Multi Part Integration (MPI) is a new concept from ArcelorMittal Tailored Blanks which is designed to incorporate many parts into one laser welded blank (LWB). MPI uses press hardenable steels (PHS) and hot stamping LWB technology to create the single part. The goal is to simplify production for OEMs.
The MPI concept brings significant benefits for OEMs including:
The MPI concept builds on the success of ArcelorMittal projects such as S-in motion® and the single-piece door ring. The door ring has been adapted for different vehicle segments and successfully introduced into several vehicles by the global automotive industry.
To help prove the practical viability of the MPI concept, teams from ArcelorMittal Tailored Blanks and ArcelorMittal Global R&D have completed an MPI analysis for the rear, underbody, and rails of an S-in motion® SUV vehicle. Known as the ‘rear H-frame’, the concept replaces 11 separate parts with one. The solution can be applied to almost any powertrain simply by adding patches to reinforce local areas.
Further projects are already in development and will be announced later in 2021.
Combining multiple parts into one greatly simplifies the part production process and associated costs. Advantages include:
Using Multi Part Integration, one modular solution can be developed for multiple powertrains. The part shape and distribution of material is similar for every powertrain.
Patches can be applied to the part to add reinforcement for a specific powertrain without increasing costs.
Multi Part Integration solutions can be used with a variety of powertrains including:
The use of hot stamped press hardenable steels (PHS) in a single LWB is key to Multi Part Integration. The LWB ensures that the right PHS steel, in the right thickness, is in the right place. LWBs have continuous weld lines which enhance energy absorption and the behaviour of the part during a crash. LWBs also eliminate weak points in the part.
ArcelorMittal PHS families such as Usibor® and Ductibor® are ideal material choices. Usibor® offers the strength and anti-intrusion properties required to protect the vehicle’s occupants and power system. Ductibor® provides ductility, enabling crash energy to be controlled and directed away from the passenger compartment and fuel source. Working in combination these grades enable engineers to dramatically enhance safety while reducing mass.
By integrating multiple parts into one, OEMs can reduce the overall mass of the part. This approach offers many sustainability benefits including:
ArcelorMittal has contracted an independent external partner to calculate the cost savings from every MPI project. The methodology uses an ideal, virtual plant which produces 150,000 vehicles annually. The calculation assumes that the same vehicle – in different powertrain versions – is produced for five years.
Each MPI study will contain more information on potential cost reductions.
To prove the validity of the MPI concept, teams from ArcelorMittal Tailored Blanks and ArcelorMittal Global R&D have developed a new LWB H-Frame solution for the rear of an SUV vehicle. The S-in motion® SUV was used as the basis for the design.
The new rear H-frame integrates 11 separate parts – including the rear rails and rear crossmember – into one LWB. The solution makes maximum use of hot stamping technology and PHS grades such as Usibor® and Ductibor®.
The rear H-frame concept has also been adapted for different vehicle powertrains including BEV and PHEV cars. The solution meets all relevant safety requirements for the global market and has been tested against both European and North American rear-crash load cases.
The solution offers key advantages for OEMs as it:
Hot stamping has been chosen as it offers the best geometric possibilities for large parts. An MPI part can be obtained with cold stamping technology, but PHS for hot stamping offer the best mechanical properties for optimal crash performance. They are also the best option to achieve significant weight savings.
More details of the MPI one-part rear H-frame will be published in 2021. Further studies are in development.