder bed fusion (L-PBF). It has been tailored to deliver microstructural uniformity, providing consistent properties and homogeneous high strength along all axes, directly after printing. It is also resilient, capable of handling a wide range of printing conditions.

Beyond the widely accepted issues, secondary factors also hinder the adoption of additive manufacturing. For example, available design software does not always provide truly lightweight optimized part designs, leading to longer print times and higher costs. Another issue is initial material selection. We have frequently heard of parts designed in aluminum to “lightweight” them being switched to titanium to lower costs when steel would have been the optimal choice for both material and printing costs. ArcelorMittal has been providing lightweighting solutions in steel to the automotive sector for over 20 years. Steel remains the material of choice for automotive applications and is the most sustainable option. We believe that while the final application may use any material, the selection process should always start with steel.

Steel can unlock new solutions

The limited selection of materials used in additive manufacturing is also linked to the low productivity and high costs of additive. Material changes would require costly downtime, so only a few standard grades are commonly used.

In contrast, ArcelorMittal supplies thousands of steel grades tailored to specific end-user needs. As metallurgists, we are eager to demonstrate what is possible. For example, our decades of experience innovating for the Automotive and Energy industries. Of present steel consumption, 70% of the grades used today did not exist 20 years ago. These are steels that have increased safety and contributed to lower fuel consumption and CO2 emissions.

Responding to market requests, at Formnext we introduced AdamIQ™ SAM 1, our innovative, lean, Cobalt-free alloy. Engineered to deliver high strength, toughness, and corrosion resistance, it is ideal for applications demanding strength and durability. It avoids the environmental and material challenges associated with traditional high alloy maraging steels.

As steelmakers, we also wanted to highlight the material performance opportunities offered by additive manufacturing, which far exceed those possible with conventional production. Thus, we developed AdamIQ™ SAM 2, an easily printable Triplex steel that delivers Duplex-level strength and Austenitic stainless-steel levels of elongation simultaneously. In simple terms, this steel offers ultra-high energy absorption capabilities, robust performance under extreme conditions (e.g. down to -70 °C), is easy to print, and has 11% lower density than traditional steels.

Think production value not part cost

Since 2018, ArcelorMittal has used additive manufacturing to produce spare parts for our own production facilities, consuming 10 tonnes of steel spares annually. These parts keep critical equipment operational, enhancing productivity and quality, and ensuring reliable and timely steel production of tens of millions of tonnes. This experience has highlighted the importance of using a total cost of ownership approach when deciding which parts should be additively manufactured, as the production uptime value is usually the deciding factor.

We are eager to collaborate in advancing this industry. If you are interested in exploring what Steel Additive Manufacturing could mean for your applications/industry, please contact us at contact.powders@arcelormittal.com or visit http://powders.arcelormittal.com for more information.

Colin Hautz, CEO of ArcelorMittal Powders, will participate at Additive Manufacturing Strategies, Feb 4-6 in New York City.