Today carmakers are facing big challenges regarding the impact of the automotive market on the environment. They must propose cars with reduced CO2 release while maintaining a high level of protection for passengers. One of the key levers to reach the target is the use of steel, which is the best automotive material in terms of its design flexibility, cost effectiveness and low emissions during manufacture. Automakers are using steel to trim vehicle weight, while improving performance and safety.
ArcelorMittal offers a complete range of steels which can fully meet the challenges carmakers face today. For every part, from the body-in-white to the external panels, ArcelorMittal can propose a lightweight steel solution which is cost-effective, easy to implement, and safe.
Within the framework of FormPlanet project, ArcelorMittal has provided several products to other partners in order to highlight their crash performance and validate the novel techniques developed by the technological sites to predict crash behaviour. Results will be compared with classical crash tests done by ArcelorMittal Research.
Press Hardenable Steels (PHS)
Press hardenable steels (PHS) offer ultra-high strength and the ability to be formed into complex shapes. This makes them ideal for hot stamping processes and enables original equipment manufacturers (OEMs) to achieve excellent weight reductions across the vehicle.
ArcelorMittal’s PHS offer includes:
- Usibor® for critical parts where strength is key.
- Ductibor® for optimized ductility and strength.
Example of potential applications of Usibor® – Ductibor® steels
Usibor® and Ductibor® are hot-formed grades which are intended for use in automotive structural and safety components. Due to their high strength, Usibor® steels are particularly suitable for anti-intrusion parts for which an ultimate load before collapse is required. Thanks to their excellent ductility, the Ductibor® steels are particularly effective for the parts which need to absorb energy during an impact.
Direct hot-stamping process for Usibor® Alusi® and Ductibor® Alusi®
The main advantages of Usibor® and Ductibor® steels are:
- Ability to obtain complex geometry due to the fact that forming has taken place in the austenitic condition in the direct stamping process or that the material exhibits good formability before heat treatment in the indirect stamping process. Very good hot formability enables steel to be usedin several functions of reinforcing parts or assemblies.
- No springback.
- Uniformity of mechanical properties obtained in parts.
- Excellent fatigue strength and impact resistance enabling substantial weight reduction to be achieved.
ArcelorMittal was the first steelmaker to offer a coated steel for hot forming: Usibor®-AS with an aluminium-silicon coating applied at quenching. The additional benefits of Usibor®-AS and Ductibor-AS steels® are:
- Simplification of the process and economic savings (elimination of the shot-blasting step after forming (no formation of scale), no specific protective atmospheres required in the austenitising furnaces.
- Excellent temporary corrosion resistance after stamping, parts not requiring oiling before assembly.
- Absence of decarburisation.
- Excellent resistance to perforation corrosion, current use in dry and wet areas (sills for example) of the vehicle.
3rd Generation Advanced High Strengh Steels (3G AHSS)
ArcelorMittal’s third generation of advanced high strength steels (AHSS) have been specifically developed for OEMs who utilise cold stamping and forming technologies. Significant weight savings can be realised thanks to their excellent mechanical properties.
The family of Fortiform® steels extends ArcelorMittal’s range of Ultra High Strength Steels (UHSS). These steels allow the realisation of lightweight structural elements by a cold forming method such as stamping. These Ultra High Strength Steels of third generation are used to provide additional weight reduction thanks to their higher mechanical properties than conventional Advanced High Strength Steels (AHSS) while keeping the same formability.
Position of Fortiform® steels in the ArcelorMittal steel range
Thanks to their excellent mechanical properties, these grades are particularly suitable for automotive safety parts intended for crash resistance.
Typical parts for Fortiform® steels
ArcelorMittal is the world’s leading steel and mining company, with approximately 191,000 employees in more than 60 countries. ArcelorMittal is the leader in all major global steel markets, including automotive, construction, household appliances and packaging, with leading R&D and technology, as well as sizeable captive supplies of raw materials and outstanding distribution networks.
More information on ArcelorMittal’s products for the automotive sector can be found here.