Fiat Chrysler Automobiles (FCA) utilises ArcelorMittal’s latest Fortiform®grades to achieve the company’s lightweighting targets while enhancing safety for vehicle users.
In this wide-ranging interview with eUpdate, Fabio D’Aiuto, Manager of the Metals Department in FCA’s Group Materials Labs outlines the company’s material strategy and his belief in the future of steel in automotive.
The Alfa Romeo Giulia from FCA has two parts in Fortiform® 1050. Could you tell us why FCA chose this new grade and whether it contributed to the vehicle’s success in the 2016 EuroCarBody award?
Fabio D’Aiuto: FCA works with our best suppliers to develop new materials which can help us achieve our lightweighting targets. Fortiform® is interesting for us because it is a new material which offers high performance, particularly in formability. We need difficult shapes and Fortiform® 1050 allowed us to achieve that, and at a lower cost than other materials. One part of the EuroCarBody evaluation relates to design and materials, so it’s clear that Fortiform® 1050 contributed to the vehicle receiving the award.
We are very interested in the Fortiform® 980 and 1180 grades ArcelorMittal is developing. We are considering using these new grades in future models.
Why is steel such an important material for carmakers such as FCA?
Fabio D’Aiuto: At FCA we’re aiming for low CO2 emissions, low fuel consumption, excellent car performance, and a high level of sustainability. Today, the material that provides the best compromise between cost, performance, and sustainability is steel.
How does Fortiform® fit into your production process and production lines?
Fabio D’Aiuto: Cold forming is associated with good formability. And good formability is something carmakers are always looking for in a steel. Since we have started using Fortiform® we never had a production or assembly issue. With ArcelorMittal’s help and the right dies, we have managed to create complex parts which can be used on a normal production line, without any special requirements.
Fortiform® was developed for cold stamped parts, but FCA also uses steels for hot stamping. Why, and what influences your choice between hot and cold stamping?
Fabio D’Aiuto: We use both cold and hot forming technologies. FCA is a leader in the use of steel, but we do search for the material with the best performance. We don’t compromise on safety or performance, but we do consider cost – although this is a secondary consideration. Within these parameters, there is a ‘best’ solution for every application. FCA started using press hardenable steels (PHS) in 2010 because they offered us the best performance at the lowest cost. In some applications, such as the body-in-white (BIW), we could use a thinner steel. But we need rigidity, so we use PHS. It offers us the performance we need.
Do you make use of laser welded blanks (LWBs)? What are your expectations of this technology?
Fabio D’Aiuto: Yes, we use LWBs – the Chrysler Pacifica is an example. There is one important consideration when we are thinking about LWBs – safety. Over the past decade, FCA has received a five-star safety rating for every model we have released. Safety is important, and we want to maintain that rating. LWBs help to save weight, but maintain the same level of safety performance. We are investigating applications for LWBs in our models for Europe, the Middle East, and Africa (EMEA). They will be similar to LWB applications we have implemented in our North American models.
For FCA, what are the main materials competing against advanced high strength steels?
Fabio D’Aiuto: The direct competitor for advanced high strength steel (AHSS) is ultra advanced high strength steel (UHSS). I’m in the benchmarking department and we do 360-degree comparisons. We analyse materials used in other vehicles and include factors such as performance and customer feeling. In our experience, other materials are not direct competitors for AHSS due to performance and cost.
How would you rate AHSS such as Fortiform® against non-steel alternatives with respect to lightweighting, cost-efficiency, and sustainability?
Fabio D’Aiuto: All three points are very important. Light weight is important for fuel consumption and emissions, and for sustainability. Steel is the best choice as it allows us to achieve the same characteristics as other materials, but at a low environmental cost. And it is recyclable, without any significant change in performance and this reduces its environmental impact further. Cost-efficiency just completes the picture because the strength of steel is very high compared to the cost.
What can you tell us about your relationships with ArcelorMittal in terms of co-engineering?
Fabio D’Aiuto: Since 2000, ArcelorMittal and Fiat (now FCA) have had a very good relationship. ArcelorMittal is very open. People inside the company have a good feeling of what is happening in automotive and ArcelorMittal creates good quality products as a result. We have carried out many co-engineering developments, with good results, and there are ongoing activities. We are encouraged by the presence of ArcelorMittal resident engineers.
What can you tell us about FCA’s material strategy for the coming years?
Fabio D’Aiuto: We are a research centre, so one of our tasks is to investigate different materials. That includes steel, aluminium, magnesium, composites, new polymers, and even textiles. Our philosophy is to have the right material in the right application, so we need to investigate all the options. For structural applications and models with higher production volumes, we mainly use steel. However, we have developed some aluminium applications for vehicles in the premium segment, and carbon fibre applications for our special cars.
How do you see the future of automotive in Europe beyond 2020?
Fabio D’Aiuto: It’s never easy to predict the future, but based on our experience we can see there will be an increase in the number of hybrid vehicles. And although the infrastructure is not ready for full-electric vehicles, we are probably at the starting point. One of the difficulties is the sustainability of electric vehicles. Electricity production has different ‘costs’ in different countries. For example, in France we have nuclear power which produces much lower CO2 emissions than coal-fired power stations. But this option is not available in every country – even within Europe.
While Fortiform® 1050 is already widely used by carmakers such as FCA, ArcelorMittal has added two new grades to the range: Fortiform® 980 and Fortiform® 1180. Both grades are already available as bare steels.
Fortiform® 980 and Fortiform® 1180 are ideal for carmakers who utilise cold stamping processes. They have significant advantages over dual phase (DP) grades including:
Fortiform® 980 is significantly more ductile than Fortiform® 1050 and allows OEMs to create parts with complex geometries. With Fortiform® 980, OEMs can achieve parts with similar geometric complexity to those created with DP600.
Although the overall formability of Fortiform® 1180 is slightly lower than that of DP780, its formability on cut edges is better. This is important for the creation of successful parts.
Crash performance models have been applied to both new Fortiform® grades. The models cover lateral (anti-intrusion crash) and longitudinal (energy absorption crash) shocks.