Click on the advert above to visit the company web site

Product category: Metals and materials, stockholding
News Release from: SSAB Tunnplat | Subject: Roll-formed high strength steel - automotive
Edited by the Manufacturingtalk Editorial Team on 28 November 2006

Car's internal waistline is roll-formed

Request your FREE weekly copy of the Manufacturingtalk email newsletter. News about Metals and materials, stockholding and more every issue. Click here for details.

Low weight, compact design and good protection performance characterize the roll-formed internal waistline reinforcement developed for the side doors of a car.

Fiat-WagonHigh energy absorption capacity and compact design characterize a new internal waistline reinforcement mounted in the doors of the new Fiat Grande Punto This structural component is designed to be accommodated in the minimal space just below the side windows

It also meets the strictest demands on protection in a collision from the side or in a head-on crash and owes its success to its optimized design and to the efficient roll-forming production method.

The new Grande Punto is a great success for Fiat.

The car has gained the best results ever in its class in the Euro NCAP safety test.

Fiat and Wagon Automotive have therefore jointly been nominated for the Swedish Steel Prize 2006.

Fiat has long actively followed the development of high strength steels.

The proportion of high strength steels in Fiat cars has gradually been increased from a few percent to around 50% in today's models, and advanced high strength steels are taking an increasing share.

Future Fiat models will incorporate an even higher proportion of high strength steels.

"Improved safety is our principal driving force, although lower weight also plays a very important role," explained Giancarlo Bertoldi, director for Body Engineering and Design at the Fiat Head Office in Turin, Italy.

"The fuel consumption is reduced and thus also the CO2 emissions." * Five star in Euro NCAP tests - Bertoldi has borne main responsibility for body development for a long succession of Fiat models, the latest of which is the new Fiat Grande Punto.

The launch of the car in Europe has been highly successful.

One of major factors to the success is the high rating awarded to the car in the Euro NCAP crash test.

The car was awarded the maximum of five stars for occupant safety, and a high safety rating is an increasingly important argument when car buyers decide on their new car.

"We are very proud of the results in the NCAP test, which confirms what can be achieved by innovative design in which the properties of advanced high strength steels are put to full use," continued Bertoldi.

"We specified a very advanced geometry for the door internal waistline reinforcement mounted just below the front side window." The design brief was that the component was to have high energy absorption capacity both in a frontal crash and in a collision from the side.

The door internal waistline reinforcement had to be accommodated in the very limited space available below the side window, while also being lightweight and suitable for cost-effective production.

The solution was a roll-formed beam made of an advanced cold-rolled high strength steel with a minimum strength of 1000 N/mm2.

* Realized by roll forming specialist Wagon Automotive - the order for producing this component was awarded to Wagon Automotive - a long-standing major supplier to Fiat.

The company is one of Europe's leading manufacturers of automotive components, and has 26 factories and around 7600 employees in a number of countries.

"We specialize in roll forming," revealed Roberto Boggione, managing director of Wagon in Italy.

"This process offers major benefits compared to pressing - higher quality and lower stresses in the material during forming.

In my opinion, major carmakers such as Fiat will soon be replacing a large proportion of the traditional pressed parts with roll-formed components." Based on the fundamental principle drawn up by Fiat, the design was refined by Wagon engineers in Turin.

"This type of structural component is normally produced in two parts that are then welded together," explained Boggione.

"But we have produced a closed profile with an asymmetric geometry, which is bent longitudinally in two planes." The door internal waistline reinforcement designs for the three-door and five-door models are somewhat different.

The one for the five-door Grande Punto is shorter and is made of 0.8mm thick material, whereas the one for the three-door model is longer and is made of 1.2mm thick steel.

Roll forming involves much lower tool costs than other production methods.

Roll forming simplifies production by enabling all holes to be made before the forming process, without compromising on the precision demands.

Roll forming also makes it simple to reset production from one product to another, and to adapt the production process to suit new steel grades.

"Roll forming is flexible and enables mild steel to be replaced by high strength steels in order to cut weight and achieve better properties," concluded Boggione.

For the work on the new door internal waistline reinforcement, Fiat and Wagon Automotive have jointly been nominated for the Swedish Steel Prize 2006.

SSAB Tunnplat: contact details and other news
Email this article to a colleague
Register for the free Manufacturingtalk email newsletter
Manufacturingtalk Home Page

Search the Pro-Talk network of sites