Lightweight Steel Mid-Size Sedan and SUV Bodies

• Steel solutions for individual vehicles, therefore, are of limited value.

The Solution – S-in motion ® Mid-size Sedan and SUV
• A catalogue of steel solutions for a mid-size PLATFORM that includes both a sedan and a SUV.
• Solutions provide impressive weight reduction.
• At an affordable light weighting cost.
• Meeting all pertinent safety and performance requirements.

Baseline: NA market representative
Mid-size vehicle
Scope: BIW + Bumpers + door in white
Objective: achieve a 20% weight
reduction at very low cost difference
thanks to advanced high strength steels

Validated loadcases: stiffness and crash requirements including IIHS frontal small overlap rigid barrier, roof crush, side MDB, side pole as well as FMVSS301 rear crash tests.

S-in motion ® Midsize is a catalog of lightweight solutions for Midsize vehicles.

2 sets of solutions: one with current grades, one with emerging grades

ArcelorMittal currently
available grades
Essentially AHSS grades
• Dual Phase family
• Complex Phase family
• Usibor ® 1500
• Laser welded blanks (especially Usibor ® 1500/Ductibor ® 500)
• MartINsite ® family up to MartINsite ®  1700

ArcelorMittal emerging grades portfolio
• New hot-stamping grades Usibor ® 2000, Ductibor ® 1000
• High formability grades Fortiform ®  980 and 1180 (980HF, 1180HF)
• MartINsite ® 2000

BIW weight without CMS* vs Curb Weight

(note: no secondary mass savings were considered for the solution vehicles)
The proposed BIW solutions are very close to aluminum intensive BIW.

The proposed BIW solution weight is close to aluminum intensive SUV BIW.

S-in motion ® Mid-size SUV Guidelines
•  Modular approach in regard to the Mid-size Sedan
• Type of body: unibody
• Worst case for transmission choice in one model:o No prop-shaft present for a more severe intrusions scenario o 4x4 transmission mass considered

The S-in motion ® Mid-size SUV model was built as a platform extension of the S-in motion ® Mid-size Sedan.

S-in motion ® Mid-size Sedan and SUV

DESIGN HIGHLIGHTS

Small Overlap Rigid Barrier crash rating :Marginal, with a high risk of “Poor” downrating due to the leg entrapment

Small Overlap Rigid Barrier crash rating : Good  

The solution is 12 kg lighter and meets Small Overlap Rigid Barrier Crash requirement

The Usibor ®  1500 laser welded B-pillar inner ensures required roof strength without a supplementary inner reinforcement.

Solution meets all global stiffness targets thanks to additional stiffening parts, as well as gauge and adhesive optimization.

Stamping analysis carried out on challenging applications:
• laser welded blanks
• hot stamped parts
• thin gauge parts

Conclusions
1. ArcelorMittal solutions have reduced the weight of the baseline by 86 kg (23%) for the Sedan and 102 kg (20%) for the SUV with steel grades commercially available today.
2. Additional weight savings of 14 kg (26% total weight reduction) for the Sedan and 10 kg (21% total) for the SUV can be achieved with steel grades that will be commercially available from ArcelorMittal within less than two years.

3. Weight savings achieved for large bandwidth, multi-vehicle platform.
4. These solutions can be implemented with only a small cost increase.
5. S-in motion ®  Mid-size Sedan and SUV solutions can be adapted to OEM’s specific designs and requirements through co-engineering projects.

• The S-in motion® Mid-size Sedan and SUV engineering design
projects were led by Ivan Viaux (Sedan) and Florin Arnautu (SUV)
from ArcelorMittal’s automotive R&D lab in Montataire, France. Ivan
and Florin also developed the content for this presentation.
• Contract engineering services were provided by Altair Engineering
for the sedan project, and by Magna Steyr for the SUV project.