thyssenkrupp has had a very close relationship with the Japanese car manufacturer for many years in its role as a supplier. One year ago, the carmaker began to look for an additional, dependable supplier specifically for the highly complex side panel for its Corolla model in Europe. A material from the thyssenkrupp Steel division came under consideration. “They were interested in a very soft deep-drawing steel that we offer for parts that need to be formed,” says Stefan Slawik, Key Account Manager for Toyota. An additional alloy layer made of zinc and iron improves the long-term protection against corrosion.
thyssenkrupp provided an additional forming aid so that the material could be integrated into Toyota’s standardized production process immediately. “The tools do not need to be adapted; the material can be used right away and the manufacturing process can proceed without any problems.” But the Japanese partner was not won over quite so quickly.
Quality holds up after extensive testing
The steel company, based in Duisburg, needed to prove itself first. “We ran a test phase that lasted several months in order to demonstrate that the material can be processed reliably,” says Dr. Jürgen Schramm, who is responsible for the Surfaces product management. “The large side panel is extremely difficult to form. The surface needs to meet the highest standards. We delivered a consistent level of quality and successfully completed the trial period.” This in turn has made it possible to use the material in other Toyota models across Europe.
The DP 1200, a material that is also intended for use at Toyota’s European operations, entailed even more intensive collaboration. The strategy of the carmaker – the second largest in the world – is to source the materials that are required for its manufacturing activities locally as far as possible. For the European operations, this means sourcing materials from reliable local suppliers to the greatest possible extent. “In this case, these materials include high-strength steel for structural components that reinforce the roof and doors,” says Schramm. “This steel is another product from our premium segment with properties that are diametrically opposed to those of the soft, deep-drawing material used for the side panel.”
The DP 1200 proved that an existing high-quality product can be adapted to the respective requirements in close collaboration with the customer, for example, by maintaining its strength while changing its yield strength. “We had special requirements for the material,” says Edip Özer Arman, Senior Engineer at Toyota Motor Europe. “We let the Steel experts know about those, and we searched for solutions together.” Slawik says: “There was a very narrow window of time, but the development phase was completed and the material approved in just two years.”
“We are ready to make DP 1200 a standard feature,” says Arman. thyssenkrupp worked very closely together with the customer during this time. Every individual production step and every change was described in detail and agreed on. A good working relationship between material suppliers and customers is essential for fast and successful completion of any project. “Our relationship is based on trust and expertise – that’s what makes us such successful partners,” says Arman. Trust and a clear commitment to one another are also the cornerstones of a successful partnership in business.