Great Designs in Steel = Great Designs in Automotive

On 22 May 2024, 1000 leaders representing automakers, the supply chain, research and development, and academia gathered for the longest running automotive materials conference in the world, Great Designs in Steel, in Novi, Michigan (USA). ArcelorMittal showcased a catalogue of design solutions for Battery Electric Vehicle (BEV) Battery Enclosures adapted for the North American market. We also unveiled new multi-phase steel grades and ArcelorMittal Multi Part Integration™ solutions to simplify vehicle design and production. Together, these offerings support automakers as they shift from internal combustion engines (ICE) to battery electric vehicles (BEV).

Laser welded seams in battery pack MPI perform well for anti-leak behavior and for protection against water or external contaminants. The formability of PHS helps maximize the volume for increased battery capacity by minimizing reinforcements and supports the production of customized designs tailored to specific applications. From an environmental perspective, the MPI solution reduces the overall gross steel used, contributing to a reduction in the battery structure's overall carbon footprint. 

In the pursuit of design and manufacturing efficiency in electric vehicle (EV) technology, this industry-first study investigates the integration of multi-functional steel cooling plates within EV battery packs. The research encompasses a thorough analysis of welding feasibility, coating assessment, and watertightness to ensure the viability and reliability of the proposed steel cold plate solution.    Advanced welding techniques are employed to assess the feasibility of joining steel cooling plates with battery pack components. Additionally, the study involves a thorough assessment of applied coatings to enhance durability and fortify resistance against environmental factors. Watertightness measures are implemented to assess the weldability at different pressure levels, ensuring the integrity of the cooling system in various environmental conditions. A diverse array of design alternatives underwent thorough assessment to discern and implement a resilient solution that stands out for its effectiveness in meeting the specified standards criteria.       
The findings indicate that the proposed steel cold plate solution not only enhances overall performance but also demonstrates excellent weldability, effective coating protection, and structural integrity. Consequently, the study demonstrates a path to designing and manufacturing cold plates with steel thus allowing for entire battery packs to be designed in steel. This comprehensive approach addresses critical concerns in the EV industry, providing valuable insights for the development of reliable and durable cooling systems with a focus on welding, coating, and structural assessments. 

The Steel-Intensive Battery Enclosure Structure (SIBES) initiative is a project that is sponsored and managed by the AISI Automotive Group. The study details the conversion of a current production extrusion-intensive aluminum battery enclosure structure to one of steel, honoring the package space and attachment points of the original design. Through exhaustive simulation, the proposed steel structure is predicted to meet or exceed the current design in stiffness and strength with only a very minor increase (+4.4%) in assembly mass. Accepted structural standards for battery enclosure performance were also evaluated for the proposed steel design and comfortably met.  

Wire Laser Additive Manufacturing (WLAM), a subset of Directed Energy Deposition (DED), introduces an innovative B-Pillar concept with the aim to simplify assembly for automotive OEMs using steel wire-based Additive Manufacturing technology. As the automotive industry shifts rapidly away from Internal Combustion Engines (ICE) towards Battery Electric Vehicles (BEV) to address the carbon challenge, reimagining car body structures and assembly processes becomes crucial. This transition involves managing multiple powertrain configurations (ICE, Hybrid, Plug-in Hybrid, BEV) and modular platforms, including heavy BEV variants. One of the challenges in BEVs is managing roof crush performance due to limited structure cross-section, while accommodating other features like seatbelts and wiring. Typically, the vehicles at the premium end of pricing and lowest volume are the heaviest, primarily due to larger batteries and heavier interior trim options. 

Our innovative approach enables customers to combine traditional stamped parts with multiple WLAM B-Pillar Inserts, facilitating gradual compliance with higher roof crush targets. With this, OEMs benefit from reduced investment in body shops and avoidance of complex tooling requirements, ensuring global deployment of vehicles with reduced capital investment and assisting in overcoming challenges in automotive electrification.